Bengt Mohlin

TMD in relation to malocclusion and orthodontic treatment

OBJECTIVE The aim of this systematic literature review was to evaluate associations between different malocclusions, orthodontic treatment, and signs and symptoms of temporomandibular disorders (TMD). MATERIALS AND METHODS This review was part of a project at the Swedish Council on Technology Assessment in Health Care focusing on malocclusion and orthodontic treatment from a health perspective. As a first step, the literature was searched in the Medline and Cochrane Library databases from 1966 to May 2003. A later update was made in January 2005. Human studies in English or in Scandinavian languages were included. RESULTS Associations between certain malocclusions and TMD were found in some studies, whereas the majority of the reviewed articles failed to identify significant and clinically important associations. TMD could not be correlated to any specific type of malocclusion, and there was no support for the belief that orthodontic treatment may cause TMD. Obvious individual variations in signs and symptoms of TMD over time according to some longitudinal studies further emphasized the difficulty in establishing malocclusion as a significant risk factor for TMD. A considerable reduction in signs and symptoms of TMD between the teenage period and young adulthood has been shown in some recent longitudinal studies. CONCLUSIONS Associations between specific types of malocclusions and development of significant signs and symptoms of TMD could not be verified. There is still a need for longitudinal studies.

Malocclusion and Temporomandibular Disorder: A Comparison of Adolescents with Moderate to Severe Dysfunction with those without Signs and Symptoms of Temporomandibular Disorder and Their Further Development to 30 Years of Age

A total of 1018 subjects were examined at the age of 11 years, 791 were reexamined at 15 years, 456 at 19 years, and 337 at 30 years. Anamnestic and clinical recordings of temporomandibular disorder (TMD) were made. Morphology, including calculation of peer assessment rating (PAR) scores, was recorded. Previous history of orthodontic treatment was assessed. Muscular endurance was recorded. The subjects completed four psychological measures. The malocclusion prevalence, occlusal contacts, psychological factors, and muscular endurance in subjects with no recorded signs and symptoms of TMD were compared with those with the most severe dysfunction at 19 years of age. The further development of TMD to 30 years of age was followed. PAR scores were significantly higher in the subjects with the most severe dysfunction. Apart from crowding of teeth, no other significant differences were found between the groups with regard to separate malocclusions, tooth contact pattern, orthodontic treatment, or extractions. A greater proportion of subjects with low endurance were found in those with TMD. Significant associations between TMD and general health and psychological well-being as well as the personality dimension of neuroticism and self-esteem were found. During the period from 19 to 30 years, the prevalence of muscular signs and symptoms showed considerable reduction, whereas clicking showed a slight increase. Locking of the joint showed a decrease from 19 to 30 years. One-quarter of the TMD subjects showed complete recovery. Thus, orthodontic treatment seems to be neither a major preventive nor a significant cause of TMD.

Long-term stability of orthodontic treatment and patient satisfaction. A systematic review.

OBJECTIVE To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment. MATERIALS AND METHODS Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies. RESULTS The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective. CONCLUSIONS This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.

Twenty-year cohort study of health gain from orthodontic treatment: Temporomandibular disorders

