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PubMed1979

Orthodontic relapse in subjects with varying degrees of anteroposterior and vertical dysplasia.

Fifty seemingly well-treated orthodontic cases were studied by means of pretreatment, posttreatment, and postretention dental casts, lateral cephalograms, and other orthodontic records. The sample was restricted to cases exhibiting anteroposterior and/or vertical dysplasia as revealed by pretreatment dental casts. The sample was divided into a stable group and a relapse group. Each group contained twenty-five cases. A double-blind design was used. The raw data were analyzed by the stepwise discriminant analysis and by the multivariate analysis of variance. On the basis of the results obtained from this study, the following conclusions can be drawn: 1. In seemingly well-treated orthodontic cases, relapse or stability can neither be predicted nor judged from one set of records alone. 2. Relapse or stability of an orthodontic case can be predicted by comparing the posttreatment variables with the pretreatment variables. 3. Relapse or stability of an orthodontic case can be judged by comparing the postretention variables to the posttreatment variables. 4. The PP-GoGn angle and the mandibular intercanine width are the two most important variables associated with orthodontic relapse. 5. Changing the PP-GoGn angle, either by treatment or by growth, was associated with relapse. In other words, changes in the PP-GoGn angle tended to be unstable. This suggests that decreasing the PP-GoGn angle should be avoided. 6. In both the stable and the relapse groups, the mandibular intercanine width decreased postretention. This decrease was associated more with the relapse group than with the stable group. 7. The mandibular intercanine width tended to relapse toward its original pretreatment value. This suggests that, at the end of active treatment, the mandibular intercanine width should be maintained as originally presented. 8. There was no significant interaction between orthodontic relapse (or stability) and Angle Class I and II cases. 9. There was no significant interaction between relapse (or stability), of an orthodontic case, and the sex of the patient. 10. There was no significant interaction between orthodontic relapse (or stability) and whether or not extraction was included as a part of the mechanotherapy. Thus, the pretreatment deep overbite is not necessarily a contraindication to extraction.

Analysis of Variance↗
PubMed1999

The orthodontic treatment need and demand of Hong Kong Chinese children.

OBJECTIVE: To investigate the need and demand for orthodontic treatment of Chinese school children in Hong Kong. METHODS: The material consisted of study casts and questionnaires collected from 765 randomly selected 12-year-old school children in Hong Kong. The need for orthodontic treatment was assessed by the Index of Orthodontic Treatment Need, and questionnaires were used in assessing demand for orthodontic treatment. RESULTS: The results indicate that 12% of the 12-year-old school children had no need of orthodontic treatment, 18% had little need (Grade 2), 33% moderate need (Grade 3), 33% great need (Grade 4), and 4% of children had very great need for orthodontic treatment (Grade 5). About two thirds of the children were not satisfied with their dental appearance, but only 40% of these would like to have orthodontic treatment. A definite relationship was found between negative self-appraisal of dental appearance and demand for orthodontic treatment. CONCLUSION: The study demonstrates that the need of orthodontic treatment among Chinese children is similar to that of Caucasian children; the attitude and demand toward treatment are also similar.

Chi-Square Distribution↗
PubMed2001

Effects of drugs and systemic factors on orthodontic treatment.

Orthodontic tooth movement and bone remodeling activity are dependent on systemic factors such as nutritional factors, metabolic bone diseases, age, and use of drugs. Therefore, a comprehensive review of the effects of these factors on orthodontic tooth movement is attempted in this article. Systemic hormones such as estrogen, androgen, and calcitonin are associated with an increase in bone mineral content, bone mass, and a decrease in the rate of bone resorption. Consequently, they could delay orthodontic tooth movement. On the contrary, thyroid hormones and corticosteroids might be involved in a more rapid orthodontic tooth movement during orthodontic therapy and have a less stable orthodontic result. Drugs such as bisphosphonates, vitamin D metabolites, and fluorides can probably cause a reduction of tooth movement after the orthodontic force is applied. Nonsteroidal anti-inflammatory drugs have also been shown to reduce bone resorption. Long-term administration of these drugs may therefore delay the necessary bone response to respective tooth-borne pressure and should not be administered for long periods of time to patients undergoing orthodontic tooth movement. Attention has also been focused on the effects of prostaglandins and leukotrienes in orthodontic tooth movement. It seems that they might have future clinical applications that could result in enhanced tooth movement. The use of the above drugs should be considered by every dentist in evaluating the treatment time and in planning treatment when tooth movement is attempted.

