Analysis of changes and correlation in condyle-fossa relationship after maxillary skeletal expansion.

OBJECTIVE: To investigate the changes in condyle-glenoid fossa relationship after maxillary skeletal expansion (MSE) and to verify the correlation between the condyle positional changes and expansion effect. METHODS: In this study, 20 patients (mean age 21.1 ± 5.7 years, 8 male, 12 female) with maxillary transverse deficiency (MTD) were treated with the MSE appliance, which contained molar bands and a expander with four micro-implants. The CBCT images were taken before expansion (T0), after expansion (T1) and after 6 months of maintenance (T2). The posterior TMJ space (PS), superior TMJ space (SS), anterior TMJ space, coronal lateral TMJ space (CLS), coronal medial TMJ space (CMS), condyle axis angle, maxillary basal bone width (BWM), inter-molars width, nasal bone width, molar inclination and molar palatal cusp height (U6H) were measured using Dolphin Imaging. RESULTS: At T1, compared with T0, the PS and SS significantly increased by 0.41 mm (P = .008) and 0.3 mm (P = .007). But only the SS significantly increased by 0.21 mm (P = .025) at T2. There was a significant difference of 0.37 mm (left-right, P = .014) between the left and right SS at T0, but no significant difference at T1 and T2. The increased BMW showed weak positive correlations with the change of PS (P = .015) and CMS (P = .031), and the decreased U6H showed weak negative correlations with the change of PS (P = .015) and CLS (P = .031) at T1. CONCLUSIONS: The use of MSE led to an increase in the SS and PS, which were weakly correlated with BWM and U6H. But this effect in the TMJ space gradually diminished after 6 months of maintenance, and the symmetry of the condyle-fossa relationship was preserved.

Ultrasound-guided arthrocentesis for condylar head fracture: a technical report.

OBJECTIVES: Double puncture arthrocentesis (DPA) of the temporomandibular joint (TMD) is considered an effective preservative option for managing mandibular condylar head fractures. However, the procedure is commonly performed by a traditional "blind" method using anatomical characteristics. In the present study, an ultrasonography (US) device was applied for the treatment of a case with a fractured mandibular condyle. METHODS: A 79-year-old female was diagnosed right side condylar head fracture complaining pain of right TMD and reduced mouth opening range: inter-incisor distance of 20 mm. Since the fracture position was high and inoperable, the decision was made to perform DPA of the TMD. The US probe was positioned parallel and slightly oblique to the major axis of the mandibular ramus. Both the posterior and anterior insertions into the joint space were performed according to the axis mentioned above, which enabled the operator to visualize the entirety of the needle. RESULTS: The device offered safety and ensured accuracy by providing real-time visual aid to the surgeon. The procedure provided an early increase in the inter-incisor distance (31 mm) and pain relief. CONCLUSIONS: Hence, for the preservative treatment of mandibular condylar head fractures, based on the present study, we recommend US-guided arthrocentesis as a safe, feasible, and effective therapeutic option instead of the conventional "blind" method.

Age-stratified analysis of temporomandibular joint osteoarthritis using cone-beam computed tomography.

Purpose: This study aimed to evaluate age-stratified radiographic features in temporomandibular joint osteoarthritis using cone-beam computed tomography. Materials and Methods: In total, 210 joints from 183 patients (144 females, 39 males, ranging from 12 to 88 years old with a mean age of 44.75±19.97 years) diagnosed with temporomandibular joint osteoarthritis were stratified by age. Mandibular condyle position and bony changes (flattening, erosion, osteophytes, subchondral sclerosis, and subchondral pseudocysts in both the condyle and articular eminence, thickening of the glenoid fossa, joint space narrowing, and joint loose bodies) were evaluated through cone-beam computed tomography. After adjusting for sex, the association between age groups and radiographic findings was analyzed using both a multiple regression model and a multinomial logistic regression model (α=0.05). Results: The prevalence of joint space narrowing and protruded condyle position in the glenoid fossa significantly increased with age (P<0.05). The risks of bony changes, including osteophytes and subchondral pseudocysts in the condyle; flattening, erosion, osteophyte, and subchondral sclerosis in the articular eminence; joint loose bodies; and thickening of the glenoid fossa, also significantly rose with increasing age (P<0.05). The number of radiographic findings increased with age; in particular, the increase was more pronounced in the temporal bone than in the mandibular condyle (P<0.05). Conclusion: Increasing age was associated with a higher frequency and greater diversity of bony changes in the temporal bone, as well as a protruded condyle position in the glenoid fossa, resulting in noticeable joint space narrowing in temporomandibular joint osteoarthritis.

