In the age of ‘Evidence Based’ orthodontic treatment: Is a Class1 occlusion outcome necessary? Where is the evidence?

This article is a summary of a long-term study over 17 years of the non-conventional orthodontic treatment of the 55% of patients who have mandibular retrognathic (MR) Class11 occlusions. Treatment was directed at achieving an optimum aesthetic arrangement of the maxillary anterior teeth which included retaining an appropriate overjet. The resulting dentitions were stabilized using permanently bonded retainers (PBRs) that were attached to all of the anterior teeth.

Abstract

Introduction: Orthodontic treatment has always been directed towards establishing an ideal Class1 occlusion for its supposed optimum function, stability and aesthetic benefits[1]. However, an accumulation of evidence from research done in this field does not fully support these suppositions. The ‘ideal Class1’ outcome obsession, when applied to the 55% majority of orthodontic patients who have a retrognathic mandible[2,3], often has unpleasant aesthetic consequences. Camouflage treatment for these patients usually results in a retrusion or ‘dishing in’ of the maxillary dentition[4].

The Aim of this study was to review the clinical and subjective consequences of the orthodontic treatment of mandibular retrognathic (MR) Class11 patients where the treatment was directed, not to establish an ideal Class 1 occlusion, but instead, at achieving an optimum aesthetic result, in particular, an attractive maxillary dentition, by aligning the dental arches and retaining an overjet and Class11 type of occlusion. Stability was achieved by using permanently bonded lingual and/or palatal retainers (PBRs).

Methods. This was a randomized retrospective study involving 200 patients of mixed age and gender with MR Class II occlusions. All patients and their parents agreed to undergo orthodontic treatment that would retain a Class11 occlusion with an aesthetically pleasing overjet, but not establish an ideal Class 1 occlusion. All treatments were performed over a period of 17 years by one clinician in a single phase using fixed appliances. They included extraction and non-extraction cases. The final occlusions had overjets > 4mm and ranged from Class II end-on to super Class II. Several years after braces were removed, the clinical outcomes were reviewed. Patients and their parents completed a questionnaire on their opinions of the treatment and its results.

Results and Conclusions.Treatments generally required less time and patient input than conventional treatments. There were very few instances of iatrogenic harm or patient co-operation ‘burn out’ due to prolonged treatment[2]. Both the clinical outcomes and subjective questionnaire results found there were no apparent functional problems or concerns caused by the retention of a Class II type of occlusion with an overjet > 4 mm. The majority of patients rated their PBRs as effective (95%), hygienic, comfortable and convenient. There was an overwhelmingly negative response from 99% of patients and 94% of parents to the question of preferring a surgical correction of their mandibular retrognathia. The aesthetic and functional outcomes generally were very pleasing for 99% of patients and 98% of parents, and had a positive impact upon the patients’ quality of life.

Introduction and literature review.

Mandibular retrognathic Class II treatment method used in this study.
An example of this treatment method is shown in Figures 1 and 2.

Fig 1. A girl aged 11 years with a mildly crowded MR Class 11 occlusion, SNA=76˚, SNB=68˚. Overjet before treatment = 9 mm, after treatment = 10 mm. Treatment involved the extraction of all second premolars and took 16 months to complete. A palatal PBR was placed immediately prior to braces removal. In the mandibular arch, a removable retainer was fitted and worn for 12 months, 6 months full time and then at night only for the next 6 months.

Fig 2.  The outcome of treatment was an aesthetically pleasing Class II occlusion with a residual overjet of 10mm. A permanently bonded maxillary retainer has been in place for 17 years and in that time it has required only one unit bond repair due to trauma from a bicycle accident. There have been no problems of tooth decay or periodontal concerns due to the PBR. The only functional problems the patient has experienced were occasional self limiting episodes of TMD, thought to be due to stress.

 The types of PBRs used in this study are shown in Figure 3. All patients and their parents agreed to the placement of such PBRs when active treatment was completed.

Fig 3. Palatal and lingual permanent bonded retainers (PBRs).
These PBR retainers consist of custom shaped looped ‘round Wilcock* 0.018 regular plus wire’ bonded to the anterior teeth with ‘OrthoSolo’# bonding agent and Unitek’s ‘3M Z 100** Universal (light cured) Composite Resin’
When correctly designed, and fitted with due care, the PBRs shown in Fig 3 have a long term reliability in excess of 20+ years with a unit bond fracture rate of less than 0.5% per annum in the first five years of their placement[5]. Patients generally find these PBRs are effective, convenient, comfortable, durable and relatively easy to clean and maintain. When comparing PBRs to removable retainers (RRs), parents and patients appreciate the convenience, effectiveness and reliability of PBRs. A survey of General Dentists[6] found they preferred PBRs to removable retainers (RRs) because most patients wearing RRs find they are an inconvenient nuisance to their daily routines. The dentists often commented that patients in retention with RRs are usually non compliant with wearing them as instructed[6,7] and subsequent relapse is common.
* AJ Wilcock Pty Ltd – 45 Yea Road / PO BOX 58, Whittlesea Victoria; 3757, Australia.
# Ormco – 1717 West Collins Avenue, Orange CA, California; 92867, USA.
** 3M Unitek Corporation, 2724 Peck Road, Monrovia CA 91016, USA.

Conventional orthodontic treatment.
The judicial system and many governing bodies of the medical professions, including dentistry, require that any treatments performed on patients, especially children, have evidence-based (EB) justification[8].       
Dr David Sackett[9], a pioneer of evidence-based medicine, has made significant contributions to how we measured the presence of diseases in populations, and in particular, how we assess the effectiveness of various forms of treatment. He has emphasized the importance of clinical trials and other forms of objective evidence in evaluating what the various possible forms of treatment accomplish, and how they can be made more effective for the patient's benefit. In 1986, he reviewed the specialty of orthodontics for its scientific validity[10] and found that ‘in terms of the number of published randomized trials, orthodontics was behind such treatment modalities as acupuncture, hypnosis, homoeopathy, and orthomolecular therapy, and on a par with scientology, dianetics and podiatry.’ He went on to say “This is, I submit, a sad state of affairs that will soon be set right as orthodontists replace rhetoric with randomization.”
The paper on ‘A critical evaluation of meta-analysis in orthodontics’ by Papadopoulos and Gkiaouris[11], done in September 2005, found only 16 studies which complied with EB requirements. This represents approximately 0.05% of a data pool of over 33,000 published orthodontic papers[12]. Their findings add support to Sackett’s concerns about the validity of many orthodontic treatment concepts and procedures.

Historically, orthodontics developed on an ‘ad hoc’ basis[1]. The first orthodontists discovered how teeth could be moved through their supporting alveolar bone simply by applying a constant pressure onto the crown of the tooth in the direction they wanted it moved. This process appears to be almost magical and the ability to move ‘crooked teeth’ into more ideal arrangements was the basis for establishing the speciality of orthodontics. Once established, acquiring credibility was necessary for its survival and development. This was achieved by Angle13 and others[1]. They observed in nature, and learnt from ‘Prosthetic Dentistry’[14], that the ‘ideal Class I occlusion’ as shown in Fig 4 appeared to be the best arrangement of the dentition for optimum function, stability and aesthetics. Common sense reasoning would have added further support to these observations.

Fig 4. The ideal Class I occlusion and dentition.