Animals↗
PubMed2001

Attitude of Chinese orthodontists towards the relationship between orthodontic treatment and temporomandibular disorders.

OBJECTIVE: To determine the attitude of some Chinese orthodontists towards the relationship between orthodontic treatment and temporomandibular disorders (TMDs). SUBJECTS AND METHODS: 25 orthodontists, in six public hospitals (Xi'an, the capital of Shaanxi Province, China), were asked to complete a 10-item questionnaire concerning orthodontics/TMD. RESULTS: 84% of orthodontists often asked their patients about the signs and symptoms of TMD before orthodontic treatment and 92% reported examining the TMJ region. 76% of orthodontists thought orthodontic treatment may possibly lead to a greater incidence of TMD, while 84 per cent claimed that orthodontic treatment might prevent TMD. Methods of orthodontic treatment, patient's age, and occlusal interference were regarded as risk factors leading to increased incidence of TMD. CONCLUSIONS: Some Chinese orthodontists realise the importance of the relationship between orthodontic treatment and TMD. Most thought that unsuitable orthodontic treatment might increase the development of TMD and that orthodontic treatment could prevent TMD.

Adult↗
PubMed2003

Orthodontic treatment provided by pediatric dentists.

The purposes of this study were to document orthodontic treatment currently provided by pediatric dentists for comparison with past and future studies and to ascertain variables that influence practitioners' orthodontic treatment patterns. A 25-item survey was mailed to 492 diplomates of the American Board of Pediatric Dentistry. Surveys returned within 16 weeks were included for statistical analysis. The response rate was 73%. Most practitioners spent less than 10% of their practice time providing orthodontic treatment and reported that this would not change in the future. Practitioners who were dual trained in pediatric dentistry and orthodontics spent more time providing orthodontic treatment, although nearly half spent at least 50% of their time providing traditional pediatric dental treatment. Most pediatric dentists provided orthodontic treatment in the primary or early mixed dentition stages. The most common conditions treated were anterior crossbite, ectopic eruption, habits, posterior crossbite, and space maintenance. The most common orthodontic appliances used were fixed rapid palatal expanders and removable Hawley appliances with finger springs. Orthodontic treatment provided by pediatric dentists has decreased since it was last surveyed in 1983 and is not expected to change in the next 5 years.

Chi-Square Distribution↗
PubMed1990

TMJ function and the effects on the masticatory system on 14-16-year-old Danish children in relation to orthodontic treatment.

The effect of orthodontic treatment on the functional status of the masticatory system was analysed in 706 children from three Danish communities. Three-hundred-and-eighty-eight (48 per cent) of the children were treated orthodontically and the 295 (37 per cent) of the total population had terminated the treatment and were included in the analysis. Fifty-seven cases (7.1%) of the total population were discontinued before the orthodontic treatment was considered finished by the orthodontist. Discontinuation did not, however, seem to influence the functional status. Increasing the orthodontic treatment frequency from 38 to 51 per cent did not decrease the functional problems of a young population. On the contrary, the community with the lowest treatment frequency (38 per cent) demonstrated fewer functional problems among the orthodontically treated subjects than did the two communities with higher treatment frequencies, indicating paradoxically that it may be a functional risk to treat the last 13 per cent with minor discrepancies. Tenderness on palpation of the musculature and the TMJ capsule were generally more prevalent among orthodontically treated subjects. Children who had their treatments performed by either orthodontist or paedodontist alone demonstrated more muscular problems than children who had been treated by a team of orthodontists and paedodontists. Related to the severity of the malocclusion these findings stress the importance of more consideration to establish a functionally satisfactory occlusion after orthodontic treatment. Functional status was not related to the type of orthodontic treatment, including extraction therapy, use of either fixed or removable appliances.

Adolescent↗
PubMed2005

Matrix metalloproteinase-1 and -8 in gingival crevicular fluid during orthodontic tooth movement: a pilot study during 1 month of follow-up after fixed appliance activation.

