Geoghegan v. Harris [2000] IEHC 65 (14th September, 2000)

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1. On the 1st of July 1992, the Defendant performed the implant and bone graft procedures on the Plaintiff in the Blackrock Clinic in an operation carried out under general anaesthetic. The operation took about two and a half hours.

3. In carrying out the bone graft, Dr. Harris had the assistance of two nurses. He had the pre-operative x-ray which he himself had taken at an earlier date. He has told the Court that, to ensure precise measurement, he normally relied on preoperative assessment from x-ray and any measurement taken on x-ray. However, he told the Court: “In reality, you rely on clinical touch, you know where the structures are”.

4. He told the Court that he commenced the bone graft by making a horizontal incision which was at the joining of the attached and unattached mucosa - just below the point A marked on the illustration contained at Appendix B (Fig 5.7).

9. Dr. Harris had available to him a metal instrument with a 7 mm flattened end which he used as his essential measuring tool. Using this implement, he placed four small burr holes in a box shape below the apices of the teeth. While his normal practice is to allow at least 5 mm between the apices of the teeth and the upper margin of the bone graft, he believes that, in the Plaintiffs case, he allowed 7 mm.

10. Two other burr holes were then placed between the four corners, making the outline of a box using the 7 mm rule, he again checked that he was 5 mm from the apices of the teeth. Using a fissure burr, the various dots were then joined up, completing the box outline.

11. The initial cut through the outer bone (cortex) was made with a burr and then continued with a separate implement, known as a fine osteotome, tapping into the bone itself. This is a hand held implement with which the surgeon makes his cuts, following the 45 ° downward angle or bevel at which the burr has accessed and cut through the outer bone.

13. Having made the necessary cuts, and the Court was not told by Dr. Harris, how many, the bone was then lifted out quite easily. The harvested bone was then packed around the implant in the upper jaw. Thereafter the graft area was cleared up and sutured. The dimensions of the bone graft site or box were 11 mm across x 5 mm down.

17. During the day Dr. Harris came to see him. The Plaintiff complained about the level of his pain and mentioned that the lower implant had not been put in. He had been able to ascertain this by moving his tongue around his mouth. He stayed in the clinic that night and was given injections and painkillers. The Plaintiff refers to only one post operation visit that day from Dr. Harris, while Dr. Harris says a second visit took place in the evening.

18. Without dwelling on the Plaintiffs symptoms any more than is necessary at this point, their severity from the outset was on a completely different level and scale of intensity from any of those mentioned either in the video or in Dr. Harris' letter to Mr. Geoghegan furnished prior to the operation.

19. As far as the Plaintiff is concerned, he had and continues to have, burning pain in the middle of his chin within the bone itself. His two central lower incisors feel completely dead, and the two outer ones have only partial life. The gum directly beneath the central incisors feels dead. While he has these difficulties, the Plaintiff also complains that his teeth are sensitive and numb. He cannot touch the teeth because they are so sore, particularly if pressed upon.

20. On the morning of the 2nd of July, a nurse informed the Plaintiff that Dr. Harris would like to see him before he went home. When he got up and dressed, the Plaintiff went down to Dr. Harris rooms, told his receptionist he would not wait (Dr. Harris apparently was in surgery) and informed the receptionist that he was going home to bed. He stated that Dr. Harris could ring him at home. In effect, therefore, he discharged himself.

21. He went home to bed. He says he experienced severe pain from that time onwards. He was in touch with his General Practitioner, who provided him with pain killers. He contacted Dr. Harris by telephone on the 5th and told him his situation. Dr. Harris brought him back in for examination on the 6th July. On this occasion he also took a DPT x-ray. Having examined the Plaintiff, Dr. Harris informed him that he was “healing beautifully”.

24. Thereafter there were telephone calls to monitor the Plaintiff’s progress and symptoms. They did not improve. Dr. Harris requested the Plaintiff to come back to the Blackrock Clinic on the 11th of July. The Plaintiff did so and Dr. Harris carried out a full examination of the Plaintiff on the 11th of July. At the conclusion of this examination, Dr. Harris stated he would like to keep the Plaintiff in overnight and bring him down to the operating theatre next morning to try and resolve the problem.

25. The following morning a nurse brought the Plaintiff his breakfast at a time when the Plaintiff thought he was being prepared for theatre. He was agitated and distressed when he discovered he might not be taken to theatre until later in the day. He got up, got dressed and walked out of the Clinic. He was later found sitting on a wall by the roadside by Dr. Harris' nurse, who asked the Plaintiff if he was all right. The Plaintiff indicated that he was and telephoned his wife on his mobile telephone to pick him up. The nursing notes in relation to the 12th of July do confirm the Plaintiff was very distressed and record some anxiety about his mental state.

27. It appears that on this occasion the Plaintiff apologised for his behaviour the previous day and Dr. Harris took a further DPT x-ray. The existence of this x-ray was not adverted to until the trial was at an advanced stage, but was available for assessment by the Radiologists on both sides when they gave evidence. Dr. Harris himself did not give any evidence about this x-ray after it came to light, either as to his reasons for taking the x-ray or as to any conclusions he may have drawn from it.

28. Thereafter Dr. Harris again saw the Plaintiff on the 27th July before referring the Plaintiff to Dr. Pat Cleary, an Endodontist, to see if root canal treatment might be indicated. Dr. Cleary, whose findings are dealt with at a later stage, saw the Plaintiff on the 27th of July 1992 but was reluctant to carry out endodontic treatment on the Plaintiff until more confirmation was available to suggest the lower central incisors were contributing to the Plaintiffs pain.

29. That evening Dr. Harris phoned the Plaintiff asking him to come back in the following day the 28th of July. This was with a view to undergoing an exploratory procedure consisting of an incision under local anaesthetic. The Plaintiff had booked a holiday and was reluctant to undergo the exploratory procedure which Dr. Harris had in mind.

30. However, with the assistance of Mrs. Geoghegan, Dr. Harris prevailed upon the Plaintiff to do so. The Plaintiff says that Dr. Harris mentioned the possibility that fluid had been or become trapped under his gum and indicated that he wished to make an insertion to see if this was so.

32. The Plaintiff says Dr. Harris remained silent throughout this procedure. When it was over, according to the Plaintiff, Dr. Harris stated: “There is absolutely nothing wrong with you”. According to the Plaintiff, Dr. Harris also stated there was nothing more he could do for the Plaintiff and that if Mr. Geoghegan wished to go elsewhere for advice he, Dr. Harris, would give him every assistance.

33. The Plaintiff in the aftermath did not improve and in fact was in such pain and so ill that he felt obliged to cancel his holiday. He was extremely upset and angry and refused to take a phone call from Dr. Harris the following day.

40. There is no dispute as to what occurred on the 6th of July, other than it was suggested the Plaintiff did not attend Dr. Harris' clinic at the appointed time. It was further suggested to the Plaintiff that Dr. Harris on this occasion gave the Plaintiff an explanation for not doing the fourth implant in the course of his operation. The Plaintiff denied that he had received an explanation, but said his wife had been informed by Dr. Harris that this implant was too near the donor site.

42. It was put to the Plaintiff that he was examined on the 11th of July at 8.30 p.m. by both Dr. Harris and Dr. Comiskey. It was put to the Plaintiff that various possibilities for his pain were discussed with him, including the possibility of bone infection at the donor site (osteitis), the possibility of a collection of fluid under the wound (haemetoma or seroma), or a localised necrosis (dead piece of bone). Mr. Geoghegan had no recollection of these possibilities being discussed with him.

44. It is important to record that it was not put to Mr. Geoghegan at this stage that Dr. Harris disclosed to him or discussed with him in any way the possibility that he, Dr. Harris, had gone too close to the apices of his teeth in the course of the operation, although as we shall see, this was very much in Dr. Harris’ mind at the time.

45. The Plaintiff agreed that he returned to Dr. Harris' surgery on the 13th of July and apologised for his behaviour in walking out of the Blackrock Clinic the previous day. He also accepted that he may have been mindful of his brothers death at that time and that this may have been a factor explaining his actions. On this occasion the Plaintiff says Dr. Harris looked in his mouth and said he was “healing beautifully”.

46. It was not put to him that he had an x-ray on that date which Dr. Harris himself took, but the Court is satisfied to hold that the taking of this x-ray is a matter which Dr. Harris failed to record and forgot about until its existence became known during the course of the hearing.

48. It was suggested to the Plaintiff that Dr. Harris explained to him that Dr. Cleary was a specialist in the treatment of teeth that had lost vitality. Mr. Geoghegan accepted that this explanation may have been given, but stated that he was aware of this fact in any event.

50. It was put to the Plaintiff that Dr. Harris informed him that Dr. Cleary had said that fluid might be present and causing pressure on the donor site which was the source of pain and that a small exploratory incision was indicated as a way of testing or checking this. The Plaintiff agreed.

51. Having carried out the incision, it was suggested to the Plaintiff that he was told by Dr. Harris that none of the possibilities he had considered proved to be the reality. In reply, Mr. Geoghegan said that Dr. Harris merely stated “there is nothing there” and “there is nothing more I can do for you”.

52. At a later stage Mr. Cooney put it to Mr. Geoghegan that Dr. Harris told him that Dr. Cleary concentrated on damage or disease to roots of the teeth. The Plaintiff replied that he had no recall of that particular part of the conversation.

53. Again, it is pertinent to point out that it was not suggested to the Plaintiff in cross-examination that Dr. Harris discussed with him that Dr. Cleary would be examining any possibility that by going too close to the Plaintiffs teeth , certain damage either to the teeth themselves, or to the vitality of the teeth, had possibly occurred.

54. Dr. Harris’ description in direct evidence of the aftermath of the operation commences with his call to Mr. Geoghegan at 4 o’clock in the afternoon on the day of the operation. He found the Plaintiff to be restless and reporting some pain that necessitated some Cyclimorph to be given. He felt it would be best if the Plaintiff stayed overnight.