It was then decided that the requirement of all orthodontic treatments should be to establish an ideal Class I occlusion. This became the ‘Gold Standard’ objective of orthodontic treatment. Whether the Class I treatment objective was really necessary was never scientifically validated, nor has it ever been challenged or scrutinised by ‘evidence based means’ within the profession[15]. It has become an entrenched law of orthodontic treatment. Even today, more than 100 years later, ‘Examining Orthodontic Boards’ around the world assess the competence of students by their ability to convert any malocclusion into an ideal Class I occlusion[16]. These ‘Boards’ adhere to this tradition; they don’t offer any explanation or evidence as to why it is necessary. On the 27’Th of February 2008, a meta-analysis of the literature reviewing the evidence of randomised clinical trials relating malocclusion to malfunction, produced the following results. Pub Med had no relevant studies, Scopus had 4 papers of unusual or rare case reports, none of which were relevant, and Google Scholar produced 73 similar papers, none of which were relevant.
There don’t appear to be any valid reasons explaining why orthodontists should treat patients to an ‘ideal Class I occlusion’ outcome which is considered to be the ‘Gold Standard” result. There is no evidence that this is always the correct or even the best way to treat all orthodontic patients.

What constitutes ‘Best Treatment’ when undertaking Orthodontic treatment?

According to an editorial by Gottlieb[17] in June 2003, ‘The Best Way to Treat’-‘produces the best occlusion, best function, best dental and facial aesthetics, the most stable results, in the shortest time, with the least number of visits, for the lowest cost, in the way that doesn’t require patient co-operation and contributes to the best oral health’. Add to this, involving minimal trauma or pain by way of extractions, surgery and extended tooth movements. Once treatment is completed, the best outcome would include having minimal ongoing or pending problems to deal with in the future such as relapse and/or impacted wisdom teeth.

 A review of the literature regarding the functioning, stability and aesthetics of the dentition does not support the need for an ideal Class1 occlusion.
 The functioning of the dentition. This can be viewed as the comfortable and easy use of the dentition in its daily tasks of eating, swallowing, speaking and socializing etc. Comfortable occlusal function comes with having no temporomandibular joint (TMJ) dysfunction (TMD) involving pain or pathology.

Mastication
The comfortable mastication and eating of food is one of the daily necessities and pleasures of life. From a study on ‘Does malocclusion affect masticatory performance’ by English et al1[18], (2002) when comparing the efficiency of different dentitions for breaking foods down into small pieces during mastication, the Class I occlusions were almost twice as efficient as Class IIs and three and a half times as efficient as Class IIIs. However, Farrell’s[19] (1956) study on ‘The Effect of Mastication on the Digestion of Food’ found most of the food types that humans eat require little or no mastication for digestion and absorption in the gastro-intestinal tract. The need to masticate food efficiently does not appear to be all that important. This would explain why Shaw et al found[20](1980) very few people with malocclusions complain of eating difficulties, including those with severe malocclusions such as severe Class11’s, Class III’s, open-bites and cleft palate patients.  A study by Pameijer et al[21] (1968) using ‘Intraoral occlusal telemetry…’ debunked the suggestions that people require an ideal cuspid guided occlusion to chew properly. Their study found chewing is more often a straight up and down crunching action rather than a circular or oval cuspid guided motion. Further support questioning the value of an ideal Class1 occlusion when eating comes from a study of ‘Adolescent mastication performance’ by Toro el al[22](2006). They concluded, in regard to ‘masticatory performance’, ‘no differences were found between normal occlusion and Class11 malocclusion’.
The literature does not present compelling arguments or confirmation of support to the suggestions that malocclusions cause eating difficulties.

Speech

There is insufficient evidence linking general malocclusions to speech difficulties. In their review of 42 papers on ‘Tooth position and speech, is there a relationship?’ Johnson and Sandy[23], (1999) concluded “while certain dental irregularities show a relationship with speech disorders, this does not appear to correlate with the severity of the malocclusion. There is no definite proof that alteration of tooth position can improve articulation disorders”. These conclusions highlight the fact that most people with malocclusions seldom have speech problems and orthodontic treatment rarely affects speech function.

Occlusal Function and TMD

Temporomandibular joint dysfunction (TMD) has long been a major concern for the dental profession as it was often assumed to be caused by malocclusion or a disturbance of the occlusion and could be brought on by incorrect orthodontic treatment[24]. There is sufficient evidence now available in the dental literature to show that only a small proportion of TMDs are due to occlusal problems.
A study of 4,289 adults in Western Pomerania by Gesch et al[25] (2004) found there were no specific morphological or functional occlusal factors associated with TMD.
John and co-researchers[26] (2002) reviewed a study group of 3,033 people varying in age from children to seniors, with overbites ranging from –8 to +15 millimetres (mm) and overjets ranging from –7 to + 14 mm. They could find no association between overbite and overjet with self reported TMD symptoms of pain, joint sound, and limited mouth opening.
 A meta-analysis of 960 articles on “Orthodontics and temporomandibular disorders” by Kim et al[27] (2003) found –‘Traditional orthodontic treatment, orthodontic appliances, and the extraction of teeth for orthodontic treatment do not appear to cause TMD’.
Other studies have shown that although TMD is often manifested in the temporomandibular joints (TMJs), the cause is usually not related to the occlusion[28].(2000) Other non-dental factors including  stress and parafunctional use of the dentition such as bruxing and clenching[29] are commonly associated with TMD. TMD symptoms are often cyclical and self-limiting in nature[30], they can appear and then disappear without any treatment[31]. Stohler’s paper[32] ‘Taking stock: from chasing occlusal contacts to vulnerability alleles’, found that “Hormonal milieus are believed to augment the inherent genetic vulnerability to TMJ diseases, explaining the greater likelihood of the condition among women in the child bearing age.”
There appear to be many factors that can contribute to TMD and how they impact and interact is still not understood.  The general consensus on treating TMD (2001) is that because TMD symptoms come and go, treatments should be very conservative and avoid any permanent alteration to the occlusion[33].
In conclusion, the scientific evidence in the dental literature supports the view that patients with malocclusions, ranging from mild to severe, usually don’t have functional problems with their dentitions. Function is rarely improved when malocclusions are altered into an ideal Class1 occlusion. Orthodontic treatments generally have little if any impact on the comfortable functioning of the dentition or TMJ’s. It is also doubtful that there are any increased or decreased risks of developing TMD in the future if a malocclusion is corrected or retained. A Medline search of the orthodontic literature in January 2008 did not find any conclusive studies claiming that functional occlusion problems can always be corrected by appropriate orthodontic treatment.

Stability of an ideal Class I occlusion.
Since orthodontic treatments first began, instability and relapse have always been acknowledged as being ‘the major problem’ after active treatment is completed. Angle[13], in 1907, devoted an entire chapter in his book ‘Treatment of Malocclusion of the Teeth’ to the problems of retention. Although he always treated his patients’ occlusions to an ideal Class 1 result, he could not guarantee their stability and recommended indefinite and sometimes permanent retention for intractable relapsing cases. To deal with the relapse problems he experienced, Angle designed many permanent retainers made from metal bands with soldered bars and spurs. These retainers were usually fitted to the anterior teeth where they were very visible and unattractive, they never became popular. In the early 1900’s, an anonymous orthodontist mentioned to Dr.CA Hawley[34], (1919) ‘If anyone would take my treated cases when they are finished, retain them and be responsible for them afterward, I would gladly give him half the fee.’ This comment is famous in orthodontics as it deals with a problem well identified with by orthodontists still today almost one hundred years later. In 2001 an editorial comment on ‘the length of retention’ by Sheridan[35] stated, “After the supervised retention period, most clinicians advise their patients to voluntarily continue with a retention regimen, with the warning that if they did not, the teeth would probably shift, perhaps to the degree that re-treatment would be necessary.”
A Cochrane Review in 2004[36] concluded that an ideal solution to the retention problems has not yet been found.
 The problems of relapse were poorly researched until a land mark study was commenced in 1947 by Dr’s R Riedel and A Moore in Seattle Washington in the USA[37]. They began recalling their completed and untreated orthodontic patients to see what happened to their occlusions as time went by. This developed into an ongoing study that is now referred to as the ‘Seattle Studies’ and was taken over by the University of Washington’s Dental School. By 2006 it had accumulated over 900 patient cases with sets of serial records, some going back over 50 years. The study has found that the concept of stability of the dental occlusion is a myth. The dental arches continue to constrict and shorten with ageing in what appears to be part of the natural ongoing physiological process. ‘The teeth are mere pawns on a constantly changing bone-scape’. With ageing, relapse and dental alignment deterioration changes occur unpredictably in most dentitions be-they un-treated or treated cases, with or without extractions, with or without arch expansion, with or without fiberotomy treatments, occlusal adjustments or enamel slenderising. Professor R Little[37], one of the principle researchers with the ‘Seattle Studies’, advises orthodontists to expect that even their best treated cases may be unstable. Upon completion of active treatment, he recommends the use of permanently bonded retention to guarantee the maintenance of the achieved orthodontic alignment. Support for the ‘Seattle studies’ findings come from other studies including those by Bishara et al[38], Durbin[39] and Linklater and Fox[40] and from the personal testimonies of many disappointed dental professionals and patients who have witnessed relapse first hand[6,7,39]. A review of the ‘Long-term post-treatment changes measured by the American Board of Orthodontics objective grading system’ by Nett and Huang[41] (2005)found that although an ideal occlusion outcome can be achieved by orthodontic treatment, this ‘perfect occlusal result does not ensure stability’ The general consensus on post treatment stability is that it can only be guaranteed if permanent retention is used. The Australian Society of Orthodontists issued the following statement during Dental Health Week in June 2007[42], ‘Lifetime retention after orthodontic treatment is now a reality if the patient wishes to guarantee that the teeth remain in the position that they are in after active orthodontic treatment is completed.’