The role of matrix metalloproteinases (MMPs) in response to mechanical forces in orthodontic tooth movement has only been partially clarified. In the present in vivo pilot study, the presence, levels, and degree of activation of MMP-1 and -8 were measured daily for 1 month in gingival crevicular fluid (GCF) of patients treated with orthodontic fixed appliances. GCF samples were collected from five orthodontic patients and three controls from one upper or lower central incisor or from one upper canine before fixed appliance activation and every 24 hours for 1 month thereafter. The molecular forms and activation degrees of MMP-1 and -8 in GCF were analysed by Western blotting, and MMP-8 levels determined by immunofluorometric assay (IFMA).IFMA revealed, during the study period, on average 12-fold higher levels (56 +/- 50 versus 4.6 +/- 4 microg/l) of MMP-8 in orthodontic GCF than in control GCF. The MMP-8 levels in orthodontic GCF were lower than those detected in gingivitis and periodontitis GCF, but significantly higher than in control GCF. IFMA analysis was confirmed by Western blot analysis showing elevated MMP-8 levels from orthodontic GCF relative to control GCF. Forty-one per cent of total MMP-8 immunoreactivities were high-molecular weight complexes (>100 kDa), 32 per cent in the 75 kDa pro-polymorphonuclear (PMN)-MMP-8 form, 14 per cent in the 60 kDa active-PMN-MMP-8 form, and 13 per cent in the 55 kDa fibroblast-type pro-MMP-8 form. In the GCF of orthodontic patients no MMP-1 immunoreactivities were detected. MMP-8 and -1 levels in the control GCF were low and not detectable. These results demonstrate that in vivo in human GCF, elevation and partial activation of multiple species of PMN- and fibroblast-type MMP-8 reflect periodontal remodelling during orthodontic tooth movement.

Adolescent↗
PubMed1997

Clinical significance of Actinobacillus actinomycetemcomitans in young individuals during orthodontic treatment. A 3-year longitudinal study.

The aim of the present study was: (1) to assess longitudinally the occurrence of Actinobacillus actinomycetemcomitans (Aa) in young subjects wearing fixed orthodontic appliances compared to matched appliance-free controls; (2) to determine whether the presence of the micro-organism at baseline could influence the periodontal status assessed 3 years later. 70 subjects, 27 male and 43 female, aged between 12 and 20 years participated in the study: 35 subjects under orthodontic treatment with fixed appliances for at least 6 months, and 35 appliance-free individuals matched for age and gender. All subjects were free of clinically demonstrable loss of attachment. They all received oral hygiene instructions 2x during the 2 months preceding the first clinical and microbiological examination. No subgingival instrumentation was performed between baseline and the 3-year examination. Clinical parameters included gingival bleeding index (GBI), pocket probing depth (PPD) and measurements of attachment level (AL). Statistically significant differences were reported regarding frequency of detection of Aa between both groups at each examination. The %s of orthodontic subjects infected with Aa at the baseline and at the 3-year examination were 86% and 80%, respectively, while the corresponding figures for control subjects were 16.6% and 26.6%. The frequency distribution of %s of Aa in the total anaerobic subgingival flora among control subjects remained fairly stable, whereas the proportion of orthodontic subjects yielding Aa at a concentration > or = 1.0% dropped significantly from 32% at baseline to 19% at the 3-year visit. Calculations of the relative risk for increasing GBI and PPD in both groups when Aa was present at baseline, revealed that the orthodontic subjects positive for Aa had a negligible relative risk of experiencing worse periodontal conditions compared to orthodontic patients where Aa was not detected at baseline. In contrast, control subjects initially infected with Aa presented with a risk for increased GBI 6.6x higher than that for subjects without Aa. In conclusion, the present study confirmed previous cross-sectional findings reporting that young individual with an integer periodontium wearing fixed orthodontic appliances harbor Aa with a statistically significant greater frequency than appliance-free matched controls. However, although orthodontic patients exhibited more inflammation, their deteriorated clinical conditions could not be accounted for by the sole presence of Aa in their sulci. In contrast, appliance-free young subjects initially infected with Aa had a higher risk of experiencing more gingival inflammation than subjects without the bacterium during a 3-year observation period.

Actinobacillus Infections↗
PubMed1998

Interrelationship between periodontics and adult orthodontics.

The purpose of this review article is to provide the dental practitioner with an understanding of the interrelationship between periodontics and orthodontics in adults. Specific areas reviewed are how periodontal tissue reacts to orthodontic forces, influence of tooth movement on the periodontium, effect of circumferential supracrestal fiberotomy in preventing orthodontic relapse, effect of orthodontic bands on the periodontium, specific microbiology associated with orthodontic bands, mucogingival considerations and time relationship between orthodontic and periodontal therapy. In addition, the relationship between orthodontics and implant restorations (e.g., using dental implants as orthodontic anchorage) will be discussed.