55. As Dr. Harris recalls it, he came back a second time to see the Plaintiff on the evening of the 1st of July. On this occasion Mr. Geoghegan asked Dr. Harris why he had not placed the implant and he explained how he was concerned it might be too close to the mental nerve.

56. Thereafter his records show an entry for the 6th of July, recording a telephone call from the Plaintiff who described being in a “lot of pain”. He took a DPT x-ray on that date which raised certain concerns in Dr. Harris' mind which will be dealt with later. He decided because of what he saw on x-ray to seek the opinion of Dr. Pat Cleary. He says he did not see any point in trying to do further x-rays at that point because he wanted to get the opinion of an expert. However, it now transpires that he did indeed take a further x-ray on the 13th July before the Plaintiff was examined by Dr. Cleary.

57. According to Dr. Harris, the Plaintiff really only complained of very severe pain for the first time on the 11th of July when he came into hospital. On the phone prior to that, when Mr. Geoghegan was saying the pain was getting worse, he said to him that he found it difficult to explain on the basis of what he had done.

59. On the 28th of July he reopened the incision to look directly into the wound and saw as far as he was concerned perfectly healing normal tissue. He also checked for all sorts of odd things like a piece of suture that had got caught or something that would not show up in x-ray, such as a piece of cotton. He also had the opportunity to look at the cut in relation to the apices of the teeth and was “quite happy on all scores”. He didn’t touch the wound which was healing with granulation tissue (which is a mature blood clot), and he placed some resorbital sutures in the incision because the Plaintiff was going away on holidays.

62. I must take Dr. Harris as understanding the potential, at least, for litigation, arising from a failed medical procedure. This was a most unusual outcome to this particular operation. Secondly, from quite an early stage the Plaintiffs behaviour was clearly volatile and disturbing, going right back to the 2nd of July when the Plaintiff discharged himself without the consent or agreement of the Defendant. On the 12th of July, a Sunday which Dr. Harris had set aside to come in and see the Plaintiff, the Plaintiff had walked out of the Blackrock Clinic and was later found sitting on a wall by the roadway.

63. I don’t think it unreasonable to conclude that any specialist in Dr. Harris’ position would have been alarmed, to say the least, by these developments and would as a result have acted with extreme prudence and caution in everything he did and said in relation to Mr. Geoghegan, certainly from the 12th July onwards.

64. It was the view of the Plaintiff’s medical experts, and not disputed by the Defendant’s medical experts, that a dental surgeon, when harvesting a bone graft from the mandible should ensure that the upper margin of the bone cut is made 5 mm or more from the apices of the teeth. Leading expert in this respect for the Plaintiff was Professor Kahnberg, Professor of the Dental Faculty in Gothenburg, and Professor in oral and Maxillofacial surgery since 1988. He has himself placed several thousand dental implants using the Branemark technique over the last 20 years and has himself been doing bone grafts in connection with implants since 1986. He told the Court that whenever you do grafting techniques or you do osteotomies, there is always a safety barrier which is at least 5mm. This is described in the literature and “is a common surgical procedure that every trainee will learn during their education”.

67. If that margin is not observed in the case of the bone graft, certain problems may be anticipated. Firstly, the teeth themselves, or, more accurately, the roots and apices of the teeth may be damaged by the cut. Obviously, this would represent a gross violation of the 5 mm zone.

68. In a paper published by Professor Kahnberg in the British Journal of Oral and Maxillo Facial Surgery (1987) it was noted in respect of osteotomies that the incision is always located a minimum of 5 mm above the apices of the maxillary teeth. It noted:-

72. It was further confirmed by one of the Defendant’s dental specialists, Dr. Beirne, that dental students who propose to practice these or analogous procedures, are instructed and taught to respect this 5 mm barrier, so whether it be described as a “rule” or “guideline” is really of little significance. It is what standard and approved medical practice requires for bone grafting procedures, and no alternative school of thought within the medical profession was offered to the Court in respect of the particular procedure with which the Court is concerned. Indeed, Dr. Harris at all times himself accepted the requirement to respect this 5 mm barrier zone.

74. Another consequence of transgressing the zone is to damage the vitality of the teeth. In this regard, the vitality means two things. Firstly, it means the vascular supply (i.e. blood supply) to the pulp of the tooth, without which the tooth will die. It also includes the nerves which supply sensation to the teeth, being branches or extensions of the incisive nerve. While either can be compromised as a result of interference, tooth sensitivity which may follow upon nerve damage usually returns over a relatively short period of time, so that symptoms from nerve damage are, in this area at least, usually of short duration only.

75. Professor Kahnberg told the Court that if you do not respect the 5 mm zone, you may devitalise the teeth, the roots, and the consequence will be that root filling of the teeth will be necessary. He also pointed out that if you come close to the apices, there will be less chance that capillaries (which provide blood supply) and nerve structures will revascularise and re-enervate.

“It is submitted that it is abundantly clear from this evidence (i.e. Professor Kahnberg, both in Court and in his published writing), and the evidence given by other experts in relation to the 5 mm guideline, that its sole purpose is to avoid damage to the teeth which are most adjacent to the area in which the surgical procedure is being carried out whether that procedure be bone harvesting or an osteotomy. The damage apprehended is loss of vitality of the teeth or altered sensation. Not one of the medical witnesses who gave evidence in this case stated that the rule had, as its purpose, or one of its purposes, the prevention of the onset of neuropathic pain.”

5 mm barrier was also more weighted or biased towards preservation of vascular supply than nerve supply. That may well be so, but nonetheless the prevention of nerve damage is one function of maintaining this 5 mm barrier and it is foreseeable that nerve damage will ensue if that barrier is not respected. Of course the barrier is not designed to prevent neuropathic pain per se. It is designed to protect teeth, the roots and apices of teeth and the vitality of teeth. The vitality of teeth comprises blood and nerve supply. Neuropathic pain is a rare consequence of damage to a nerve. That is what all the experts agree has occurred in this case. The fact that other more radical intervention and surgery is not associated historically with the form of injury sustained by the Plaintiff may perhaps be explicable in terms of the different modus operandi involved in different procedures such as removal of sections of bone, alteration of the configuration of the mandible, treatment of serious fractures, extraction of wisdom teeth, apicectomies etc.

79. In carrying out this operation his 7 mm measuring tool was essential because on many occasions he would be working with magnifying groups that would enlarge the area under examination by two or by four, so it was essential to have a point of reference.

80. As previously mentioned, he would rely on pre-operative assessment from any x-ray and any measurement that might be taken on the x-ray, but in reality he would rely on his clinical touch, knowing where the structures were in the mouth. He explained he had an DPT machine for taking extra-oral x-rays in his rooms. He has x-ray viewers on his desk.

81. He rejected any suggestion, and I accept his evidence in this respect, that he carried out this procedure without having the pre-operative x-ray which he himself had taken. He also explained that if, for any reason it was not available, it would have taken only two minutes to do another one.

82. While the operation notes refer to the bone graft as having been taken below the lower right one, two and lower left one, two, they do not record the distance the graft was taken below the apices. The measuring tool does not contain a 5 mm calibration. He estimated distance from it. He did not use calipers to measure off, as suggested by Professor Kahnberg, the Plaintiff’s leading expert, who has special expertise in bone grafting of this type.

83. In the aftermath of the operation, Dr. Harris was obviously concerned with the complaints of pain which were being conveyed to him by Mr. Geoghegan. While he states that Mr. Geoghegan did not complain of really severe pain until the 11th July, his own notes record that Mr. Geoghegan complained of being in "a lot of pain" when he spoke to Dr. Harris on the telephone on the 5th July.

84. When he saw the Plaintiff on the 6th July, he took a DPT x-ray of the Plaintiff and was concerned about the appearance of the radio-lucency which represented the bone graft. It did appear looking at the x-ray that the shadow was closer to the apices of the teeth than he would have expected. He felt he might have caused some damage to the teeth which might be accounting for the pain and therefore decided to seek the opinion of Dr. Cleary, an endodontist.

88. In his direct evidence, Dr. Harris told the Court that he considered three possibilities for the Plaintiff's pain. Firstly, it was possible the Plaintiff had a haematoma or blood clot underneath the wound. Secondly, there was the possibility of an infection in the bone, producing a type of dry socket reaction, a condition described as osteitis. The third possibility was an inflammatory reaction of the roots to the teeth.

92. He did not, however, avail of what has transpired to be a final opportunity to measure the gap between the apices and the bone graft site. Given the fraught situation which was developing with Mr. Geoghegan and the level of his symptoms, this seems an extraordinary omission, given Dr. Harris’ worry that he had gone too close.

93. However, Dr. Harris told the Court that he estimated the gap between the apices and the upper margin of the graft as being "at least 5 mm away". This, of course, is at variance with his description of the operation itself where he estimated he had commenced the bone graft at a distance of 7 mm from the apices of the teeth.

94. I should mention briefly another possibility which Dr. Harris told the Court about, namely, that the Plaintiff symptoms were in some way attributable to a cardiac condition. It is possible, apparently, that a person with a cardiac condition could have referred pain radiating to the jaw. That was why Dr. Comiskey attended the examination on the 11th July. This possibility was quickly eliminated

95. Dr. Harris told the Court that he explained to the Plaintiff on the 11th July the three possibilities mentioned above. This is not accepted by the Plaintiff who says he has no recollection that such a thing happened. By way of reaction to the information allegedly given to the Plaintiff, Dr. Harris stated merely that Mr. Geoghegan indicated he did not want another general anaesthetic.

97. Significantly, no mention appears in these clinical notes of any possibility of teeth or the roots of teeth being damaged or of Dr. Harris having gone too close to the teeth. Given that this was the Defendant’s first worry, this omission to record it seems odd.

