Towards clinically applicable automated mandibular canal segmentation on CBCT.

OBJECTIVES: To develop a deep learning-based system for precise, robust, and fully automated segmentation of the mandibular canal on cone beam computed tomography (CBCT) images. METHODS: The system was developed on 536 CBCT scans (training set: 376, validation set: 80, testing set: 80) from one center and validated on an external dataset of 89 CBCT scans from 3 centers. Each scan was annotated using a multi-stage annotation method and refined by oral and maxillofacial radiologists. We proposed a three-step strategy for the mandibular canal segmentation: extraction of the region of interest based on 2D U-Net, global segmentation of the mandibular canal, and segmentation refinement based on 3D U-Net. RESULTS: The system consistently achieved accurate mandibular canal segmentation in the internal set (Dice similarity coefficient [DSC], 0.952; intersection over union [IoU], 0.912; average symmetric surface distance [ASSD], 0.046 mm; 95% Hausdorff distance [HD95], 0.325 mm) and the external set (DSC, 0.960; IoU, 0.924; ASSD, 0.040 mm; HD95, 0.288 mm). CONCLUSIONS: These results demonstrated the potential clinical application of this AI system in facilitating clinical workflows related to mandibular canal localization. CLINICAL SIGNIFICANCE: Accurate delineation of the mandibular canal on CBCT images is critical for implant placement, mandibular third molar extraction, and orthognathic surgery. This AI system enables accurate segmentation across different models, which could contribute to more efficient and precise dental automation systems.

Age distribution of East Asian TMD patients and age-related differences in DC/TMD axis I findings.

OBJECTIVES: The pattern of age distribution in East Asian temporomandibular disorder (TMD) patients and age-related differences in DC/TMD diagnostic subtypes/categories were evaluated. SUBJECTS AND METHODS: TMD patients from two University-based centers in China and South Korea were enrolled. Axis I physical diagnoses were rendered according to DC/TMD. Patients were categorized into six age groups (15-24, 25-34, 35-44, 45-54, 55-64, and 65-84 years; Groups A-F respectively). RESULTS: Youths/young adults (Groups A-C) formed 74.1% of TMD patients. TMJ disc displacements (74.9%), arthralgia (49.2%), and degenerative joint disease [DJD] (36.8%) were the most common TMD subtypes. The majority had combined (54.0%) and chronic (58.5%) TMDs. Youths/young adults and middle-aged/old adults had substantially lower frequencies of merely pain-related (6.2-14.5%) and intra-articular (13.8-16.8%) TMDs correspondingly. "Being female" increased the prospects of pain-related/combined TMDs by 96%/49%, respectively. CONCLUSIONS: East Asian TMD patients comprised mostly of youths/young adults who had an alarmingly high prevalence of TMJ DJD.

DC/TMD axis I subtyping: generational and gender variations among East Asian TMD patients.

OBJECTIVES: This study examined the generational-gender distinctions in Diagnostic Criteria for Temporomandibular disorders (DC/TMD) subtypes among East Asian patients. METHODS: Consecutive "first-visit" TMD patients presenting at two university-based TMD/orofacial pain clinics in China and South Korea were enlisted. Demographic information along with symptom history was gathered and clinical examinations were performed according to the DC/TMD methodology. Axis I physical diagnoses were rendered with the DC/TMD algorithms and categorized into painful and non-painful TMDs. Patients were categorized into three birth cohorts, specifically Gen X, Y, and Z (born 1965-1980, 1981-1999, and 2000-2012 respectively) and the two genders. Data were evaluated using Chi-square/Kruskal-Wallis plus post-hoc tests and logistic regression analyses (α = 0.05). RESULTS: Gen X, Y, and Z formed 17.2%, 62.1%, and 20.7% of the 1717 eligible patients examined (mean age 29.7 ± 10.6 years; 75.7% women). Significant differences in prevalences of arthralgia, myalgia, headache (Gen X ≥ Y > Z), and disc displacements (Gen Z > Y > X) were observed among the three generations. Gen Z had substantially fewer pain-related and more intra-articular conditions than the other generations. Women presented a significantly greater frequency of degenerative joint disease and number of intra-articular conditions than men. After controlling for generation-gender interactions, multivariate analyses showed that "being Gen X" and female increased the risk of painful TMDs (OR = 2.20) and reduced the odds of non-painful TMDs (OR = 0.46). CONCLUSIONS: Generational-gender diversities in DC/TMD subtypes exist and are important for guiding TMD care and future research endeavors.