Investigating the Association between Obstructive Sleep Apnea and Temporomandibular Joint Disorders: A Case-Control Study.

Background: This study aims to explore the connection between obstructive sleep apnea (OSA) and temporomandibular joint disorders (TMD) through a case-control investigation. OSA is a sleep-related breathing disorder that affects breathing during sleep, whereas TMD involves pain and dysfunction in the jaw joint. Understanding any potential association between these two conditions could contribute to improved diagnostic and therapeutic approaches. Materials and Methods: A total of 50 participants were included in both the OSA group and the control group. Participants with diagnosed OSA constituted the OSA group, whereas individuals without OSA formed the control group. TMD symptoms were assessed using standardized diagnostic criteria. Statistical analysis was performed to compare the prevalence of TMD symptoms between the two groups. Results: In the OSA group, 36 out of 50 participants exhibited TMD symptoms, whereas in the control group, 18 out of 50 participants displayed such symptoms. The calculated P value was found to be 0.023, indicating a statistically significant association between OSA and TMD. Conclusion: The findings of this study suggest a notable association between OSA and TMD. Individuals with OSA are more likely to experience TMD symptoms compared to those without OSA. This underscores the importance of considering TMD symptoms in individuals with OSA and vice versa for a comprehensive approach to diagnosis and management.

Surgical vs. Non-Surgical Management of Temporomandibular Joint Disorders: Clinical Outcomes.

Background: Temporomandibular joint disorders (TMDs) encompass a range of clinical conditions affecting the temporomandibular joint (TMJ) and associated structures. Management approaches for TMDs vary and include both surgical and non-surgical interventions. Materials and Methods: In this retrospective cohort study, medical records of 150 patients diagnosed with TMDs were reviewed. Patients were categorized into two groups: surgical intervention and non-surgical intervention. The surgical group underwent various surgical procedures, including arthroscopy, arthroplasty, and joint replacement, while the non-surgical group received conservative treatments such as physical therapy, pharmacotherapy, and occlusal splints. Pain levels, TMJ function, quality of life (QoL), and patient satisfaction were assessed at baseline and post-treatment (6 months and 1 year). Results: At the 6-month follow-up, both groups experienced a significant reduction in pain scores (surgical group: 6.3 ± 1.2 to 2.4 ± 0.9, non-surgical group: 6.1 ± 1.1 to 3.2 ± 1.0). TMJ function improved in both groups (surgical group: 2.5 ± 0.8 to 4.8 ± 0.6, non-surgical group: 2.6 ± 0.7 to 4.2 ± 0.9). QoL scores increased (surgical group: 35.2 ± 4.6 to 50.3 ± 5.1, non-surgical group: 35.5 ± 4.2 to 45.7 ± 4.8), and patient satisfaction rates were high (surgical group: 92%, non-surgical group: 87%) at the 1-year follow-up. Conclusion: Both surgical and non-surgical management approaches demonstrated significant improvements in pain relief, TMJ function, QoL, and patient satisfaction for individuals with TMDs.

Correlations with clinical and radiologic findings and prevalence of osteopenia/osteoporosis in the patients with bilateral temporomandibular joint osteoarthritis.

This study aimed to evaluate the prevalence of osteopenia/osteoporosis in patients with bilateral temporomandibular joint osteoarthritis (TMJ-OA) and its correlations with clinical and radiological findings. A total of 95 patients with bilateral TMJ-OA diagnosed by CBCT were included in the study. Clinical and radiological findings and bone mineral density (BMD) scores were recorded. Descriptive statistics and the Spearman rho correlation tests were performed. Osteopenia/osteoporosis was found in 44 of 95 patients (46.32 %) (30, osteopenia; 14 osteoporosis). Osteopenia/osteoporosis is significantly associated with postmenopausal status and age over 40 years, but it is not associated with clinical and radiological findings of TMJ-OA. Patients with bilateral TMJ-OA have a high prevalence of osteopenia/osteoporosis.