98. When he saw the Plaintiff on the 27th July however, Dr. Harris told the Court that he explained to Mr. Geoghegan how concerned he was about the possibility of some damage to his teeth and that he would like to seek the opinion of an expert in the area. He went on to say that his concern was based on the DPT and also because he wanted to try and further investigate the three possible causes. He said that he rang Dr. Cleary and explained the situation and Dr. Cleary agreed to see the Plaintiff straight away. In cross-examination, Dr. Harris stated that he had a long discussion with Dr. Cleary following Dr. Cleary's examination. He had put a specific question to Dr. Cleary about the possibility of damaging the teeth.

99. In dealing with what Dr. Cleary said after his examination, Dr. Harris stated that Dr. Cleary told him that he could not explain the pain, but felt there was a possibility of fluid at the site of the pain. According to Dr. Harris, he suggested that draining might be worthwhile, but "he did not feel at that stage that the teeth had been damaged and did not feel that he should commence root treating the teeth. He felt that the lack of vitality he recorded at that time might well be expected in any event following this type of procedure."

100. This description of his dealings with Dr. Cleary is considerably at variance with the account furnished by Dr. Cleary who simply stated that Dr. Harris told him the Plaintiff had had a surgical procedure carried out and was in pain afterwards. Dr. Cleary told the Court that Dr. Harris simply wanted an opinion as to whether root canal treatment might be of some assistance. Insofar as Dr. Cleary advised of queries submitted by Dr. Harris, he was not invited or questioned for the type of detail which might have corroborated Dr. Harris account of his stated concerns including excessive proximity to the apices in the taking of the graft.

101. In cross-examination Dr. Harris said that while the x-ray shadow was closer to the apices than he believed he had been from his own measurements at surgery, he was concerned that he might have caused damage, not direct physical damage in actually cutting the roots, but interference with vitality. Dr. Harris clarified that "vitality" meant blood and nerve supply to the tooth or teeth.

102. He was satisfied there was a border of bone between the apices and the radio-lucent area, from which the Court must obviously infer that Dr. Harris looked very closely at the x-ray of the 6th July. There was no other change in Dr. Harris’ views following the DPT of 13th July - he still wanted the Plaintiff to see Dr. Cleary.

103. Not surprisingly, Dr. Harris was pressed very strongly in cross-examination as to why he did not tell the Plaintiff that he might have gone too close to the apices. Dr. Harris stated that he would have explained that to the Plaintiff by reference to the possibility of an inflammatory reaction of the teeth. It’s hard to see on the face of it to see how mention of an “inflammatory reaction” would, without a great deal of clarification and detail, have conveyed to the Plaintiff that Dr. Harris felt he might have erred by straying too close to the tooth apices.

107. When asked by the Court why, if in any doubt about the accuracy of the x-ray of the 6th July, he did not repeat the x-ray, Dr. Harris stated a number of reasons for not doing so, including stating at a later stage that he wished he had done so. He stated that it was not easy to position a patient who was in pain in the DPT machine. Secondly, he claimed that x-rays in this area are unreliable and in any event he still needed an expert opinion to see if the teeth had been damaged. He did not therefore take another x-ray. However, the accuracy, if not truthfulness, of his explanation is largely negatived by the subsequent production in the trial of a DPT x-ray in fact taken by Dr. Harris on the 13th July. This is the "forgotten" x-ray and I should stress there has been no suggestion at any time that Dr. Harris wilfully concealed the existence of this x-ray or knowingly denied its existence. The significance however, of the discovery of the x-ray is to greatly undermine Dr. Harris's credibility in terms of his reasons for not seeking a confirmatory x-ray. It also strongly suggests that the x-ray of the 13th July was, in fact, a confirmatory x-ray and that Dr. Harris reached no other conclusion having studied that x-ray than he did on reading the first x-ray of the 6th July, namely, that he had gone too close to the apices.

108. The Court felt obliged to recall Mr. Geoghegan to the stand so that it could be put to him for the first time that Dr. Harris had explained to him on the 11th July, or indeed at any time, that in addition to the three possibilities canvassed, Dr. Harris had further explained to him that he might have gone too close to the teeth.

109. This was forcibly denied by the Plaintiff. He says that Dr. Harris told him merely to go down to Dr. Cleary who was an endodontist who would have a look at him and to bring his x-ray with him. I accept the Plaintiff's evidence in this regard.

110. I do not believe Dr. Harris informed the Plaintiff at any stage that he believed he had gone too close to the apices of the Plaintiff's teeth. Nor do I feel he discussed the x-ray which he took on the 6th July in any detail with Mr. Geoghegan. Nor do I believe or accept that Dr. Harris gave to Mr. Geoghegan as his reason for referring him to Dr. Cleary the possibility that his teeth, might have been damaged or their vitality comprised as a result of his having gone too close to the apices during the operation. I find it inconceivable that Mr. Geoghegan, in causing his Solicitors to write the originating letter at the 17th August 1992, would not have included a reference to the bone graft having been taken too close to the tooth apices if such information had been given to him as claimed by Dr. Harris. Even if nothing could be proved at that time, an admission consistent with error on the part of the Defendant would hardly have been omitted from a letter which was the precursor to legal action.

111. In his evidence, Dr. Harris repeatedly criticised the accuracy of x-rays in showing the relationship of structures, particularly when they are not in the same plane. Dr. Harris has a DPT machine for taking extra oral x-rays in his rooms and has full access to the x-ray facilities of the Blackrock Clinic. He accepts it is an essential "tool of his trade" and that it would be unthinkable for him to execute an operation without having the x-ray up on the viewing frame during the operation. However, he took no measurement from his x-ray.

112. At one point in his evidence, Dr. Harris pointed out that he would rely on pre-operative assessment from x-rays and any measurement that might be taken on the x-ray, even though he stressed the primacy of the clinical touch. Then he stated that when you see things on x-ray, you know they can be projected up or down as a shadow. A DPT is not reliable for telling accurately the position of various objects, according to Dr. Harris. He stated that he would never believe x-rays when it comes to three dimensional relationship of one thing to another. Also, he said, the quality and projections of x-rays, if not taken correctly, can vary what you see. In his x-ray of the 6th July, the Plaintiff's head had rotated and his teeth in the apices were not in focus.

113. I found Dr. Harris's evidence in relation to the x-rays wholly unsatisfactory. One must ask at once why one should avail of x-ray technology at all if it is as fallible as suggested by Dr. Harris. Alternatively, why not resort to another form of x-ray, namely a peri-apical, if that offers a more reliable view of distances measured at close quarters? Equally, the Court could not understand why if Dr. Harris was in any doubt as to what the x-ray of the 6th July revealed, why he did not at once do repeat x-rays or a series of x-rays to eliminate any uncertainty. The explanation he gave for not doing so is demonstrably unsustainable. In fact, as subsequently emerged, he did do a further x-ray and the evidence later considered in relation to the x-rays establishes that it confirmed what was apparent on the x-ray on the 6th July. Why did he take this form of DPT x-ray if he had no confidence in the technology as a reliable measuring technique? Why do dental specialists continue to use the technology if it is in any way unsafe to do so?

114. Finally, Dr. Harris is himself well aware of any supposed foibles associated with x-rays and, given his level of dental expertise, was well placed to make an expert evaluation of same. Mr. Hirshmann, a Radiologist who was called on behalf of the Defendant, informed the Court that dental experts are aware of these slight variations in x-rays and can take them into account when reading the x-ray.

115. I have reached the conclusion that Dr. Harris felt very strongly on the 6th July that he had gone too close to the apices of the teeth. This was, in the Court's view, a probability in the Defendant's mind and the other three possibilities which he wrote up in his clinical notes were exactly that, possibilities only, to be eliminated or checked in the hope that they might provide an alternative source of explanation.

116. Again, as stated in relation to causation in the context of informed consent, actions speak louder than words. What Dr. Harris thought and did, having inspected this x-ray, was that he should refer the Plaintiff to Dr. Pat Cleary, whose speciality was to investigate and treat damaged teeth and roots. Yet he made no entry of his real fears in his notes, nor did he discuss his belief or apprehension with the Plaintiff. His failure to do so has meant in this case that the Plaintiff spent months, if not years, trying to ascertain the source of his problem and, indeed, was greatly criticised in cross-examination for the delay in bringing forward his allegation of medical negligence, a criticism which in the light of these findings was quite unjustified.

117. It is the view of the Court that Dr. Harris was unwilling or unable to confront what was obvious to him from the outset, namely, the probability that he had gone too close to the apices of the teeth. He simply could not bring himself to believe it.

118. His mental attitude is well illustrated by an astonishing claim which he made in the course of cross-examination that an entry of measurement in his own clinical notes of "5 mm" representing where the labial flap had been taken from the gingival margin, should in fact, and indeed was in fact , an entry which stated "15 mm". Dr. Harris told the Court that when he was looking at his notes on the very morning he gave this evidence, it seemed to him to read 15 mm. Yet it clearly and very obviously reads “5 mm” (see Appendix C). He went on to say (A32, day 11):-

120. It is perhaps extremely difficult for a surgeon as accomplished as the Defendant to accept that he has made an error, but my interpretation of his evidence can only be that Dr. Harris himself believed that he transgressed the 5 mm margin.

121. The very criticism which he levelled at the Plaintiff's experts is perhaps important to revisit insofar as the x-rays are concerned. Dr. Harris stated that "none of these surgeons (i.e. called on behalf of the Plaintiff) had the opportunity to look at the reality and I did. Therefore their views are incorrect."

122. This Court has come to the conclusion that the only inferences it can draw from Dr. Harris's evidence is that, despite his assertions to the contrary, he did in fact believe from the 6th July onwards that he had transgressed the 5 mm barrier.

124. While certain symptoms, such as numbness of the chin and lip, may be expected, albeit as transient symptoms, a successful procedure is understandably free of damage to teeth. Indeed, it would entirely defeat the purpose of the operation if such sequelae were either a normal or occasional concomitant of an implant and bone graft procedure.

126. The first person to carry out a test on the vitality of Mr. Geoghegan's teeth post-operatively was Dr. Cleary, an endodontist who specialises in root canal treatment, who saw the Plaintiff on the 27th July, 1992. He did so at Dr. Harris's request and following a telephone conversation with him. He described the reason given by Dr. Harris in requesting the examination.