Comparison of painful temporomandibular disorders, psychological characteristics, sleep quality, and oral health-related quality of life of patients seeking care before and during the Covid-19 pandemic.

BACKGROUND: Literature concerning Temporomandibular disorders (TMDs) and the Covid-19 pandemic is limited and disparate findings related to TMD frequencies, psychological distress, and quality of life were presented. This study investigated the prevalence of painful Temporomandibular disorders (TMDs) and compared the psychological, sleep, and oral health-related quality of life profiles of patients seeking TMD care before and during the Covid-19 pandemic. METHODS: Data were accrued from consecutive adult patients 12 months before (BC; control) and during (DC; case group) the Covid-19 pandemic. The Diagnostic Criteria for TMDs (DC/TMD), Depression, Anxiety, Stress Scales (DASS)-21, Pittsburgh Sleep Quality Index (PSQI), and Oral Health Impact Profile (OHIP)-TMDs were utilized and statistical analysis was performed using Chi-square/non-parametric tests (α = 0.05). RESULTS: The prevalence of painful TMDs was 50.8% before and 46.3% during the pandemic. Significant differences in PSQI and OHIP component scores were discerned between the BC and DC groups contingent on TMD pain. Total-DASS was moderately correlated to total-PSQI/OHIP (rs = 0.41-0.63). CONCLUSION: The covid-19 pandemic did not appear to exacerbate psychological distress but affected sleep and increased unease over TMD dysfunction.

Descending serotonergic modulation from rostral ventromedial medulla to spinal trigeminal nucleus is involved in experimental occlusal interference-induced chronic orofacial hyperalgesia.

BACKGROUND: Dental treatment associated with unadaptable occlusal alteration can cause chronic primary myofascial orofacial pain. The serotonin (5-HT) pathway from the rostral ventromedial medulla (RVM) exerts descending modulation on nociceptive transmission in the spinal trigeminal nucleus (Sp5) and facilitates chronic pain. The aim of this study was to investigate whether descending 5-HT modulation from the RVM to the Sp5 is involved in the maintenance of primary myofascial orofacial hyperalgesia after persistent experimental occlusal interference (PEOI) or after delayed removal of experimental occlusal interference (REOI). METHODS: Expressions of 5-HT3A and 5-HT3B receptor subtypes in the Sp5 were assessed by immunofluorescence staining and Western blotting. The release and metabolism of 5-HT in the Sp5 were measured by high-performance liquid chromatography. Changes in the pain behavior of these rats were examined after specific pharmacologic antagonism of the 5-HT3 receptor, chemogenetic manipulation of the RVM 5-HT neurons, or selective down-regulation of 5-HT synthesis in the RVM. RESULTS: Upregulation of the 5-HT3B receptor subtype in the Sp5 was found in REOI and PEOI rats. The concentration of 5-HT in Sp5 increased significantly only in REOI rats. Intrathecal administration of Y-25130 (a selective 5-HT3 receptor antagonist) dose-dependently reversed the hyperalgesia in REOI rats but only transiently reversed the hyperalgesia in PEOI rats. Chemogenetic inhibition of the RVM 5-HT neurons reversed the hyperalgesia in REOI rats; selective down-regulation of 5-HT in advance also prevented the development of hyperalgesia in REOI rats; the above two manipulations did not affect the hyperalgesia in PEOI rats. However, chemogenetic activation of the RVM 5-HT neurons exacerbated the hyperalgesia both in REOI and PEOI rats. CONCLUSIONS: These results provide several lines of evidence that the descending pathway from 5-HT neurons in the RVM to 5-HT3 receptors in the Sp5, plays an important role in facilitating the maintained orofacial hyperalgesia after delayed EOI removal, but has a limited role in that after persistent EOI.