Adult↗
PubMed1999

Evidence-based care in orthodontics and periodontics: a review of the literature.

BACKGROUND: In this article, the author reviews the evidence-based literature in the fields of periodontics and orthodontics to clarify the relationship between orthodontic tooth movement and various types of common periodontal disorders. TYPES OF STUDIES REVIEWED: The first section is a review of the literature on common periodontal disorders. The second is a review of evidence-based studies in the combined fields of orthodontics and periodontics, with a focus on orthodontic treatment possibilities, limitations and risks inherent in patients with periodontal disorders, particularly active periodontal disease. RESULTS: The literature on orthodontic tooth movement as it relates to periodontal disease shows that proper orthodontic treatment in patients with excellent oral hygiene and the absence of significant periodontal disorders should not pose any significant periodontal risk. In the presence of poor oral hygiene, however, and under circumstances of certain types of periodontal disorders, fixed orthodontic appliances and tooth movement can contribute to significant deleterious periodontal consequences. CLINICAL IMPLICATIONS: This review provides a clear understanding of what is known about orthodontic treatment possibilities, limitations and inherent risks in patients who may have certain types of periodontal disorders. It also underscores the importance of teamwork among the restorative dentist, periodontist and orthodontist when planning treatment for these patients. The author also offers a specific patient management protocol for this interdisciplinary dental team to follow.

Clinical Protocols↗
PubMed2006

[Orthodontics for mentally handicapped patients].

The mentally handicapped exhibit a 3 times higher incidence of malocclusions and related functional problems than the general population. In contrast there is little available literature relating to the orthodontic treatment of handicapped patients. Based on published articles on orthodontic treatment of disabled patients the following recommendations can be given. First of all for each patient a 'problem list' should be drawn up, based on the diagnosis. In this list the orthodontic problems are formulated. Additionally, the list makes clear who is responsible for providing services related to orthodontic care, such as oral hygiene and transportation of the patient to the orthodontist. When deciding whether or not orthodontic treatment should be administered to a patient with a mental handicap the same functional and aesthetic considerations as with any other orthodontic case must be taken into account. Furthermore, the severity of the handicap and possible associated psychosocial and medical limitations as well as the extent to which it will be possible to treat the patient have to be considered. Contraindications are a severe mental handicap, inability to remain still in the dental chair, insufficient co-operation of parents/carers, open bite resulting from abnormal oral function, and a mild malocclusion. The orthodontic treatment should aim for an acceptable result, and not for orthodontic perfection.

Dental Care for Persons with Disabilities↗
PubMed1987

Thoughts on the future of orthodontic education and practice.

Only by involvement and constructive planning for our specialty can we as a group influence dental education--specifically, orthodontic training--and the conditions for practice we will face in the future. The development of undergraduate orthodontic teaching has been slow. It is argued that it is a necessity, and in our best interest, that we formulate an innovative curricular standard for orthodontic instruction to be included in the strategic planning for the future dental educational program. Regarding advanced training, orthodontics as a specialty branch of dentistry would be at a disadvantage if the number of places in orthodontic specialty programs is significantly reduced. Rather, assuming the accuracy of predictions of future increased demands for orthodontic care under decent economic conditions, it is suggested that if we allow for a slow but steady increase in the number of orthodontic specialists, we are going to create reasonably sound circumstances for future orthodontic specialty practice.

Dentistry↗
PubMed1976

Interrelationships between orthodontics and periodontics.

At the present time, periodontists have no evidence to indicate that orthodontic treatment in the child will either enhance or detract from the periodontal health of the patient or that it will increase or decrease the longevity of the teeth. Many periodontists believe that much orthodontic treatment is undertaken on an esthetic or empirical basis. Proper emphasis on plaque control procedures prior to initial banding, altered and reinforced during the entire period of orthodontic treatment, may well minimize the inflammatory lesion often found during therapy. Gingival, periodontal, and mucogingival problems should be treated as soon as they are diagnosed. Limiting our orthodontic objectives in adult patients because of the possibility of inducing supporting alveolar bone loss and other problems that did not previously exist may be a worthwhile compromise. Orthodontic movement in periodontally healthy adults, and especially in those with periodontally involved teeth, constitutes a problem distinct from routine orthodontics. When periodontal disease has already produced significant destruction of supporting tissue and secondary occlusal trauma is a complicating factor, orthodontic treatment may possibly serve as another mode of treatment to reestablish the correct occlusal plane and alter bony deformities. Various methods can be used to try and place teeth into better bone. One should make certain that teeth are being moved into a greater volume of bone. The bite plane is of great value in allowing continuous eruption of the teeth and their supporting structures and in eliminating additional trauma by enabling the teeth to move into their correct cusp-fossa relationships unimpeded by the inclined planes of the opposing teeth. Since little is known about the interrelationships between orthodontic treatment and periodontal health and disease, there is still a great deal to learn. In spite of this lack of knowledge, the general practitioners and the various specialists of dentistry, each seeking a rationale for his preventive and therapeutic procedures, subject the patient to treatment based on concepts of the occlusion which have yet to be corroborated. In addition to the need for research in this field, a common language between the periodontist and the orthodontist must be established to eliminate the existing communications barrier. Once basic principles can be determined, elucidated, and applied correctly, the movement of teeth in periodontal cases will be limited only by the imagination of the operator.