Aesthetics and the perfect Class I occlusion An unattractive dentition is difficult to hide from view and often causes embarrassment and psychosocial problems for its owner. People with crooked teeth have sought orthodontic treatment primarily for its aesthetic benefits, that is, to obtain straight attractive teeth and a beautiful smile[1, 43, 44].(Baldwin,(1980)Hunt et al(2001). Berry[45] describes how in society, the ‘Beauty Bias’ gives attractive people social power and many advantages over the plain. The teeth are ranked second to the eyes in importance of beauty of the face[46]. Optimum dental aesthetics are mainly achieved by the ideal alignment and positioning of the maxillary dentition. Schlosser et al[47] (2005) found the most aesthetically pleasing position of the upper incisors is from the recommended cephalometric ideal normal position and up to +4mm of prominence. Moore[48] (2005) found the upper arch should be broad rather than narrow to avoid creating dark buccal corridors “Having minimal buccal corridors is a preferred aesthetic feature in both men and women…”
Excellent aesthetic results from orthodontic treatment are usually easy to achieve when treating patients with a Class I skeletal base and occlusion as the skeletal base doesn’t need to be altered. However, approximately 20% of the population have a MR Class 11 skeletal base[3] (1994) and for this group, the main anatomical concern is with the skeletal deficiency of the mandible. The ideal treatment solution is to enlarge the mandible to an optimum size. Achieving this by orthopaedic and / or surgical interventions has a high relapse rate. Pancherz[49] found the beneficial orthopaedic changes achieved by Herbst appliance treatments all reverted within 7.5 years. In an editorial review of the effects of orthopaedic orthodontic treatments, Turpin[50] commented that the results of recent EB meta-analysis by a Cochrane Review found these appliances only have an effect on the dento-alveolar structures and are not able to enhance or modify the growth of the jaw bones. A long-term post surgery analysis by Joss and Thuer[51] found the benefits of mandibular bilateral sagittal split and advancement osteotomies, secured with rigid fixation, would relapse by 60% within 12.5 years. These studies raise serious ethical concerns of the benefits of orthopaedic and mandibular surgical advancement procedures for retrognathic patients, in particular, children who are too young to assess the full implications, short-comings and risks associated with these treatments. Orthodontic treatments which attempt to camouflage MR Class11 malocclusions and establish an ideal Class I occlusion by retruding the maxillary dentition or downsizing it onto the deficient mandibular dentition4 have unpleasant aesthetic consequences that are manifested as a ‘dishing in’ of the dentition. The orthodontic professions use of lip posture[52, 53] (2007) as the measure of the aesthetic outcome of orthodontic treatment is contentious as it ignores the aesthetic impact of the arrangement and position of the teeth on the attractiveness of the face when smiling. An attractive lip posture is not uncommon even in people with an unattractive dentition as demonstrated in Fig 5. To assume that patients and parents don’t notice a ‘dished- in’ aesthetic result is foolish.

Fig 5. The appearance of a ‘dished-in’ occlusion with poor dental aesthetics but good lip profile aesthetics.    

Fig 6. The same patient as shown in Fig 5 with an aligned MR Class II occlusion 5 years post treatment. The results of his treatment were a Class II end on occlusion with an overjet of 6mm. He has no functional problems or concerns and both he and his parents are very pleased with the aesthetic outcome. Note the improvement in the appearance of his dentition and smile.

Malocclusion and dental health.
Another unsubstantiated claim about the benefits of orthodontic treatment is that improved dental health occurs because it is easier to clean well aligned teeth. A study by Helm and Peterson[54] (1989) concluded that it is the patient’s motivation and willingness to maintain good oral hygiene rather than having well aligned teeth which is more important in reducing dental disease.

There is insufficient evidence in the literature to confirm the necessity for orthodontic treatment to establish an ideal Class1 occlusion for functional[18-33], stability[13, 37-42]or dental health[54] reasons. The evidence suggests that within the general community there exists a wide range of different types of occlusions[1] and the majority of them function adequately[20]. They only need to be modified if the patient wants this done. The primary benefits of orthodontic treatment are to enhance the beauty of the face and smile[43-45]; any functional benefits are usually minor and rarely necessary.

Perspectives in orthodontics.
Approximately 50% of the population require orthodontic treatment[55] and although exact figures are not known, it is estimated that in sophisticated societies approximately 30% undergo treatment. A graduate study by Pinskaya et al[2] showed that within the patient group who undergo orthodontic treatment, the following dental malocclusion types occur in approximate percentages of ;-
Class1                                -  30%
            Class11 Division 1            -  49%
            Class11 Division 11          -   5%
            Class11 Sub-division R/L -   9%
            Class111                            -   7%
The most common malocclusion type is Class11 comprising 63% of this group and according to Mc Namara and Brudon[3], 8% have a prominent maxillary dentition and 55% have a retrognathic mandible.
Skeletal Base types for patients who undergo orthodontic treatment include:-
            Class111                          - 7%
            Class1                              -38%
            Class11 retrognathic        -55%
The patients with MR Class 11 occlusions represent approximately 55% of all orthodontic patients[2,3]. As with all orthodontic patients, their treatment desires[17] are to have an aesthetically pleasing, pain free, adequately functional and stable occlusion. They want treatment to occur in the shortest possible time, involve the least inconvenience, discomfort and cost to themselves or their parents and require minimum cooperation and effort.
The evidence in the literature highlights the best aesthetic results are determined by the position and arrangement of the maxillary dentition. The maxillary dentition should not be retrusive. The SNA angle should be between 80 and 84˚[47],and the dental arches should be broad to reduce unattractive buccal corridors[48]. The main concern with MR Class 11 patients for the dental profession is the excessive overjet problem which they believe must be eliminated by treatment. Why this is necessary has never been explained or validated scientifically. Research has shown that having an overjet between -7 to +14mm does not always cause TMD[26] and rarely causes other functional1[9-33] and aesthetic concerns. The profession now acknowledges that the stability of the dentition after orthodontic treatment can only be guaranteed with properly designed, constructed and fitted PBRs[5, 37, 39, 42, 56-58]. PBRs now have a proven reliability of over 20 years with patients finding them effective, convenient, comfortable and hygienic[5 , 6, 56-58].
If it is acknowledged that the evidence available in the literature is correct, it follows that an ‘ideal Class1 occlusion’ is not required as an essential outcome from orthodontic treatment and that all treatment outcomes require permanent retention to guarantee their maintenance. This allows for the consideration of new treatment options, especially for that large group of 55% of orthodontic patients who have a mandibular retrognathic (MR) Class11 occlusion.
 
