Assessment of condylar volume and ramus height in JIA patients with unilateral and bilateral TMJ involvement: retrospective case-control study.

OBJECTIVES: The objectives of the study are to analyze volumetric differences of condylar volumes in patients with unilateral and bilateral JIA and to compare results with control condylar volumes. MATERIALS AND METHODS: Forty-six CBCT images were analyzed for all patients affected by JIA, 37 females and 9 males (mean age 10.8 ± 4.2) with TMJ involvement (19 unilaterally, mean age 10.9 ± 4.5; 27 bilaterally, mean age 10.7 ± 4.5), and 25 CBCT of subjects without diagnosis of JIA were selected as controls (mean age 10.8 ± 4.2 years). In the case of unilateral JIA, condylar volumes and ramus lengths were compared with healthy condyle and with the compromised one. In the case of bilateral JIA, condyle volume and ramus lengths were compared with healthy one. The Shapiro-Wilk test was used to assess whether the data was normally distributed. Paired t test was applied to compare affected and non-affected condyle in the same patients (P < 0.05). Independent t test was used to evaluate whether the difference between the groups were comparable or significantly different (P < 0.05). RESULTS: For the unilateral JIA group, significant differences comparing affected and non-affected condyles were found. A statistically significant reduction of the volume of the head, neck, and ramus was found in the affected side (P < 0.01). For the bilateral JIA group, statistically significant differences have been found considering the condylar head and neck, the whole condylar volume, and the ramus length compared with the control group (P < 0.05). CONCLUSIONS: Subjects with unilateral JIA have condyles volumetrically smaller than those of the unaffected side and those found in healthy patients. A considerable decrease of the volume of all the anatomical structures considered in the patients with bilateral JIA was found compared with control group. CLINICAL RELEVANCE: The study presents the effects of JIA on different anatomical structures highlighting their dimensional changes, whose sequelae are irreversible if not diagnosed and treated early.

TMJ pathomorphology in patients with JIA-radiographic parameters for early diagnosis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is often accompanied by pathomorphological changes to the temporomandibular joint (TMJ). By analyzing orthodontical orthopantomograms of JIA patients the aims of the study were a) classification of condyle changes, b) quantification of bony asymmetries of condylar destruction and c) detection of relationships between disease duration and TMJ-involvement. PATIENTS/METHODS: 46 caucasian JIA-patients (28 female; 18 male; < 16.0 years) were enrolled, each joint (n = 92) was morphologically assessed by means of orthopantomogram, quantitatively analysed and compared with duration of general disease. Condyle morphology was assessed using the Billiau scale for severity of destruction [1]. The quantitative analysis was based on ratios of condyle, ramus and mandible height. RESULTS: Patients were divided into groups (Group I - slightly affected, n = 36; Billiau severity 0-2; condyle findings: X-ray normal, condyle erosions, condylar flattening; Group II - severely affected, N = 10; Billiau severity 3-4; condyle findings: condylar flattenings and erosions, unilateral/bilateral complete loss of condyles), based on morphological analysis of condylar destruction. Duration of disease was significantly longer in Group II (8.9 ± 5.2 years) than in Group I (4.6 ± 4.7 years). Asymmetries of condyle, ramus and mandible height, quantitatively analysed by contralateral comparison, were significantly more marked in patients of Group II than of Group I. CONCLUSIONS: Orthopantomogram imaging can be used in orthodontics clinical routine to detect TMJ-pathologies and is an important reference for monitoring progression of JIA. Classification into severe and slightly affected TMJ is possible by analysis of condylar pathomorphology. An association between degree of destruction, extent of lower jaw asymmetry and disease duration is suggested by the results.