TMJ degenerative joint disease: relationships between CBCT findings, clinical symptoms, and signs.

OBJECTIVES: The relationships between cone-beam computed tomography (CBCT) findings, Temporomandibular disorder (TMD) symptoms, and signs were investigated in patients with TMJ degenerative joint disease (DJD). MATERIAL AND METHODS: Adult patients with Diagnostic Criteria for TMDs (DC/TMD)-defined intra-articular conditions were enrolled and subjected to CBCT assessment. The participants were organized into three groups, namely no (NT), early (ET), and late (LT) TMJ DJD based on radiographic findings. TMD symptoms/signs were appraised using the DC/TMD methodology. Statistical analyses were performed using Chi-square/non-parametric tests and Kappa statistics (α = 0.05). RESULTS: The mean age of the participants (n = 877) was 30.60 ± 11.50 years (86.6% women). NT, ET, and LT were observed in 39.7%, 17.0%, and 43.3% of the study sample. Significant differences in the prevalence of TMD symptoms (TMD pain, TMJ sounds, opening, and closing difficulty) and signs (TMD/TMJ pain, TMJ clicking/crepitus, and opening limitation) were discerned among the three groups (p ≤ .001). TMD/TMJ pain and opening difficulty/limitation were more prevalent in early rather than late degenerative changes. While moderate agreements between symptoms and signs were observed for TMD pain/opening limitation, the concurrence for TMJ sounds was fair. CONCLUSIONS: Young adults with TMJ sounds and pain should be examined with CBCT to establish the extent/progress of osseous changes.

The influence of the COVID-19 pandemic, sex, and age on temporomandibular disorders subtypes in East Asian patients: a retrospective observational study.

BACKGROUND: Despite its major existential, societal, and health impacts, research concerning the COVID-19 pandemic and Temporomandibular disorders (TMDs) is still limited. This study examined the effect of the pandemic on TMD subtypes and elucidated the influence of the pandemic, sex, and age on the prospect of pain-related (PT) and/or intra-articular (IT) TMDs in East Asian patients. METHODS: Data were accrued from consecutive new patients attending two university-based TMD/orofacial pain clinics in China and South Korea, 12 months before (BC; Mar 2019-Feb 2020) and during (DC; Mar 2020-Feb 2021) the COVID-19 pandemic. TMD diagnoses were derived from pertinent symptoms, signs, and radiographic findings according to the Diagnostic Criteria for TMDs (DC/TMD) methodology. Patients were subsequently categorized into those with PT, IT, and combined TMDs (CT) and also stratified by attendance period, sex, and age groups (adolescents/young adults [AY] and middle-aged/older adults [MO]) for statistical analyses using Chi-square/Mann-Whitney U tests and logistic regression analyses (α = 0.05). RESULTS: The BC and DC groups comprised 367 (75.2% females; 82.8% AY) and 471 (74.3% females; 78.3% AY) patients correspondingly. No significant differences in sex and age group distributions were observed. The DC group had significantly more PT/IT conditions with higher prevalence of myalgia, headache, and degenerative joint disease than the BC group. Univariate analyses showed that PT/CT was associated with sex and age, whereas IT was related to the pandemic and age. However, multivariate analyses indicated that the odds of PT were affected by sex (OR = 2.52) and age (OR = 1.04) while the odds of IT (OR = 0.95) and CT (OR = 1.02) were influenced by age only. CONCLUSIONS: The COVID-19 pandemic, as an impact event, did not influence the prospect of PT and/or IT. Sex and age appeared to play more crucial roles in the development of PT and IT/CT respectively.

Rasch validation of the oral health impact profile for temporomandibular disorders.