The Aim of this study was to review the clinical and subjective consequences of treating mandibular retrognathic (MR) Class11 patients by aligning the dental arches to an optimum aesthetic result, retaining an overjet and Class11 type of occlusion and not establishing an ideal Class1 occlusion. Stability was achieved by using permanently bonded lingual and palatal retainers (PBRs), attached to all of the anterior teeth as shown in Fig 3.

Methods
This was a non-selective retrospective study involving 200 MR Class II patients of mixed age and gender, randomly chosen from a pool of over 1500 patients. They were all treated by one orthodontist using fixed Begg or Edgewise appliances during a period of 17 years. All patients and parents agreed to the treatment achieving an optimum aesthetic outcome and not an optimum Class I occlusion. A Class11 type of occlusion would be the outcome and PBRs would be fitted after active treatment was completed to maintain anterior dental alignment.
Patient selection was based upon having a MR Class II occlusion with an overjet greater than or equal to 4mm at the end of their treatment, this allowed for the inclusion of Class II Division 1 and Class 11 Division II patients as shown in Figs No 1-2 & 5-6. The study group included non-extraction and extraction cases. Extraction cases included the removal of 7’s, 6’s, 5’s, 4’s, lower incisors, retained deciduous teeth or any combinations of these. All patients were treated by a single operator in one stage of treatment. No removable or fixed functional appliances were used. Upon completion of their active treatment, patients had permanent bonded retainers (PBRs) as shown in figure 3 fitted to all the anterior teeth of any treated dental arch. These PBRs were made from round stainless steel 0.018 inch regular plus Wilcock Wire. They were attached to the teeth with Ormco’s OrthoSolo bonding agent and 3M Z100 Universal light cured composite paste. The wire frames were looped interproximally wherever practical as shown in Fig 3 to provide additional flexibility, easy access for interproximal cleaning and to prevent root torque relapse. Treatment records included panoramic radiographs, digital photographs, cephalometric radiographs where indicated and clinical temporomandibular joint (TMJ) assessments. Treatment notes were comprehensive throughout the active treatment and retention phases. All patients were kept on recall review until their third molars had either successfully erupted or their extraction had been arranged. Patients were asked to report any problems or concerns arising during or after their treatment.
 Two hundred qualifying patients who had completed their treatment were randomly selected and invited to be involved in this study by way of a telephone enquiry. Participation was voluntary and involved completing a questionnaire regarding their treatment and treatment outcome, where applicably, their parents were also asked to complete a similar but modified questionnaire. Both the patients and parents were also invited to comment upon any treatment matters they wished to express their opinions on and writing space was provided at the end of each section for this. Both surveys contained sections asking for a rating on a numbered scale between 1 and 10, where 1-3 was very poor, 4-6 was average, 7-8 was good and 9-10 was very good.

The survey questionnaire for the patients included their assessments of:

a) The treatment time.
b) The treatment result.
c) Would you have preferred to have had your lower jaw advanced surgically?

a) Rating the difficulty in cleaning their teeth and the PBRs.
b) How often do they brush, floss and use tooth picks or inter-brushes?
c) How often do they visit a general dentist to have a dental examination and their     teeth cleaned?

Writing space was provided at the end of each section for individual comments.

 The survey questionnaire for the parents included their assessment of;

             a)  The risks and trauma involved with surgery               Yes / No.
             b)  The additional cost of the surgery                             Yes / No
             c)  You don’t feel that surgery was necessary                 Yes / No
             4.  Would you participate in a follow-up survey in 5 years time?
           
Writing space was provided at the end of each section for individual comments.
All participants were asked if they would like to be sent a summary of the results?

RESULTS

From the initial group of 200 possible participants, 178 were located and contacted by phone, 176 agreed to participate, the other two ‘don’t do surveys’. The agreeing participants were all posted the questionnaires with a stamped and addressed return envelope. Of the 176 questionnaires sent out, 148 (84%) were completed and returned. The 28 (16%) who didn’t return their questionnaires were not recontacted to find out why, this was considered to be inappropriate as participants were initially told their participation was purely voluntary on their part.

General Information about the study group.

The study group cohort.
The orthodontic records of the randomly selected 200 participants were used to provide the general and clinical information required for this study. The number of patients who were contacted was 178; the other 22 had either changed address, moved away or could not be contacted. Two patients ‘don’t do surveys’ leaving 176 participants who were sent a questionnaire. From this group, 148 (84%) patients and 137 parents replied. A very small number of questions were not completed entirely and these were not included in the results.

Fig 7.The study group cohort is presented showing the total numbers, percentages and gender of participants who were asked to participate - 100%; who did - 84% and who didn’t - 16%. Approximately two thirds of each group were female and one third was male.

Fig 8. The gender and age of participants when orthodontic treatment commenced.

Fig 9. The treatment by extraction type, excluding third molars, showed more than half of these treatments, 55%, were done without extracting any teeth mesial to the third molars. The most common extraction types were of the 7s involving 19.5%, followed by 5s involving 14.5%. The remaining groups involved the other teeth at less than 5% each.

Within this non-extraction group, 80% had all third molars extracted at a later date. All third molars erupted successfully for 12% of this group and 8% had one or more congenitally missing third molars. In the cases where third molars were congenitally absent, the third molars that were present were extracted. The consequences of the third molars of the patients who had other teeth extracted were not recorded as it involved too many variables.

The net results regarding the extraction of teeth in this study group of orthodontic patients were;  94% either had teeth extracted or teeth were congenitally absent, only 6% had enough space available in their dentitions to accommodate the full compliment of 32 teeth.

Fig 10. The active treatment time and treatment by extraction types are shown with maximum, mean and minimum treatment times.

Protracted treatments were usually associated with additional complications such as impacted canines or congenitally missing teeth.
 The majority of treatments involved an active mean treatment time ranging between 13.7 for non-extraction cases to 13.6 months for 7’s extractions cases and 20 to 22 months for premolar extraction cases. There were very few cases involving iatrogenic harm to the dentition due to poor patient co-operation and there were no cases of patient cooperation ‘burn out’ as described by Pinskaya et al (2004)2.

Overjet changes.

              
Fig 11. The overjet (OJ) values before and after treatment were;
- 37% of patients had a normal OJ of 1 to 3 mm before treatment and none after treatment.
- 17.5% of patients had a moderate OJ of 4 to 6 mm before treatment and this increased to 56.5% after treatment.
- 30% of patients had a full Class II occlusion, OJ of 7 to 9 mm before treatment and this increased to 40% after treatment.
.-15.5% of patients had a roaring  Class II occlusion, OJ > 9 mm before treatment and this decreased to 3.5% after treatment.

Overbite changes.

Overbite was measured as a % overlap of the upper incisors over the lower incisors as opposed to using a millimetre (mm) length gauge. This was done to reduce the confusion which arises when comparing patients with large teeth to patients with small teeth where the millimetre (mm) descriptions are less clear.

Fig 12. The overbite values before and after treatment;
-  3% of patients with open bites before treatment decreased to 1% after treatment.
-  38% of patients with acceptable overbites of 30% to 60% before treatment increased to            93%after treatment.
-  59%of patients with excessive overbites >90% before treatment reduced considerably to 6% after treatment.

There was a significant improvement in the ideal levels of overbite in the 30% to 60% range with an initially 38% in this group increasing to 93% as a result of treatment.

Incidence of TMD.

