LEE HAU CHI MARIAM TERESA v. CHUNG CHEE KEUNG PETER AND OTHERS

DCPI 1594 /2006

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

PERSONAL INJURIES ACTION NO. 1594 OF 2006

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JUDGMENT

Introduction

1.  This is a case concerning medical negligence. 

2.  In 1996, the Plaintiff received a combined orthognathic treatment by the 1^st Defendant (an orthodontist) and the 4^th Defendant (a maxillofacial surgeon) with a view to improving her dental and facial appearance.  The “treatment plan” was, in simple terms, that the 4^th Defendant would first perform an operation on the Plaintiff’s upper and lower jaw-bones with the extractions of 4 first premolars (teeth 14, 24, 34 and 44) (“the 1^st surgery”), and the 1^st Defendant would then provide a period of orthodontic treatment to the Plaintiff afterwards. 

3.  The 1^st surgery was successfully performed.  However, in the course of receiving the orthodontic treatment from the 1^st Defendant, it was noticed that there was a shift of midline of the Plaintiff’s lower front teeth with also anterior open bite.  Consequently, the Plaintiff received another maxillofacial surgery (“the 2^nd surgery”) followed by another period of orthodontic treatment. 

4.  The Plaintiff alleges that due to the prolonged and underperformed orthodontic treatment by the 1^st Defendant, the lower front teeth of the Plaintiff suffered root resorption that caused them to become mobile and less durable which would not have happened but for the negligence of the Defendants.  A tooth (25) was abscessed already and might need to be extracted in 10 years’ time. Moreover, she has suffered unnecessary pain and sufferings in having to undergo the 2^nd surgery.   

5.  The 2^nd Defendant is a service company owned by the 1^st Defendant. The 5^th Defendant is a consultant of the Pamela Youde Nethersole Eastern Hospital (“the hospital”) who was the superior of the 4^th Defendant at the material times. The 6^th Defendant was sued on the hospital behalf.

6.  Contribution notices had been served by the 4^th, 5^th and 6^th Defendants against the 1^st and 2^nd Defendants and vice versa.  At the start of this trial Miss Wong, counsel for the 1^st and 2^nd Defendants, indicated that they withdraw their contribution proceedings against the other defendants.

7.  The experts’ evidence on liability was substantially conflicting. 

8.  The Plaintiff relied on the evidence of 2 expert witnesses from the United Kingdom, namely Mr. Stephen Powell, the Postgraduate Orthodontic Director at King’s College, London University, and Mr. Timothy William Lloyd, a consultant in maxillofacial surgery in the Eastman Hospital and University College Hospital in London.

9.  The 1^st and 2^nd Defendants also called 2 expert witnesses to give opinion in court, including Professor Cheung Lim-Kwong, the Personal Chair Professor of the Oral and Maxillofacial Surgery Department of the Faculty of Dentistry in the University of Hong Kong, and Professor Erik Urban Oskar Hagg, Chair of Orthodontics of the Faculty of Dentistry in the University of Hong Kong.

10.  The 4^th, 5^th and 6^th Defendants called Professor Henk Tideman, the Emeritus Professor of the University of Hong Kong and Professor in Oral and Maxillofacial Surgery of University of Sonklar in Thailand.

11.  Apart from their expert reports, the above named experts have also put together their credentials for my reference.  They are all without doubt the cream of their respective fields and their expertise is in no way challengeable.  Suffice it to say is that, although their opinions are in some respect very different to each others, I am satisfied that all of them had given their opinions impartially.

12.  Professor Cheung and Professor Hagg had examined the Plaintiff before preparing their reports whereas Mr. Powell and Mr. Lloyd had only the opportunity to observe a dental surgeon in Hong Kong to do an examination on the Plaintiff shortly before this trial.

Factual Background

13.  The Plaintiff was 26 years old when she sought orthodontic treatment from the 1^st Defendant in 1996 at the Yang Dental Clinic which was managed by the 3^rd Defendant (all claims against the 3^rd Defendant had been withdrawn in 2004).  The 3^rd Defendant was an approved charitable institution in Hong Kong.

14.  The Plaintiff sought orthodontic treatment in order to improve the appearance of her front teeth as she thought they were oversized and the upper and lower teeth only touched at the edges (instead of the upper teeth being in front of the lowers).  She complained that her upper and lower lips were bulging, having a problem of excessive showing of gingivae, and her face was long.  She learnt from her friend that the Yang Dental Clinic offered orthodontic treatment at a reasonable charge.

15.  On 17^th September 1996, the Plaintiff was diagnosed by the 1^st Defendant to have suffered upper and lower dentoalveolar hyperplasia (abnormal increase).  There were deformities between her upper and lower jaw bones and orthodontic treatment alone could not correct her problem.  In order to correct the malalignment of the Plaintiff’s teeth, elective maxillofacial surgical interventions to her upper and lower jaws were necessary prior to the commencement of orthodontic treatment.

16.  The 1^st Defendant referred the Plaintiff to the Oral and Maxillofacial Surgery & Dental Unit at the hospital for consultation.

17.  On 25^th October 1996, the 4^th Defendant, at the time a Senior Dental Officer of the Oral and Maxillofacial Surgery & Dental Unit at the hospital, diagnosed that the Plaintiff had maxillary (upper jaw) and mandibular (lower jaw) dentoalveolar hyperplasia.  He advised the Plaintiff that the 1^st surgery would include “Wunderer and Hofer” osteotomies (surgical operation whereby the dimension of the bone is modified by cutting), extractions of four first premolars and genioplasty (chin augmentation operation) reduction and advancement.

18.  A joint orthognathic consultation was held at the hospital on 30^th January 1997 in which the 1^st, 4^th, and 5^th Defendants were all present.  Several treatment options were offered and explained to the Plaintiff for consideration at the joint consultation.  It was the consensus of the 1^st and 4^th Defendants that the treatment plan was the best option.  Details of the 1^st surgery had been explained to the Plaintiff.

19.  On 13^th February 1997, the 4^th Defendant explained the treatment plan to the Plaintiff again and in more detail.  He explained to her, amongst other things, that the whole treatment process would take about 2 to 3 years and the Plaintiff was warned of many adverse physical effects on her during the early post-operative phase.  According to the 4^th Defendant, the Plaintiff expressed that she fully understood the treatment plan and agreed to accept the same.             

20.  On 17^th February 1997, the Plaintiff was admitted to the hospital.  She signed a document titled “Consent for Operation” on the same day.

21.  The 1^st operation was performed on 19^th February 1997.  It was uneventful and the Plaintiff was discharged from the hospital on 21^st February 1997.  Thereafter, the Plaintiff attended several follow-up appointments with the 4^th Defendant and her recovery was normal.  In the beginning of April 1997, the 4^th Defendant referred the Plaintiff back to the 1^st Defendant for post-surgical orthodontic alignment.

22.  From 10^th April 1997 onwards until at least March 2000, the Plaintiff had been undergoing orthodontic treatment with the 1^st Defendant.  What had happened during this period of time is very significant and is under dispute.   

23.  However, it is not in dispute that at least as at March 2000, it was noticeable that there had been some adverse changes occurred to the Plaintiff’s occlusion.  The lower dental mid-line was deviated more to the right, there was anterior open bite with increased overjet, the edentulous gap at the lower right posterior region between teeth 45 and 47 (“the Space”) was almost closed and the lower teeth were lingually tilted.

