Correlation of temporomandibular joint clinical signs with cone beam computed tomography radiologic features in juvenile idiopathic arthritis patients.

OBJECTIVE: Patients with juvenile idiopathic arthritis (JIA) have a high risk of temporomandibular joint (TMJ) involvement. Early detection of osseous destruction of the TMJ that can be seen radiographically is vital to provide appropriate treatment before significant craniofacial deformities and problems with occlusion arise. The aim of study was to evaluate whether there is a correlation between the clinical signs and cone beam computed tomography (CBCT) radiologic features of TMJ in patients with JIA. MATERIAL AND METHODS: Study group consisted of 65 patients (46 females and 19 males) aged 10 to 17 years with a confirmed JIA diagnosis and mean disease duration 2 years 9 month, all patients underwent a clinical examination of the TMJ and masticatory muscles as well as a radiological assessment of the TMJ osseous structures by CBCT. RESULTS: Majority of the patients' study population experienced 2 or 3 clinical signs with mean number 2.1 (standard deviation (SD) =1.00) and 3-5 radiological features related to the TMJ destruction with mean number 4.9 (SD=1.96). Statistically significant weak correlation only between pain and condyle surface flattening (Spearman`s Rho test (rho) =0.396; p value (p) =0.001) was found. No correlation between number of clinical signs and radiological features was found. CONCLUSIONS: There was no conclusive evidence found regarding correlation between TMJ clinical signs and radiological features of osseous destruction in patients with JIA - only weak correlation between pain and condyle surface flattening was observed. The number of clinical TMJ signs does not correlate with number of radiological features. For the clinical decision both clinical examination and CBCT would be useful in the early detection of osseous destruction of the TMJ in JIA patients.

Radiologic features of temporomandibular joint osseous structures in children with juvenile idiopathic arthritis. Cone beam computed tomography study.

INTRODUCTION: Patients with juvenile idiopathic arthritis (JIA) have a high risk of temporomandibular joint (TMJ) involvement. Lesions in the TMJ appear early in the course of this disease. Evaluating the structure of the TMJ in JIA patients using cone beam computed tomography (CBCT) provides an understanding of the typical radiologic features of morphological change in TMJs of JIA patients. This study aims to report these features as seen in CBCT and thus comparing them with the features observed in a control group within the same age group and in females and males. MATERIALS AND METHODS: Cross-sectional observational study whereby CBCTs of 65 (130 joints) patients with a confirmed JIA diagnosis and 30 (60 joints) control group - patients without JIA upto the age of 17. Structural radiologic features of the joint's hard tissues were assessed according to the research diagnostic criteria for temporomandibular disorders as developed by Ahmad et al. RESULTS: The radiologic features of the osseous structures of the TMJ occurred asymmetrically between the right and left sides when compared in the JIA and control groups. The most prevalent feature in the JIA group is condyle surface flattening for both sides. Condyle surface erosion and osteophyte were also frequent and occurred with high statistical significance in both males and females. CONCLUSIONS: TMJ destruction features observed in CBCT images were prevalent in the JIA group and occurred infrequently in the control group.

The relationship between mandibular rotation and osseous structure of the TMJ in pre-surgery orthognathic patients: A cone beam CT study.

The aim of the study was to assess the relationship between vertical skeletal pattern in terms of mandibular rotation and osseous structural changes of the TMJ in pre- surgical orthognatic patients. TMJ skeletal morphology was evaluated in cone beam computer tomography images of 117 consecutive patients with Class II and Class III dentofacial deformities according to the research diagnostic criteria of the osseous components of the TMJ related to the maxillary-mandibular plane (MM) angle. The distribution of the number and percentage of joints with structural changes in Class II was markedly different in groups divided according to the MM angle. Statistically significant increase was found in the percentage of TMJ's with osseous changes separately for each side, i.e., right (p=0.001), left (p=0.04) and both together (p=0.0001), in the Class II patient group, an increased MM angle indicated backward rotation of the mandible. In Class III patients, there were no statistically significant differences in the number of joints with TMJ structural changes. The presence of mentioned changes was asymmetrical between the left and right joints in both the Class II and Class III patient groups. In conclusion, structural changes in the osseous parts of the TMJ are more common in patients with Class II skeletal dentofacial deformities with backward rotation of the mandible than in Class III pre-surgery orthognathic patients.

Shear bond strength after multiple bracket bonding with or without repeated etching.

The purpose of the study was to measure the in vitro shear bond strength (SBS) of metal brackets after multiple bonding and debonding with and without repeated etching. One hundred and twenty extracted premolars were divided into three equal groups. In group 1, the brackets were bonded and debonded three times with repeated enamel etching and in groups 2 and 3 without repeated etching. In group 2, all composite remnants were removed before bonding, while in group 3, the remnants were levelled. Analysis of variance was used to determine significant differences in SBS with Bonferroni adjustment for the multiple testing procedures. The results showed that in group 1, the mean SBS was 11.69 MPa (SD 2.65) at the first, 14.30 MPa (SD 2.69) at the second, and 12.19 MPa (SD 2.26) at the third debonding. In group 2, SBS decreased from 12.57 MPa (SD 2.54) to below 8.0 MPa. In group 3, SBS remained constant from the first (11.93 MPa; SD 2.14) to the second (12.06 MPa; SD 1.65) debonding and only decreased significantly to 9.74 MPa (SD 1.80) at the third debonding. Less composite remained on the teeth after each debonding sequence. This was characterized by a shift from adhesive remnant index (ARI) scores 2 and 3 after the first debonding to ARI scores 1 and 2 after the second debonding to predominantly scores 0 and 1 after the third debonding. After bracket loss and levelling of composite remnants, the SBS is sufficient for application of orthodontic forces. Repeated etching may involve a higher risk of enamel tear-outs during debonding.