Adult↗
PubMed1999

Site-specific subgingival colonization by Actinobacillus actinomycetemcomitans in orthodontic patients.

A high prevalence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque in patients for orthodontia already has been observed. The present study had the following aims: 1) to ascertain a direct relationship between the orthodontic appliance placement and the subgingival colonization by Aa, and 2) to determine whether the Aa growth specifically occurred on teeth with braces attached or whether the presence of orthodontic appliances could also cause the isolation of Aa in teeth free from therapeutic appliances. Twenty-four young systemically and periodontally healthy subjects with malaligned and crowded teeth in the anterior sextants of both dental arches participated in this study. After 1 session of ultrasonic scaling with oral hygiene instructions during the first experimental session, the mesiobuccal sites of the first molars and the distobuccal sites of the lateral incisors in both dental arches in each participant were subjected to clinical and microbiologic examination for the recovery of Aa. Clinical examination consisted of recording the presence of plaque and the examination of gingival bleeding on probing and probing depth. Microbiologic sampling was obtained with the insertion of 3 sterile paper points at the deepest part of each gingival sulcus. Altogether, 192 periodontal sites were examined. After the examinations, the patients received fixed orthodontic appliances in only 1 dental arch (test sites) and the other one was left free from appliances (control sites). Clinical examination and microbiologic sampling were repeated in the same experimental test and control sites after 4, 8, and 12 weeks. At the 12-week session, the orthodontic appliance was removed from the test arch, and, 4 weeks later, a further clinical and microbiologic examination was performed. The results showed that, during the period with orthodontic appliances, the presence of plaque scores and the gingival bleeding on probing scores were increased significantly and that Aa, initially absent from all but 1 subject, was isolated in 19 and 20 subjects after 4 and 8 weeks, respectively. Furthermore, no gingival sites from the control teeth (free from Aa colonization at baseline) showed positive results for the sought-after bacterium throughout the entire length of the study. It was concluded that the placement of orthodontic appliances promotes the subgingival growth of Aa; this specific microbial change is specifically restricted to subgingival plaque from orthodontic appliance-bearing teeth. The presence of orthodontic bands and brackets therefore cannot affect the microbiologic condition of the whole mouth.

Adolescent↗
PubMed2004

Orthodontic care in suburban Cuyahoga County, Ohio: who provides treatment and whom do they treat?

It has been reported that orthodontic services are being provided to a larger segment of the population by an increasing number of providers. The present study surveyed the dental and orthodontic experiences of 10th grade students attending 16 public and two parochial high schools in suburban Cuyahoga County, Ohio, as well as two schools from the city of Cleveland. Questionnaires were distributed in the classroom and data obtained for 2808 students. Approximately 50% of the sample were girls with an average age of 15.5 +/- 0.8 years. Results of the survey revealed that 84% (2371/2808) had seen a dentist within the past year, and 37% (1047/2808) of the students had received orthodontic treatment from 171 different providers. Of those treated, 87.2% (913/1047) were treated by a specialist in orthodontics, 10.8% (114/1047) by a general dentist, and 0.7% (7/1047) by a pediatric dentist, with 1.3% missing or unknown (13/1047). Patients who had seen a dentist within the past year were more likely to have had orthodontic treatment. Only 7% of the untreated students were told by a dental professional that they needed braces compared with 71% of the treated group. Therefore, we conclude that orthodontic specialists provide most of the orthodontic services in the suburbs of Cuyahoga County, and visiting a general dentist positively influences the utilization of orthodontic services.