Optimal Depth of Penetration to Access the Superior Joint Space in Temporomandibular Joint Arthroscopy: A Single Institutional Retrospective Study.

Aim: To identify the optimal depth of penetration required to access the superior joint space (SJS) for arthroscopic procedures of the temporomandibular joint (TMJ) among the study population. Materials and Methods: The study included all patients with internal derangement (ID) of the TMJ, managed by TMJ arthroscopy in our institution. The study was conducted with data retrieved from the hospital records over five years (January 2018-April 2022). Demographic factors and depth of penetration (mms) were the variables included in our study. For all the statistical interpretations, p < 0.05 was considered statistically significant. Results: The study included 66 patients (males, n = 25; females, n = 41) who underwent arthroscopic procedures of the TMJ (right = 29, left = 37). The mean duration between the development of symptoms and the point of intervention (TMJ arthroscopy) in our study was 3.94 months. The mean depth of penetration of the arthroscope as measured from the skin to the point of entry into the SJS was 20.60 ± 1.85 mms in males and 19.56 ± 1.38 mms in females (p value < 0.05). Variables such as age, duration of symptoms, side involved and stage of ID did not have any influence on the optimal depth of penetration required to access the joint space among our study population. Conclusion: The optimal depth of penetration (mean) required to access the SJS was less than 25 mms in our study population.

Comparison of Autologous Blood Injection and Dextrose Prolotherapy in the Treatment of Chronic Recurrent Temporomandibular Dislocation: A Randomized Clinical Trial.

Introduction: Prolotherapy is a minimally invasive technique that aims to functionally restore or repair the soft and hard tissues of the TMJ by injecting a stimulant. The present study was conducted to compare the effectiveness of dextrose and autologous blood injection (ABI) as prolotherapy agents in the treatment of patients with chronic recurrent TMJ dislocation (CRTD). Materials and Method: Thirty-two patients were divided into two groups-ABI and dextrose (n = 16 each). The superior joint space was located by means of cantho-tragal line and lavage. Delivery of prolotherapy agent was performed by single-needle technique. An elastic bandage was applied for a week and rehabilitation was initiated three weeks after the treatment. Pain level, joint hypermobility, maximal mouth opening, and frequency of dislocations were recorded at various follow-up intervals up to one year post-treatment. Results: No significant difference (p > 0.05) was seen for the values between both groups at all time intervals in the pain level. At the 6-month and annual follow-ups, the mouth opening of the patients treated with ABI was significantly lower (p < 0.01) as compared to those treated with dextrose. The patients treated with ABI therapy exhibited fewer dislocations (p < 0.05) within the following year. Conclusion: Prolotherapy is a relatively noninvasive, safer, and effective treatment modality with a high success rate for patients with CRTD. Both, ABI and dextrose, proved effective in reducing the pain and joint hypermobility associated with CTRDs within a week. ABI proved to be more efficient in reducing the mouth opening and limiting the dislocation of TMJ as compared to dextrose therapy.

The relation between persistent foramen tympanicum and degenerative bone alterations in temporomandibular joint region.

OBJECTIVES: The aim of this study was to evaluate, using cone-beam computed tomography (CBCT), the relationship of persistent foramen tympanicum (PFT) with degenerative changes in the temporomandibular joint (TMJ) and the presence of pneumatized glenoid fossae and articular eminences. METHOD: Two experienced oral and maxillofacial radiologists evaluated 510 CBCT scans, from which 94 patients were divided into two groups: G1-patients with PFT and G2-control group. The location of the PFT, presence, or absence of degenerative TMJ changes and morphology were evaluated. Similarly, all images were evaluated for the presence of pneumatized articular eminence and glenoid fossa. The Chi-square test and Fisher's Exact test were used for the categorical variables. A multinomial logistic regression model was performed for subgroup analysis. To assess the estimation-chance occurrence of TMJ alterations the Odds Ratio analysis was used. RESULTS: Statistically significant results were found for erosion, planning, and subchondral cyst. Regarding TMJ morphology, significant results were found for: round, flat, and others. Moreover, it was possible to observe that patients who had the PFT were approximately 48 times more likely to manifest TMJ alterations and approximately 3 times more likely to manifest articular eminence pneumatization. CONCLUSION: Since individuals who have FTP have a greater chance of having TMJ and PEA changes, it is important for the dental radiologist to be aware of these signs in CBCT scans for a correct diagnosis. TRIAL REGISTRATION NUMBER: CAAE: 34328214.3.0000.0104 (11/30/2014).

