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.

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.

Effusions are common among patients with disorders of the temporomandibular joint (TMJ), but publications are limited and results inconsistent about the correlation between them and important clinical variables, in particular severity of pain and degenerative disease. We organised a retrospective study of patients who presented for the evaluation and management of arthralgia of the TMJ and myofascial pain at the University of Michigan between 2011 and 2014. Inclusion criteria were: patients who had pain that was primarily arthrogenous, and coexisting myogenous pain, who had had initial non-surgical treatment, and arthroscopy of the TMJ with or without intramuscular injection of onabotulinumtoxinA (Botox,® Allegan, Weston, Fl, USA). The primary outcome variables were pain at rest as measured by visual analogue score (VAS) and the presence of degenerative disease of the joint. The secondary outcome variables included the position of the disc and whether it was perforated, signs of synovitis, maximal interincisal opening (MIO), and duration of symptoms. We studied 47 patients (94 TMJ) who met the inclusion criteria. We found no significant differences in pain at rest before or after arthroscopy, between patients with and without effusions, or in maximal MIO or duration of symptoms between the two groups. There was, however, a significant relation between effusions and degenerative joint disease. Effusions were also associated with a lower probability of the disc being in a normal position and a higher probability of anterior disc displacement without reduction.

Previous research has shown that many chronic pain patients display hypersensitivity not only to noxious stimuli, but also to other sensory modalities like audition and vision. Still, the neural mechanisms underlying this generalized sensitivity have yet to be fully elucidated. The present study used a combination of quantitative sensory testing (QST), proton magnetic resonance spectroscopy (1H-MRS), and psychosocial questionnaires to compare a group of 12 temporomandibular disorder (TMD) patients (age = 32.7 ± 10.6 years) with 10 pain-free controls (41.4 ± 15.7). Subjects rated the perceived loudness and unpleasantness (0–100 scales) of 3-sec, 2,000 Hz, binaural tones that were presented pseudorandomly at amplitudes ranging from 40–90 dB SPL. Participants also completed the 2011 ACR Fibromyalgia Survey Criteria as a surrogate measure of pain centralization, and a median split was performed to separate patients into low and high centralization. Brain metabolite concentrations were acquired using a point resolved spectroscopy sequence (PRESS) in a 3T GE Signa scanner, in a 2x2x2 cm voxel positioned in the perigenual anterior cingulate cortex (pgACC). 1H-MRS data were processed using LCModel and were corrected for CSF and age. Statistical tests were conducted in SPSS v24 with an α level of p < .05. The TMD patients with high centralization perceived the tones to be significantly more unpleasant (33.0/100) than the patients with low FM scores combined with controls (15.8/100; p = .029). In TMD patients, pgACC Glx (i.e. glutamate + glutamine) levels were positively correlated with perceived loudness of the tones (r = .71,p = .009) and with current TMD pain (r = .65, p = .021). Choline levels were positively correlated with perceived loudness (r = .69, p < .001) and unpleasantness (r = .51, p = .02) of the tones in all subjects. Given the known excitatory role of glutamate and the idea that choline levels reflect membrane turnover and cellular metabolism, these results suggest that auditory hypersensitivity in chronic pain may be related to increased excitatory tone in the pgACC.