Adolescent↗
PubMed2002

Efficacy of training dental students in the index of orthodontic treatment need.

Orthodontic studies over several decades have found generally inconsistent opinions among dentists when evaluating orthodontic treatment need. There has also been recent concern that dental school education does not sufficiently prepare dentists to diagnose malocclusion and make appropriate referrals of potential orthodontic patients. The purpose of this study was to investigate the efficacy of using the index of orthodontic treatment need (IOTN) as a tool to improve dental students' ability to assess orthodontic treatment need. Fourth-year dental students were randomly divided into control, sham-control, and experimental groups stratified for mean grade point average. On 2 occasions, the subjects evaluated 30 orthodontic study models with a gold standard previously established by an expert panel of 15 orthodontists for orthodontic treatment need. The experimental group reevaluated the models after IOTN instruction. Kappa statistics, sensitivity, and specificity were calculated for each subject. Analysis of covariance (ANCOVA) showed that the experimental group had significantly higher agreement with the expert panel after IOTN training than did either control group. IOTN is a promising teaching aid for improving educational outcomes for orthodontic referral.

Analysis of Variance↗
PubMed1995

Morphological characteristics of dentitions developing excessive root resorption during orthodontic treatment.

The present study focuses on orthodontically provoked, excessive root resorption. The purpose was to identify in these cases common morphological features in radiographic diagnostic material taken before treatment. The material was submitted by 35 Danish orthodontists. The goal was to improve the future orthodontic diagnostics of the dentition in order to prevent severe root resorption during treatment. The study indicates that: (1) there is a strong connection between various dental morphological characteristics, such as invagination, length of root, and root shapes, especially taurodontism, and the tendency to root resorption during orthodontic treatment; (2) there is a connection between anomalies in the dentition, particularly ectopia and agenesis, and the tendency to root resorption during orthodontic treatment; (3) there seems to be a connection between the pattern of resorption in the primary dentition and the tendency to root resorption in the permanent dentition following orthodontic treatment; (4) girls are more susceptible to root resorption during orthodontic treatment than boys; (5) one ought to be on the lookout for connections between condylar changes, root resorptions, and anterior open bites in connection with orthodontic treatment. The observation regarding root resorption in dentitions in which invaginations and taurodontic root shapes occur has not previously been reported. Also, the findings of deviant resorption patterns in both the primary and permanent dentitions in a considerable number of patients are new observations, which ought to be incorporated into orthodontic treatment planning.

Adolescent↗
PubMed2000

Long-term follow-up of clinical symptoms in TMD patients who underwent occlusal reconstruction by orthodontic treatment.

Fifty-eight patients (mean age 18.4 years) who had received splint therapy for internal derangement of the temporomandibular joint (TMJ) were examined retrospectively to investigate the efficacy of occlusal reconstruction by orthodontic treatment. The subjects were divided into three groups: 18 patients (mean age 18.6 years) who underwent orthodontic treatment combined with the use of splints (ST group); 27 patients (mean age 18.2 years) who underwent orthodontic treatment without the use of splints (NST group); and 13 patients (mean age 17.9 years) who received only splint therapy for temporomandibular joint disorders (TMD; control group). TMJ sound, pain on movement and restriction of mandibular movement were examined at the initial examination (T1), at the end of the splint therapy for TMD or beginning of orthodontic treatment (T2), at the end of orthodontic treatment (T3), and at recall or 1 year after orthodontic treatment (T4). The following results were found. (1) The percentage of patients with no joint sound at T2 was 20-30 per cent. The percentage of such patients in both the ST and NST groups increased to over 50 per cent at T3, but slightly decreased to 39-50 per cent at T4. There were no significant inter-group differences at any time point. (2) The number of patients who had no pain on movement at T2 was 60-80 per cent. The percentage of such patients in both the ST and NST groups increased to over 90 per cent at T3, but then slightly decreased to 80 per cent at T4. There were no significant inter-group differences at any time point. (3) None of the patients showed restriction of movement of the TMJ at T2 or T4. One patient in the ST group was found to have restriction at T3. There were no significant inter-group differences at any time point. (4) The most frequent type of malocclusion in both ST and NST groups was anterior open bite. These results suggest that TMD symptoms that have been eliminated by splint therapy are not likely to recur due to subsequent orthodontic treatment, but it cannot be concluded that orthodontic treatment itself had a positive effect on TMD symptoms. The results also indicate that there is a relationship between anterior open bite and TMD.

Adolescent↗