INTRODUCTION Temporomandibular disorder (TMD) is a common condition. Studies of TMD in relation to orthodontic treatment did not show an association, but longitudinal studies from adolescence to adulthood are lacking. The aim of this study was to investigate the relationship between orthodontic treatment and TMD with a longitudinal study design. METHODS This prospective cohort study was conducted in South Wales, United Kingdom. The baseline investigation was carried out in 1981 and involved children aged 11 to 12 years (n = 1018). Follow-up investigations were done in 1984 (n = 792), 1989 (n = 456), and 2000 (n = 337). RESULTS Overall TMD prevalence increased from the baseline (3.2%) to age 19 to 20 (17.6%) and decreased by age 30 to 31 (9.9%). TMD prevalence was higher in females at all follow-up points, except the baseline. Overall, incidences of TMD were 11.9%, 11.5%, and 6.0% at the first, second, and last follow-ups, respectively. Females were more likely to develop TMD than males (hazard ratio [HR], 2.1; 95% CI, 1.3 and 3.3), and those with high self-esteem were less likely to develop TMD (HR, 0.6; 95% CI, 0.4 and 0.8). There was no association between orthodontic treatment and new TMD onset. The incidences of persistent TMD were 20.0%, 34.9%, and 28.0% at the first, second, and last follow-ups, respectively. Females were more likely to have persistent TMD than males (HR, 2.5; 95% CI, 1.0 and 6.1). There was no association between orthodontic treatment and persistent TMD. The only significant predictors of TMD in adults aged 30 to 31 were female sex (odd ratio, 3.0; 95% CI, 1.1 and 8.2) and TMD in adolescence (odds ratio, 4.5; 95% CI, 2.0 and 10.0). CONCLUSIONS Orthodontic treatment neither causes nor prevents TMD. Female sex and TMD in adolescence were the only predictors of TMD in young adulthood.

Social life aspects of young adults with cleft lip and palate: Grounded theory approach

Objectives. The findings of many questionnaire and inventory studies suggest that people with cleft lip and/or palate report a decreased quality of life. Common problems include dissatisfaction with the external appearance of the lips and nose, speech problems, depression, and anxiety. This qualitative study aimed to explore the subjective perceptions and values of young adults with clefts, particularly with regard to their social lives. Material and methods. Twelve persons participated in an in-depth interview. Among those, seven had a repaired isolated cleft palate involving only the hard/soft palate. Five had a repaired bilateral cleft lip and palate that had been a continuous lesion of the lip, the alveolar process, and the palate. A grounded theory approach was used to conduct and analyze the interviews. Results. The study revealed seven important categories – hoping to be like other people, being treated differently from others, experiencing deviation from others, regarding oneself as being different from others, lack of recognition, low self-esteem, and receiving recognition from significant others – with hoping to be like other people as the core category. Conclusion. Young adults with either cleft lip and palate or isolated cleft palate who received recognition from significant others reported increased self-esteem and greater ability to cope with their social lives.

Relapse tendency after orthodontic correction of upper front teeth retained with a bonded retainer.

OBJECTIVE To investigate the amount and pattern of relapse of maxillary front teeth previously retained with a bonded retainer. MATERIALS AND METHODS The study group consisted of 135 study casts from 45 patients. Recordings from study models before treatment (T1), at debonding (T2), and 1 year after removal of the retainer (T3) were present. All patients had been treated with fixed edgewise appliances. The irregularity index (sum of contact point displacement [CPD]) and rotations of front teeth toward the raphe line were calculated at T1, T2, and T3. RESULTS The mean irregularity index at T1 was 10.1 (range 3.0-29.9, SD 5.4). At T2 it was 0.7 (range 0.0-2.1, SD 0.7), and at T3 it was 1.4 (range 0.0-5.1, SD 1.2). Fifty-five teeth in 42 patients were corrected more than 20 degrees between T1 and T2 (mean correction 31.4 degrees range 20.0-61.7), and mean relapse in this group was 7.3 degrees (range 0.0-20.5). Regarding alignment of the maxillary front teeth, the contact relationship between the laterals and centrals seems to be the most critical. A significant positive correlation was found between the amount of correction of incisor rotation and the magnitude of relapse but not between the amount of correction of CPD and the magnitude of relapse. Eighty-four percent of the overcorrected CPDs returned to a desired position. CONCLUSIONS Minor or no relapse was noted at the 1-year follow-up.

Dental agenesis patterns of permanent teeth in Apert syndrome.