128. The Plaintiff brought with him a radiograph from which Dr. Cleary noted that Mr. Geoghegan's teeth appeared to be normal. He then carried out pulp testing on Mr. Geoghegan's two lower central incisors. His pulpal diagnosis in respect of those teeth was uncertain. However, his "cold tests" elicited no response from Mr. Geoghegan's two lower central incisors. A "cold test" involves applying a very cold medium to the teeth which a patient with normal teeth will feel. If he did not feel the cold, it would be an indication that there might be a pulpal death or that a root canal treatment had already been carried out. On palpation, the four lower incisors were tender.

"Advised him that vitality test indicates that lower centrals may be non-vital but not conclusive due to numbness in the area. I was reluctant to do endo on teeth at present until more confirmation that these teeth are contributing to pain. Some feeling of fluctuance in the lower central incisor apical area. Feels swollen.

Contacted David Harris and advised him of my findings. May need endo but told patient I would only do endo at present if patient signed a letter stating that he realised that endo may not be necessary but to rule out pulp as possible causes of pain he wished treatment to proceed."

132. Subsequently, Dr. O'Grady carried out vitality tests on the 14th October, 1992. Mr. Geoghegan's lower right central incisor was found to be very tender and non-vital to ethyl chloride, a form of vitality testing which was not considered very reliable.

133. Later, Mr. Geoghegan visited Mr. Michael Kelleher in London, and later Dr. Hammer in the United States. This was in February, 1994. Dr. Hammer drilled a very small hole in one of Mr. Geoghegan's lower anterior teeth and found that it had normal vitality, but recommended Mr. Geoghegan to see a neurologist. Dr. Hammer felt the Plaintiffs pain was “in some way” associated with the oral surgery the Plaintiff had undergone.

134. In October, 1995 he attended Dr. Lordan, endodontist, at the Northbrook Clinic in Ranelagh who undertook electrical pulp testing. This showed the Plaintiff's lower central incisors were somewhat abnormal, but vital. However, by 1999 the Plaintiff's lower incisors were testing up to the full scale of 80 on Dr. Lordan's electrical pulp test without receiving any response. This indicated to Dr. Lordan that the teeth, somewhere between 1995 and 1999 had become non-vital.

135. Dr. Lordan performed root canal treatment on the Plaintiff's teeth as part of a diagnostic procedure without any difficulty or complaint from the Plaintiff. Typically, in an non-vital tooth, this would at worst have been, according to Dr. Lordan, mildly uncomfortable. While he found no evidence of vital tissue within the root canal, Dr. Lordan noted that the Plaintiff started to experience discomfort when Dr. Lordan progressed within 2 mm to 3 mm of the apex of the tooth. The administration of local anaesthetic into the root canal exacerbated the situation and created even more discomfort which took quite a while to dissipate. Dr. Lordan found this to be an unusual and abnormal response. He gave an infiltration and the symptoms subsided which enabled the root canal therapy to be concluded. He found it a contradiction that there should be any vital tissue within a canal that had tested negative to multiple tests and that he was able to access without local anaesthetic.

137. Vitality involves two considerations (a) vascularity, i.e. blood supply and (b) nerve supply, i.e. sensation. Of these two, the most important is vascularity, because without that the tooth dies and can necrose and blacken. The Defendant's experts stress that the 5 mm barrier is more important from the point of vascularity than innervation. Nerve supply can be interrupted or interfered with, but usually regenerates. However, interference with the blood supply can cause teeth to become non-vital and one gets signs and symptoms of non-vitality.

138. It seems impossible to escape the conclusion that the Plaintiff's lower incisors suffered partial non-vitality in the early years leading by 1999 to non-vitality in both lower central incisors which led to the necessity to carry out root canal treatment to the lower right central incisor.

139. One must immediately ask what explanations apart from the operation the Defendant offers for this dramatic deterioration in these particular teeth of the Plaintiff. Several theories were canvassed in cross-examination of Dr. Lordan. One possibility canvassed was that Dr. Hammer's drilling of a tooth in 1994 contributed to the ultimate loss of vitality in that tooth. This was dismissed by Dr. Lordan, who stated that the dentine is sensitive and conducts pain long before one actually incurs damage to the pulp within the tooth.

140. A further possibility canvassed in cross examination was that the unusual symptoms evident in Mr. Geoghegan's lower incisors occurred through natural causes or wear and tear over the passage of the years. This was also dismissed by Dr. Lordan who told the Court it would not be a natural progression for a tooth to become non-vital “in the absence of very obvious incursion, either through caries (i.e. decay) or trauma or chemicals or this type of thing”.

141. Finally, it was suggested that Mr. Geoghegan, because of the absence of teeth at the back of his mouth was applying more than usual strain with those at the front and that this accordingly may have been a contributory factor to the loss of the vitality of his lower central incisors. Dr. Lordan felt this was a very tenuous connection. Theoretically it was possible, but clinically, it was rarely encountered.

142. Mr. Blackburn, oral surgeon from Hull and Professor Sleeman, Professor of Dental Surgery in Cork, both gave evidence on behalf of the Defendant of examining the Plaintiffs chin, the former in March 2000 and the latter in 1997 and 1999. Mr. Blackburn applied ethyl chloride to four lower teeth and evinced a response at the left lateral incisor. He did not, however, note the distance from the apices to the graft. Professor Sleeman stated that there was a line of bone between the apices and the graft. He noted the teeth were tender which could be because they were on top of a tender area. He suggested that if there had been a loss of vitality since the operation, that maybe there had been some intervening trauma. However, no such trauma was identified. He carried out tooth vitality tests on both occasions and found little response on electronic testing. He felt that while on x-rays the graft appeared to be close to the teeth, that may not be important once a bony bridge is maintained. He felt that three lower teeth had no nerve supply.

143. Mr. Beirne, Consultant at St. James’ and Beaumount Hospitals’, also examined the Plaintiff in August 1998. He found the lower incisors tender to percussion. Ethyl Chloride testing showed two lower incisors did not respond. However, clinically the teeth appeared well and he thought they were vital.

144. While Mr. Geoghegan's lower incisors have not blackened, which is a feature associated with tooth death, the evidence of Dr. Lordan satisfies me that the teeth are now non-vital. Necrosis is caused essentially by a breach of the blood supply, and all experts in the case confirm that blood supply is sent to the tooth through capillaries that are immediately adjacent to the nerves which go to the teeth and are inextricably linked with them.

145. It is impossible to escape the conclusion that the surgery in July, 1992 caused collateral damage to both of the Plaintiff's incisors which has led to either complete non-vitality or a condition, without blackening of teeth, which is virtually the same thing.

146. No credible reason has been offered by the Defendant as to how the Plaintiff's teeth became non-vital otherwise than as a direct consequence of Dr. Harris's bone graft procedure. I accept the Plaintiff's submission that the only credible inference to be drawn from the foregoing is that Dr. Harris in carrying out the procedure, compromised the nerve and blood supply to the Plaintiff's lower central incisors in a manner which had led to their loss of vitality.

147. Since the purpose of the 5 mm rule was to preserve vitality in the teeth, and since it is clear that the teeth lost their vitality as a result of the procedure carried out by the Defendant, it seems to this Court that the most likely reason for the loss of vitality in the Plaintiff's teeth is that the Defendant violated the 5 mm zone when he carried out the bone graft procedure.

148. While the various experts called on behalf of the Plaintiff gave their opinion as to the characteristics of the incisive nerve and its branches, the anatomical evidence in the case was furnished by an expert witness for the Defendant, Dr. Robin O'Sullivan who is a lecturer in anatomy in University College Cork. His formal training is in the peripheral nervous system and he has taught dental anatomy. He is highly qualified and I found his evidence to be impressive and credible. That evidence was supplemented by reference to diagrams enclosed at Appendix D and also by reference to a number of skull models which were demonstrated in Court.

149. He described how the inferior alveolar nerve enters the mandible through a hole called the mandibular foramen. This leads to a bony canal which runs quite close to the roots of the wisdom tooth. As it continues forward in the bone, it gradually sinks to a lower and lower level. In the premolar region, the nerve divides into two branches, namely, the incisive nerve, which continues on in the mandible, and the mental nerve, which runs upwards and outwards to emerge through the mental foramen.

150. The division of the nerve occurs at a level below the mental foramen. The mental foramen is a small hole located between the two lower premolar teeth, these being one on either side. Having emerged from the mental foramen, the mental nerve divides into a number of branches, one of which innervates the soft tissues and the periosteum covering the bone in the area of the chin with which this case is concerned. Two other branches of the nerve supply the lips. Figure 3 in Appendix D contains a diagrammatic representation of the terminal branches of the mental nerve, showing how it crosses the mid-line of the chin and re-enters the labial plate of the mandible.

151. At the point of formation of the incisive nerve in the region of the premolar teeth, the nerve consists of a single nerve trunk. It runs forwards and almost immediately breaks up into a network of branches and filaments. It no longer exists as an individual entity from the time it reaches the region of the canine tooth. It supplies sensation to the bone, teeth and periostium over the bone.

154. I prefer Dr. O'Sullivan's evidence on this point to that of Professor Kahnberg or Dr. Sambrook both of whom felt the trunk of the nerve was within a few mm’s of the apices of the teeth. I am satisfied that the area of the chin where the Plaintiff sustained his injury was traversed not by any trunk of the incisive nerve as such, but by branches thereof which move vertically upwards and outwards in their course of travel.

155. While much was made of this distinction by Mr. Cooney, the medical experts are agreed that the Plaintiff's condition of chronic neuropathic pain arises as a result of damage to the incisive nerve, and whether the damage is to the main trunk or to a branch or extension thereof seems to me to be a point of little importance. This was the view of Mr. James, the dental surgeon called on behalf of the Plaintiff and it was not contradicted or refuted by any of the Defendants experts.

