The association between chronotype profile and temporomandibular disorders among college students.

BACKGROUND: Temporomandibular joint disorders (TMDs) are common in young adults, and the link between chronotype profile and TMDs is unclear. OBJECTIVE: This study examined TMD prevalence and chronotype distribution and explored the relationship between chronotype and TMDs in young adults. MATERIALS AND METHODS: A total of 663 students from Sichuan University completed questionnaires. Chronotype profiles were assessed using the Morningness-Eveningness Questionnaire, and TMDs were screened using the Fonseca Memory Index. To validate the findings, 68 TMD patients and 136 controls were enrolled. RESULTS: The prevalence of TMDs was 69.7%, with significant differences among chronotype profiles. The intermediate profile was the most common chronotype. Eveningness profile was associated with higher TMDs prevalence and severity. Muscle pain and side movement difficulty scores were higher in eveningness and intermediate profiles. Female gender (OR 2.345; 95% CI 1.668-3.297) was a TMD risk factor, while morningness profile (OR 0.537; 95% CI 0.297-0.970) was protective. Validation with TMD patients and controls supported these findings, showing higher eveningness profile prevalence in the TMD groups. CONCLUSIONS: TMDs have a high prevalence in college students, chronotype profiles shown to be associated with TMDs. Morningness is the protection factor in TMDs and PT, eveningness is a risk factor for IT.

Temporomandibular disorder patients with excessive daytime sleepiness present greater pain intensity and reduced jaw function.

BACKGROUND: Sleep disorders are associated with temporomandibular disorders (TMDs). Limited studies have focused on excessive daytime sleepiness (EDS) and its impact on jaw functions in TMD patients. OBJECTIVE: The aim of the present investigation was to identify the impact of EDS on pain and jaw function in TMD patients. METHODS: A total of 338 TMD patients (50 males and 288 females) was included. The Epworth Sleepiness Scale (ESS) was used to classify patients into EDS group (score ≥ 10) and non-EDS group (score < 10). The Jaw Functional Limitation Scale 8-item (JFLS-8) was used to assess the severity of jaw dysfunction. Pain intensity was evaluated using the Visual Analogue Scale (VAS). Anxiety and depression were evaluated using the Generalised Anxiety Disorder 7-item (GAD-7) and the Patient Health Questionnaire 9-item (PHQ-9). All included patients were diagnosed with pain-related TMD (PT), intra-articular TMD (IT) or combined TMD (CT). RESULTS: Compared with non-EDS patients, EDS patients exhibited more severe jaw dysfunction, greater pain intensity and higher PHQ-9 scores (p < .05). Multivariate analyses showed that EDS (B = 3.69), female gender (B = 3.69), and elevated GAD-7 score (B = 0.73) were significantly associated with an increased score on the JFLS-8 (p < .05). Moreover, bivariate logistic regression analysis indicated a significant relationship between EDS and PT (OR = 2.70, p = .007). CONCLUSION: The presence of EDS was more closely related to PT, but the causal relationship between them needs to be further confirmed. More concern and intervention to alleviate poor sleep quality might be highlighted during the treatment of TMD, especially PT subtype.

Exploring the effect of disc displacement on the risk and severity of condylar erosion in adult temporomandibular disorder patients: A CBCT and MRI study.

OBJECTIVE: The objective of the study was to investigate the relationship between types of disc displacement (DD) diagnosed by magnetic resonance imaging (MRI), and the risk (presence or absence) and severity of condylar erosion (CE) graded using cone-beam computed tomography (CBCT) in adult Temporomandibular disorders (TMD) patients. METHODS: A total of 353 TMD patients (283 females, 70 males) underwent MRI scans to categorise DD as normal (NA), anterior displacement with reduction (ADDR), or anterior displacement without reduction (ADDNR). CE severity was graded on a scale of 0-3 (absence, mild, moderate or severe) using CBCT. To establish the plausibility and cut-off points for CE diagnosis, the severity of CE was then further divided into three classifications: Grade 0 versus 1 + 2 + 3; Grades 0 + 1 versus 2 + 3; Grades 0 + 1 + 2 versus 3. Logistic regression analysis was performed, adjusting for age, gender and joint correlation. RESULTS: ADDNR significantly increased the risk of CE compared with NA (OR = 10.04, 95% CI: [6.41, 15.73]) and showed a significant increase in CE severity across all classifications (ORs = 10.04-18.95). The effects of ADDNR were significant in both genders (p < .001) and had a greater impact in females. ADDR was predominantly associated with mild CE. CONCLUSIONS: ADDNR significantly increased the risk and severity of CE independent of gender when compared to NA, whereas ADDR was mainly associated with mild CE. Slight cortical discontinuity may represent a subclinical diagnosis requiring further investigation.

Low income is associated with impaired jaw function via anxiety and depression in patients with temporomandibular disorders.