The incidence of TMD before, during and after treatment as assessed by the patients and the orthodontist are shown in Figures 12a and 12b. Patients were asked in the questionnaire to record any incidence(s) of jaw joint problems, what were they, how long did they last and how painful were they? The main TMD symptom registered was joint sounds. Only 2% of patients mentioned pain as a symptom.

Fig13a. The incidence of TMD before, during and after treatment as self-assessed by patients.
 The incidence of TMD before treatment was 8%, during treatment is was 10% and after treatment it was 12%.The concurrence of TMD affecting patients before and during treatment was only 1.5% while during and after treatment it was 2%. Most patients who experienced TMD before, during or after treatment had a single passing episode.
           

                                                                                                                                               
Fig 13b. The clinical assessment of TMD by the orthodontist before and after treatment.
 The incidence of TMD before treatment as recorded by the clinician at 17% which was double   the patients’ score. After treatment, it was 12%, which matched the patients’ score. The coincidental readings were double that of the patients’.
There were no routinely taken TMD recordings during treatment as treatment constantly alters the occlusion and any TMD episodes would be considered as unreliable evidence of TMD.

Questionnaire Results;
Some sections of the questionnaires were not completed fully or correctly and no reason is offered as to why. These parts were not included in the analysis.
The N values in each graph show how many patients/parents completed each section.
 
Patient’s qualitative assessment of their permanent bonded retainers (PBRs).

Fig 14. The perception of the effectiveness of PBR’s as rated by patients.

Fig 15.  The different times taken for patients to adapt to their PBRs

Fig 16.  Patients’ rating of the comfort of their PBRs.

              
Fig 17a.  Patients oral hygiene routines involving brushing, flossing and                                  
the use of toothpicks or interdental brushes. The results were;
Daily brushing                          100%               
Daily flossing                            26%             Daily toothpick use                       7.5%               
X weekly flossing                   11%             X weekly tooth pick use                2%
Weekly flossing                        16%             Weekly tooth pick use                     2%               
Occasional flossing                   20%             Toothpick use (occasional)           16%                
Patients who never floss            27%             Never use toothpicks                    72.5% 

Fig 17b.  Patients’ attendance to general dental examinations, professional scaling and cleaning.

Fig 18. How patients rated the oral hygiene of their PBRs

Patients and parents qualitative assessment of their orthodontic treatment experience

Fig 19. The main reason why patients and parents undertook orthodontic treatment;
The main reason for 84% of patients and 73% of parents was to improve the appearance of the teeth and smile. Functional reasons, for patients 12% and parents 24%, were mainly to do with concerns about an excessive overjet and/or overbite. Other reasons, patients 4% and parents 3%, were mainly because of recommendations from their referring dentist to have orthodontic treatment.

 
Fig 20. How patients and parents rated the straightness of the teeth after orthodontic treatment.
 For patients, the results were very good 86%, good 13% and average 1%. For parents, the ratings were very good 77%, good 16% and average 7%. No patients or parents rated the result as a poor outcome.

Fig 21. How patients and parents rated the overall outcome of the treatment.
 Patients found the outcome was very good, 84%, good 15% and average 1%. Parents were very similar at very good 82%, good 16% and average 2%. No patients or parents rated the result as a poor outcome.

Fig 22. Rating the time taken to complete active treatment, parents were pleased with the time required with 0.5% regarding it as poor compared to 15% of the patients. Patients were more critical of treatment time with 72% regarding it as average and 15% as poor.

 Would patients or parents have preferred to undergo mandibular advancement surgery to correct the mandibular deficiency?

Fig 23. The response when patients and parents were asked if they would have preferred a surgical solution to their mandibular retrognathia, the answers were No, for 99% of patients and 94% of parents. Some parents, 4.5%, answered Maybe and 1.5% answered Yes while only 1% of patients answered Yes.
The main reason for not undertaking a surgical treatment was because the majority of patients and parents did not think their Class11 problem was severe enough to warrant surgery. The option to have a surgical correction was still available at the completion of orthodontic treatment but no patients or parents requested it.

Fig 24. The result to the question – ‘Would you go through this treatment again? For patients, 89% said yes, 1% said no and 10% said maybe, 98% of parents said yes, 1% said no and 1% said maybe. In the group of patients who answered maybe, 2% were boys and 8% were girls.

When asked if they would participate in a similar study in 5 years time, 88% of patients and 90% of parents said – Yes.

Fig 25. When parents were asked to assess the impact of orthodontic treatment upon their child’s quality of life, 62% said it was very good, 29% said good, 10% said average and 2% said poor. The ‘poor’ group of 2, one male and one female, did have a good outcome from their treatment according to three independent observers, however, the parents thought otherwise.

There were no comments made by any patients or parents that suggested their final Class11’ish occlusions caused them functional problems.
There were no requests for a surgical correction of their mandibular retrognathia.

Discussion

The use of an evidence based treatment philosophy doesn’t work well for many orthodontic treatment methods because orthodontic treatment outcomes are not instantly apparent. Treatments often take two years and more[2] to demonstrate if they are successful and retrospective analysis has been the common tool used to evaluate outcomes. Coupled to this is the huge number of ‘anecdotal’ type case reports[12] which strongly suggest certain treatments will fail, for example, using arch expansion methods to align mildly crowded dentitions[59]. A moral and ethical dilemma arises from designing prospective randomized controlled trials (RCTs) which involve children to validate or debunk a treatment method where the anecdotal evidence overwhelmingly indicates the outcome will fail[6, 7, 37-42]. The ‘evidence based scientists’ need to accommodate and include the evidence gained from clinical experience in the chain of scientific merit, especially where large numbers of competent and experienced clinicians agree about the benefits or shortcomings of particular treatment methods.
 The initial development of vaccines by Edward Jenner in 1796[60] to prevent infection by the smallpox virus was achieved by his listening to anecdotal ‘milk maid’ tales of becoming immune to smallpox after being infected with cowpox. He did not achieve this by prospective RCTs.
In orthodontics, the failure of removable retainers in preventing relapse over the long term is a common experience[6,7] that has not been verified by a Cochrane review of EB research[36] in this field. To undertake prospective RCTs comparing removable retainers (RRs) to permanent bonded retainers (PBRs) would be difficult to justify both ethically and morally as it is common ‘anecdotal knowledge’ that relapses would likely occur in the RR group. Who would then accept responsibility to retreat any relapsed cases? And how would patients be compensated for the cost and grief associated with re-treatment?
This study involved the clinical assessment of orthodontic treatment on 200 mandibular retrognathic Class II patients and approximately 148 patients and 137 parents for the subjective assessment of the treatment outcome by way of questionnaires. These numbers are adequate for a valid scientific analysis of this type[61]. The participation rate by patients and parents at 84% was well above the usual response rate for questionnaires of between 52 to 61% [61].
MR Class II patients make up approximately 55% of all orthodontic patients[2,3]. Most treatments – 80%, commenced between the ages of 12 and 15 years. Non-growing adults made up 7% of patients. Regarding extractions, 45% of patients had extractions prior to treatment and from the non-extraction group before treatment, 88% had their third molars removed at a later date, that is, 49% of the total group. Overall, 6% of patients could accommodate all 32 teeth.
 Pinskaya et al[2] found in their graduate training program ‘A progressive decrease in the quality of finished cases that was associated with a treatment time increase from 28.9 to 39.3 months’. Overall, longer active treatment times resulted in a diminished clinical outcome, primarily due to “patient burnout”. If treatment drags on beyond the expected completion date, it is not uncommon for some patients to cease cooperating or even caring about their treatment outcome; - they just want their braces off! In the Pinskaya et al study[2], the most common dental aesthetic problem caused by non-cooperation was enamel decalcification which occurred in 29% of patients. An extreme example of this problem is shown in Fig 26.