159. He also indicated that the greater concentration of nerve fibres per square millimetre of sectioned bone is to be found lower in the jaw, whereas branching of nerve fibres takes place as the nerve is "sprouting" in its direction of upwards travel.

160. In re-examination, Dr. O'Sullivan gave evidence which I regard as extremely significant in terms of understanding the possible mechanism of the Plaintiff's injury. He stressed that the incisive nerve after it branches off runs in the same orientation as the inferior alveolar nerve. It therefore remains near the lower border of the mandible.

163. While these drawings were introduced to illustrate the location of the trunk of the incisive nerve in relation to the premolar tooth, the plates illustrate both how low the incisive nerve lies in the bone at the point where it may first be seen on plate 29. It is not at all visible on plate 27. Plate 29 shows a position further forward in the jaw profile. Dr. O'Sullivan described how plate 29 shows the incisive nerve dividing into branches which run more vertically than horizontally. These branches run vertically upwards and outwards through the bone.

This outwards movement or path of travel of the incisive nerve suggests that the branches of the incisive nerve are more likely to be compromised the further up they travel on the buccal plate. It is a factor, and I think a significant factor, tending to show that the Plaintiff sustained damage to his incisive nerve because the cut was made at a higher, rather than a lower, point.

164. As Professor Kahnberg pointed out, the lower down the jaw one goes, the less one is likely to compromise the incisive nerve. His conclusion was right even if his reason may have been wrong. Dr. O'Sullivan's evidence quite clearly fits in with Professor Kahnberg’s conclusion and supplies a reason which clearly suggests the mechanism of how the injury occurred.

165. Also, it seems to me that the statistical infrequency of this damage speaks for itself. Mr. Cooney described this case as "unique". That is in itself a matter of some significance and may be taken as supporting the proposition that a bone graft, taken from a point lower down the jaw, is less likely to damage the incisive nerve because the nerve is located more deeply in the jaw at that point. It is only as the branches move upwards and outwards that the risk of compromise is increased. The closer one approaches the apices, the greater the risk of such compromise or damage.

166. Accordingly, while I accept Dr. O'Sullivan's evidence as regards the location of the trunk of the incisive nerve, it would be my interpretation and conclusion in relation to his remaining evidence that the line of travel of the branches of the incisive nerve supports the view that the graft was taken at a point close to the apices of the teeth. Further, the fact that no such incident has ever been recorded at a location outside the 5 mm zone, further buttresses a conclusion that portion at least of the graft was taken within the 5 mm zone.

168. Firstly, all medical experts in the case agree that an x-ray is an essential technique for the proper execution of the procedure in question. It enables the dental surgeon to identify the location of the apices of the teeth in a pre-operative context. It also enables the surgeon to make measurements. It also enables the surgeon form a more complete picture of the area under investigation to supplement his own clinical assessment. As has already been pointed out, Dr. Harris saw the x-ray as an essential tool of his trade and had facilities for taking DPT x-rays in his rooms. Furthermore, he had immediately available to him all the x-ray technology of the Blackrock Clinic whereby he could, if he so wished, have availed of other x-ray techniques. He had on his desk a viewing screen for assessing x-rays and equally had a viewing screen in the operating theatre which he could consult as required.

169. One might be forgiven for thinking that an x-ray would conclusively determine the location at which the bone graft in this case was taken, given that the bone grafted area shows up as a radio-lucency on x-ray which is clearly visible. Indeed, insofar as the Plaintiff's experts are concerned, the x-rays are clear and conclusive, particularly when x-rays taken by different techniques support each other. The interpretation of the various x-rays by the Plaintiff's experts, including the Plaintiff's radiologist, Dr. Brown, is to the effect that the radio-lucency appears very close to the apices of the Plaintiff's teeth at a distance of about 2 mm, having made all the due allowances for all x-ray characteristics including magnification (on DPT only) and beam geometry.

170. Using a "back-projection" technique, the Defendant's expert Radiologist, Professor Grondahl took the view that despite the appearances on the x-ray, the reality, when the x-ray was properly interpreted, was to place the bone graft at its upper margin some 5 mm below the apices of the teeth.

171. The Court viewed with some initial concern the suggestion that x-rays may have certain characteristics rendering them unreliable, particularly in terms of measuring minute or fine distances. However, those fears were greatly allayed on hearing of the different x-ray techniques available to a surgeon carrying out this kind of work and indeed the evidence of one of the Defendant's own experts, Mr. Hirshmann who advised that dental surgeons carrying out such work are well familiar with any variations from ‘reality’ apparent on x-ray and make appropriate allowances for same when carrying out their work.

172. To put it at its simplest, the Defendant's case about x-rays and lack of accuracy derives from the manner in which an x-ray beam is projected. The greater the angle of upward projection, the greater the degree of distortion. If a beam is aimed upwards from the floor of a room towards its wall with an intervening object in the line of the beam, the projection on the wall will be greatly lengthened, so that a five foot man might appear to be six foot in height or more. At least two of the x-ray technologies do involve a degree of angulation, although in DPT x-rays this is very slight.

173. Firstly, the dental panoramic tomogram (DPT) is taken extra-orally in circumstances whereby the x-ray tube and the film move around a central point which remains in focus, the idea being that other things in front and behind blur out. The film is outside the patient's mouth. The image is coming from behind the patient and is coming from the inside of the jaw upward at an angle of about 6 to 8 ° to reach the film outside the patient's mouth.

174. Then there are peri-apical x-rays, with which ordinary visitors to the dentist are more familiar. These are small box film slides which the patient holds with his fingertip against his teeth on the inside while the person taking the x-ray manoeuvres the machine into position. Essentially two techniques are available when x-rays of this sort are taken. The first involves a paralleling technique whereby the x-ray beam comes from outside through the jaw to reach the film that is sitting behind the teeth. As everything is lined up in a parallel fashion, the degree of angulation involved in such an x-ray is greatly reduced. It would strike a layman as the obvious type of x-ray to take for the purpose of assessing at close quarters fine distances between objects which are on different planes. This was also the view of the experts on both sides.

175. Peri-apical x-rays may also be taken using another technique, namely bisectional angle methodology, whereby the x-ray machine is brought to the patient's chin while again the patient holds the film inside his teeth. Such x-rays are normally taken at an upward angle of 16 - 25 °. The Radiologist attempts to get the occlusal plane of the lower teeth horizontal. The angle of the beam is then at 90 ° towards the line which bisects the angle between the root of the tooth and the film. It is a standard form of x-ray which permits accurate measurement of tooth length.

176. In this case some seven x-rays were taken, which are listed hereunder, firstly, by reference to the date upon which the x-rays were taken. There then appears in initial form a description of the technique involved. For example, a peri-apical x-ray taken using the bisectional angle technique is described as "PABA" where as a peri-apical x-ray taken while using a paralleling technique is described as "PAP". Thereafter the name of the person who took the x-ray in question is furnished.

178. When the trial commenced, the Court was informed that the pre-operative x-ray had gone missing. However, this x-ray and a further DPT x-ray taken on the 13th July, 1992 were discovered during the course of the hearing (they had been sent to some other medical expert and not returned). The x-rays taken by Dr. Canavan were not explored in evidence, the reason being that the radio-lucency representing the bone graft had disappeared through rehealing by the time they were taken in 1995. Finally, while Dr. Brown saw the peri-apical x-ray taken using the paralleling technique by Dr. Bossola in the United States, this x-ray was not proved in evidence because the Plaintiff was unable to produce Dr. Bossola in Court to prove same.

179. Essentially therefore, the whole question of interpretation of x-rays revolves around those x-rays taken in July and October of 1992 and one peri-apical x-ray taken in February, 1993, together with information to be gleaned from the CT Scan. Commencing with the DPT x-rays, there is a machine setting which determines the angulation of the beam which, as previously stated, is between 6 °- 8 °.

180. Insofar as bisectional angle periapical x-rays are concerned, both the patients head and the x-ray camera must be positioned by the person who takes the x-ray. It is perhaps appropriate therefore to commence the analysis with a description of how Mr. O’Grady took his two periapical x-rays which are so critical to the issues in the case.

181. Both the x-ray of the 14th of October 1992 and the x-ray of the 24th of February 1993 were taken by Mr. O’Grady in his rooms using the bisecting angle technique. This is perhaps best illustrated at appendix F, which is an extract from “Essentials of Dental Radiography and Radiology” by Whaites and Casson (1992) , wherein the positioning of both the x-ray machine, the patients head and the bisecting angle are clearly illustrated.

182. Mr. O’Grady described how he put the patient sitting in the chair in an upright position. He would then tilt the patients head back so that the plain from the ala or the tragus of the ear to the corner of the mouth is horizontal to the floor. He would then place the packet for the film of the x-ray into the patients mouth behind the lower front teeth and would then get the patient to hold the film usually with their left hand. He would then point the x-ray cone at the chin, bisecting the angle between the root of the tooth and the film, so that the appropriate bisecting angle would thereby be created, at which stage he would take the x-ray.

184. In a nutshell, Mr. O’Grady followed the standard and approved method of taking this form of x-ray and, despite the high degree of controversy about the angulation of the PABA, he was not challenged on either of his appearances in the witness box with any suggestion that he had departed from approved practice in the manner in which he positioned either the patient or the machine.

185. It is also important to bear in mind that Mr. O’Grady is a highly experienced dental specialist who works in close association with the Defendant in the Blackrock Clinic and that these x-rays were taken at a time when relations between the Plaintiff and the Defendant had broken down more or less completely. It must be assumed therefore that Mr. O’Grady would have been particularly careful about the manner in which he took these x-rays and would have repeated any x-ray with which he was not satisfied. This did not in fact occur. It is also pertinent to observe that in referring the Plaintiff to Mr. Frank Brady, Mr. O’Grady noted that his interpretation of his own x-rays was to the effect that the bone graft site was “ very close” to the tooth apices.