24.  According to the Plaintiff, she noticed that her front teeth began to tilt inwards and shift aside as early as in the end of 1997.  She also noticed a gap began to appear between her left top and bottom front teeth.  She mentioned these observations to the 1^st Defendant every time when she attended his clinic but he just ignored them.  She also mentioned her concern of the changes in position of her front teeth to the 4^th Defendant in February 1998 but the 4^th Defendant made no response to her.  She repeated her concerns to the 1^st and 4^th Defendants in subsequent appointments but they just simply ignored her.

25.  According to the 1^st Defendant in his first statement made in July 2006, at the beginning of the post-surgical orthodontic treatment, he used 022” x 028” multibanded straight wire appliances on the Plaintiff’s teeth and advised her that the treatment would usually take about 2 years.  By July 1997, initial leveling and alignment with 015” multiflex, 014” 016” 018” round wires were completed.  In about August 1997, both upper and lower 017” x 025” rectangular wires were placed in order to close the spaces in all segments except the Space.  At a later stage when more root control was required, the regular wires were changed to 018” x 025”.

26.  It is convenient to explain more about the Space at this stage as the attempt to close or narrow the same became a very, if not the most, important part of the Plaintiff’s complaints against the 1^st Defendant.  The Space is the gap left by the early loss of the Plaintiff’s right lower first molar (tooth 46).  The Plaintiff’s right upper molar (tooth 16) above the Space is  “over-erupted” and the tip of which extends to the level of the lower teeth when the Plaintiff bites which, according to the Plaintiff’s expert, would block any movement of the Plaintiff’s tooth 47 towards the Space. 

27.  It is also the Plaintiff’s case that the attempt by the 1^st Defendant to close the Space by orthodontic means (i.e., moving the adjacent tooth 47 to fill the gap) was impossible.  There was simply insufficient alveolar bone at the Space to allow tooth 47 to move onto it.

28.  According to the 1^st Defendant, he noted the Space at his first appointment with the Plaintiff on 17^th September 1996.  At that time, he advised the Plaintiff that the Space had to be replaced by a bridge/denture in future after completion of the surgery and the construction of the bridge/denture would be carried out by another dental practitioner.  At the early stage of the post-surgical treatment when multibanded appliances were placed, he proposed to the Plaintiff that the Space might be reduced by intra-elastics in order to allow a shorter span for future prosthetic replacement.  He did not suggest nor attempt to close the Space.  The Plaintiff consented to the proposed treatment and intra-elastics were then placed from the molar teeth to the hooks.

29.  It is the 1^st Defendant’s evidence that he noted subsequently that the lower labial segment of the Plaintiff moved much faster in a posterior manner to the right.  He then advised the Plaintiff to wear intermaxillary elastics in order to counteract the posterior movement of the lower anterior segments.  The Plaintiff accepted his advice and he taught her how to put the elastics on the teeth and provided her with elastics for her own use.

30.  The 1^st Defendant said in his statement that in subsequent appointments the Plaintiff confessed to him that she did not wear the elastics as taught.  He said as a result there was an increased overjet as well as a lower centerline shift of the Plaintiff’s teeth.

31.  According to the 1^st Defendant, at the end of the year 1999, the 4^th Defendant had a telephone conversation with him about the progress of the Plaintiff’s treatment.  The 4^th Defendant told him that he noted the slow progress of the orthodontic treatment and there was a shift of the centre line to the right.  He told the 4^th Defendant that it took a long time to level the over-erupted tooth 16 and the lower front teeth of the Plaintiff were moving too fast lingually inward to the right and the Plaintiff was not wearing the elastics as instructed.

32.  In view of the fact that the Plaintiff’s problems of overjet and midline shift became more significant, the 1^st Defendant increased the number of intermaxillary elastics on 29^th October 1999 from 1 piece to 2 pieces and on 25^th January 2000 from 2 pieces to 3 pieces in order to increase the orthodontic force to counteract the inward movement of the lower anterior segments.

33.  The 1^st Defendant alleged that the Plaintiff still did not wear the elastics sufficiently and confessed to him that she did not wear the elastics at work during the daytime but only wear them at night.

34.  The 1^st Defendant has in his supplemental witness statement given details as to the orthodontic treatments he performed on the Plaintiff at the material times.  This supplemental witness statement was to explain the 1^st Defendant’s very brief notes of the treatment history of the Plaintiff.  I should say, without the 1^st Defendant’s explanation it would be very difficult, if not impossible, for anyone to comprehend in a meaningful way the contents of them.

35.  Another main area of complaint of the Plaintiff is that the 1^st Defendant failed to maintain the medical notes of the Plaintiff properly.  However, as I have indicated times and again to Mr. Fan, counsel for the Plaintiff, it seemed to me that the Plaintiff had not sufficiently identified to the court the causal link between this alleged insufficient keeping of medical notes and the damages that the Plaintiff suffered.

36.  On 28^th March 2000, the Plaintiff informed the 1^st Defendant that the hospital suggested her to receive a second surgery.  On 31^st March 2000, in a joint consultation held at the hospital with the attendances of the 1^st, 4^th, and 5^th Defendants, the Plaintiff was advised of 2 options to cure her problems by either a further orthodontic adjustment or surgical intervention.

37.  The Plaintiff attended Yang Dental Clinic 2 more times to see the 1^st Defendant in May 2000.  Thereafter, the 1^st Defendant did not see the Plaintiff until after commencement of the present proceedings.  The Plaintiff was receiving treatment from another orthodontist named Dr. Tommy Chan. (“Dr. Chan”)

38.  According to the 1^st Defendant, the Plaintiff was passive and silent during the appointments with him and did not complain to him about her occlusions as alleged.

39.  The 4^th Defendant confirmed in his statement that the 1^st Defendant had mentioned to him in a telephone conversation in August 1999 about the Plaintiff not wearing the elastics as instructed.  He also confirmed that the 1^st Defendant mentioned that it took a long time to level the over-erupted tooth 16. 

40.  According to the 4^th Defendant, the Plaintiff complained to him about the changes of her occlusion and lower front teeth for the first time on 10^th March 2000.  On that occasion he also noticed the other problems of the Plaintiff and he had the view that it is in the best interest of the Plaintiff to have another joint orthognathic consultation with the 1^st Defendant.

41.  There had been some cross-examinations by Mr. Fan against the 4^th Defendant on his medical notes of the Plaintiff for the post-surgery consultations.  Mr. Fan suggested that according to what was recorded in the medical notes (e.g. a shift of lower dental midline), the 4^th Defendant should have noticed the Plaintiff’s problem on her occlusion as early as in August 1999.     

42.  The further joint orthognathic consultation was held on 31^st March 2000.  The 4^th Defendant said the 1^st Defendant had told him that the change of the Plaintiff’s occlusion was the result of an attempt to close the Space orthodontically, which had not been discussed as part of the treatment objective during the first joint consultation on 30^th January 1997.

43.  The 4^th Defendant explained the 2 options at length to the Plaintiff in the joint consultation.  The surgical option included a Hofer Osteotomy to match the lower anterior segment with the upper arch.  It was a repositioning of the lower anterior dentoalveolar segment to facilitate the orthodontist to improve the Plaintiff’s occlusion with minimal orthodontic adjustment.

44.  The Plaintiff opted for the surgical option and changed her orthodontist to Dr. Chan.  She was admitted to the hospital on 4^th July 2000 to prepare for the surgery and had signed a copy of “Consent for Operation” on the same day.