Poor condyle position after mandibular reconstruction and a classification system for patients with "VSCU" based on computed tomography: a cross-sectional study with retrospective data collection.

Background: Although the application of vascularized free bone muscle flap to reconstruct the mandible has become a standardized approach for mandible reconstruction, the results of its reconstruction are not always satisfactory. The purpose of this study was to identify the types of mandibular and condylar defects by analyzing the unsatisfactory cases of mandibular reconstruction in clinical practice, and to provide some clinical experience of reconstruction. Methods: Our study retrospectively analyzed 364 patients who underwent mandibular resection and vascularized free bone flap reconstruction of the mandible and temporomandibular joint (TMJ). We innovatively proposed a "VSCU" classification system (V: vertical position, S: sagittal position, C: coronal position, U: condylar resection is not required) by analyzing computed tomography (CT) scans of mandibular branches and TMJs. Results: In all, 221 cases of free iliac muscle flap and 143 cases of fibula muscle flap were included in this study, of which 23 cases had unsatisfactory results after TMJ reconstruction. We classified 23 patients with unsatisfactory mandibular reconstruction according to the "VSCU" classification system. The most common type was U + V + SfC (n=8), followed by V - SfC + U + (n=4), V - s + C + U + (n=3), V - sbcou - (n=3), V - SBC + U + (n=2), V - s + C + U - (n=1). The most common classification was insufficient mandibular rami length, followed by condylar sagittal anteriorization. There was no significant change in the position of condyle on the healthy side during mandibular reconstruction involving condyle. P1 on the affected side was 52.28±4.17 mm before operation and 58.94±5.65 mm after operation, P<0.01; P2 was 12.83±3.49 mm before operation and 24.90±7.15 mm after operation. S2 was 4.54±2.84 mm before operation and 19.10±8.54 mm after operation. A2 was 11.46±3.35 mm before operation and 24.15±8.29 mm after operation. The P values were all less than 0.01, and the differences were statistically significant. Conclusions: We propose to use the "VSCU" classification system for accurate 3-dimensional (3D) analysis and positioning, and then obtain accurate models through computer-aided design and manufacturing (CAD/CAM), which can reduce the occurrence of poor reconstruction effect and unreasonable joint position, and is worthy of clinical promotion.

A Three-branch Jointed Feature and Topology Decoder guided by game-theoretic interactions for temporomandibular joint segmentation.

Segmentation of the temporomandibular joint (TMJ) disc and condyle from magnetic resonance imaging (MRI) is a crucial task in TMJ internal derangement research. The automatic segmentation of the disc structure presents challenges due to its intricate and variable shapes, low contrast, and unclear boundaries. Existing TMJ segmentation methods often overlook spatial and channel information in features and neglect overall topological considerations, with few studies exploring the interaction between segmentation and topology preservation. To address these challenges, we propose a Three-Branch Jointed Feature and Topology Decoder (TFTD) for the segmentation of TMJ disc and condyle in MRI. This structure effectively preserves the topological information of the disc structure and enhances features. We introduce a cross-dimensional spatial and channel attention mechanism (SCIA) to enhance features. This mechanism captures spatial, channel, and cross-dimensional information of the decoded features, leading to improved segmentation performance. Moreover, we explore the interaction between topology preservation and segmentation from the perspective of game theory. Based on this interaction, we design the Joint Loss Function (JLF) to fully leverage the features of segmentation, topology preservation, and joint interaction branches. Results on the TMJ MRI dataset demonstrate the superior performance of our TFTD compared to existing methods.

Association between oral health-related quality of life and symptoms of temporomandibular disorder among older adults: A cross-sectional study.