Fig 26.  Iatrogenic harm (demineralisation and staining) caused to the dentition due to prolonged treatment and patient co-operation ‘burn out’.

In this study, average treatment durations vary from 13.6 months for non-extraction and 13.7 months for second molar extraction cases to 22 months for pre-molar and first molar-extraction cases. The conventional treatment of MR Class II patients often take more than 2 years to complete[2,62] because of the clinicians insistence of achieving a Class I occlusion and the long distances molars may need to be moved. When patients are forewarned of the expected treatment time, they are usually accepting of this and cooperation is good. When treatment drags on well beyond the time expected, patients sometimes become despondent and their cooperation wanes. Fortunately, this rarely happened in this study as the distances most teeth needed to be moved were short, treatment times were short, and the dental tissue damage often caused by protracted treatments and non-cooperation was minimal.
 Parents were pleased with the duration of treatment, 93% rating it as good or very good and only 0.5% rating them as poor. The patients were far more critical with 72% rating it as average and 15% rating it as poor. There were no recorded cases of patient ‘burn out’.

The overjet changes occurring in this study resulted in 56.5% of patients having a residual overjet between 4 to 6mm, 40% were between 7 to 9mm and 3.5% were greater than 9mm. However, these overjet results were aesthetically pleasing with 99% of patients and 98% of parents rating their treatment outcome as very good or good. There were no comments made by any of the patients or parents regarding functional problems or concerns to do with their retained overjet. No patients or parents asked for a surgical reduction of their overjet after treatment was completed. The obsession within the dental profession for orthodontic treatment to establish an ideal overjet is based on entrenched long held anecdotal claims of being a necessary requirement for the ideal functioning, stability and aesthetics of the dentition. It is not based upon any scientifically validated facts and the results of this study strongly suggest the requirement for treatment to establish an ideal overjet needs to be reassessed.

Overbite changes due to treatment were favourable with 59% of patients having excessive overbites greater than 90% before treatment and 93% of patients having more ideal overbites between 30 to 60% after treatment.

The incidence of TMD was all relatively low at < 17% before, 10% during and 12% after treatment. The symptoms were predominantly joint noises; pain was rare affecting less than 2% of patients. The TMD experienced by patients were mostly single episodes which went away in time. These findings concur with those of professors Gross and Gale [63](1983) who examined 1000 consecutive dental patients of mixed ages and gender. Their findings were also dominated by joint sounds with very few painful cases. Their conclusions included the comment that joint sounds were common for 30% of the population but were not indicative of TMJ pathology. This study found there was no increase in TMD as the result of treatment that retained an overjet > 4mm.

Permanent bonded retention.
The patients’ personal assessments of their PBRs were, for effectiveness, 95% found they were good or very good and for comfort, 93% found they were good or very good. The time taken to adapt to and no longer be aware of their PBRs varied from within one week for 82%, within two weeks, 95% and 5% took more than two weeks.

No patients requested the removal of their PBRs.
The most common comment about PBRs was that the wires caught food at times but this problem was easily managed and more a nuisance rather than a serious concern. Only 4% of patients felt their oral hygiene was compromised by their PBRs. The oral hygiene routine of patients was an improvement on what was recorded in other studies [64](1998) . In this study group, all patients brushed their teeth every day. Approximately 30% used floss or toothpicks daily. In spite of being individually shown clinically on more than two occasions, and asked to include this in their daily routine, 27% of participants never use dental floss and 72.5% never used toothpicks. What can one do to achieve better results?
Patient attendance at their dentist for regular check-ups was good with 92% going once or twice each year, and professional cleaning of their teeth was done each year for 71% of this group.
The main reason 84% of patients and 73% of parents undertook orthodontic treatment was for its aesthetic enhancement. Twelve percent of patients and 24% of parents were concerned that a deep overbite or excessive overjet would cause functional problems in the future. No patients complained of having mastication or speech problems because of their malocclusion either before or after treatment. The remaining group of 4% of patients and 3% of parents sought treatment on the advice of their dentist.
The results of these treatments were rated as good or very good for 99% of patients and 98% of parents. No one considered their treatment outcome was poor. When asked if they would go through treatment again for the same result, 98% of parents and 89% of patients said yes. 1% of each said no, and 10% of patients said maybe.
Would a surgical solution have been a preferred option? 99% of patients and 94% of parents said No! The main comments made in this regard were that they didn’t think their problem was severe enough to warrant surgery. Only 1% of patients and 1.5% of parents said they would have preferred surgery, however, although this option was still available to them, no one took it up.
When considering the impact of treatment on the patients’ quality of life, 91% of parents said it was good or very good, 8% said average and 1% said poor.
There were no comments regarding post-treatment functional problems with mastication, speech or TMJ function. Across the entire range of questions, most comments were very positive about both the treatment and the treatment outcome. Most parents were complimentary of the nature of the treatment generally, the time required to complete the treatment and the impact of treatment on their children’s teeth and facial appearance. When asked if they would participate in a similar study in the future, 88% of patients and 90% of parents said yes.
The overall response to this treatment was extremely favourable with about 98% of patients and parents rating it as good or very good, and less than 2% rating it as average or poor. This is very encouraging for many aspects of orthodontic treatment as it infers treatment outcomes don’t need to be an ideal Class I occlusion which is sometimes very difficult to achieve for skeletally compromised patients. Patient burn-out problems are fewer and the iatrogenic damage caused by prolonged treatment is less compared to what can happen as shown in Fig 25.
The PBRs now have a proven record of patient and parent acceptance[6-7, 37, 54-56], they are effective, comfortable and durable. They don’t create dental health concerns if patients maintain a sensible daily oral hygiene regime and yearly examinations and maintenance.                                     
The aesthetic benefits for MR Class II patients are positive and obvious when they smile. In the ‘Age of evidence and enhancement[16], these treatments satisfy the patients and parents wishes of achieving an optimum aesthetic outcome of straight teeth and an attractive smile.
This study highlights the fact that the dental profession needs to review its attitude towards “Ideal Orthodontic Treatment”, especially for patients who don’t have a Class I skeletal base.  What is necessary for adequate function, stability, dental health and aesthetics? What part should patients and parents play in determining the nature of the orthodontic treatment they undertake?
 Orthodontic Examining Boards have a policy of assessing students primarily on their mechanical abilities to convert any malocclusion into an ideal Class I occlusion. Ackerman, Rinchuse and Rinchuse[16] highlight how these Boards overlook other important issues such as, being up to date with their clinical knowledge, psychomotor and critical thinking skills, diagnostic acumen, patient management ability, and patient centered ethics. Should these Examining Boards review their archaic, entrenched and scientifically questionable dogma of attaining an ideal Class I occlusion as the necessary gold standard outcome of treatment? Should they reconsider just what treatments are required in view of the new evidence available in the literature?
The concept of establishing an ideal Class I occlusion at all costs, be they time, effort, sacrificed aesthetics and without regard for the burden such treatments place on their patients and families, is today, out of touch with what is practical and sensible. The broad dental literature provides insufficient justification for such a treatment policy.

Consider the following two MR Class II cases, both treated to an optimum aesthetic outcome and not an ideal Class I occlusion.

Fig 27. A boy with an overjet of 11mm reduced to 6 mm (Fig 27) by non extraction braces treatment over 15 months.

Fig 28. The end result of Fig 27 treatment, 5 years later, overjet = 6 mm. He has no apparent functional problems or concerns. Both he and his parents are very pleased with the outcome.

Consider the treatment and the outcome shown in Fig 29.

BEFORE AT AGE 11.6 YEARS

	AFTER AT AGE 16.8 YEARS

Fig 29. This shows the treatment of a patient with a MR Class11 occlusion by aligning the teeth in their respective arches and retaining an aesthetically pleasing overjet of 6mm; the active treatment time was12 months. There were no apparent functional or stability problems pre or post-treatment. Both the patient and her parents were very pleased with the treatment outcome.