45.  The 4^th Defendant performed the 2^nd surgery on 5^th July 2000 with the assistance of 2 other practitioners under the supervision of the 5^th Defendant.  The surgery was uneventful and the result was satisfactory.  The Plaintiff was discharged on 8^th July 2000.

46.  Six weeks after the operation, the 4^th Defendant referred the Plaintiff back to Dr. Chan for further orthodontic alignment.  In the 2 follow-up consultations by the 4^th Defendant held on 2^nd December 2000 and 7^th July 2001 respectively, the occlusion of the Plaintiff was found to be stable with normal overjet and overbite.  On the second follow-up consultation, it was noted that the missing tooth 46 was replaced with a Maryland bridge from tooth 45 to tooth 47.

47.   The 4^th Defendant was later on posted to another government hospital (North District Hospital) and the Plaintiff requested to have her case followed up by the 4^th Defendant there.  The 4^th Defendant continued to attend to the Plaintiff until 8^th April 2004.

Particulars of negligence

48.  It would be convenient to first deal with the Plaintiff’s allegations against the 1^st and 4^th Defendants.

49.  The particulars of the 1^st Defendant’s negligence are set out under paragraph 27 of the Amended Statement of Claim as follows:-

(a)	Failing to obtain the informed consent of the Plaintiff by failing to explain fully to the Plaintiff regarding the nature and the limitations of the proposed surgical and orthodontic treatment, the risks of the treatment, and the options of any other treatment opened to the Plaintiff;
(b)	Failing to observe the Code of Professional Discipline laid down by the Dental Council of Hong Kong, in particular, to render dental treatment to the Plaintiff which no dental practitioner of reasonable skill exercising reasonable care would carry out;
(c)	Failing to carry out proper assessment and analysis of the orthodontic problems of the Plaintiff;
(d)	Failing to keep proper treatment records of the Plaintiff;
(e)	Failing to complete the post surgical orthodontic treatment within a reasonable period of time;
(f)	Failing to exercise reasonable skill and care as expected of a competent dental practitioner in carrying out the orthodontic diagnosis and treatment on the Plaintiff;
(g)	Failing to observe the retroclining of the lower labial segment which was causing an undesirable effect on the occlusion of the Plaintiff;
(h)	Attempting to close the space of the missing lower right 1st permanent molar orthodontically when he knew and ought to have known that it was impossible to achieve;
(i)	To carry out unjustified prolonged orthodontic treatment on the Plaintiff when he knew and ought to have known that the prolonged orthodontic treatment would cause excessive external root resorption of the teeth;
(j)	Failing to monitor the root length of the teeth and to prevent the excessive external root resorption of the teeth;
(k)	Failing to take any notice and to investigate the constant complaints of the Plaintiff regarding her deteriorating occlusion and the discolouration and discomfort of her upper left 2nd premolar;
(l)	Failing to observe and realize the failure of the orthodontic treatment rendered to the Plaintiff and to remedy the problems created by the failure of the said orthodontic treatment at the first possible opportunity;
(m)	Failing to prevent foreseeable injuries to the teeth, jaw and the psychological state of the Plaintiff by rendering the prolonged and unnecessary orthodontic treatment.

50.  The particulars of the 4^th Defendant’s negligence are pleaded as follows:-

(a)	Failing to obtain the informed consent of the Plaintiff by failing to explain fully to the Plaintiff regarding the nature and the limitations of the proposed surgical and orthodontic treatment, the risks of the treatment, and the options of any other treatment opened to the Plaintiff;
(b)	Failing to exercise reasonable skill and care as expected of a competent dental practitioner in carrying out the treatment planning on the Plaintiff;
(c)	Failing to carry out complete pre-surgical assessment including a cephalometric analysis;
(d)	Failing to keep proper record of the Plaintiff;
(e)	Failing to note and investigate the complaints of the Plaintiff regarding the deterioration of the occlusion, the discolouration and discomfort of her upper left 2nd premolar, and the prolonged post-surgical orthodontic treatment at the first available opportunity;
(f)	Failing to monitor the root length of the teeth when he knew that the active phase of post-surgical orthodontic treatment had been excessively prolonged;
(g)	Failing to notice the severe external root resorption of the teeth;
(h)	At the regular review appointments of the Plaintiff, failing to notice the retroclining of the lower labial segment which was causing an undesirable effect on the occlusion;
(i)	Failing to monitor the progress of the post-surgical orthodontic treatment and to liaise with the 1st Defendant regarding the same;
(j)	Failing to discuss with the 1st Defendant and to take steps to rectify the deterioration of the occlusion of the Plaintiff;
(k)	Failing to give proper consideration to the rectification of the occlusal problem of the Plaintiff by offering her a second osteotomy which was unnecessary;
(l)	Failing to take reasonable steps to prevent foreseeable physical and psychological injuries to the Plaintiff;
(m)	Failing to seek guidance, advice and/or assistance from the 5th Defendant, who was his superior, to resolve the complaints and orthodontic problems encountered by the Plaintiff.

51.   For both defendants, the first pleaded particular of negligence is the lack of informed consent.  However, in his final submission Mr. Fan mentioned only briefly on this issue.  On the other hand, he put a lot of emphasis on the Defendants’ failure to keep proper medical records which he did not mention at all in his opening submission.

52.   As regard the issue of informed consent, Mr. Fan said only this in his written final submission:

“	52.	In the Plaintiff’s clinical notes, it is unknown if the Plaintiff has been given all the relevant information, including options of the proposed treatment, and that the Plaintiff did understand fully before giving her informed consent to the treatment.
	53.	Prior to the 2nd surgery, there is no evidence that the Plaintiff was offered the option to seek a second opinion especially from another oral and maxillofacial surgeon.”

53.    In his opening submission, Mr. Fan said:  “Taking the matter at a glance, the blame appears to rest solely on D1 as he failed to obtain the informed consent of the Plaintiff before attempting to close the gap at the back of the Plaintiff’s lower right jaw.  Moreover, D1 was attempting the impossible which should have never taken place.”

54.  There is an obvious shift of the Plaintiff’s case in this regard. 

55.  Mr. Fan also submitted that the 1^st and 4^th Defendants did not monitor the progress of the post-surgical teeth alignment of the Plaintiff properly.  He said “the Defendants are jointly and severally liable for the final outcome of the treatment, which depends on the satisfactory outcome of the treatments rendered by them”.  He stressed that the treatment was a “joint treatment” but there was insufficient “team work” demonstrated by the Defendants.

56.  In relation to the issue of attempting to close the Space, apparently Mr. Fan has also changed his case.  In his written final submission he did not say anymore, as he did in his opening, that “D1 was attempting the impossible which should have never taken place” but to intermingle the issue with the alleged inadequacy of medical records and failure to monitor the reduction of the Space by the Defendants.  He even speculated that “There is a good chance that due to the absence of a written treatment plan and the grossly inadequate entries of clinical records, D1 had confused the treatment of the Plaintiff with another patient and he therefore proceeded to close the Gap without even realizing that he should not have attempted to do so.”  With respect, there is simply no evidence before the court to support this wild guess. 