Three-dimensional evaluation of musculoskeletal in Class II and Class III patients.

OBJECTIVE: To evaluate and compare dimensional morphology of masseter and medial pterygoid muscles and mandibular skeletal parameters between subjects with skeletal Class II and Class III. MATERIALS AND METHODS: The sample consisted of 13 patients with skeletal Class II and 10 patients with skeletal Class III prior to the start of combined orthodontic treatment and orthognathic surgery with correspondence to definite inclusion and exclusion criteria. Magnetic resonance imaging was performed for mandibular muscles and following 2D and 3D measurements were done: cross-sectional area (CSA), thickness, width, longitudinal dimension and volume. 3D multi-slice computed tomography investigation was performed for the assessment of skeletal mandibular parametres and following measurements were done: height of mandibular ramus, length af mandibular corpus, overall mandibular length, intergonial width. All the measurements were done bilaterally. Data were analyzed using descriptive statistics, t-test, and correlation coefficients. RESULTS: It was found that values of all mandibular and medial pterygoid measurements were higher in Class III subjects with statistical significance (p<0.05). There was a tendency of all masseter variables to be higher in Class III patients. Positive correlations were found between muscles' volume and CSA in both groups, muscles' volume and all mandibular parameters in Class II group, CSAs and all mandibular variables except intergonial width in Class II group. Overall symmetry was observed between left and right sides in all muscular and mandibular measurements in both groups. CONCLUSIONS: The data were acquired using two different imaging techniques - MRI and MSCT that can be mentioned as a novelty in this field of research. Remarkable differences were observed between study groups for both skeletal and muscular measurements.

Three-dimensional evaluation of TMJ parameters in Class II and Class III patients.

The aim of our study was to assess condylar parameters and condyle position within glenoid fossa of TMJ in volumetric 3D imaging in patients with Class II and Class III malocclusions. MATERIALS AND METHODS. The study group included 15 patients with severe skeletal Class II (mean age 18.0 yrs) and 14 patients with severe skeletal Class III ( mean age 19,2 yrs) with an indication for combined orthodontic and orthognathic treatment. CT examination was performed, pictures were reconstructed in three - dimensional (3D) rendering and measured in two dimension projection (2D) pictures using IAC review and Transparent bone programs to quantify following condylar and glenoid fossa parameters - glenoid fossa width and height; tuberculum articulare angle; anterior, superior and posterior joint space; height and width of condyle, height of procesus condylaris. Mean values were calculated separately for left and right side. Differences of the mean values were tested using paired t-test. RESULTS. There were statistically significant differences (p<0,05) between two study groups for all spatial measurements on both sides with larger spatial measurements in patients with Class II malocclusions. Also the height of procesus condylaris varied between groups with statistical difference. Unilateral differences were detected for width of fossa glenoidale and height of condyle. CONCLUSION. Results show that there are a tendency for smaller condyle and wider spaces between condyle and walls of glenoid fossa comparing TMJ of Class II with Class III patients.

Condylar and mandibular morphological criteria in the 2D and 3D MSCT imaging for patients with Class II division 1 subdivision malocclusion.

UNLABELLED: The condyle has a special multidirectional capacity for the growth and adaptive remodeling of temporomandibular joint (TMJ). Being part of TMJ structure, it plays an important role in the stability of long-term treatment results for orthodontic and orthognatic patients with Class II division 1 subdivision malocclusions. Several computed tomography (CT) investigation modes have been used to evaluate the craniofacial morphology and particularly, for TMJ. Dimensional images, acquired using new generation multislice CT (MSCT) and cone beam CT scanning data, are becoming increasingly popular in the clinical work and research. The aim of the study was to develop a new CT investigation protocol for the quantification of morphological structures and skeletal landmarks of condyle, procesus condylaris and mandible. For this purpose we created two dimensional (2D) and three dimensional (3D) reconstruction images from primary axial MSCT scans using IAC review and Transparent bone programms and acquired accordant measurements of condylar and mandibular structures. This technic allowed to get truly volumetric reflexion of the joint components in its real anatomical size and avoided the bony superimpositions. Our material included 12 patients with skeletal Class II division 1 subdivision malocclusion who had indications for combined orthodontic and orthognatic treatment. CT examination was performed before the start of treatment. For statistical analysis paired Student t-tests were applied to test the diferences of mean values and correlation coefficients were calculated to assess possible interrelations between measurements. The preliminary results showed weak corrrelation between condylar and mandibular measurements. More significant correlation was observed between procesus condylaris and mandible. It was a significant difference between right and left side in the height of procesus condylaris in patients without clinicaly relevant facial asymetry which could be considered in the individual planning of orthognatic treatment. CONCLUSION: The developed combined 2D and 3D MSCT investigation protocol for condylar and mandibular measurements provides precise and demonstrative quantitative images of condylar and mandibular structures and its dimensional relationships., which could be qualified as informative criteria for the individual treatment planning for patients with Class II division 1 subdivision malocclusion.