186. While Dr. Brown gave some evidence early on in the case, it became clear, for a number of technical reasons that she would require to be recalled at a later stage, not least because there had been non disclosure and non discovery by the Defendant of a CT Scan taken in November 1998 from which Professor Grondahl had drawn for the purpose of preparing his transparencies and diagrams. I think it is only fair to say that the complex nature of the material produced an unusual situation at the hearing because of necessity Counsel for both side were receiving further technical instructions as the case progressed. Ultimately, however, this had the probably helpful outcome that Professor Grondahl, the Defendants Radiologist, in effect went first in evidence and produced his transparencies, diagrams and illustrations. Dr. Brown, on being recalled later, was able to comment on these projections and diagrams and produce her own commentary in projections incorporating Professor Grondahl drawings. Thereafter the Defendant called a further Radiologist, Mr. Hirshman, Consultant Dental Radiologist at the Leeds Dental Institute.

187. It is frankly impossible in the context of a written judgment to adequately deal with every slide or projection shown in Court on a screen, and would probably create only confusion to endeavour to do so. I have accordingly incorporated only two diagrams from Professor Grondahl, showing the beam geometry of the periapical x-ray on the one hand and the DPT on the other. Equally, insofar as Dr. Brown is concerned, I have incorporated only two of her diagrams, effectively based on Professor Grondahl’s drawings, but with her own interpretation drawn thereon. Finally, I have also included a separate illustration prepared by Dr. Brown which is so important to the understanding of her evidence that I believe it is necessary to include same. This is at Appendix K.

188. Professor Grondahl is a Swedish citizen and presently Professor and head of the Department of Oral and Maxillosacial Radiology in the University of Gothenburg. He has been a recognised specialist in oral and maxillosacial radiology since 1981. He had in fact worked as a specialist for many years before that. His wife has been closely involved in the whole area of dental implantology pioneered by Professor Brunemark. He has published some 10 text books or text book chapters and written an additional 160 scientific papers. He has lectured mostly on implant radiography, including panoramic radiography. He is a highly qualified expert of world renown.

189. For the purpose of giving evidence in this case he was supplied with the periapical x-rays and the DPT dated the 6th July, 1992. He did not have the DPT of the 13th July, 1992 because the same only came to light after he had concluded his evidence the Court being informed of this discovery on the 16th day of the trial on the 9th of May 2000. He also had a CT Scan taken of Mr. Geoghegan’s skull in November 1998 in Beaumount Hospital. This scan contains a scout film showing the left profile of the Plaintiffs skull and lower jaw.

192. In giving his evidence, Professor Grondahl availed of a projector to project transparencies he has prepared onto a screen. If this matter is to be revisited by the Supreme Court, I believe it will be necessary for the parties to provide some sort of similar exposition to that Court in some form to be arranged between the parties.

193. Essentially, Professor Grondahl’s methodology and theory is as follows. If on looking at the x-ray itself, the upper margin of the bone graft appears on the x-ray to coincide with the tooth apex (which he states is a generous assumption from the Plaintiff’s point of view), one can then proceed to make a proper calculation as to where the true site of the bone graft lies at what he calls a process of “backwards projection”. Shown in Appendix G is the periapical film which the patient has placed in his mouth in what is, or should be, a known and verifiable position.

194. One then identifies a point on the film by reference to the beam angle, or supposed beam angle of the x-ray which can to some degree be inferred from what is visible on the x-ray itself. By joining that point with the tooth apex and proceeding back towards the camera, one can then ascertain the true position of the upper margin of the bone graft on the patients chin. This, according to Professor Grondahl is the only safe method whereby to ascertain the true position of objects which are in different spatial and dimensional relationships to each other.

195. He then drew in the box area representing the bone graft, showing same to have been cut at a downward angle of 45 ° into the Plaintiff’s chin bone, as Dr. Harris had testified. On drawing a line backwards from the film, Professor Grondahl calculates that a distance of 5 mm is maintained between the apex of the tooth and the upper margin of the bone graft at all times. It is important to stress that this is an angular measurement. In other words, if one placed the tip of a compass at the apex of the tooth and conducted a 5 mm sweep with the other arm of the compass, that other arm would not touch the bone graft at any point.

196. For Professor Grondahl to be correct, and for there to be a bone graft site located more than 5mm away from the apices of the central incisors, it was necessary for Professor Grondahl to find that Mr. O’Grady had taken two sets of periapical x-rays using an extremely steep angle, of about 50 °, and not 20 ° as Dr. O’Grady testified.

197. Key to Professor Grondahl’s thinking was the fact that the upper margin of the mental protuberance could be seen in the periapicals, which he felt was only consistent with Dr. O’Grady having positioned either the patients head or the camera at incorrect angles to each other.

198. Also key to Professor Grondahl’s approach was that the film resting against the crown of the tooth was at its ideal position and that Dr. Harris had made his downward cuts into the Plaintiff’s chin at a constant angle of 45 °. Needless to remark, it follows that if Dr. Harris had made his cut in this fashion, it would keep the bone graft, as it descended, further away from the tooth apex.

200. Another factor which Professor Grondahl held as being indicative of Dr. O’Grady having availed of an excessively steep angle was that the enamel on one side of the crown of the incisor was higher than the other, whereas normally it would be reproduced as level.

203. As appears from the drawing, Professor Grondahl felt the middle of the sharp layer lay more to the front, i.e., from the crown of the tooth to the bone graft site, so that the roots and apices do not appear in the zone of sharp focus. He felt it was difficult to measure exactly from these x-rays because they were prone to a number of uncertainties.

205. Professor Grondahl measured the gap between the apices and the graft on DPT as seen on the film at 3mm on the plane of the film. Again, applying his theory of backward projection, he found that the transparencies coincided with each other in once again placing the gap between the tooth apices and the upper margin of the bone graft site at 5mm. In other words, one form of x-ray result confirmed the other.

207. It is perhaps pertinent to point out at this juncture, given that Mr. Hirshman accepted it later, that Professor Grondahl’s diagram’s show the tooth apex some 4mm north of where in fact it should be. This has no implications for the gap between the apices and the bone graft site, but is of relevance in a single regard to which I will shortly return in relation to the appearance of the mental protuberance in the periapical x-ray.

209. For example, he was compelled to accept that on careful measurement the gap between the graft site and the tooth apex was only 4.5 mm on his drawings. He also accepted in cross-examination that the measurement on the plane of the film of a gap of 3mm was incorrect. Having oscillated between 2 mm and 2.5 mm he eventually opted for the latter measurement. He then further accepted that if the figure of 2.5 mm was substituted for 3 mm on the plane of the film, the gap of 4.5 in the ‘real zone’ would be further foreshortened.

213. Dr. Brown, the Radiologist who gave evidence for the Plaintiff, is a highly qualified Consultant in Dental Radiology in Guys Dental Hospital in London. She has a Degree in Dental Surgery, an MSC in Dental Radiology and is a fellow of the Royal College of Physicians and Surgeons of Glasgow. She also has a diploma in Dental Radiology from the Royal College of Radiologist and is a Consultant in Dental Radiology both at Guys’ and Kings’ and St. Thomas’. She is also a Dental Radiologist at the Eastmond Dental Hospital which is a post graduate Dental Hospital in London.

214. Her interpretation of the x-rays, allowing for any possible variations, distortions or peculiarities, which in any event she regards as minimal, places the upper margin of the bone graft within 2 mm from the tooth apices. Her approach might best be described as a practical one, in that she has taken as accurate the evidence of Dr. John O’Grady as to the manner in which he took his x-rays in October 1992 and February 1993. These were standard setting for the bisectional angle x-rays which Dr. O’Grady took. If Dr. O’Gradys evidence is correct, she believes that the beam projection will not create any significant distortion, nor does she believe that any significant angle projection was created by the manner in which Dr. O’Grady took his x-rays. If Dr. O’Grady had availed of an excessively steep angle, one would expect the DPT x-rays to have shown a much wider gap and this is well illustrated at Appendix K in the illustration which Dr. Brown prepared to illustrate what should have happened if Professor Grondahl’s theory were correct.

215. She accepted that DPT x-rays do have certain peculiarities. Having seen all three DPT’s taken by Dr. Harris, she felt they showed a slight error of positioning of the patient, that he was slightly rotated and nearer the film on the left side than on the right. Also his chin was in a very slightly different position in each one.

216. She felt the x-ray of the 13th of July was entirely consistent with that of the 6th of July with some slight differences. For example, there was an increase in the size of the graft area in its horizontal form because the patient was not quite as far into the machine, which increases magnification in a horizontal direction. The area however is visualised better with less spine and shadow. The margins were slightly blurred due to some resorbtion of bony margins.

221. She also felt that Professor Grondahl had made his measurement using an incorrect standard. The measurement was not one to be made on an angular basis as the crow files, but rather as a vertical measurement between the objects on different planes.

223. A. The fact that Professor Grondahl’s drawings misrepresented the actual position of the tooth apex and bone graft site which should in fact have been 4 mm further “south”, an alteration, a necessary alteration, which she felt might explain why this margin was visible in the periapical x-rays.

224. B. She felt that the position of the buccal cortical plate as shown in the CT Scan in November 1998 could not be assumed to be identical to that of July 1992, since repair and remodelling may have occurred in the intervening years which might have altered this portion of the bone.

225. She acknowledged that the approach adopted by Professor Grondahl was a scientific one, subject to the reservations she had expressed. She felt her own was at least an equally reliable method. She also drew support from and found extremely persuasive the fact

that the DPT of 13th July 1992 (being the missing x-ray in respect which Dr. Harris gave no evidence) confirmed the results of the first DPT x-ray and the DPT x-rays in turn confirmed the findings of the periapical x-rays. All of these x-rays properly interpreted show the upper margin of the bone graft to be not more than 2 mm from the apices of the incisor teeth.