OBJECTIVES: This study examined the metric properties of the Oral Health Impact Profile for Temporomandibular Disorders (OHIP-TMD) using Factor/Rasch analyses and created a short-form version of the measure. SUBJECTS AND METHODS: Aggregated OHIP-TMD data were obtained from a cross-sectional study involving 844 TMD patients with diagnostic criteria for TMDs defined conditions. The dimensionality of the OHIP-TMD was first evaluated with exploratory factor analysis. An eigenvalue >1.0 and oblique oblimin rotation were applied for extracting the factors. Rasch analysis was subsequently performed on the primary dimension using the ConQuest software. RESULTS: Multi-dimensionality of the OHIP-TMD was observed with the primary dimension comprising ten items. Adequate fit to the Rasch model was noted after deleting item 8 with infit/outfit mean-square values ranging from 0.75 to 1.40 logits. Item difficulty ranged from -0.75 to 1.05 logits, while participants' ability to respond varied from -4.55 to 5.19 logits. The respondent spread was slightly skewed and satisfactory item-response targeting was present. CONCLUSIONS: The 22-item OHIP-TMD demonstrated multi-dimensionality with the primary dimension consisting of nine reliable items with adequate fit to the Rasch model. The 9-item short-form version of the OHIP-TMD (SOHIP-TMD) is a promising tool for evaluating OHRQoL.

Increased joint loading induces subchondral bone loss of the temporomandibular joint via the RANTES-CCRs-Akt2 axis.

Early-stage temporomandibular joint osteoarthritis (TMJOA) is characterized by excessive subchondral bone loss. Emerging evidence suggests that TMJ disc displacement is involved, but the pathogenic mechanism remains unclear. Here, we established a rat model of TMJOA that simulated disc displacement with a capacitance-based force-sensing system to directly measure articular surface pressure in vivo. Micro-CT, histological staining, immunofluorescence staining, IHC staining, and Western blot were used to assess pathological changes and underlying mechanisms of TMJOA in the rat model in vivo as well as in RAW264.7 cells in vitro. We found that disc displacement led to significantly higher pressure on the articular surface, which caused rapid subchondral bone loss via activation of the RANTES-chemokine receptors-Akt2 (RANTES-CCRs-Akt2) axis. Inhibition of RANTES or Akt2 attenuated subchondral bone loss and resulted in improved subchondral bone microstructure. Cytological studies substantiated that RANTES regulated osteoclast formation by binding to its receptor CCRs and activating the Akt2 pathway. The clinical evidence further supported that RANTES was a potential biomarker for predicting subchondral bone loss in early-stage TMJOA. Taken together, this study demonstrates important functions of the RANTES-CCRs-Akt2 axis in the regulation of subchondral bone remodeling and provides further knowledge of how disc displacement causes TMJOA.

Degenerative temporomandibular joint diseases and their relation with sleep and emotional disturbance.

OBJECTIVE: The relation of degenerative temporomandibular joint (TMJ) diseases (DJDs) with sleep and emotional disturbance were investigated. METHODS: CBCT examination of patients (n = 358) with DC/TMD-defined intra-articular temporomandibular disorders was performed and stratified into NN: no DJD and no arthralgia; NA: no DJD with arthralgia; TO: osteoarthrosis; and TR: osteoarthritis. Sleep and emotional disturbance were assessed with the Pittsburgh Sleep Quality Index (PSQI) and Depression Anxiety Stress Scale-21 (DASS-21). Data were evaluated using non-parametric and multivariate logistic regression analyses (α = 0.05). RESULTS: Distributions of NN, NA, TO, and TR groups were 23.2%, 27.1%,19.0%, and 30.7%, respectively. No significant differences in total-PSQI/DASS scores were detected among the four groups. The presence of pain and stress predicted poor quality sleep with odds ratios of 10.75 and 1.07, accordingly. CONCLUSION: Sleep quality was affected more by arthralgia and stress than the presence of TMJ DJDs.

Viability of the quintessential 5 temporomandibular disorder symptoms as a TMD screener.