OBJECTIVE: Evaluate the association between oral health-related quality of life (OHRQoL) and self-reported symptoms of TMD. METHODS: Representative samples of older adults (≥60 years) were included (n = 569). Both TMD symptoms and OHRQoL were assessed by Fonseca Anamnestic Index (FAI) and Oral Health Impact Profile-14 (OHIP-14), respectively. Prevalence (those answering "frequently" or "always" in at least one question), severity (total means scores), and extent (number of questions answered as "frequently" or "always") of OHRQoL were estimated. RESULTS: Overall, 33.4% and 9.5% had mild or moderate/severe TMD symptoms. Those with any symptom of TMD had a prevalence ratio (PR) 38% higher for the worst OHRQoL (95% confidence interval [95%CI]:1.04-1.82) compared to those without TMD symptoms. Worst OHRQoL were observed for those with mild (PR:1.35; 95%CI:1.01-1.81) and moderate/severe TMD (PR:1.53; 95%CI:1.04-2.26). Similar results were detected in the severity and extent of OHRQoL. CONCLUSION: Severity TMD was associated with worse ORHQoL.

Ultrasound Guided Vs Non-Guided Prolotherapy for Internal Derangement of Temporomandibular Joint. A Randomized Clinical Trial.

OBJECTIVES: This randomized clinical trial study aims to compare ultrasound-guided versus non-guided Dextrose 10% injections in patients suffering from internal derangement in the temporomandibular joint (TMJ). MATERIAL AND METHODS: The study population included 22 patients and 43 TMJs suffering from unilateral or bilateral TMJ painful clicking, magnetic resonance imaging (MRI) proved disc displacement with reduction (DDWR), refractory to or failed conservative treatment. The patients were divided randomly into two groups (non-guided and ultrasound (US)-guided groups). The procedure involved injection of 2 mL solution of a mixture of 0.75 mL 0.9% normal saline solution, 0.3 mL 2% lidocaine and 0.75 mL dextrose 10% using a 25G needle in the joint and 1 mL intramuscular injection to the masseter muscle at the most tender point. The Visual Analogue Score (VAS) was used to compare joint pain intensity over four different periods, beginning with pre-injection, 1-, 2-, and 6-months postinjection. RESULTS: Twenty-two patients 5 males (n = 5/22, 22.7%) and 17 females (n = 17/22, 77.2%) were included in this study. The mean age was 27.3 ± 7.4 years (30.2 ± 7.0) for the non-guided group and 24.3 ± 6.9 for the US-guided group. The dextrose injection reduced intensity over time in both groups with statistically significant improvement (P value <.05) at 2 and 6 months in both groups. There was no statistically significant difference in VAS assessment between both groups. CONCLUSION: Intra-articular injection of dextrose 10% for patients with painful clicking and DDWR resulted in reduced pain intensity in both US-guided and non-guided groups with significant symptomatic improvement over time in both groups. US guidance allowed accurate anatomical localization and safe procedure with a single joint puncture.

Occurrence of Cervical Spine Pain and Its Intensity in Young People with Temporomandibular Disorders.

Background: The main aim of this cross-sectional study was to compare the occurrence and severity of cervical spine pain in young adults diagnosed with TMDs with a healthy control group (without TMDs). Methods: The study was conducted from June to July 2023. Inclusion criteria were age (18-30 years), cervical spine pain (for at least 1 month), and consent to participate in the study. The study was conducted based on RDC/TMD protocol, an original questionnaire, and a physiotherapeutic examination focused on detecting TMDs. The cervical pain level was assessed using the Visual Analogue Scale (VAS). Thus, a total of 95 subjects were registered for the trials, 51 people (53.7%) constituted the control group (without TMDs), while 44 (46.3%) people constituted the study group (with TMDs). Results: The mean age of people participating in the study was 22.2 ± 2.2 years in the study group and 22.5 ± 3.1 years in the control group. The largest group was people aged 21-25 (n = 51 people, 53.7%). Patients from the study group more often experienced pain in the stomatognathic system during palpation (both in the muscle, joint, and musculoskeletal groups) and had reduced mobility of the temporomandibular joints in every movement (p < 0.001). People from the study group were also characterized by less mobility of the cervical spine (p < 0.05), apart from extension movement (p > 0.05). The analysis showed that of the 95 people participating in the study, 85.4% reported problems in the cervical spine area (n = 81), of which almost all people in the study group struggled with this problem (n = 43, 97.7%). It was found that cervical spine pain was significantly more common in people with TMDs (p < 0.05, chi2 = 10.118, df = 1, rc = 0.31). The level of pain was significantly higher in people from the study group (p < 0.001, chi2 = 45.765, df = 4, rc = 0.57). Conclusions: Our research has shown that the occurrence of cervical spine pain is more common in the group of young people with temporomandibular disorders (TMDs). In young people, this problem is rarely recognized and properly treated.

Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques.

OBJECTIVES: To compare the changes in condylar position after mandibular reconstruction with free fibular flap(FFF) and the differences between computer-assisted techniques and traditional methods on CT images. METHODS: Thirty-four patients who underwent mandibular reconstruction with free fibular flap were selected according to the inclusion and exclusion criteria. In the 3D group, virtual surgical planning (VSP) with osteotomy cutting plate and placement guiding plate were used, while the traditional group underwent freehand reconstruction. The CT data of 68 temporomandibular joints (TMJs) were recorded before and immediately after surgery. The condylar position was evaluated by measuring the anterior space (AS), posterior space (PS) and superior space (SS), and the ln (PS/AS) was calculated according to the method proposed by Pullinger and Hollender. RESULTS: In the patients included in the 3D group, the condyle on the ipsilateral side moved slightly backward; however, in the patients in the traditional group, the ipsilateral side moved considerably anteroinferior. No obvious changes on the contralateral side were noted. In the 3D group, 33% of ipsilateral condyles were in the posterior position postoperatively when compared with the preoperative position (13%). In the traditional group, the number of ipsilateral condyles in the anterior position increased from 4 to 10, accounting for 53% postoperatively. Contrary to the traditional group, the 3D group presented less condylar displacement on the ipsilateral side postoperatively. CONCLUSIONS: This study showed a decreased percentage of change in condylar position postoperatively when VSP was used. Virtual surgical planning improved the accuracy of FFF mandibular reconstruction and made the condylar position more stable.

[Preliminarily study of arthrocentesis combined with liquid phase concentrated growth factor injection in the treatment of unilateral temporomandibular joint osteoarthritis].

OBJECTIVE: To observe the clinical effect of arthrocentesis combined with liquid phase concentrated growth factor (CGF) injection in the treatment of unilateral temporomandibular joint osteoarthritis (TMJOA), in order to provide a new treatment option for TMJOA patients. METHODS: In this non-randomized controlled study, patients diagnosed with unilateral TMJOA who visited the center for temporomandibular joint disorder and orofacial pain of Peking University School and Hospital of Stomatology from June 2021 to January 2023 were selected as research objects. The patients were divided into experimental group and control group, which were selected by patients themselves. The experimental group received arthrocentesis combined with liquid phase CGF injection and the control group received arthrocentesis combined with HA injection. Both groups were treated 3 times, once every two weeks. The clinical effect was evaluated by the maximum mouth opening, pain value and the degree of mandibular function limitation 6 months after treatment. The change of condylar bone was evaluated by cone beam CT (CBCT) image fusion technology before and after treatment. RESULTS: A total of 20 patients were included in the experimental group, including 3 males and 17 females, with an average age of (34.40±8.41) years. A total of 15 patients were included in the control group, including 1 male and 14 females, with an average age of (32.20±12.00) years. There was no statistical difference in general information between the two groups (P > 0.05). There were no statistical differences in the mouth opening, pain value and the degree of jaw function limitation between the two groups before treatment (P > 0.05), and all of them improved 6 months after treatment compared with before treatment (P < 0.05). However, the mouth opening of experimental group was significantly higher than that of control group 6 months after treatment (P < 0.05), and the degree of jaw function limitation was significantly lower than that of control group (P < 0.05). CBCT 2D images showed that the condylar bone of both groups was smoother after treatment than before treatment, and image fusion results showed that 10 patients (50.0%) in the experimental group and 5 patients (33.3%) in the control group had reparative remodeling area of condylar bone, and there was no statistical difference between them (P > 0.05). Except for one CGF patient, the other patients in both groups had some absorption areas of condylar bone. CONCLUSION: The arthrocentesis combined with liquid phase CGF injection can improve the clinical symptoms and signs of unilateral TMJOA patients in short term, and is better than HA in increasing mouth opening and improving jaw function. CBCT fusion images of both patient groups show some cases of condylar bone reparative remodeling and its relevance to treatment plans still requires further study.