57.  As I have mentioned previously in this judgment, the medical notes kept by the 1^st Defendant are clearly inadequate and difficult to understand.  This might account for the fact that Mr. Fan relied heavily on this and made it the trump card of the Plaintiff’s case in his final submission.  However, in going through the Amended Statement of Claim, there was nothing pleaded as to the relationship between the inadequacy of records and the injuries the Plaintiff suffered.  In other words, nothing was said about how the failure to keep proper medical records caused the alleged injuries.  Even worse is that, there is nothing in the evidence to demonstrate how the improperly kept medical records contributed to the Plaintiff’s alleged injuries.

58.  For the purpose of further discussions, I would categorize the Plaintiff’s complaints against the 1^st and 4^th Defendants as follows:-

(a)	Failing to keep adequate records
(b)	Failing to obtain informed consent;
(c)	Prolonged treatment;
(d)	Closing or narrowing the Space; and
(e)	Insufficient teamwork.

Discussions

Causation

59.  It is trite law that “the onus of proving causation lies on the pursuer or plaintiff”.  Wilsher v. Essex Area Health Authority [1988] A.C. 1074. 

60.  Before we move on to consider whether the Defendants are liable to negligence, it is necessary to investigate first about the cause of the Plaintiff’s injuries.  That is to find out, first of all, the cause of the collapse of the Plaintiff’s lower front teeth that led to the 2^nd surgery and secondly, the reason why the Plaintiff’s teeth became mobile.

(a) Cause of the collapse of lower front teeth

61.   As regard the collapse of the lower front teeth (teeth 45, 43, 42 and 41), Mr. Powell, expert for the Plaintiff, explained that as tooth 47 could not be pulled forward to the Space, it became a “perfect anchorage” that pulled the lower front teeth backward.  The centerline was therefore pulled to the right and as the lower front teeth had moved backward, anterior open bite was resulted.

62.  Mr. Powell opined that there was insufficient bone at the Space to allow tooth 47 to move onto it and the over-erupted upper molar 16 also blocked the way.  He described the shape of the Space as a “col” which is in his words “like the top of a mountain whereby there is a peak but as you come away from the peak the mountain falls rapidly away and there is no material save at the peak.”  This is called “necking” or an “atrophic alveolar” and “the bone does not exist laterally in the area of the missing tooth”. 

63.  Mr. Powell relied on a textbook by William Proffit which stated that “when teeth are extracted and the space is not closed the bone which contain the teeth gets eaten away.  It atrophies.”  He said one can feel by touching the space in clinical examination to tell whether there is sufficient bone but he can also tell from the study cast of the Plaintiff that there was insufficient bone for movement.

64.  Mr. Powell stressed that the 1^st Defendant did not start to intrude tooth 16 only until after 22 months of the orthodontic treatment.  In his view, during this period of time the 1^st Defendant had been using forces to try to bring forward tooth 47 whereas it was blocked by tooth 16 whenever the Plaintiff bites.

65.  As to whether there was sufficient bone to move tooth 47, Professor Hagg, expert of the 1^st Defendant, took a different view from Mr. Powell.  In giving his evidence, he referred to a case from the book by Vincent Kokich that involved the movement of tooth 47 to space 46 with necking condition similar to the present case.    He also demonstrated to the court some cases of himself and his students involving movement of the molar to a necking space.  It is Professor Hagg’s evidence that this kind of orthodontic treatment can be done nowadays. 

66.  In this part of his evidence Professor Hagg was asked to explain about the “ridge augmentation technique” to add extra bone to accommodate implants and he answered that an oral surgeon or maxillofacial surgeon would be more qualified to do so. 

67.  On the other hand, Professor Tideman, expert of the 4^th Defendant who is a renowned surgeon, testified that the clinical photos and x-rays showed that the height of the bone between teeth 45 and 47 have been lowered and the bone at the buccolingual region is thin.  This means that there is not enough bone to push the tooth in and he believed that any surgeon or orthodontist would agree that it is not possible to close or to bring teeth to the Space or to close it.

68.  The 1^st Defendant gave evidence that although there was some necking of the Space, it was not impossible to move 47 forward.  By looking at the Orthopantomopgraph radiograph (“OPG”) of the Plaintiff, he determined that there was sufficient alveolar bone to enable movement of tooth 47.  It is his evidence that tooth 47 had actually moved and the Space was reduced as early as in September 1998.

69.  There was a dispute between the experts’ evidence as to whether tooth 47 had actually moved or only “tipped” towards the Space.  Mr. Powell gave evidence that after the intrusion of tooth 16, that is when the gate is open, the crown of tooth 47 tipped forward by 3 mm whereas tooth 45 (followed by 43, 42 and 41) retracted by 5 to 7 mm. 

70.  On the other hand, Professor Hagg said tooth 47 was not more tilted than it was before treatment.  He arrived at the conclusion by looking at the OPG and the study casts and comparing the position of tooth 47 as against the upper teeth 17 and 16.

71.  It is common ground that tooth 16 has to be leveled in order to move tooth 47.

72.  In approaching expert evidence, the court cannot speculate upon medical matters or come to conclusions or diagnoses which are not supported by at least one of the experts.  On the other hand, where there is dispute upon an issue of the medical fact, the court may prefer the evidence of one party’s experts over that of the other’s.  Jackson & Powell on Professional Liability, 6^th Edition at 13-037.

73.  As agreed by Mr. Powell, the best person to tell whether there was sufficient bone would be the 1^st Defendant as he was the one who performed clinical examination on the Plaintiff at that time.  However, in his evidence he said only that he found that there was sufficient bone by looking at the OPG of the Plaintiff.  He could have arrived at a conclusion by touching and feeling the Space as suggested by Mr. Powell but he mentioned nothing about this.  Furthermore, he did not go on to explain or demonstrate to the court in more detail how he formed his view by looking at the OPG alone.  It is in my view not safe to just rely on his evidence to conclude that there was sufficient bone to move the tooth 47.

74.  Having said that, however, the evidence of Professor Hagg is not without force.  Not only that he showed this court examples of similar cases allowing the movement of teeth with necking conditions, he also demonstrated that the tooth has actually moved in spite of the necking condition of the Space.

75.  In saying that the tooth 47 has actually moved I have accepted the evidence of Professor Hagg that it has not just tipped for 3 mm as suggested by Mr. Powell.  By comparing the OPGs taken at different time, even bearing in mind that there would be discrepancies on settings when taking the same, it is obvious that tooth 47 has moved if we make reference to the relative positions of its roots at different stages to the position of teeth 17 and 16.

76.   With this conclusion in mind I should move on to consider the issue of the intrusion of tooth 16 before I come back to determine the relevance of the sufficiency of bone.

77.  In his supplemental witness statement the 1^st Defendant stated that as early as in April 1997 when the Plaintiff was first referring back to him by the 4^th Defendant after the 1^st surgery, he decided that tooth 47 should be moved forward to minimize the Space in order to allow a shorter prosthesis to be made and he realized that “it was necessary to level the over-erupted 16 because it was in the way of the movement of tooth 47.”  He also explained the same to the Plaintiff.

78.  In paragraph 13 of the statement (quite contrary to what he has stated in his first statement as mentioned in Paragraph 25 herein) the 1^st Defendant said, “At the next appointment on 12 August 1997, I considered that it was the appropriate moment to apply traction force to close the Extraction Spaces to minimize the space left by the loss of tooth 46.  This course of treatment continued smoothly and without change till early February 1998.”

