Background Degenerative joint disease (DJD) can be associated with disc displacement (DD) in temporomandibular disorder (TMD) patients. However, the relationship between different types of DDs and DJD remains unclear. Objectives To investigate the odds ratios of different types of sagittal and coronal DDs confirmed by magnetic resonance imaging (MRI) and DJD confirmed by cone‐beam computed tomography (CBCT) in TMD patients. Methods Radiographic data from 69 males and 232 females were collected for analysis. CBCT was used to diagnose DJD, with criteria including erosion, osteophytes, generalised sclerosis and cysts in the joint. Eight types of DDs were evaluated by sagittal and coronal MRIs: NA, no abnormality; SW, sideways; ADDR, anterior with reduction; ADDR+SW; ADDNR, anterior without reduction; ADDNR + SW; single SW; PDD, posterior; PDD + SW. The odds ratios of DJD in joints with different types of DDs were determined after joint correlation, age and gender adjustment. Results Compared with NA, the odds ratio of DJD in ADDR was 2.397 (95% CI [confidence interval]: 1.070–5.368), ADDR + SW was 4.808 (95% CI: 1.709–3.528), ADDNR was 29.982 (95% CI: 15.512–57.950) and ADDNR + SW was 25.974 (95% CI: 12.743–52.945). Erosion was significantly increased in ADDR, ADDR + SW, ADDNR and ADDNR + SW; osteophytes were significantly increased in ADDR + SW, ADDNR and ADDNR + SW; and generalised sclerosis and cysts were significantly increased in ADDNR and ADDNR + SW. There were no significant associations between single SW, PDD, PDD + SW and the DJD. Conclusions ADDR, ADDR+SW, ADDNR and ADDNR+SW were associated with DJD. ADDNR had a significantly higher prevalence of DJD than ADDR. There were no significant relationships between single SW, PDD, PDD + SW and the DJD.

Disc displacement (DD) appears in the majority of temporomandibular disorder (TMD) patients. The correlation between craniofacial morphology and different disc positions has been underlined, while the craniofacial morphological differences based on sex and sagittal skeletal pattern stratification have been insufficiently studied. In this study, 304 patients with TMD complaints were included and classified into normal position, disc displacement with reduction (DDwR) and disc displacement without reduction (DDwoR) groups according to magnetic resonance imaging. A total of 24 cephalometric measurements, covering the cranial base, vertical relationship, sagittal relationship, mandible position and morphology, and dental relationship, were assessed using lateral cephalograms. A stratified analysis was performed based on the sex and sagittal skeletal pattern. Overall, DD patients had distinctive craniofacial morphological features. The posterior cranial base length and mandibular arc angle were statistically different only in females, while the Y-axis angle, occlusal plane angle and sella nasion point A angle (SNA) might be unique features in males. Skeletal class II had the most statistically different measurements compared to the others. Differences in the Frankfort mandibular incisor angle (FMIA) and saddle angle were especially displayed in skeletal class III patients. The sex and skeletal sagittal pattern could affect the morphological differences in TMD patients with different disc positions.

Purpose. To evaluate head and cervical posture in individuals with or without temporomandibular disorders (TMDs) and to assess the correlations between pain, severity of symptoms, and posture. Methods. A total of 384 patients (129 males and 255 females) was included. The Fonseca Anamnestic Index (FAI) was used to assess the severity and prevalence of TMD and the presence of temporomandibular joint (TMJ) pain. Patients were divided into three groups: the TMD-free group, TMD without TMJ pain group, and TMD with TMJ pain group. Subsequently, the patients with TMJ pain were further divided into mild TMD and moderate/severe TMD groups. Nine parameters were traced on cephalograms to characterize the head and cervical posture. Results. TMD patients with TMJ pain showed increased forward head posture (FHP) than patients without TMJ pain and TMD-free subjects. No significant difference was observed between the TMD patients without TMJ pain and TMD-free subjects. In the TMD patients with the TMJ pain group, the moderate/severe TMD patients demonstrated increased FHP compared to mild TMD patients. TMD patients with joint pain had greater CVT/RL (B = 3.099), OPT/RL (B = 2.117), and NSL/C2’ (B = 4.646) than the patients without joint pain after adjusting for confounding variables ( P < 0.05 ). Conclusion. TMD patients with TMJ pain showed increased FHP compared to other groups, and FHP became more significant as TMD severity increased in male patients, indicating the FHP might play an important role in the development of TMJ pain. In the clinical assessment of TMD, the patients’ abnormal head and cervical posture might be considered.

