Quantitative bone imaging biomarkers to diagnose temporomandibular joint osteoarthritis.

Bone degradation of the condylar surface is seen in temporomandibular joint osteoarthritis (TMJ OA); however, the initial changes occur in the subchondral bone. This cross-sectional study was performed to evaluate 23 subchondral bone imaging biomarkers for TMJ OA. The sample consisted of high-resolution cone beam computed tomography scans of 84 subjects, divided into two groups: TMJ OA (45 patients with TMJ OA) and control (39 asymptomatic subjects). Six regions of each mandibular condyle scan were extracted for computation of five bone morphometric and 18 grey-level texture-based variables. The groups were compared using the Mann-Whitney U-test, and the receiver operating characteristics (ROC) curve was determined for each variable that showed a statically significance difference. The results showed statistically significant differences in the subchondral bone microstructure in the lateral and central condylar regions between the control and TMJ OA groups (P< 0.05). The area under the ROC curve (AUC) for these variables was between 0.620 and 0.710. In conclusion, 13 imaging bone biomarkers presented an acceptable diagnostic performance for the diagnosis of TMJ OA, indicating that the texture and geometry of the subchondral bone microarchitecture may be useful for quantitative grading of the disease.

Minimally Invasive Approach for Diagnosing TMJ Osteoarthritis.

This study's objectives were to test correlations among groups of biomarkers that are associated with condylar morphology and to apply artificial intelligence to test shape analysis features in a neural network (NN) to stage condylar morphology in temporomandibular joint osteoarthritis (TMJOA). Seventeen TMJOA patients (39.9 ± 11.7 y) experiencing signs and symptoms of the disease for less than 10 y and 17 age- and sex-matched control subjects (39.4 ± 15.2 y) completed a questionnaire, had a temporomandibular joint clinical exam, had blood and saliva samples drawn, and had high-resolution cone beam computed tomography scans taken. Serum and salivary levels of 17 inflammatory biomarkers were quantified using protein microarrays. A NN was trained with 259 other condyles to detect and classify the stage of TMJOA and then compared to repeated clinical experts' classifications. Levels of the salivary biomarkers MMP-3, VE-cadherin, 6Ckine, and PAI-1 were correlated to each other in TMJOA patients and were significantly correlated with condylar morphological variability on the posterior surface of the condyle. In serum, VE-cadherin and VEGF were correlated with one another and with significant morphological variability on the anterior surface of the condyle, while MMP-3 and CXCL16 presented statistically significant associations with variability on the anterior surface, lateral pole, and superior-posterior surface of the condyle. The range of mouth opening variables were the clinical markers with the most significant associations with morphological variability at the medial and lateral condylar poles. The repeated clinician consensus classification had 97.8% agreement on degree of degeneration within 1 group difference. Predictive analytics of the NN's staging of TMJOA compared to the repeated clinicians' consensus revealed 73.5% and 91.2% accuracy. This study demonstrated significant correlations among variations in protein expression levels, clinical symptoms, and condylar surface morphology. The results suggest that 3-dimensional variability in TMJOA condylar morphology can be comprehensively phenotyped by the NN.

Three-dimensional analysis of condylar changes in surgical correction for open bite patients with skeletal class II and class III malocclusions.

The aim of this study was to quantify three-dimensional condylar displacements as a result of two-jaw surgery for open bite correction in patients with skeletal class II and class III malocclusion. Pre-surgical (T1) and post-surgical (T2) cone beam computed tomography scans were taken for 16 patients with skeletal class II (mean age 22.3±9.47years) and 14 patients with skeletal class III (mean age 25.6±6.27years). T2 scans were registered to T1 scans at the cranial base. Translational and rotational condylar changes were calculated by x,y,z coordinates of corresponding landmarks. The directions and amounts of condylar displacement were assessed by intra- and inter-class Mann-Whitney U-test or t-test. Class II patients presented significantly greater amounts of lateral (P=0.002) and inferior (P=0.038) translation than class III patients. The magnitudes of condylar translational displacements were small for both groups. Skeletal class III patients had predominantly medial (P=0.024) and superior (P=0.047) condylar translation. Skeletal class II patients presented greater condylar counterclockwise pitch (P=0.007) than class III patients. Two-jaw surgery for the correction of open bite led to different directions and amounts of condylar rotational displacement in patients with skeletal class II compared to class III malocclusion, with greater rotational than translational displacements.