Internal derangement in the temporomandibular joint of juveniles with clinical signs of TMD : MRI-assessed association with skeletal and dental classes.

AIM: The aim of this study was to investigate possible correlation of specific skeletal or dental class in children and adolescents with clinical signs of temporomandibular dysfunction (TMD) with the severity of internal derangement (ID) of the temporomandibular joint. MATERIALS AND METHODS: Based on MRI images, the ID of 232 juvenile temporomandibular joints in 116 patients were retrospectively recorded. The distribution of the ID stages within the skeletal and dental classes was compared by means of the χ 2 test. RESULTS: Excluding the comparison between skeletal Class I (S I) and skeletal Class II (S II; p < 0.05), no statistically significant differences in the distribution of the ID stages were found between the skeletal classes (p > 0.05). No statistically significant differences were found when comparing the distribution of the ID stages between the dental classes (p > 0.05). CONCLUSION: According to these findings, there is no skeletal or dental class that is related to higher degrees of internal derangement in the TMJs of children and adolescents presenting clinical signs of TMD. Therefore, it is not possible to draw conclusions about the severity of the ID in relation to the dental and skeletal class in symptomatic juvenile TMJs.

Prevalence of class III malocclusion and crossbite among children and adolescents with craniomandibular dysfunction.

Numerous studies have been devoted to the causes of craniomandibular dysfunction (CMD). This investigation addressed the effect of class III malocclusion and crossbite on CMD based on a sample of 115 prepubertal and adolescent patients of both sexes. Although class III malocclusion only accounted for 12.2% of the total sample, thus, being the smallest group, the percentage of crossbite (71.4%) among these patients was disproportionately higher than among the other classes. Of the total sample, the prevalence of crossbite was 30.4%. We compared these findings to a large-scale (n=4727) study by Thilander et al. (2002), who reported a strikingly high percentage of class I patients compared to our findings (72.7% versus 27.8%) and a lower percentage of crossbite cases (8.0% versus 30.4%). In accordance with the "orthodontic risk child" concept by Grabowski et al. (2007) and Stahl et al. (2007), we conclude that class III malocclusion and crossbite are keys in the pathogenesis of CMD.

Treatment timing of MARA and fixed appliance therapy of Class II malocclusion.

The objective of this study is to evaluate the effect of timing on Mandibular Anterior Repositioning Appliance (MARA) and fixed appliance treatment of Class II malocclusion in a prospective clinical trial. The treated sample consisted of 51 consecutively treated patients at prepubertal (n = 21), pubertal (n = 15), and postpubertal (n = 15) stages of development. Control groups for the three treated groups were generated from growth data of untreated Class II subjects. Lateral cephalograms were digitized and superimposed via cephalometric software at T1 (pre-treatment) and T2 (after comprehensive treatment). The T1-T2 changes in the treated groups were compared to those in their corresponding control groups with Mann-Whitney tests with Bonferroni correction. Mandibular elongation was greater at the pubertal stage (Co-Gn +2.6 mm, with respect to controls). Headgear effect on the maxilla was greater in the pre-peak sample (Co-A -1.9 mm, with respect to controls). Dentoalveolar compensations (proclination of lower incisors, extrusion and mesialization of lower molars, and reduction in the overbite) were significant in the pre-peak and post-peak groups. Optimal timing for Class II treatment with MARA appliance is at the pubertal growth spurt, with enhanced mandibular skeletal changes and minimal dentoalveolar compensations.

Treatment and posttreatment outcomes induced by the Mandibular Advancement Repositioning Appliance; a controlled clinical study.