79.  In the same statement the 1^st Defendant stated that in September 1998,he “observed that tooth 47 had moved slightly forward mesiallyand that the width of the gap between the teeth 45 and 47 had been reduced.  This was a good indication that the gap left by the loss of the tooth 46 could be minimized, and that the tooth 47 was capable of bodily movement without demonstrating undue side effects.  I decided to continue with this course of treatment and to continue to monitor the movements of the tooth 47.”

80.  However, it was not until February 1999 that action was taken to level tooth 16 with tooth 17 bonded in order to achieve the same. 

81.   According to the 1^st Defendant, in or about October 1998, unexpectedly he noticed that the Plaintiff’s lower anterior segment was moving in a posterior manner to the right and in turn led to an increased overjet.  He saidin his statement that “[he] suspected that slow bone healing in the surgical site following the 1^st surgery may have been the cause.”   He was forced to and indeed retracted this statement in cross-examination.

82.   It is the 1^st Defendant’s evidence that inter-maxillary class II elastics had been applied to improve the Plaintiff’s overjet.  He explained that“…the use of CL II elastics will enable the lower teeth to move forward anteriorly.  The elastics are placed from the anterior hook on the upper arch wire and posteriorly to the lower molar band hook.  This force vector will be translated into a horizontal force component.  Because all the lower teeth are linked with an arch wire, this horizontal force component will move the lower teeth in particular the lower anterior forward.”

83.  The 1^st Defendant stated that by the end of 1998, it became apparent to him that the Plaintiff did not wear the inter-maxillary elastics sufficiently because the undesirable movements of the lower anterior segment had not stabilized as expected.  He had the impression that the Plaintiff was growing reluctant to wear them.  And he said “[t]his situation caused me some concern because I had long intended to embark on the orthodontic procedures required to intrude and level the over-erupted tooth 16, which would in turn facilitate further progress in minimizing the spaces in the mandibular arch.  This course of treatment should have begun months ago but for the delays caused, amongst other things, by the loosened, and the need to allow some time for the inter-maxillary elastics to take effect. Despite the delays, I had adopted a conservative approach to treatment and preferred not to begin the next phase of treatment until the lower anterior segment of her teeth exhibited a certain degree of stability.  One reason for this is that the use of inter-maxillary elastics had to be halted for a few months in the interim.  This in turn meant that the movements of the lower anterior segment had to go unchecked during this time, the outcome of which could not be predicted.” This is how the 1^st Defendant sought to explain why the intrusion of tooth 16 was done at such a late stage.

84.  However, this explanation does not sit well with what was described to have occurred.

85.  First of all, the 1^st Defendant did not actually explain why the leveling of tooth 16 could not have started before he decided to apply inter-maxillary elastics to the Plaintiff.  According to him, it was apparent at the outset that tooth 16 had to be leveled.  There is no reason why it could not be done before his attempt to move tooth 47.

86.  Secondly, the 1^st Defendant embarked on the intrusion of tooth 16 after, according to him, the Plaintiff’s agreement to cooperate and he observed some improvement in the condition of her lower anterior segment.  Nothing was mentioned about the stability of the lower anterior segment.

87.  I have a serious doubt about the reason given by the 1^st Defendant as to why he only started to level tooth 16 at such a late stage.

88.  The 1^st Defendant also accused the Plaintiff of not wearing the inter-maxillary class II elastics sufficiently after it was applied again on 20 April 1999.  According to him, later on he noticed that the centerline shift in the lower arch and the overjet became more significant than before and the Plaintiff confessed to him that she did not wear the elastics as instructed because of inconvenience at work.   Double elastics were therefore prescribed on 21 October 1999.  However, the Plaintiff’s lower anterior segment continued to retrocline and symptoms appeared to aggravate rapidly from the beginning of 2000.  He stated that in light of the Plaintiff’s failure to wear the inter-maxillary elastics sufficiently as instructed, triple inter-maxillary elastics were prescribed on 25 January 2000.

89.  It is difficult to understand the logic behind the evidence of the 1^st Defendant given above.  If the cause of the aggravation of the Plaintiff’s problem were her failure to apply the elastics properly, what would be the purpose of keep on increasing the force of the elastics?  Obviously it was the 1^st Defendant’s view that the force then applying was insufficient when he decided to double or triple the elastics to be applied.

90.  Although as some stage the Plaintiff might have manifested her unwillingness to wear the inter-maxillary elastics that caused the 1^st Defendant to complain to the 4^th Defendant about it, I do not accept that this was the cause of the problem of the Plaintiff’s occlusion.  I agree to Mr. Powell’s view that without the Plaintiff’s cooperation to wear the elastics, the teeth of the Plaintiff would not have moved in such a way. 

91.  The 1^st Defendant did not impress me as a reliable witness as I observed him giving evidence.  He even retracted what he said in his witness statement.  The supplemental witness statement seeking to explain his medical notes was filed shortly before the trial started, and the contents of which is, as I have set out above, hardly convincing and in part inconsistent with his previous statement.  I do not accept the 1^st Defendant’s evidence as an accurate reflection of what actually happened and his state of mind at the material times.

92.  I accept the evidence of Mr. Powell that the cause of the collapse of the Plaintiff’s lower front teeth was the 1^st Defendant’s failure to intrude or level tooth 16 before he applied forces to move tooth 47 forward.  Although the 1^st Defendant did later on make effort to intrude tooth 16 and indeed it was, damage had already been done to the Plaintiff’s lower teeth. 

93.  I note that after the intrusion of tooth 16 the midline shift and overjet of the Plaintiff’s occlusion did not stop.  It was in fact aggravated.  Although I have found that there was sufficient bone for tooth 47 to move a bit forward, I take also the view that there was insufficient bone for the tooth to move further.  Due to the lack of bone for tooth 47 to travel, the lower front segment was forced to further retrocline and no matter what force applied by the 1^st Defendant by way of elastics, the problem could not be improved.

(b) Cause of the mobility of teeth

94.  Professor Cheung, expert of the 1^st and 2^nd Defendants, recorded in his report his findings of the degree of mobility of the Plaintiff’s teeth as at August 2005 and January 2007 respectively.  The figures can be represented as below:

Teeth	43	42	41	31	32	33
Mobility (grade) 16/8/2005	1	1	1	1	1	0
Mobility (grade) 11/1/2007	0	2	2	2	2	1

Grade 0 = no mobility, Grade 1 = 0-1mm, Grade 2 = 1-2 mm, Grade 3 = 2-3 mm or more.

95.  Mr. Powell, relied on the findings of Dr. Thomas Li (who has not been called to give evidence by any party) that the Plaintiff suffered 50% root resorption in August 2003, gave opinion that the mobility of the Plaintiff’s teeth was a result of the severe root resorption and the Plaintiff will lose the mobile teeth in 5 years’ time.

96.  The Plaintiff’s case is that, the severe root resorption was caused by the prolonged orthodontic treatment, or as suggested by Mr. Powell in his oral evidence, by the excessive force of the elastics applied.

97.  On the other hand, Professor Cheung and Professor Hagg opined that the mobility was not caused by root resorption.  Professor Cheung said the mobility was probably caused by periodontal disease and Professor Hagg added that the self-administration by the Plaintiff of movable retainers might be a cause.

98.  Professor Cheung explained the relationship between orthodontic treatment and root resorption in this way – “…the basis of orthodontics is to apply a force to the teeth using devices that attach to the teeth…to move the teeth across the bone in order to align the teeth into desired position.  So by moving the teeth in bone a force is being generated in the tooth and on the directions where it is moving, on the front end of where it is moving there will be bone resorption…the cells in the bone will eat away the bone in order to allow the teeth to move across in the jaw whereas on the other hand the bone-forming cells will then generate bone in replacing the space that is created from the tooth being moved away.”