226. She felt that if the periapical was taken with a steeply angled upward projection, it could indeed disguise the fact that the graft site was in reality lower down, but the DPT x-ray, coming as it does from a different direction, should show it in it’s true position and show a much bigger gap. That, however, is not what happened and therefore an excessively steep angle could not have been used.

227. In cross-examination, Dr. Brown was criticised for initially giving evidence on the basis of measurements taken off the x-rays themselves without making allowances for any element of projection. However, she pointed out, and I accept, that she did in direct evidence highlight, a 20% magnification factor so that her measurements of 1.5 mm under one incisor and 3 mm under another on the DPT, required adjustment to 1 mm to 2 mm on that account. Further, she had reported on the ‘beam geometry’ factor to the Plaintiff’s solicitors and told the court she factored in an element to allow for beam geometry in her calculations. She did not and could not go further than that because she did not have the CT Scan (which was only disclosed by the Defendant during the hearing) from which the length of the teeth, the position of same and the shape of the jaw could be assessed so as to permit the kind of exercise which Professor Grondahl carried out. She felt she could not have been more precise at the initial stages because x-rays are very difficult to draw any very accurate measurements from. This seems to me a more than adequate explanation by Dr. Brown.

228. Asked about the difficulties associated with DPT x-rays, Dr. Brown accepted they can be problematic and unwanted objects can intervene in the image. However, the rotation of the patient in this particular case had allowed the spinal superimposition to be placed slightly to one side, allowing a reasonably undistorted image in a vertical direction. Also, the mid line on the DPT x-ray appeared well located in the sharp zone. Even if the sharp zone was a little more forward, as stated by Professor Grondahl, the vertical dimension did not much change.

229. She also pointed out that the diagram or diagrams prepared by Professor Grondahl placed the tooth higher in the bone than they actually were, a view with which I must concur having regard to the fact that Mr. Hirshmann also accepted this to be the case.

230. Asked about the proposition advanced in support of the steep angle on the periapical, namely, that the enamel on one side of the tooth was higher than on the other side, were as normally it should be level, Dr. Brown felt you could not safely assume in every case that the tip of every tooth was level.

231. She said that the CT slices made clear that the apices were lower down than represented on the Grondahl diagrams. Everything should drop down about 4 mm, which may explain why the mental protuberance may be seen in the periapicals.

232. Under further cross-examination, she agreed readily that the concept of chin remodelling was not an area on which she had any particular expertise and was offering this possibility based on conversations she had had with other experts. She accepted that a specialist from some other field would be necessary to deal appropriately with that issue.

234. Dr. Harris’ second radiological expert was Mr. Hirshmann. He felt Professor Grondahl’s approach was preferable for getting somewhere nearer the anatomical truth of the spatial relationship of the various objects shown on the x-rays. He felt Dr. Brown’s approach lacked the same level of scientific expertise. However, under cross examination he conceded that Professor Grondahl’s drawings were not in fact an accurate description of what was apparent on the CT scan since the apices of Mr. Geoghegan’s lower central incisors were shown located 4 mm or so north of where they ought to have been.

235. Again Mr. Hirshmann endeavoured to explain how the peri-apical x-rays of the 14th October 1992 taken by Dr O’Grady must have been taken with a steep angle. He introduced the “Essentials of Dental Radiography and Radiology” by Whaites and Cawson and the diagram included in the appendices. However, it emerged during the evidence that the diagrams in question were somewhat misleading. What was indicated as an angle of 25 ° in figure 8.22a turned out to be 36 °. However, it was clearly intended that the diagram would convey to a student that the correct angle for the tube should be in the order of 25 °. The actual photograph demonstrated in figure 8.22a shows the x-ray machine itself at an angle of 16 °.

236. Mr. Hirshmann accepted that the correct angle in the ordinary case for x-ray tube, pointed at the chin, would normally be in that general region of 16 - 25 °. This is consistent with the evidence given by Dr. O’Grady as to what he did.

237. Mr. Hirshmann in his evidence agreed that dental experts are familiar with the characteristics of x-rays, including in the case of the DPT x-ray, a degree of magnification of the subject image and make appropriate allowances for same.

238. Mr. Hirshmann, rather incongruously, sought to argue that Dr. O’Grady must have made a special adjustment to the head/camera angle when taking x-rays of the Plaintiff on the basis that the Plaintiff had “buck teeth”, a suggestion which was never canvassed with Dr. O’Grady. Indeed, Dr. O’Grady was never questioned to suggest that the Plaintiff constituted an exception to the requirements of normal technique used in such circumstances.

240. In another respect, however, Mr. Hirshmann raised some doubt in the mind of the Court as to whether or not Dr. Harris had in fact used a bevelled cut at a 45 ° angle, because he confirmed he saw no sign of a bevelled margin on either of the two periapical x-rays or the two DPT’s. He apparently believed the bevelled margin would have been visible on x-ray and the width of the margin would have been somewhere in the region of

2.8 mm and that could have been seen on the x-rays’. However, I do not propose to make a positive finding against Dr. Harris on this particular point which, as previously indicated, I believe to be incapable of proof one way or the other. This witness too ran into difficulty with measurements stating at one point (B.20. P79) that one could become “mired” in difficulties in trying to effect accurate measurements.

(1) Her approach seems to me at least as scientific as that adopted by Professor Grondahl. Dr. Brown, in relation to the periapical x-rays, used the evidence of Dr. O’Grady as to how he took the x-ray to see if it would yield the results shown on those x-rays as depicted in Professor Grondahl’s diagrams. She took Dr. O’Grady’s head position for the Plaintiff, took the tooth length of 20 - 21 mm (agreed by all sides) and Dr. O’Grady’s stated angle of camera projection and found this would produce a gap of 1 - 2 mm. The same outcome emerged from both periapical studies.

242. In relation to the DPT, she measured vertically on the different planes to get a measurement of 2 mm. In other words, she adopted the scientifically approved mode of measuring the distance between the tooth apex and the bone graft margin. I fail to see any thing wrong in the way in which Dr. Brown conducted her analysis, moving from the known evidence to draw certain conclusions.

243. While Professor Grondahl felt justified in doubting, Mr O’Grady’s chosen angulation in taking the periapical x-rays, he nonetheless seems to have assumed that a hand held chisel could be absolutely relied upon to penetrate bone at an unwavering angle of 45° over a short distance and in very confined circumstances.

244. If an experienced dentist, taking a periapical x-ray, can be accused of fallibility of significant dimensions when positioning a large camera to the chin of a patient, how much more likely is it that similar errors will occur in the much more confined area of a chin graft where the surgeon does not have a mechanical device to guarantee angle accuracy? This is not to say the Dr. Harris did proceed in fact at an angle of other than 45° . Quite clearly that is an matter which it is incapable of proof at this stage by any witness. What I mean simply is that this particular element in Professor Groundahl’s calculations cannot of necessity be said to have a scientific or conclusively known component.

(3) For Professor Grondahl to be correct and for there to be a bone graft site located 5 mm or more away from the apices of the central incisors, it was necessary for Professor Grondahl to find that Mr. O’Grady had taken two sets of periapical x-rays at a projection angle of 50° to a head held upright in the normal position..

245. It seems to me essentially impossible to base a theory upon such a marked departure from approved practice for taking such x-rays without laying the basis for doing so by a full and frank challenge of the witness who took the x-rays, in this case a highly reputable dentist, Mr. John O’Grady, who takes x-rays of this sort day in day out. I reject any implied criticism that he erred significantly on the two separate occasions he took x-rays - particularly having regard to the background circumstances in which they were taken.

246. Against that backdrop, I am not sure the Court need speculate further as to why the mental protuberance may appear in the periapical x-rays. However, the explanation that the tooth and bone graft site should be depicted 4 mm lower on the buccal plate than represented on Professor Groundahl’s drawings, may well account for that phenomenon.

(4) I accept as very persuasive the corroborative nature of x-rays taken by different techniques. This is illustrated graphically in Appendix K. If an unusually steep angle had been adopted by Dr. O’Grady, a much bigger gap would of necessity have appeared on the DPT x-ray, but this never in fact happened. The fact is that virtually identical results are yielded up by both forms of technology. The corroborative approach was adopted by Professor Grondahl when superimposing his transparencies over each other, so it must be assumed that two forms of beam geometry, approaching an object from different directions and yielding the same result, produce a very credible result.

(5). There is no radiological or other expert evidence to suggest that dental practitioners have desisted from using any form of these x-rays since 1992. If the technology is as fallible as Dr. Harris suggests and needful of such careful interpretation, as suggested by Professor Grondahl, one might reasonably have anticipated evidence of a change of status quo over the intervening years in the use of such x-ray’s, which was not forthcoming.

(6) Professor Grondahl took his 5 mm measurement in a straight line, “as the crow flies” from the apices of the lower central incisors to the upper margin of the bone graft site. That involved a calculation of the distance in a diagonal or angled manner. In fact, as pointed out by Mr. Trainor SC, the literature indicates that the correct way in which the distance should be calculated is vertically, i.e. by the distance between the apices and lower border of the mandible (Hoppenreiss et al... “the chin as a donor site in early secondary osteoplasty..a retrospect of clinical and radiological evaluation”) when measured on different vertical planes. When measured in this way, the gap narrows to 2 mm, which tallies with Dr. Brown’s own view of what was apparent from the DPT x-ray itself after factoring out the magnification element. Professor Grondahl was seemingly unaware of the requirement to measure on vertical planes

(7) Dr. Brown’s evidence and estimate than the upper margin of the bone graft was at or within 2 mm of the apices of the lower central incisors was supported by Mr. Vaughan, Senior Consultant at the Regional Centre for Maxillofacial Surgery Liverpool, Professor Khanberg and Mr. David James, Consultant Maxillofacial Surgeon at Great Ormond Street in London and examiner in oral Maxillofacial Surgery in the Royal College of Surgeons in Edinburgh. There is no similar body of evidence in contradiction.