Conclusions
            This study found the orthodontic treatment of mandibular retrognathic Class11 patients which did not establish an ideal Class I occlusion but instead, focused on achieving an optimum aesthetic outcome by ideally positioning and aligning the maxillary dentition, retaining an attractive overjet, and uses permanently bonded retainers (PBRs) to prevent relapse, was functionally acceptable, stable and aesthetically pleasing. Such treatments were well accepted by 99% of patients and 98% of their parents. The burden/benefits of this style of treatment were favourable for the patients, clinician and the parents. In most cases, treatments took less time than what is usually required with conventional treatments.  The concerns that retaining some overjet and a Class 11’ish occlusion would result in functional problems with particular regard to mastication, speech and the TMJs did not eventuate.
            The results of this study suggest that with regard to the ‘evidence’ available in the orthodontic literature, an evidence based review is needed of the historical and entrenched anecdotal claims emphasising the need for orthodontic treatment to achieve an ideal Class I occlusion for the optimum functioning, stability and aesthetics of the dentition[1, 16].
 The results from this study raise serious concerns of the present methods of treatment and of assessing the competence of graduate training programmes in orthodontics. They strongly infer that orthodontic treatments should be directed at achieving an optimum aesthetic result that is functionally adequate and stable, which is what patients and their parents want and expect most from their orthodontic treatment[16, 17, 37-42].  

References

1.         Graber TM. Orthodontics - Principles and Practice - Chapter I; Development of a Concept. 3rd ed. Philadelphia: WB Saunders Co; 1972:1-26.
2.         Pinskaya YB, Hsieh TJ, Roberts WE, Hartsfield JKJ. Comprehensive clinical evaluation as an outcome assessment for a graduate orthodontic program. Am J Orthod Dentofacial Orthop 2004;126:533-43.
3.         McNamara JAJr, Brudon WL. Orthodontic and Orthopedic Treatment in the Mixed Dentition. Fourth printing, February 1994 Ed. Ann Arbor, Michigan: Needham Press Inc. USA; 1994.
4.         Pfeiffer JP, Grobety D. The Class II malocclusion: differential diagnosis and clinical application of activators, extraoral traction, and fixed appliances. Am J Orthod 1975;68:499-544.
5.         Cerny R. The reliability of bonded lingual retainers. Aust Orthod J 2007;23:24-9.
6.         Cerny R. Permanent retention in orthodontics: the opinions of dentists. J Clin Orthod 2008. (In press)
7.         Wong P, Freer TJ. Patients attitudes towards compliance with retainer wear. Aust Orthod J 2005;21:45-53.
8.         Mouradin WE, Omnell ML, Williams B. Ethics in orthodontics. Angle Orthod. 1999;69:295-9.
9.         Sackett DL. The Canadian Medical Hall of Fame- Medi-Centre. London Ontario: Virtual Museum Canada; 2002: Biography.
10.       Sackett DL. The science of the art of clinical management. Craniofacial growth series 1986:237-51.
11.       Papadopoulos MA, Gkiaouris I. A critical evaluation of meta-analyses in orthodontics. Am J Orthod Dentofacial Orthop 2007;131:589-99.
12.       Keim RG. The Editor's Corner - The Power of the Pyramid. J Clin Orthod 2007;10:587-8.
13.       Angle EH. Treatment of Malocclusion of the Teeth: Angle's System. Philadelphia: The S.S. White Dental Manufacturing Company; 1907.
 14.      Hayakawa I. Principles and Practices of Complete Dentures. Yokoyo: Quintessence Publishing Co Ltd; 1999.
15.       Ackerman JL, Martin RK, Ackerman MB. A Philadelphia Fable: How Ideal Occlusion Became the Philosopher's Stone of Orthodontics. Angle Orthod 2007;77:192-4.
16.       Ackerman MB. Enhancement Orthodontics. Theory and Practice. Philadelphia, Pennsylvania: Blackwell Munksgaard; 2007.
17.       Gottlieb EL. The Editor's Corner. The Best Way to Treat. J Clin Orthod 2003;6:291-2.
18.       English JD, Buschang PH, Throckmorton GS. Does malocclusion affect masticatory performance? Angle Orthod 2002;72:21-7.
19.       Farrell JH. The Effect of Mastication on the Digestion of Food. Br Dent J 1956;100:149-55.
20.       Shaw WC, Addy M, Ray C. Dental and social effects of malocclusion and effectiveness of orthodontic treatment: a review. Comm Dent Oral Epid 1980;8:36-45.
21.       Pameijer JHN, Glickman I, Roeber FW. Intraoral occlusal telemetry. Part II. Registration of tooth contacts in chewing and swallowing. J Prosthet Dent 1968;19:151-59.
22.       Toro A, Buschang PH, Throckmorton G, Roldan S. Masticatory performance in children and adolescents with Class I and II malocclusions. Eur J Orthod 2006;28:112-9.
23.       Johnson NCL, Sandy JR. Tooth position and speech - is there a relationship? Angle Orthod 1999;69:306-10.
24.       Hendrikson T, Nilner M. Temporomandibular disorders, occlusion and orthodontic treatment. J Orthod 2003;30:129-37.
25.       Gesch D, Bernhardt O, Kocher T, John U, Hensel E, Alte D. Association of Malocclusion and Functional Occlusion With Signs of Temporomandibular Disorders in Adults: Results of the Population-based Study of Health in Pomerania. Angle Orthod 2004;74:512-20.
26.       John MT, Hirsch C, Drangsholt MT, Manci LA, Setz JM. Overbite and overjet are not related to self-report of temporormandibular disorder symptoms. J Dent Res 2002;81:164-9.
27.       Kim MR, Graber TM, Vian MA. Orthodontics and temporomandibular disorder: a meta-analysis. Am J Orthod Dentofacial Orthop 2002;121:438-46.
28.       Pullinger A, Seligman D. Quantification and validation of predictive values of occlusal variables in temporomandibular disorders using a multifactorial analysis. J Prosthet Dent 2000;83:66-75.
29.       Conti A, Freitas M, Conti P, Henriques J, Janson G. Relationship Between Signs and Symptoms of Temporomandibular Disorders and Orthodontic Treatment: A Cross-sectional Study. Angle Orthod 2003;73:411-7.
30.       Suvinen TI. An 8-year Follow-up Study of Temporomandibular Disorder and Psychosomatic Symptoms from Adolescence to Young Adulthood. J Orofac Pain 2004;18:126-30.
31.       Wahlund K, List T, Larsson B. Treatment of temporomandibular disorders among adolescents: a comparison between occlusal appliance, relaxation training, and brief information. ACTA Odontal Scand 2003;61:203-11.
32.       Stohler CS. Taking stock: from chasing occlusal contacts to vulnerability alleles. Orthod Craniofacial Res 2004;7:157-61.
33.       Greene CS. Etiology of temporomandibular disorders: implications for treatment. J Orofac Pain 2001;15:93-105.
34.       Hawley CA. A Removable Retainer. The Dental Cosmos. 1919;LX1(6):449-55.
35.       Sheridan JJ. The Readers' Corner. J Clin Orthod 2001;1:31-5.
36.       Littlewood SJ, Millett DT, Doubleday B, Bearn DR, Worthington HV. Retention procedures for stabilising tooth position after treatment with orthodontic braces (Cochrane Review). The Cochrane Library 2004 2004;3).
37.       Little RM. Treatment outcomes/ complications. In: AAO 104th Annual Session, 2004; Orlando, Florida: Audio tape, 19.2004;29A.
38.       Bishara SE, Treder JE, Damon P, Olsen M. Changes in the dental arches and dentition between 25 and 45 years of age. Angle Orthod 1996;66:417-22.
39.       Durbin DD. Relapse and the need for permanent fixed retention. J Clin Orthod 2001;25:723-7.
40.       Linklater RA, Fox NA. The long-term benefits of orthodontic treatment. Br Dent J 2002;192:583-7.
41.       Nett BC, Huang GJ. Long-term posttreatment changes measured by the American Board of Orthodontics objective grading system. Am J Orthod Dentofacial Orthop 2005;127:444-50.
42.       Lenz. G. Oral Health Dental Health Week Orthodontics for 18-25 year olds. NSW, ADA News Bulletin 2007 June;355:20-5.
43.       Baldwin DC. Appearance and aesthetics in oral health. Comm Dent Oral Edip 1980:244-56.
44.       Hunt O, Hepper P, Johnston C, Stevenson M, Burdon D. Professional perceptions of the benefits of orthodontic treatment. Eur J Orthod 2001;23:315-23.
45.       Berry B. Beauty Bias. 1'st ed. Westport,CT 06881 USA: Greenwood Publishing Group Inc; 2007.
46.       Keim RG. Adult Treatment in the 21st Century. J Clin Orthod 2005;4:193-4.
47.       Schlosser JB, Preston CB, Lampasso J. The effects of computer-aided anteroposterior maxillary incisor movement on ratings of facial attractiveness. Am J Orthod Dentofacial Orthop 2005;127:17-24.
48.       Moore T. Buccal corridors and smile esthetics. Am J Orthod Dentofacial Orthop 2005;127:208-13.
49.       Pancherz H. Long-term effects of Herbst treatment. Lecture; AAO Annual Convention. USA; 1995:37 minutes.
50.       Turpin DL. The long-awaited Cochrane review of 2-phase treatment. Am J Orthod Dentofacial Orthop 2007;132:423-24.
51.       Joss CU, Thuer UW. Stability of the hard and soft tissue profile after mandibular advancement in sagittal split osteotomies: a longitudinal and long-term follow-up study. Eur J Orthod. 2008;30:16-23.
52.       Angle EH. Treatment of Malocclusion of the Teeth: Angle's System. Chapter III  Facial Art. 7'th ed. Philadelphia: The S.S.White Dental Manufacturing Company 1907: 60-87
53.       Tadic N, Woods M. Contemporary Class II orthodontic and orthopaedic treatment: a review. Aust Dent J 2007;52:168-74.
54.       Helm S, Peterson PE. Casual relation between malocclusion and caries. ACTA Odontal Scand 1989;47:217-21.
55.       Christopherson EA, Briskie D, Inglehart MR. 1670 Incidence of Malocclusion in Pre-Adolescents- Objective Indicators and Self Perceptions. 2007 21-24/03/2007.
56.       Pandis N, Vlahopoulos K, Madianos P, Eliades T. Long-term periodontal status of patients with mandibular lingual fixed retention. Eur J Orthod 2007;29:471-6.
57.       Zachrisson BU. Long-Term Experience with Direct-Bonded Retainers: Update and Clinical Advice. J Clin Orthod 2007;12:728-37.
58.       Booth F, Edelman J, Proffit W. Twenty-year follow-up of patients with permanently bonded mandibular canine-to-canine retainers. Am J Orthod Dentofacial Orthop 2008;133:70-6.
59.       Little RM. Stability and relapse: Early treatment of arch length deficiency. Am J Orthod Dentofacial Orthop 2002;121:578-81.
60.       bbc.co.uk. Historic Figures: Edward Jenner (1749-1823). BBC; 2008 [cited 2008 12/04/08]; Available from: http://www.bbc.co.uk/history/historic_figures/jenner_edward.shtml.
61.       Cummings SM, Savitz LA, Konrad T. Reported response rates to mailed physician questionnaires. HSR: Health Services Res 2001;35:1347-55.
62.       Fink DF, Smith RJ. The duration of orthodontic treatment. Am J Orthod Dentofacial Orthop 1992;102:45-51.
63.       Gross A, Gale EN. A prevalence study of the clinical signs associated with mandibular dysfunction. J Am Dent Assoc 1983;107:932-6.
64.       Nuttall N. A guide to the UK adult dental health survey 1998. Br Dent J 1998;1. London UK; Br Dent J Books:0-56.