OBJECTIVE: This study explored the viability of using the 5 temporomandibular disorder (TMD) symptoms (5Ts) of the Diagnostic Criteria for TMDs (DC/TMD) as a TMD screener. STUDY DESIGN: A total of 1039 adults (≥18 years old) with a mean age of 32.65 ± 12.95 years (77.4% women) from a tertiary dental hospital were enrolled. The 5Ts questionnaire (involving items on TMD/facial pain, headaches, temporomandibular joint noises, and closed- and open-locking) was administered, and TMD diagnoses were derived through clinical interviews and examinations, radiographic investigations, and the DC/TMD diagnostic algorithms and diagnostic tree. Diagnostic accuracy of the 5Ts was assessed using the area under the receiver operating characteristics curve and various measures, including sensitivity, specificity, predictive values, and likelihood ratios. RESULTS: Among the participants, 80.2% (n = 833) were 5Ts-positive, and 19.8% (n = 206) were 5Ts-negative, whereas 51.3% and 85.7% received at least 1 pain-related and intra-articular DC/TMD diagnosis, respectively. The 5Ts showed high accuracy for detecting all TMDs, pain-related and intra-articular, with area under the receiver operating characteristics curves of 0.98, 1.00, and 0.98, respectively. Sensitivity ranged from 96.1% to 99.2%, whereas specificity was 100.0%. CONCLUSIONS: The 5Ts demonstrated high diagnostic accuracy for identifying pain-related and/or intra-articular disorders.

CXCR3 signalling partially contributes to the pathogenesis of neuropathic pain in male rodents.

BACKGROUND: Currently, there is a lack of effective therapy for chronic pain. Increasing evidence has shown that chemokines and their correlative receptors involved in the neuron-glial cell cross-talk could contribute to the pathogenesis of neuropathic pain. Our previous studies suggested that CXCR3 expression was elevated in the spinal dorsal horn after nerve injury. OBJECTIVES: In this study, we aimed to explore the role of CXCR3 signalling in chronic pain modulation. METHODS: Reverse transcription quantitative PCR and Western blotting were used to measure the expression of CXCR3 and its ligands in the spinal cord following chronic constriction injury (CCI) of the sciatic nerve. Cxcr3 -knockout mice were used to observe the effect of the receptor on pain-related behaviour and microglial activation. Immunohistochemistry was used to investigate the expression of two activation markers for spinal microglia, Iba-1 and phosphorylated-p38 (p-p38) in these mice. RESULTS: The expression of CXCR3 and its ligand CXCL11 was upregulated in the lumbar dorsal horn of the spinal cord in CCI models. In Cxcr3 -knockout mice, CCI-induced tactile allodynia and thermal hyperalgesia were observed to be alleviated during the early stage of pain processing. Meanwhile, the expression of the glial activation markers, namely, Iba-1 and p-p38, was decreased. CONCLUSION: Our results demonstrate that CXCR3 could be a key modulator involved in pain modulation of the spinal cord; therefore, CXCR3-related signalling pathways could be potential targets for the treatment of intractable pathological pain.

Deep learning-based evaluation of the relationship between mandibular third molar and mandibular canal on CBCT.

OBJECTIVES: The objective of our study was to develop and validate a deep learning approach based on convolutional neural networks (CNNs) for automatic detection of the mandibular third molar (M3) and the mandibular canal (MC) and evaluation of the relationship between them on CBCT. MATERIALS AND METHODS: A dataset of 254 CBCT scans with annotations by radiologists was used for the training, the validation, and the test. The proposed approach consisted of two modules: (1) detection and pixel-wise segmentation of M3 and MC based on U-Nets; (2) M3-MC relation classification based on ResNet-34. The performances were evaluated with the test set. The classification performance of our approach was compared with two residents in oral and maxillofacial radiology. RESULTS: For segmentation performance, the M3 had a mean Dice similarity coefficient (mDSC) of 0.9730 and a mean intersection over union (mIoU) of 0.9606; the MC had a mDSC of 0.9248 and a mIoU of 0.9003. The classification models achieved a mean sensitivity of 90.2%, a mean specificity of 95.0%, and a mean accuracy of 93.3%, which was on par with the residents. CONCLUSIONS: Our approach based on CNNs demonstrated an encouraging performance for the automatic detection and evaluation of the M3 and MC on CBCT. Clinical relevance An automated approach based on CNNs for detection and evaluation of M3 and MC on CBCT has been established, which can be utilized to improve diagnostic efficiency and facilitate the precision diagnosis and treatment of M3.