247. I should finally address one other criticism made of Dr. Brown by Mr. Cooney. This was a criticism of her for failing to elicit from Mr. O’Grady, before she commenced her evidence, the technique whereby he had taken his two PABA’s. Her explanation was, in effect, that the results of those x-rays were so similar to the 1994 PAP of Dr. Bossola that it suggested the same technique was likely to have been applied in both sets of periapicals. This seems to me an entirely reasonable assumption to have made by way of an initial assumption, and I find that criticism of her on that account and any other criticism of her for giving “lectures” by way of replies to questions to be entirely misplaced. I found Dr. Brown to be a most impressive witness, who gave her evidence with great care and composure.

248. Insofar as the x-rays are concerned, the Court finds it impossible to accept the criticisms made by the Defendant’s experts. Firstly, the DPT x-ray’s were taken by Doctor Harris himself who had the option available to him to have a further x-ray taken at once if any first x-ray was unsatisfactory in his expert opinion. He studied the x-ray of the 6th July extremely closely and did not opt to repeat that x-ray on that date. He was clearly satisfied with the adequacy of the image produced.

249. He was clearly satisfied with the technology, because when excessive proximity to the teeth became an issue in his mind on the 6th July, the form of x-ray he adopted to explore the matter further on the 13th July was the identical form of x-ray, namely a DPT. Again, on the 13th July, he did not seek to repeat the x-ray in question nor has he sought to give any evidence to suggest that what is to be seen on that x-ray is in any way different from what can be seen on the x-ray of the 6th July. The DPT x-rays confirm the peri-apical x-rays and vice versa, there being a remarkable consistency between the results yielded by the two techniques.

250. That being so, and given the preference which the Court feel for Dr. Brown’s evidence over that given by Professor Grondahl, the Court finds that the x-ray evidence supports the finding which the Court makes, namely, that the upper margin of the bone graft was 2 mm from the tooth apices.

252. I think it only appropriate to add that the very uniqueness of this case may perhaps itself be seen as a fifth factor tending to point towards an intrusion into the 5 mm zone. Mr. Geoghegan’s condition has been caused by damage to his incisive nerve. On this all experts are agreed. In no other operation to date where bone grafting has occurred outside the 5 mm zone in the context of this particular procedure, has there been a similar outcome.

253. Far from having adverse consequences for carrying out operations of this nature, it seems to me the findings of fact in the case support precisely the opposite contention, namely, that if this 5 mm zone is respected, this outcome is most unlikely to eventuate. And this hopefully will provide some measure of solace for Dr. Harris in view of the findings of fact I have made.

(a) was the cut which caused the damage inside or outside the 5 mm zone? On whom does the onus fall to argue the proposition that, on the balance of probabilities, it may have been outside the 5 mm zone, notwithstanding the fact that the upper margin of the bone graft has been found to have been 2 mm from the apices of the teeth?

255. Before the Court for its decision today is the issue whether or not, in performing a bone graft operation on the Plaintiff’s chin on the 1st of July 1992, the Defendant had transgressed a 5 mm barrier zone between the tips or apices of the Plaintiff’s lower frontal incisor teeth and the upper margin of the bone graft. This is the factual issue upon which an allegation of medical negligence has been raised by the Plaintiff against the Defendant.

256. I have already dealt separately with the issue of informed consent, wherein I found against the Plaintiff on the basis that he would not have been deterred from undergoing this procedure even if a warning had been given to him of the remote possibility that chronic neuropathic pain might occur as a result of nerve damage occasioned during the bone graft procedure.

264. When subsequent to the operation, he carried out a further x-ray on the 6th of July, his first thought on studying this x-ray was that he had in fact gone too close to the apices. However, he made no entry to this effect in his notes, nor did he communicate this belief to the Plaintiff. He wanted at an early stage to refer the Plaintiff to Dr. Cleary, whose very speciality is dealing with damaged teeth, roots and compromised vitality in the teeth.

265. He referred both in his notes and in evidence to other possibilities which he had in mind and asserted that in fact he had told the Plaintiff of his concern that he had gone too close to the apices of the teeth. He did not do any further x-ray, he said, because of the “pain”, this might cause the Plaintiff and because he did not see that it would serve any useful purpose.

266. However, during the hearing of the case, it transpired that he did in fact take another x-ray on the 13th of July, 1992, using precisely the same x-ray technology that he had availed of one week previously, from which one can readily infer he thought the technology was “up to the job”, despite his reservations expressed in Court as to the reliability of this form of x-ray when measuring fine distances.

267. He did nothing different following that x-ray, nor was his mind or purpose diverted in any way, so again one can only infer that this x-ray confirmed in Dr. Harris’ mind the opinion he formed up from his interpretation of the first x-ray of the 6th of July.

268. Dr. Harris accepts that if he transgressed the 5 mm zone, he would have been in error. He does not believe that he did transgress that zone, or at least he so stated to the Court. However, the Court has concluded that at all times subsequent to the 6th of July, Dr. Harris in fact believed that he had transgressed the zone and his behaviour from that time onwards corroborates that view. For example, if he had the slightest reservation about the accuracy or reliability of what was to be seen on the x-rays’ of the 6th of July, or indeed the 13th of July, he had available to him all the resources of the Blackrock Clinic to carry out x-rays’ by alternative techniques which might produce clearer images and involve less complicated beam geometry. This he did not do.

269. The Court does not accept that Dr. Harris told the Plaintiff of his suspicions, as otherwise it would be quite inconceivable that the Plaintiff’s originating letter of complaint, dated 17th August 1992, would not have adverted to the fact, if not the reality, of such an admission of error. Nor would the Plaintiff have been obliged to undertake lengthy inquiries of his own to try and ascertain the cause of his pain.

271. I am satisfied to accept his evidence as to the location of the main trunk of the incisive nerve, namely, a course which runs forward and deep in the bone below the mental foramina, before sprouting in branches upwards and outwards to supply the incisor teeth.

272. While this evidence was introduced to counter the evidence of Professor Kahmberg, who felt the trunk of the nerve lay within a few mm within of the tooth apices, and while I believe Dr. O’Sullivan’s evidence shows that not to be so, his evidence also, it seems to me, supplies a possible mechanism for how this injury occurred.

273. Further down the chin, the location of the incisive nerve is deep within the bone. Various scout films tendered in evidence show precisely how this is so, with the mental nerve being visible ahead of the incisive nerve. Accordingly, the further down one harvests the graft, the less likely one is to damage the incisive nerve, precisely because of it’s deep position within the bone at that location. However, the further up the chin one goes, the greater the risk that cutting through bone would produce a compromise of the branches of this incisive nerve as they move upwards and outwards to reach the incisor teeth.

275. Despite testing in an inconsistent manner following this procedure, the position now is that the Plaintiffs’ lower incisors have progressed to total non-vitality. Obviously this is something which should not occur following a properly conducted bone graft.

276. A number of possibilities were canvassed by or on behalf of the Defendant as to why this might have occurred, including excessive wear and tear on these teeth and Dr. Hammer’s intervention when he drilled a hole in one of these teeth in 1994. However, Dr. Lordon, Endodontist, rejected these criticisms as being altogether too speculative.

277. In the absence of any alternative explanation, it is extremely difficult to conclude other than that these teeth were compromised as a result of the procedure carried out in July 1992. This result, it need hardly be said, should not follow a bone graft procedure which respects the 5 mm zone.

279. In finding and concluding that the bone graft was taken 2 mm from the tooth apices, Dr. Brown is supported by Professor Kahnberg, Mr. David James, Dental Surgeon and Mr. Vaughan, the dental surgeon from Liverpool. There is further support from the evidence of Dr. John O’Grady who having examined his own x-rays, felt they showed the upper margin of the bone graft to be “very close” to the tooth apices.

280. While accepting as valuable Professor Grondahl’s theory of backward projection as a means of ascertaining the true position of objects in a three dimensional relationship, there are certain problems associated with his approach, including the mistaken belief on his part that distances should be measured “as the crow flies” rather than vertically on the different planes. This theory is further weakened by errors in measurement and by making assumptions that certain things are known certainties which simply cannot be so described. For example, an unknown element which Professor Grondahl treated as a certainty is the angle of cut into the bone which Dr. Harris estimated as 45°. It seems to me, from the evidence, that the angle and depth of cut are unknown.

281. More significantly, however, Professor Grondahl, in placing the gap at 5 mm on the periapical x-ray, had to assume Dr. O’Grady took his x-ray on two separate occasions at an excessively steep angle and contrary to good practice guidelines. I do not believe this did occur, not least because Dr. O’Grady is extremely familiar with the taking of such x-rays, but also because he was not challenged that he had made any such supposed errors. I would find it hard to believe that such an expert, who works in close association with the Defendant in the Blackrock Clinic, and who was conscious of the importance of his x-rays in the fraught circumstances which had arisen, would not attend to these particular x-rays with the utmost care and diligence.

282. Crucially, however, neither of the Defendant’s radiological experts were able to explain to the Court’s satisfaction how, if a 5 mm gap existed in reality on the periapical x-rays, a much wider gap could not be seen on the DPT x-rays.

283. Dr. Brown points out that x-rays taken by different beam geometry with projections from different directions and yielding the same results constitute an extremely persuasive form of mutual corroboration and I agree with her view in that respect. Indeed, Professor Grondahl himself implicitly adopted this theory of corroboration by placing one of his transparencies (using the bisection angle technique) over another, (using the DPT technique).

(A) Was the cut which caused the damage inside or outside the 5 mm zone? On whom does the onus fall to argue the proposition, that, on the balance of probabilities, it may have been outside the 5 mm zone, not withstanding the fact that the upper margin of the graft was at 2 mm from the tooth apices?

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You are here: BAILII >> Databases >> High Court of Ireland Decisions >> Geoghegan v. Harris [2000] IEHC 65 (14th September, 2000) URL: http://www.bailii.org/ie/cases/IEHC/2000/65.html Cite as: [2000] IEHC 65

High Court of Ireland Decisions

Geoghegan v. Harris [2000] IEHC 65 (14th September, 2000)