Figures Legends.

 Fig 1. A girl aged 11 years with a mildly crowded MR Class 11 occlusion, SNA=76˚, SNB=68˚. Overjet before treatment = 9 mm, after treatment = 10 mm.

Fig 2.  The outcome of treatment was an aesthetically pleasing Class II occlusion with a residual overjet of 10mm.

Fig 3. Palatal and lingual permanent bonded retainers (PBRs).

Fig 4. The ideal Class I occlusion and dentition.

Fig 5. The appearance of a ‘dished-in’ occlusion with poor dental aesthetics but good lip profile aesthetics.

Fig 6. The same patient as shown in Fig 5 with an aligned MR Class II occlusion 5 years post treatment.

Fig 7.The study group cohort is presented showing the total numbers, percentages and gender of participants who were asked to participate - 100%; who did - 84% and who didn’t - 16%. Approximately two thirds of each group were female and one third was male.

Fig 8. The gender and age of participants when orthodontic treatment commenced.

Fig 9. The treatment by extraction type, excluding third molars

Fig 10. The active treatment time and treatment by extraction types are shown with maximum, mean and minimum treatment times.

Fig 11. The overjet (OJ) values before and after treatment were

Fig 12. The overbite values before and after treatment

Fig13a. The incidence of TMD before, during and after treatment as self-assessed by patients

Fig 13b. The clinical assessment of TMD by the orthodontist before and after treatment.

Fig 14. The perception of the effectiveness of PBR’s as rated by patients

Fig 15.  The different times taken for patients to adapt to their PBRs

Fig 16.  Patients’ rating of the comfort of their PBRs

Fig 17a.  Patients oral hygiene routines involving brushing, flossing and                                  
the use of toothpicks or interdental brushes. The results were

Fig 17b.  Patients’ attendance to general dental examinations, professional scaling and cleaning.

Fig 18. How patients rated the oral hygiene of their PBRs

Fig 19. The main reason why patients and parents undertook orthodontic treatment

Fig 20. How patients and parents rated the straightness of the teeth after orthodontic treatment.

Fig 21. How patients and parents rated the overall outcome of the treatment

Fig 22. Rating the time taken to complete active treatment

Fig 23. The response when patients and parents were asked if they would have preferred a surgical solution to their mandibular retrognathia

Fig 24. The result to the question – ‘Would you go through this treatment again?

Fig 25. When parents were asked to assess the impact of orthodontic treatment upon their child’s quality of life

Fig 26.  Iatrogenic harm (demineralisation and staining) caused to the dentition due to prolonged treatment and patient co-operation ‘burn out’.

Fig 27. A boy with an overjet of 11mm reduced to 6 mm (Fig 27) by non extraction braces treatment over 15 months.

Fig 28. The end result of Fig 27 treatment, 5 years later, overjet = 6 mm. He has no apparent functional problems or concerns.

Fig 29. This shows the treatment of a patient with a MR Class11 occlusion by aligning the teeth in their respective arches and retaining an aesthetically pleasing overjet of 6mm;.

Original Article.

Title:-
In the age of ‘Evidence Based’ orthodontic treatment: - Is a Class1 occlusion outcome necessary? Where is the evidence?

By Robert Cerny.       BDS;       - 1972,  University of Sydney. Australia.
                                     MDSc;     - 1978,  University of Sydney. Australia.

Address.
Dr Robert Cerny.
1’st Floor. 139 Scott Street
Newcastle, NSW, 2300
Australia.

Phone:- +61-(0)2-49295885 (work)               +61-(0)2-49291336 (home)
Fax:-     +61-(0)2-49264221 (work)

E-mail:-  rcerny48@gmail.com