OBJECTIVE: To evaluate the treatment and posttreatment dentoskeletal effects induced by the Mandibular Advancement Repositioning Appliance (MARA) in the treatment of Class II malocclusion. MATERIALS AND METHODS: The treated sample consisted of 23 consecutively treated patients at prepubertal or pubertal stages, as assessed by the cervical vertebral maturation method. A control group of untreated Class II subjects was generated from published normative growth data. Lateral cephalograms were digitized and superimposed via cephalometric software at three different times: T1, pretreatment; T2, post-MARA treatment; and T3, at least 1 year after T2. The T1-T2, T2-T3, and T1-T3 changes in the treated group were compared to those in the control group with independent-sample Student's t-tests. RESULTS: Skeletal and dentoalveolar effects of MARA were assessed after the active phase of the treatment (T1-T2). Mandibular elongation in length (Co-Gn, +2.2 mm) was evident together with lower incisor proclination (IMPA, +5.8 mm). A relapse tendency for IMPA was noticed after removing the appliance (IMPA, -2.1° during T2-T3). Significant skeletal effects (Co-Gn, +2.0 mm) and headgear effects on the maxilla (SNA, -1.2°) were significant in the long term (T1-T3). CONCLUSIONS: The MARA appliance provides an effective correction of Class II malocclusion, which is maintained at a posttreatment observation with a moderate skeletal effect.

Modified camouflage therapy in an adult class I patient with TMJ complaints. A case report.

The present case report documents the hitherto unusual application of camouflage orthodontics in one of our patients. Our female patient had previously been treated orthodontically alio loco and had also undergone bimaxillary orthognathic surgery. She presented with TMJ complaints, with associated pains. Despite a dental Class I and centrally seated condyles, her discs had prolapsed anteriorly without reduction and she had developed a massive degenerative-inflammatory TMJ disease. Skeletally, she was a Class II case despite previous orthognathic surgery. In addition, there was also an initial suspicion of rheumatic involvement that could not be confirmed. We distalized the entire lower dental arch without bicuspid extraction. Then we advanced the mandible with the Mandibular Anterior Repositioning Appliance (MARA).We discuss exactly how the modified camouflage therapy was structured and how the individual treatment steps took place.

The use of MRI diagnostics in orthognathic surgery: prevalence of TMJ pathologies in Angle Class I, II, III patients.

AIM: Occasionally, undesirable post-surgical symptoms of temporomandibular disorder (TMD) and pain have been observed. The aim of this paper is to show how often and to which degree TMJ pathologies occur in orthognathic surgery candidates before surgery, making it recommendable to consider these TMJ pathologies during treatment planning. PATIENTS AND METHODS: Between 2002 and 2004, Magnetic Resonance Imaging (MRI) of the TMJ were made in 58 randomly chosen orthognathic surgery patients. 69% of the patients were female, 31% were male. Age averaged 31.6 years (16-61 years). Gender and malocclusion (Class I, II and III) were looked at during analysis of the data (n = 58 patients, n = 116 TMJs). MRI scans were made at the beginning of treatment. We wanted to investigate the TMJ condition before surgery. RESULTS: The largest patients group of this study were the female Class II patients (n = 25). Most patients displayed an Angle Class II (53.4%). The Class III patients followed (32.8%). A Class I molar relationship was found in 13.8% of the studied patients. A similar distribution could be observed in the parameters we studied: 1. condyle (position, degeneration), 2. disc (position, degeneration, prolapse and reduction). 76% of the TMJs (66.7%) showed dorsocranial condylar displacement. 26 of the 114 studied condyles (22.8%) were dorsally displaced. 108 of the studied joints (94.7%) showed condylar displacement. In 31 TMJs (28,4%) we found moderate, in 25 joints (22.9%) severe and in 26 joints (23.9%) we observed slight condylar degeneration. Most discs were displaced ventrally (31%). 22 of the studied 113 discs (19.5%) were displaced medially. 93% of the studied discs were not positioned correctly. 58 of the studied discs (58.6%) displayed flattening, in 8 (8%) we observed both flattening and disc adhesions. Two each of the studied TMJs had discs with perforations and adhesions or only perforations. In 57 (50.4%) of the studied discs we observed partial disc prolapse. Disc prolapse was total in 42.5% (n = 48 TMJs) of the TMJs. Eight TMJs (7%) of the 113 TMJs we analyzed showed no disc prolapse. Disc reduction was total in 71 (62.8%) of the studied TMJs. 15% (n = 17 TMJs) showed a partially reduced disc. 25 (22.1%) of the studied joints showed no disc reduction. CONCLUSION: Apparently, MRI scans of the TMJ are necessary in almost all potential orthognathic surgery patients to achieve optimal surgical results. Female Class II patients recruited the largest patient group among the studied collective. It is this group that deserves the greatest caution before and after surgery (TMJ pathologies!). In patients with jaw discrepancies, a TMJ examination should be made prior to surgery in order to be able to include the condition of the TMJs in the planning of treatment. This examination best includes Magnetic Resonance Imaging (MRI) and Manual Functional Analysis (MFA).