Alloplastic TMJ replacement in the skeletally immature patient - A systematic review.

This study assessed the current evidence for the use of TMJR reconstruction in skeletally immature patients. A systematic review was conducted according to PRISMA guidelines. An electronic search in PubMed and Embase was performed. Meta-analysis randomized controlled trials (RCTs), cohort studies, observational studies, case series, and case reports were eligible for inclusion. Case reports were also included due to the limited number of publications identified with the predefined terms. Exclusion criteria were: (1) studies written in a language other than English; (2) full-text unavailability (i.e., posters and conference abstracts). The selected studies were assessed for risk of bias. A meta-analysis was not performed as it necessitates a substantial between-study design homogeneity; hence, a descriptive synthesis of data was performed. There were 9 TMJR device reconstruction studies involving 14 subjects 13 years of age or younger. Follow-up ranged from 7 months to 120 months. All papers reported significant decrease in pain and improvement of diet. All prostheses were functional. No material failures of the prosthesis components were observed. The mandible continued to show limited growth following TMJR and most of the cases required no secondary or revision surgery even when the patient reached skeletal maturity. This systematic review had some limitations. The studies included had a low level of evidence and a high risk of bias. Most of the studies had a small patient sample, and no study had a control group. The literature reviewed supports the use of TMJR devices in the restoration of mandibular function and form in skeletally immature patients.

The influence of COVID-19 on temporo-mandibular disorders.

Temporomandibular disorders are multi-factorial conditions affected by psychological, biomechanical, and neuromuscular factors. Stress and anxiety experienced during the pandemic are capable of influencing and aggravating temporomandibular disorders and orofacial pain. The study aimed to analyze whether the coronavirus infection can directly affect these diseases. All participants were asked to complete the Pain Screener and Patients Health Questionnaire and were assigned to Group I: healthy participants and Group 2: participants with existing complaints. In group II participants filled the questionnaires twice the Temporomandibular Disorders Symptom Questionnaire and Graded Chronic Pain Scale. The first time to self-report the severity of chronic pain before COVID-19 (T1 timeline) and the second time- to self-report the level of pain after COVID-19 infection (T2 timeline). Totally 150 participants were included in the study. In group II the difference between T1 and T2 timeline was significant for the level of average pain (p = 0.022) and highest facial pain (p = 0.043); Difference in level of interference of daily activities (p > 0.05), recreational activities (p > 0.05) and ability to work (p > 0.05) was statistically not significant. Graded chronic pain status was the same "Grade I" for T1 and T2 timeline. There was no statistically significant difference in stress level between group I and II.

Kinematic performance of a novel temporomandibular joint replacement prosthesis under bite-force conditions in dogs and cats.

OBJECTIVE: To evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite forces and mouth opening. ANIMALS: Sixteen cadaver skulls from domestic cats (n = 8) and medium- to large-breed dogs (n = 8). METHODS: Intact TMJs were tested. Following condylectomy and coronoidectomy, the skulls were fitted with a TMJR prosthesis unilaterally and retested. Prosthesis was similarly implanted in the contralateral TMJ in 4 cats and 4 dogs before retesting. Left and right bite motions were evaluated before bite contact to peak bite force (200 N in dogs, 63 N in cats). Mouth opening motion was recorded. Mandibular displacement under load was evaluated in 3 orthogonal planes. Maximal displacement was compared between TMJR groups and native TMJ. Prosthesis-bone motion of the temporal and mandibular components was evaluated during simulated bites and mouth opening. RESULTS: TMJR resulted in joint motion not demonstrably different from the native TMJ, with the ability to fully open and close the mouth and with minimal laterotrusion. The TMJR prosthesis demonstrated similar stability after unilateral and bilateral replacement during bite force and with an open mouth. Mean implant-bone motion during bite simulations for the temporal and mandibular TMJR components was ≤ 60 µm in cats and ≤ 30 µm in dogs. CLINICAL RELEVANCE: A novel TMJR can be implanted and allows normal jaw motion. Joint stability is maintained after TMJR implantation in the TMJ of dogs and cats TMJ that is devoid of muscular support.