OBJECTIVE: The association between jaw function and income in patients with temporomandibular disorders (TMDs) remain unclear. The aim of this study was to explore this association and its relationship with anxiety and depression. SUBJECTS AND METHODS: A total of 451 TMD patients, including 361 males and 90 females, participated in this study. The sociodemographic information of patients and their questionnaires including the Generalised Anxiety Disorder 7-item (GAD-7), Patient Health Questionnaire 9-item (PHQ-9), and Jaw Functional Limitation Scale-8 (JFLS-8) were collected. Patients were divided into the high-income and low-income groups based on a household per capita income of 6000 RMB per month. Multiple regression and mediation analysis were used to explore the association between variables. The bootstrap method was applied to estimate confidence intervals (CIs). RESULTS: Higher JFLS-8 scores were significantly correlated with higher GAD-7 scores (r = 0.361, p < .001), PHQ-9 scores (r = 0.339, p < .001). Females and patients with low income had statistically higher JFLS-8 scores (p < .01, p < .001). Mediation analysis with 10 000 bootstrap simulations revealed a significant direct association between JFLS-8 scores and income (-2.920, 95% CI [-4.757, -1.044], p = .002). A significant indirect association of JFLS-8 scores with income via GAD-7 scores and PHQ-9 scores was also observed (-0.889, 95% CI [-1.728, -0.164], p = .025), accounting for 23.3% of the total association. CONCLUSIONS: Low income is associated with impaired jaw function via anxiety and depression in patients with TMD. Clinicians may need to pay more attention to the psychological status of low-income TMD patients in clinical practice.

Risk estimation of degenerative joint disease in temporomandibular disorder patients with different types of sagittal and coronal disc displacements: MRI and CBCT analysis.

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.

Relationship Between Temporomandibular Joint Effusion, Pain, and Jaw Function Limitation: A 2D and 3D Comparative Study.

Purpose: This study aimed to investigate the relationship between temporomandibular joint (TMJ) effusion and TMJ pain, as well as jaw function limitation in patients via two-dimensional (2D) and three-dimensional (3D) magnetic resonance imaging (MRI) evaluation. Patients and Methods: 121 patients diagnosed with temporomandibular disorder (TMD) were included. TMJ effusion was assessed qualitatively using MRI and quantified with 3D Slicer software, then graded accordingly. In addition, a visual analogue scale (VAS) was employed for pain reporting and an 8-item Jaw Functional Limitations Scale (JFLS-8) was utilized to evaluate jaw function limitation. Statistical analyses were performed appropriately for group comparisons and association determination. A probability of p<0.05 was considered statistically significant. Results: 2D qualitative and 3D quantitative strategies were in high agreement for TMJ effusion grades (κ = 0.766). No significant associations were found between joint effusion and TMJ pain, nor with disc displacement and JLFS-8 scores. Moreover, the binary logistic regression analysis showed significant association between sex and the presence of TMJ effusion, exhibiting an Odds Ratio of 5.168 for females (p = 0.008). Conclusion: 2D qualitative evaluation was as effective as 3D quantitative assessment for TMJ effusion diagnosis. No significant associations were found between TMJ effusion and TMJ pain, disc displacement or jaw function limitation. However, it was suggested that female patients suffering from TMD may be at a risk for TMJ effusion. Further prospective research is needed for validation.

Craniofacial Morphology of Temporomandibular Disorder Patients with Different Disc Positions: Stratifying Features Based on Sex and Sagittal Skeletal Pattern.

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.

Age and Gender, but Not Pain are Associated with Pressure Pain Thresholds in Patients with Temporomandibular Disorders: A Cross-Sectional Study.

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 (ß=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 [ß=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) [ß=-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 [ß=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 [ß=-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.

Enlarged occipital spur and craniofacial morphology: a cephalometric analysis.

OBJECTIVE: This cross-sectional study aimed to investigate the association between the occipital spur length and craniofacial morphology in individuals with occipital spur (OS). METHODS: The study included cephalometric images from 451 individuals (196 females, 255 males, age range was 9-84 years). The spur length and craniofacial characteristics were evaluated using cephalograms. Based on spur length, subjects were divided into two groups: the OS group (N = 209) and the enlarged occipital spur (EOS) group (N = 242). Descriptive statistics, Independent T-test, Mann-Whitney U test, chi-square test, Kruskal-Wallis test, and age- and sex-based stratified analyses were performed. The level of significance was set at p < 0.05. RESULTS: Males had significantly larger spur length than females. Spur length was shorter in individuals under 18 than the groups over 18. After adjusting for gender and age, ramus height, mandibular body length, effective length of maxilla, effective length of mandible, anterior cranial base length, posterior cranial base length, anterior facial height, posterior facial height, facial height index, and lower anterior facial height had statistically significant differences between OS group and EOS group. CONCLUSIONS: Males exhibit greater spur length than females. Patients under 18 had a shorter spur length than adults. Linear craniofacial measurements were found to be greater in subjects with EOS than the individuals with OS. The craniofacial growth and development of an individual might be associated with EOS. The causal relationship between EOS and craniofacial development requires further longitudinal studies.

Do Temporomandibular Disorder Patients with Joint Pain Exhibit Forward Head Posture? A Cephalometric Study.

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.

Do Specific Craniomaxillofacial Features Correlate with Psychological Distress in Adult Pretreatment Orthodontic Patients? A Cephalometric Study.

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.