99.  It is generally accepted that orthodontic treatment causes a certain degree of root resorption.  As submitted by Miss Wong, there are many factors that could cause variations in the degree of root resorption experienced, and this could range from the classic differences of age, gender and morphology of the teeth to the more subtle and even almost impossible to quantify factors of individual tissue/tooth response to different orthodontic forces and techniques, as well as genetics.  Professor Hagg described root resorption as an unavoidable biological price of orthodontics.

100.  However, as agreed by Mr. Powell, the likelihood of severe root resorption materializing is very low or in his own words, severe and generalized root resorption (resulted from orthodontic treatment) is very rare.

101.  On the other hand, there are studies showing that the length of orthodontic treatment has a positive correlation with the degree of root resorption.

102.  Root resorption manifests no clinical symptoms unless hypermobility results and the only way to diagnose it is by taking of radiographs or specifically, periapicals.

103.  The tooth roots exposed to external root resorption due to orthodontic treatment would heal once treatment stops.  It is noted that this factor turned out to be crucial in determining the causation of the mobility of the Plaintiff’s teeth.

104.   As can be seen from the table under paragraph 97 hereinabove, the mobility of the teeth had generally increased from 2005 to 2007.  It is noteworthy that orthodontic treatment on the Plaintiff had already ceased before 2005.    Since root resorption would be healed or at least stabilized after cessation of orthodontic treatment, the increase in mobility could not be caused by increase of root resorption.  This proposition is consistent with the scientific findings of Professor Cheung by measuring the ratio of changes in the crown length.  It follows that there should be other factor(s) that have contributed to the increase in mobility.

105.  The support of the dentition is a balance between the periodontium, the length of the roots and a range of other factors.  The loss of periodontal bone can contribute mobility to teeth and is a result of periodontal disease.  In order to find out the reason behind the increase in mobility, Professor Cheung compared the radiographs between 2003 and 2007 of the Plaintiff and measured the root-crown ratio of the Plaintiff’s lower anterior teeth.  The result was that it indicated an increase of crown length but there was no change in the total tooth length which meant that there was likely a loss of periodontal bone around the lower anterior teeth.  Together with the clinical finding of deteriorating gingival recession and root dentine exposure, it is consistent with the diagnosis of periodontal disease.

106.  It is noted that in his latest observation of clinical examination of the Plaintiff performed by the local practitioner this year, Mr. Powell could not see any inflammation or pocketing which one would normally expect to see for periodontal disease.  However, he agreed that there was an occurrence of descending bone loss which is normally ascribed to inflammatory changes. He could not explain the phenomenon but only say that there was an “anomaly” in it.    

107.  Professor Hagg gave evidence that, when it comes to the support of teeth, the effect of a 3 mm resorption of the root corresponds only to 1 mm loss at the “marginal crest” (the most superior part of the bone near the crown).  That is to say, bone loss has a much more significant effect on mobility of teeth than root resorption.  He mentioned a study by “Levander and Malmgren” that even for a tooth with severe root resorption of over 50%, it can still maintain its vitality and is still functioning. 

108.   Furthermore, Professor Hagg said that at the time when he examined the Plaintiff in 2005, the Plaintiff had been self-administrating a removable retainer to her lower front teeth.  She told him that when she used it there was a gap between the teeth but when she did not use it the teeth closed.  The teeth were therefore going back and forth (jiggling) depending on whether she was using the retainer.  According to Professor Hagg, this jiggling effect together with poor oral hygiene created an unfavourable environment which then contributed to the breakdown of marginal bone.

109.   On balancing the evidence of the experts, I tend to accept the propositions put forward by Professor Cheung and Professor Hagg.  Professor Cheung’s evidence was founded by scientific measurements and there was nothing in the circumstances that their theories could not explain.  On the other hand, there was a so-called “anomaly” in Mr. Powell’s theory and it could not explain why there was an increase of mobility whilst the degree of root resorption remained the same.  Besides, Mr. Powell did not actually perform the examination on the Plaintiff himself and his “observations” might not be wholly accurate.

110.  I conclude as a fact that the mobility of the Plaintiff’s teeth was caused mainly by the loss of periodontal bone as a result of periodontal disease and the Plaintiff’s administration of movable retainers.

111.  Having said that, however, it is against commonsense to suggest that severe root resorption can play no part in mobility of teeth.  Nonetheless, it is the Plaintiff’s burden to prove that root resorption had materially contributed to the mobility of the Plaintiff’s teeth and my view is that the Plaintiff has failed to do so in view of my previous findings. 

112.  In any event, I have also the view that the Plaintiff also failed to prove that the alleged prolonged treatment has caused the severe root resorption.  I will allude to this point later on below.

113.  As regard the issue of excessive force being applied, I agree to Miss Wong that there was simply insufficient evidence to prove what scale of force the 1^st Defendant had used and therefore nothing to prove that an excessive force had been applied.

Negligence

The standard of care in medical negligence

114.  In Law Wing Cheung v. Yap Chau Chung HCPI 43/2005 , Mr. Justice Suffiad had this to say at paragraphs 33 and 34 of his judgment:

“	33.	There is no dispute that the test applied by these courts in cases of medical negligence is that expounded by MacNair J in the case of Bolam v. Friern Hospital Management Committee [1957] 2 All ER 118 and later amplified in Bolitho v. City and Hackney Health Authority [1998] AC 232 contained in the following words :
		“	(a medical practitioner) is not guilty of negligence if he has acted in accordance with practice accepted as proper by a reasonable body of medical men skilled in that particular art … merely because there was a body of opinion who would take a contrary view.”
	34.	Applying that test laid down in Bolam’s case, a plaintiff, in order to establish medical negligence, must prove (i) there is a normal practice which is applicable to the case; (ii) the defendant has not adopted it; and (iii) the course taken by the defendant was one which no professional man of ordinary skill would have taken, had he been taking ordinary care.”

115.  In Ng Yuk Ha v. Yip Siu Keung  HCPI 1167/2002, his Lordship said:

“

Perhaps this would be as good a time as any for me to remind legal practitioners particularly those handling medical negligence cases that the proper criteria and applicable standard of care for medical negligence is as set out in the words of McNair J in the case of Bolam v. Friern Hospital Management Committee.  In order to satisfy the duty in tort, the standard of care and skill to be attained is that of the ordinary competent medical practitioner, exercising an ordinary degree of professional skill.  Although the standard is a high one, a medical practitioner charged with negligence can clear himself if he shows that he acted in accordance with general and approved practice.”

Failing to keep adequate records

116.  There should not be any dispute that a dentist or medical doctor should keep proper medical notes or records of every patient in order to allow either himself or other practitioners to make reference to which when rendering treatment to the patient.  Needless to say, adequacy and accuracy of the medical notes or records are very important as the lack of which may cause a practitioner making incorrect judgment in treating his patients.

117.  The medical notes of the 1^st Defendant on his treatment to the Plaintiff was clearly inadequate, whoever it is to take over the Plaintiff’s case could not have known sufficiently what treatment had been rendered to the Plaintiff by the 1^st Defendant.  The 1^st Defendant had obviously in breach of his duty to keep a proper record.