Comparison of psychological states and oral health-related quality of life of patients with differing severity of temporomandibular disorders.

BACKGROUND: Studies on temporomandibular disorder (TMD) severity in patient populations are scarce. OBJECTIVES: This study sought to compare the psychological states and oral health-related quality of life (OHRQoL) among patients with differing TMD severity. METHODS: Adult patients (≥18 years old) with and without (controls) TMDs were recruited from the TMD/oro-facial pain centre and prosthodontics department, respectively. The presence and severity of TMDs were established with the Fonseca Anamnestic Index (FAI), and TMD diagnoses were confirmed with the Diagnostic Criteria for TMDs (DC/TMD). Psychological states and OHRQoL were examined with the Depression, Anxiety, Stress Scales-21 (DASS-21) and Oral Health Impact Profile for TMDs (OHIP-TMD). Data were subjected to chi-square, Kruskal-Wallis/Mann-Whitney U tests and Spearman's correlation (α = .05). RESULTS: A total of 961 participants with a mean age of 32.99 ± 13.14 years (71.19% women) were assessed. Frequencies of the various TMD categories were as follows: no TMD/controls (12.07%), mild TMD (24.56%), moderate TMD (40.37%) and severe TMD (23.00%). The three most common TMD-related symptoms were TMJ noises, mouth opening difficulty and muscle pain. Participants with moderate/severe TMD presented a higher proportion of intra-articular and/or combined disorders. They reported significantly higher levels of depression, anxiety, stress and poorer OHRQoL than their counterparts with no/mild TMD (p < .001). Moderate-to-strong correlations were observed between FAI and DASS-21/OHIP-TMD scores (rs = 0.42-0.72). CONCLUSIONS: Patients with moderate/severe TMD had significantly higher levels of psychological disturbance and poorer OHRQoL. As OHRQoL and psychological states are correlated, psychological well-being must be considered when managing patients with moderate/severe TMDs.

Astrocytes in the rostral ventromedial medulla contribute to the maintenance of oro-facial hyperalgesia induced by late removal of dental occlusal interference.

BACKGROUND: Astrocytes in the rostral ventromedial medulla (RVM) contribute to descending pain modulation, but their role in oro-facial pain induced by persistent experimental dental occlusal interference (PEOI) or following EOI removal (REOI) is unknown. OBJECTIVE: To explore the involvement of RVM astrocytes in PEOI-induced oro-facial hyperalgesia or its maintenance following REOI. METHODS: Male rats were randomly assigned into five groups: sham-EOI, postoperative day 6 and 14 of PEOI (PEOI 6 d and PEOI 14 d), postoperative day 6 following REOI on day 3 (REOI 3 d) and postoperative day 14 following REOI on day 8 (REOI 8 d). The nociceptive head withdrawal threshold (HWT) and activities of RVM ON- or OFF-cells were recorded before and after intra-RVM astrocyte gap junction blocker carbenoxolone (CBX) microinjection. RVM astrocytes were labelled immunohistochemically with glial fibrillary acidic protein (GFAP) and analysed semi-quantitatively. RESULTS: Persistent experimental dental occlusal interference-induced oro-facial hyperalgesia, as reflected in decreased HWTs, was partially inhibited by REOI at day 3 but not at day 8 after EOI placement. Increased GFAP-staining area occurred only in REOI 8 d group in which CBX could inhibit the maintained hyperalgesia; CBX was ineffective in inhibiting hyperalgesia in PEOI 14 d group. OFF-cell activities showed no change, but the spontaneous activity and responses of ON-cells were significantly enhanced that could be suppressed by CBX in REOI 8 d group. CONCLUSION: Rostral ventromedial medulla astrocytes may not participate in PEOI-induced oro-facial hyperalgesia or hyperalgesia inhibition by early REOI but are involved in the maintenance of oro-facial hyperalgesia by late REOI.