Purpose. To explore the relationship between craniomaxillofacial features and psychological distress among adult pretreatment orthodontic patients. Methods. A group of 190 patients (95 males and 95 females) was included. Questionnaires including the Kessler psychological distress scale (K10) were sent to patients, and cephalograms were collected. Patients were divided into two groups according to K10 score: psychological distress group ( score ≥ 20 ) and no psychological distress group ( score < 20 ). Nineteen hard tissue and thirteen soft tissue parameters were traced on cephalograms to characterize the craniomaxillofacial features. Results. There was no significant difference in gender or age distribution between the two groups. Male patients with psychological distress showed statistically significantly larger anterior facial height (AFH) (126.62 mm vs. 120.97 mm), upper lip length (25.11 mm vs. 23.26 mm), and smaller overbite (1.21 mm vs. 2.75 mm) than patients without psychological distress. Male patients with hyperdivergent pattern and open bite were more likely to have psychological distress. None of the parameters showed statistical differences across groups in females. Frankfort-mandibular plane angle ( r = 0.235 ), Bjork’s sum ( r = 0.311 ), AFH ( r = 0.322 ), overbite ( r = − 0.238 ), AFH/posterior facial height ( r = 0.251 ), and upper anterior facial height (UAFH)/lower anterior facial height (LAFH) ( r = − 0.230 ) were correlated with K10 score in males. After adjusting gender and age, the AFH ( B = 0.147 ) and UAFH/LAFH ( B = − 14.923 ) were significantly related with the K10 score. Conclusion. Psychological distress was mainly correlated with hyperdivergent pattern, open bite, and larger lower anterior facial height proportion in pretreatment orthodontic patients. Orthodontists should be aware of the possible underlying psychological distress in patients with specific craniomaxillofacial features. Clinical assessment of psychological distress may need to take into account gender differences in patients.

Purpose This study aims to explore the association of pressure pain thresholds (PPTs) with age, gender, and pain in patients with temporomandibular disorders (TMD). Patients and Methods A total of 301 TMD patients (248 female and 53 male) were recruited and classified into the high and low age groups according to their median age of 26 years. Patients’ demographics, pain-related variables, TMD-related variables, and PPTs of both left and right temporomandibular joints (TMJs), masseter, and temporalis were collected. Results Pain duration and visual analog scale of pain (VAS) showed no significant correlations with PPTs ( P >0.05). Multiple linear regression analysis revealed a significant positive association of PPTs of all six sites with males (β=0.41–0.72 kg·cm −2 , 95% CI (0.19–0.38, 0.74–0.99), P <0.001), as well as with the high age group [β=0.28–0.36 kg·cm −2 , 95% CI (0.07–0.20, 0.47–0.53), P <0.020]. Furthermore, PPTs of the left TMJ showed a significant negative association with left pain-related TMD (PT) [β=−0.21 kg·cm −2 , 95% CI (−0.38, −0.04), P =0.026], but PPTs of the remaining sites did not show a significant association with PT ( P >0.05). Stratified analysis showed that PPTs in females were associated with the high age group [β=0.25–0.37 kg·cm −2 , 95% CI (0.04–0.20, 0.45–0.56), P <0.020] and that PPT of the left TMJ was associated with left PT [β=−0.21 kg·cm −2 , 95% CI (−0.39, −0.03), P =0.043]. The remaining PPTs did not show a significant association with PT ( P >0.05). In males, PPTs did not show significant correlations with age, PT and VAS ( P >0.05). Conclusion PPTs in the orofacial region are associated with gender and age in TMD patients. Pain duration and intensity show no significant correlations with PPTs in TMD patients. Researchers and dentists should take age and gender into account when using PPTs as auxiliary diagnostic indicators for PT.