118.  On the other hand, I do not agree with Mr. Fan that the records of the Plaintiff kept by the hospital were inadequate. 

119.  However, as I have explained hereinabove, the Plaintiff has failed to prove the causal link between the inadequacy of records and her injuries.  This is particularly so in view of my previous findings on causations.

120.  I do not find any of the defendants liable to negligence under this head.   Here I shall borrow the sentence cited by Mr. Fan himself of Smith J. in Rhodes v Spokes and Farbridge [1996] 7 Med LR, at p.139, that “The failure to take a proper note is not [in itself] evidence of a doctor’s negligence or of the inadequacy of treatment.”

Informed Consent

121.  The Bolam test also applies to determine what risks need to be disclosed in the issue of informed consent. Sidaway v. Government of Bethlem Royal Hospital [1985] 1 AC 871.

“

…what degree of disclosure of risks is best calculated to assist a particular patient to make a rational choice as to whether or not to undergo a particular treatment must primarily be a matter of clinical judgment.  It would follow that the issue whether nondisclosure in a particular case should be condemned as a breach of the doctor’s duty of care is an issue to be decided primarily on the basis of expert medical evidence, apply the Bolam test.”  Per Lord Bridge at p.900.

122.  In cross-examination, the Plaintiff admitted that the 1^st Defendant did tell her that he intended to minimize the Space and she had no objection to this course of treatment.  This could be the reason why Mr. Fan had put a different emphasis on this issue in his final submission.  In view of the Plaintiff’s latest version of evidence, there was nothing from her expert that suggested what else the 1^st Defendant should have explained to her in this regard.

123.  The only relevant point worth mentioning, even it had not been mentioned in Mr. Fan’s final submission, is the advice of the risk of root resorption.  

124.  On this issue I have in mind Professor Hagg’s evidence that “we know that every patient will have some degree of root resorption but it is very small and a kind of cost benefit which, so to say, which is accepted by the profession as such”.  I accept that the general and approved practice of Hong Kong at that time did not require an orthodontist to advise a patient about the risk of root resorption.

125.  In relation to the 2^nd surgery, the Plaintiff had in fact obtained advice from another orthodontist, i.e. Dr. Chan, before she agreed to receive it and a standardized consent form was signed.  Given that the Plaintiff had received a similar operation before and obtained a second opinion, I do not think the time for deliberation was insufficient and again, I am not satisfied that any of the defendants was in breach of the duty of obtaining informed consent. 

126.   As regard whether it is necessary to perform the 2^nd surgery, I quote the evidence of Mr. Lloyd, expert for the Plaintiff, as follows:

“

The second surgery was only necessary because of the initial post-surgical orthodontic treatment ‘closing the lower right first molar space’ resulted in a malocclusion.  The patient was given the option of further orthodontic treatment or surgery and she opted for surgery…certainly the malocclusion problems were a result of the orthodontic treatment and the position of the teeth rather than relapse of the surgery, in my view, and therefore one would consider that it would be possible to correct that orthodontically with braces alone.  The problem is that the on-going orthodontic treatment had caused problems itself with regards to root resorption and damage to the teeth and … further prolonged orthodontic treatment was likely to cause further damage.  But there is also risk associated with further surgery.  I have to say if I was in this situation, one would have to explain the risks of either the surgical option or the orthodontic option to the patient, and ultimately, they would need to make the decision, and I believe that this decision would not be easy…”

127.  There were pros and cons for a further orthodontic treatment as against a second surgery.  In view of the result of the 2^nd surgery, which was successful, it could not be said that the 2^nd surgery was not a reasonable option that the Plaintiff could take.

Prolonged treatment

128.  It is the Plaintiff’s case that the orthodontic treatment was unnecessarily prolonged resulting in a severe root resorption on the Plaintiff’s teeth that affected their longevity.

129.  Mr. Powell’s view was that an orthodontic treatment should last not more than 3 years and the treatment rendered to the Plaintiff had been too long in the present case.

130.  Professor Hagg gave a different opinion that orthodontic treatment can last for 3 years or even longer, depending on circumstances.  He mentioned about a study published in America that the average treatment time was 27 months.  There was also a case in a Norwegian study that had lasted for 7 years.  However, those studies involved pure orthodontic treatment only with no surgical treatment beforehand.

131.  According to Professor Tideman, for post-operative treatment the maximum treatment time would be around 2 years.

132.  The 1^st Defendant first applied orthodontic treatment to the Plaintiff on 10^th April 1997.  3 years had passed when the 1^st Defendant decided to receive the 2^nd surgery to remedy the problem of her occlusion.    In my view, such length of treatment is definitely on the high side of its kind but it can hardly be described as significantly prolonged.  I do not think that the length of the treatment in itself suggested any impropriety of the treatment.

133.  As I have mentioned hereinabove, the degree of root resorption due to orthodontic treatment varies depending on a range of factors (paragraph 99).  The length of treatment is just one of the factors and severe root resorption materializing is rare. 

134.  While I appreciated that the evidence of Dr. Li had not been tested in any manner, it had not been challenged either as there had been no application taken out by the defendants to call him for cross-examination.  Although there was nothing before the court to make reference to for the basis of Dr. Li to conclude that there existed a 50% root resorption, in consideration of the evidence of the experts testified before the court, I have no doubt that root resorption did occur and in my view the resorption occurred was severe.  Here I refer to the evidence of Professor Hagg that a root resorption of over 25% can be regarded as a severe one. 

135.  Besides, it is probable that but for the decision of the 1^st Defendant to narrow the Space and turned out to be unsuccessful that led to the collapse of the lower front teeth of the Plaintiff, the treatment time would have been shorter.

136.  Nevertheless, I was given no clue as to what degree of extra root resorption, if any, could be attributable to the said “prolonged orthodontic treatment”.  Would a 3-year treatment, as against a 2-year one, long enough to render the root resorption deteriorate from an acceptable degree to a “severe” one?  I can have no idea.

137.  As such, the Plaintiff has failed to prove that the prolonged treatment itself caused or contributed materially to the severe root resorption of her teeth.  In any event, as I have found already that the Plaintiff has also failed to prove that her injuries were caused by root resorption, this issue is already academic.

Closing or narrowing the Space

138.  The 1^st Defendant had taken a wrong move in attempting to move tooth 47 in such a way that caused the Plaintiff’s lower front teeth to collapse and hence the need to undergo the 2^nd surgery. 

139.    According to the 1^st Defendant, the purpose of his narrowing the Space was to allow a shorter prosthesis to be made and in addition, the cost of bridging could be reduced too.  It was the contemplation at that time of the 1^st Defendant and the Plaintiff that the Space was to be dealt with by another dental practitioner (presumably a restorative dentist) in future.

140.  Obviously, the 1^st Defendant was well aware that there were several options open to the restorative dentist to fill up the Space, for instances, conventional bridge, Maryland bridge, cantilever bridge or even an implant.  In my view, in seeking to reduce the Space the 1^st Defendant was in fact to a certain extent making a decision for the restorative dentist which was, with respect, unnecessary.

141.    Although it was Professor Hagg’s view that it was an advantage for the restorative dentist to carry out his work by reducing the Space, I agree with Mr. Powell that there could have little benefit in partially closing the Space which means that at the end of the day, say for example, a prosthesis is still necessary. 

142.  I take the view that narrowing the Space at that stage was totally unnecessary in achieving the purpose of treatment to the Plaintiff.