Effect of the MARA appliance on the position of the lower anteriors in children, adolescents and adults with Class II malocclusion.

AIM: Aim of this retrospective study was to investigate the effect of the fixed functional appliance MARA (Mandibular Anterior Repositioning Appliance) on the position of the lower anteriors. PATIENTS AND METHODS: For 1.3 years on average, 90 patients with a skeletal and dental Angle Class II malocclusion were treated simultaneously with the MARA and multi-bracket appliances to attain anterior mandibular repositioning. The patients were divided into the following age groups: 36 patients, mean age 10.6 years (children), 28 patients, mean age 14.9 years (adolescents) and 26 patients, mean age 33.7 years (adults). Lateral headfilms were taken at the onset of MARA treatment (T1), upon MARA removal (T2), and one year after MARA removal (T3). IMP angle (IMPA), incisor position with relation to the pogonion perpendicular, ANB angle, overjet and facial type were analyzed using cephalometric software. The degree of crowding was assessed on the study models. The data were subjected to Welch's paired t-test for statistical analysis. RESULTS: In children, an average 0.4 mm mesial shift of the lower incisors (change in proclination +1.7 degrees ) was observed. This movement averaged 1.0 mm in adolescents (change in proclination +3.6 degrees ). The adult age group averaged 1.7 mm (change in proclination +4.5 degrees ). In all age groups, a significant linear correlation was detected between position shift of the lower anteriors and the IMPA angle at T1: strongly protruded lower incisors showed less mesial shift than lingually inclined anteriors. CONCLUSIONS: The MARA fixed-functional appliance was an effective device in treating Class II patients in all the age groups studied. The dentoalveolar effect on the lower anteriors was more pronounced in the adult patient group than in the adolescents and children. When the literature on other fixed Class II mechanics is compared, the MARA is revealed as among those with the most Isprinminimal side-effects on the position of the lower anteriors. Ultimately, incisor inclination can be controlled well by therapy with multi-bracket systems.

Visualization of the articular disk of the temporomandibular joint in near-real-time MRI: feasibility study.

While static MRI of the TMJ is the method of choice to evaluate the articular disk (AD), dynamic MRI so far has failed to display the AD. The capability of a modified True-FISP sequence to visualize the AD in dynamic near-real-time imaging (NRTI) was evaluated. Twelve healthy subjects and 17 patients were investigated. Besides static routine imaging, sagittal NRTI of both TMJs was performed with a True-FISP sequence at 1.5 T with TE/TR=1.84/3.68 ms. Two temporal resolutions (250/500 ms) were tested. The quality of the visualization of the AD was rated on a four-point scale (1= very good to 4= poor visualization) by two observers in consensus. ADs of the volunteers were visualized with high quality in all stages of movement (score: 1.69). In patients with internal derangement, disk-motion was clearly depicted, including fast reposition movements. Due to degenerative changes of the AD, the quality of the depiction in patients was slightly lower (score: 2.4). According to the preliminary results of this feasibility study, the suggested NRTI True-FISP sequence is capable of visualizing the entire motion of the AD of the TMJ in normal and pathologic stages with high quality. Further studies are needed to prove the clinical usefulness of this new technique.