Diagnostic accuracy of the short-form Fonseca Anamnestic Index in relation to the Diagnostic Criteria for Temporomandibular Disorders.

STATEMENT OF PROBLEM: Screening for temporomandibular disorders (TMDs) is important in research and clinical practice. The short-form Fonseca Anamnestic Index (SFAI) was recently introduced but had only been validated for muscle disorders. PURPOSE: The purpose of this clinical study was to determine the diagnostic accuracy of the SFAI and its discrete and pooled items in relation to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) benchmark. MATERIAL AND METHODS: A total of 866 consecutive participants with TMDs and 57 TMD-free controls (aged ≥18 years) were recruited. The participants (n=923; mean age 32.8 ±13.3 years; women 79.2%) answered the FAI, and TMD diagnoses were derived based on the DC/TMD protocol and algorithms. The 5-item SFAI, which comprised 2 pain-related and 3 function-related TMD questions, was subsequently acquired and assessed with reference to the DC/TMD diagnoses. The receiver operating characteristics (ROC) was used to verify accuracy (area under the curve [AUC]) and the best cutoff points. Sensitivity, specificity, predictive values, and likelihood ratios were also examined. RESULTS: Pain-related (PT) and intra-articular (IT) TMDs were present in 48.3% (446/923) and 82.7% (763/923) of the participants, respectively. The SFAI demonstrated high accuracy for identifying all TMDs, PT, and IT (AUC of 0.97, 0.99, and 0.97, respectively). The best cutoff points were 12.5 for all TMDs/IT and 17.5 for PT. Sensitivity of the SFAI ranged from 90.7% to 97.5% while specificity varied from 93.0% to 96.5%, with the highest values for PT. As positive predictive values (99.4% to 99.5%) were greater than negative ones (41.7% to 83.3%), the SFAI was better at detecting the presence than the absence of TMDs. With reference to PT, the sensitivity, and specificity of the 2 discrete and pooled pain-related questions (questions 3 and 4), extended from 82.3% to 99.3% and 77.2% to 96.5% respectively. With regard to IT diagnoses, sensitivity and specificity ranged from 56.0% to 98.3% and 86.0% to 98.3% for the 3 discrete and pooled function-related items (questions 1, 2, and 5). CONCLUSIONS: The SFAI presented high degrees of diagnostic accuracy in relation to the DC/TMD and can be used for screening TMDs. SFAI scores between 15 and 50 points should be used to identify the presence of TMDs, with scores ≥20 points specifying possible pain-related TMDs.

Oral health-related quality of life of patients with acute and chronic temporomandibular disorder diagnostic subtypes.

BACKGROUND: Studies have indicated the negative effects of temporomandibular disorders (TMDs) on oral health-related quality of life (OHRQoL). The authors investigated the OHRQoL of patients with acute and chronic TMD subtypes. METHODS: The authors recruited a total of 830 patients. They derived TMD diagnoses using the Diagnostic Criteria for TMDs protocol involving symptom history, physical examination, and diagnostic imaging as indicated. The authors categorized patients into acute (≤ 3 months) or chronic (> 3 months) pain-related TMD (PT), nonpainful intra-articular TMD (IT), and combined TMD (CT) groups. They also gathered sociodemographic information and assessed OHRQoL with the Oral Health Impact Profile (OHIP)-TMDs. The authors evaluated data using 2-way analysis of variance and Bonferroni test and multiple regression analysis. RESULTS: Patients in the chronic PT and CT subgroups had significantly higher mean global OHIP scores than their acute counterparts. The authors observed significant acute-chronic differences in OHIP-TMDs domain scores in 5 and 2 domains for the PT and CT groups, respectively. Patients in the acute IT group had significantly higher functional limitation scores than those in the chronic IT group. The ranking of mean global scores, in descending order was CT, PT, and IT for acute TMDs and PT, CT, and IT for chronic TMDs, with significant differences observed among the 3 TMD subtypes (P < .001). CONCLUSIONS: Both TMD chronicity and subtypes influenced OHRQoL. Painful TMDs (PT and CT) were associated with significantly poorer OHRQoL than nonpainful TMDs. TMD chronicity appeared to affect OHRQoL only for the painful TMD conditions. Future work on the impact of TMDs on OHRQoL should strive to stratify patients by TMD chronicity and subtypes. PRACTICAL IMPLICATIONS: TMD chronicity and subtypes influence the impact of TMDs on OHRQoL. Given that chronic painful TMDs impair quality of life, early biopsychosocial intervention of acute TMD pain is important for minimizing chronification and OHRQoL deterioration.