143.  It is common ground that tooth 16 has to be intruded or even extracted in order to move tooth 47 into the Space.  An ordinary competent orthodontist, exercising an ordinary degree of professional skill would not have chosen to move tooth 47 in a way the 1^st Defendant had taken.

144.  Furthermore, it would be obvious to the 1^st Defendant that sufficiency of bone was an issue for consideration given the necking condition of the Space.  Although tooth 47 did move a bit in the end, an ordinary competent orthodontist, exercising an ordinary degree of professional skill, would have appreciated the insufficiency of bone for moving the tooth any more and would not have continued to apply further force trying to bring it forward.

145.  Although the mode of treatment adopted by the 1^st Defendant was approved by Professor Hagg in his evidence, I see it illogical or unreasonable for the 1^st Defendant choosing to move tooth 47 in such a way given the circumstances that I have outlined hereinabove.

146.  The judgment of Lord Browne-Wilkinson in Bolitho v City and Hackney Health Authority [1998] AC 232, which had been cited in Miss Wong’s final submission, is of assistance.  .

“

My Lords, I agree with these submissions to the extent that, in my view, the court is not bound to hold that a defendant doctor escapes liability for negligent treatment or diagnosis just because he leads evidence from a number of medical experts who are genuinely of opinion that the defendant’s treatment or diagnosis accorded with sound medical practice.  In the Bolam case itself, McNair J. stated at [1957] 1 W. L. R. 583 at 587, that the defendant had to have acted in accordance with the practice accepted as proper by a “responsible body of medical men”.  Later, at page 588, he referred to “a standard of practice recognized as proper by a competent reasonable body of opinion”.  Again, in the passage which I have cited from Marynard’s case, Lord Scarman refers to a “respectable” body of professional opinion.  The use of these adjectives—responsible, reasonable and respectable—all show that the court has to be satisfied that the exponents of the body of opinion relied upon can demonstrate that such opinion has a logical basis.  In particular in cases involving, as they so often do, the weighing of risks against benefits, the judge before accepting a body of opinion as being responsible, reasonable or respectable, will need to be satisfied that, in forming their views, the experts have directed their minds to the question of comparative risks and benefits and have reached a defensible conclusion on the matter.” (at 587)

147.   In the circumstances, I conclude that the 1^st Defendant had been negligent in choosing to move and moving tooth 47 the way he did.

Insufficient teamwork

148.  There is no question that in the present case it was a joint treatment that had been given to the Plaintiff by the 1^st and 4^th Defendants. They ought to be cooperative but it does not mean that the defendants, who possessed separate specialties, should trespass to the other’s discipline and scrutinize the other’s work in rendering the treatment. 

149.  As explained by Professor Tideman, the present case was a referral from a private practitioner to the hospital for treatment.  It was not practicable in this case for the 1^st and 4^th Defendants to work as a “team” in the manner Mr. Lloyd had suggested, as it is totally different from the situation in London where both areas of treatment were provided by the same hospital.

150.  Moving tooth 47 was never a part of the treatment plan agreed by the 4^th Defendant.  Seeing the Plaintiff by the 4^th Defendant in intervals of 6-month after the 1^st surgery was not criticized at all by the experts.  By looking at the records of the hospital, I could not find any necessity for the 4^th Defendant to intervene the orthodontic treatment of the Plaintiff before March 2000.

151.  The 4^th Defendant impressed me as a credible witness.  He gave consistent evidence all along and I accept his evidence in full.  On the other hand, the evidence of the Plaintiff is less reliable in that she had changed some of her positions (e.g. what had been explained to him before treatment) in giving her evidence.  As regard whether the Plaintiff had all along been complaining to him about the problems of her occlusion and the 4^th Defendant had ignored her, I prefer the evidence of the 4^th Defendant to that of the Plaintiff. 

152.  I do not see any deviation from the usual practice in Hong Kong for similar kind of joint orthognathic treatment as regard the cooperation between the orthodontist and the maxillofacial surgeon in the present case.  

Liabilities

153.  I find the 1^st Defendant liable to the Plaintiff for negligence in relation to the damages suffered by her for having to undergo the 2^nd surgery.

154.  In relation to the 2^nd Defendant, I accept that it was only a service company used by the 1^st Defendant at the material times and I rule that there was no basis to make it liable to the 1^st Defendant’s negligence.

155.  As regard the 4^th Defendant, in view of my findings hereinabove, I find that there was no negligence on his part.  It follows that the 5^th and 6^th Defendants are equally not liable.

156.  As between the 1^st Defendant and the 4^th, 5^th, and 6^th Defendants, since there was no liability established as against the latter, there could be nothing for the 1^st Defendant to contribute or indemnify.

Quantum

157.  In view of my above findings, the Plaintiff would only be entitled to damages for the Pain, Suffering and Loss of Amenity (PSLA) in having to undergo the 2^nd surgery and the special damages in relation thereto.

158.  For PSLA, parties referred to me only a few authorities relating to injury on jaw bone or teeth and I find the case Hau Kwok Fong v. The Kowloon Motor Bus Co. (1933) Ltd. & Ors HCPI 101/97, dated 4 March 1999 most applicable to the present case.  I find also that the sum of HK$180,000 awarded under that case a suitable sum also for the present case.

159.  For special damages, the Plaintiff is entitled to items 1(a), 1(b), 1(c), 2(a), 2(b), 2(c), 2(d) and 2(e) under this head in her Amended Revised Statement of Damages and I find that the amount stated therein reasonable.

160.  In the event that I am incorrect in ruling that the Plaintiff is not entitled to the damages in respect of her root resorption and mobility of teeth, notionally I would find that the PSLA to be awarded should be HK$300,000 and the amount of special damages stated under the Amended Statement of Damages would be awarded in full, given that the 1^st Defendant’s expert on quantum, Professor Cheung, was in my view not qualified to give such opinions.

Order

161.  Judgment be entered against the 1^st Defendant in the sum of HK$209,976 (HK$29,976+ HK$180,000) together with interest thereon at 2% for special damages from the date of writ and 5% for general damages from 12 August 1997 until the date of handing down of this judgment and thereafter at Judgment Rate until payment.

162.  The Plaintiff’s claims against the 2^nd, 4^th, 5^th and 6^th Defendants be dismissed.

163.  The claim of contribution of the 4^th, 5^th and 6^th Defendants against the 1^st Defendant be dismissed.

164.  And I make the following cost order nisi, to be made absolute upon the expiry of 14 days from today, that:-

(a)	As between the Plaintiff and the 1st Defendant, costs to the Plaintiff to be taxed if not agreed;
(b)	As between the Plaintiff and the 2nd Defendant, costs to the 2nd Defendant to be taxed if not agreed;
(c)	As between the Plaintiff and the 4th, 5th and 6th Defendants, costs to the 4th, 5th and 6th Defendants to be taxed if not agreed; and
(d)	As between the 1st Defendant and the 4th, 5th and 6th Defendants, no order as to costs.
(e)	The Plaintiff’s own costs be taxed in accordance with legal aid regulations.

164.  I understand that this matter had dragged on for a long period of time and parties are anxious to have it concluded as soon as possible.  It is unfortunate that I have got very little assistance on the issue of causation from the Plaintiff’s perspective that I have to go through the vast amount of transcripts of evidence unaided in preparing this Judgment.  I hope that the time for deliberation of this Judgment would not cause extra anxiety to parties.