Dental agenesis may either occur as an isolated trait (non-syndromic) or as a component in a congenital syndrome. The aim of the present study was to identify the prevalence of dental agenesis for each type of tooth and to look for dental agenesis patterns in persons with Apert syndrome. Serial panoramic radiographs of 23 individuals (five male patients and 18 female patients) were examined. Third molars were excluded. The prevalence of agenesis for at least one tooth was 34.8%. Up to two missing teeth were found for individuals with Apert syndrome. Maxillary lateral incisors and mandibular second premolars were the most frequently missing teeth. Four different dental agenesis patterns of the entire dentition were identified by using the tooth agenesis code (TAC). Two patterns occurred more frequently, both of which were symmetrical. One involved the simultaneous absence of teeth 12 and 22, and the other showed agenesis of teeth 35 and 45. In conclusion, patients with Apert syndrome were found to exhibit a high prevalence of dental agenesis. All dental agenesis patterns in which more than one tooth was missing were symmetrical.

Pattern and amount of change after orthodontic correction of upper front teeth 7 years postretention.

OBJECTIVE To investigate the amount and pattern of changes of maxillary front teeth 7 years postretention, which previously were retained with a bonded retainer. MATERIALS AND METHODS The study group consisted of 27 patients. Study models before treatment (T1), at debonding (T2), 1 year after removal of the upper bonded retainer (T3), and 7 years postretention (T4) were present. The irregularity index (sum of contact point displacements) and the rotations of front teeth toward the raphe line were calculated. RESULTS The irregularity index of the maxillary front teeth changes very little or not at all during the first year postretention. Further change long term resulted in an irregularity index of mean 2.0 (range 0.0-5.8). The contact relationship between the laterals and centrals seems to be the most critical. Forty rotated teeth in 21 patients were corrected more than 20 degrees . Mean relapse during the first year postretention was 6.7 degrees (range 0.0 degrees -14.7 degrees ). Mean changes during 7 years was 8.2 degrees (range 0.0 degrees -19.3 degrees ). CONCLUSIONS Relapse of upper front teeth retained with a bonded retainer is minor in both the short and long term. If permanent retention is required after 3 years of retention, it is enough to retain the incisors.

Pain, discomfort, and use of analgesics following the extraction of primary canines in children with palatally displaced canines

BACKGROUND. Pain following the extraction of the primary canine in children with palatally displaced canines (PDC) as an interceptive treatment has not been investigated. AIMS. To describe pain, discomfort, dental anxiety, and use of analgesics following the extraction of primary canines in children with PDC. DESIGN. Forty-four children, aged 10-13 with PDC, were included. Pain intensity, discomfort, and analgesic consumption were rated the first evening and 1 week after the extraction of the primary canine. Dental anxiety was assessed pre-extraction, using the dental anxiety scale (DAS). A matched reference group also completed the DAS. RESULTS. No significant differences were found between the study and the reference group regarding the pre-extraction assessments. Post-extraction pain and discomfort was low. The experience of the injection was graded worse than the extraction, and more pain was rated at the evening post-extraction than during the extraction. Analgesics were used only the first evening. High correlation was detected between DAS and pain during injection and extraction. CONCLUSIONS. The experience of pain and discomfort during and after extraction of the primary canines is low, despite that 42% of the children used analgesics. Therefore, appropriate analgesics and recommendation doses pre- and post-extraction should be prescribed.

Living with Crouzon syndrome: transition from childhood to adulthood

Abstract Objective. The aim of this qualitative investigation is to study the subjective experiences of transition from childhood to adulthood in individuals with Crouzon syndrome. Material and methods. Telephone interviews were carried out with eight informants and data were analysed according to grounded theory. Results. A core category emerged labelled facing barriers when developing self-image, which illuminates the different barriers the child had to face when trying to develop a self-image during the transition from childhood to adulthood. Facing barriers should not be confused with the actual barriered development. These barriers are further illuminated in five descriptive categories. Conclusions. These children face a variety of stressful barriers when developing their self-image during the transition from childhood to adulthood. The produced psychological outcome seems to be related to a complex interaction among multiple variables, including variables related to the individual with Crouzon syndr...