Functional, physical and psychosocial impact of degenerative temporomandibular joint disease.

OBJECTIVES: This study evaluated the functional, physical and psychosocial impacts of TMJ degenerative joint disease (DJD). The bearing of TMJ osteoarthrosis/osteoarthritis and early/late TMJ DJD on oral health-related quality of life (OHRQoL) were also compared. METHODS: Participants were enrolled from a TMD/oro-facial pain centre. Those diagnosed with intra-articular conditions based on the Diagnostic Criteria for Temporomandibular disorders (DC/TMD) were subjected to CBCT assessment and categorised into four discrete groups: NN-no TMJ DJD and no arthralgia; NA-no TMJ DJD with arthralgia; TO-TMJ osteoarthrosis; and TR-TMJ osteoarthritis. The TO/TR groups were subdivided into early/late TMJ osteoarthrosis (EO/LO) and osteoarthritis (ER/LR). OHRQoL was examined using the OHIP-TMD, and data were appraised with the Kruskal-Wallis/Mann-Whitney U tests (α = 0.05). RESULTS: The study participant (n = 358) had a mean age of 31.85 ± 12.39 years (85.6% women). Frequencies of the TMD groups were as follows: NN-23.2%; NA-27.1%; TO-19.0%; and TR-30.7%. Participants with TR/NA had significantly worse OHRQoL than those with TO/NN. Additionally, participants with ER/LR reported significantly poorer OHRQoL than their counterparts with EO/LO. For all TMD groups and TMJ DJD subgroups, the psychological discomfort domain was generally the most impaired. Differences in global OHIP scores were significant between participants with and without arthralgia (i.e., NA-NN, ER-EO and LR-LO). CONCLUSIONS: The presence of TMJ pain appeared to impair OHRQoL more than the severity of TMJ DJD. As psychological domains were most impacted, psychosocial care should be incorporated when managing patients with painful TMJ DJD.

Lateral Lingual Foramina and Canals in the Mandible: CBCT Evaluation of 506 Patients in North China.

OBJECTIVE: To assess the prevalence, location, diameter, course and anastomosis of the lateral lingual foramina (LLF) and canals (LLCs) in a northern Chinese population using CBCT. METHODS: CBCT images of 506 patients (181 male and 325 female, mean age 21.03 ± 8.11 years) were collected. The prevalence, location, diameter, length, angle and anastomosis of the LLF and LLCs were assessed. The measurement variables were analysed by sex and age. Statistical analysis was performed using SPSS (v. 25, IBM, Armonk, NY, USA). RESULTS: A total of 461 LLF were detected in 307 (60.7%) subjects, 175 (57.0%) of whom had unilateral LLF and 132 (43.0%) of whom had bilateral LLF, with each lateral having one to four LLF. The majority of LLF (375/461, 81.3%) were located below the premolars, particularly the first premolar. The mean diameter of the LLF was 0.58 ± 0.20 mm. The mean vertical distance from the LLF to the inferior border and the alveolar crest was 6.68 ± 1.43 mm and 23.65 ± 2.89 mm, respectively. In total, 197 LLCs were visible in the cancellous bone and evaluated. The mean length of LLCs was 6.26 ± 1.29 mm, and the mean angle of LLCs was 140.64° ± 17.29°. The overwhelming majority (93.4%) of LLCs communicated with the mandibular incisive canal and the rest connected with the mandibular canal. CONCLUSION: The prevalence of LLCs was high in the northern Chinese population. The presence of LLCs is a significant predictor of communication with the mandibular incisive canal.