Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.
Humans ; Mastication/physiology* ; Temporomandibular Joint/physiology* ; Temporomandibular Joint Disorders/etiology* ; Mandible/physiology*

Pain of the orofacial region is the primary complaint for which patients seek treatment. Of all the orofacial pain conditions, one condition that possess a significant global health problem is temporomandibular disorder (TMD). Patients with TMD typically frequently complaints of pain as a symptom. TMD can occur due to complex interplay between peripheral and central sensitization, endogenous modulatory pathways, and cortical processing. For diagnosis of TMD pain a descriptive history, clinical assessment, and imaging is needed. However, due to the complex nature of pain an additional step is needed to render a definitive TMD diagnosis. In this review we explicate the role of different biomarkers involved in painful TMD. In painful TMD conditions, the role of biomarkers is still elusive. We believe that the identification of biomarkers associated with painful TMD may stimulate researchers and clinician to understand the mechanism underlying the pathogenesis of TMD and help them in developing newer methods for the diagnosis and management of TMD. Therefore, to understand the potential relationship of biomarkers, and painful TMD we categorize the biomarkers as molecular biomarkers, neuroimaging biomarkers and sensory biomarkers. In addition, we will briefly discuss pain genetics and the role of potential microRNA (miRNA) involved in TMD pain.
Biomarkers ; Humans ; MicroRNAs ; Pain/etiology* ; Temporomandibular Joint Disorders/diagnosis*

This article summarized the advances in treatment and research of temporomandibular joint surgery in the last 5 years which was presented in "The 2nd Condyle Fracture and Temporomandibular Joint Ankylosis Symposium". The content includes 5 parts: non-surgical treatment of children condyle fracture and long-term follow-up, the improvement of operative approach for condyle fracture and key techniques, the importance and the method for the simultanesous reduction of disc in condylar fracture treatment, the development of traumatic temporomandibular joint ankylosis similar to hypertrophic non-union and the improved safety and accuracy by applying digital surgery in joint surgery.
Ankylosis ; etiology ; Humans ; Mandibular Condyle ; injuries ; Mandibular Fractures ; complications ; therapy ; Temporomandibular Joint ; surgery ; Temporomandibular Joint Disorders ; etiology

Ankylosis ; etiology ; Humans ; Mandibular Condyle ; injuries ; Mandibular Fractures ; complications ; Temporomandibular Joint Disc ; injuries ; Temporomandibular Joint Disorders ; etiology

Objective: To observe the different imaging manifestations of condylar sclerosis in temporomandibular joint osteoarthrosis and explore the imaging significance of condylar sclerosis. Methods: From January 2018 to December 2020, 50 patients with temporomandibular joint condylar sclerosis were examined by cone-beam CT (CBCT) and underwent spiral CT, MRI and radionuclide bone imaging at the Department of Oral and Maxillofacial Surgery in General Hospital of Chinese PLA. There were 15 males and 35 females aged from 16 to 65 years with age of (42.7±14.5) years. The imaging manifestations of CBCT, spiral CT, MRI and radionuclide bone imaging, joint disc displacement and abnormal bone metabolism of condylar sclerosis were analyzed. And the area of condylar sclerosis was graded according to the image of CBCT. Results: A total of 50 patients were included, including 38 unilateral condylar sclerosis, 12 patients with bilateral condylar sclerosis, the total condylar sclerosis were 66. There was no significant difference between the detection rate of further spiral CT (95.5%, 63/66) and CBCT (100.0%, 66/66) (corrected χ²=1.36,P=0.244). The area of condylar sclerosis was (35.5±4.5) mm², ranged from 1 to 100 mm². In addition, spiral CT showed more clearly condylar sclerosis than CBCT. Sclerosis can occur in all parts of condyle, mainly in the upper middle region (68.2%,45/66) in coronal position and in the upper front region (71.2%,47/66) in sagittal position. Fifty-seven condylar sclerosis were detected by MRI, including 4(4/19) condylar sclerosis less than 4 mm². There was significant difference in the displacement of temporomandibular joint disc between the sclerotic side and the non sclerotic side (χ²=10.09, P=0.006). MRI display the condylar sclerosis showed low signal (56/62), followed by high signal (5/62) and medium signal (1/62). Radionuclide bone imaging showed that 4 of the 38 patients with unilateral condyle sclerosis had symmetrical bone metabolism, 34 had abnormal bone metabolism, and 21 patients had concentrated on the non-sclerotic side. Radionuclide bone imaging showed that 4 of the 38 patients with unilateral condyle sclerosis had symmetrical bone metabolism and 34 had abnormal bone metabolism. Conclusions: Spiral CT is more accurate than CBCT in terms of condyle sclerosis through different imaging analysis, and the detection rate of both is higher than MRI. Most of condylar sclerosis showed different degrees of low signal on MRI. The condylar sclerosis side is usually manifested by abnormal bone metabolism.
Male ; Female ; Humans ; Mandibular Condyle/diagnostic imaging* ; Sclerosis/diagnostic imaging* ; Temporomandibular Joint/diagnostic imaging* ; Temporomandibular Joint Disorders/etiology* ; Temporomandibular Joint Disc/diagnostic imaging* ; Cone-Beam Computed Tomography ; Temporomandibular Joint Dysfunction Syndrome ; Osteoarthritis/etiology* ; Magnetic Resonance Imaging

OBJECTIVETo analyze the relationship between symptoms and signs of temporomandibular disorders (TMD) and the patients' quality of life (QOL).

METHODSA total of 492 TMD patients were included in this study. The clinical examination results were recorded using Fricton index of temporomandibular joint function. "Visual analog scale (VAS) evaluation of QOL disturbance" was designed to quantitate patients' QOL, to evaluate the degree that the patients QOL was affected.

RESULTSChewing, daily life and emotion among all 8 items of QOL were frequently affected by TMD, and joint clicking had the least influence on QOL. Intermittent closed lock had more severe interference with QOL than joint clicking only. Severe and moderate pain or limited mouth opening affected the QOL more severely than mild pain or mild limited mouth opening. The simple linear relationship between Fricton index and patients' QOL was poor (r < 0.4).

CONCLUSIONSPain is the most frequently seen symptom in TMD. TMD could affect patients' QOL, including both physical and social-psychological functions. The results suggest that the patients' QOL as well as TMD symptoms and signs should be considered in the management of TMD.

Adult ; Facial Pain ; etiology ; Female ; Humans ; Male ; Quality of Life ; Temporomandibular Joint Disorders ; complications

Anterior disc displacement is a common subtype seen in temporomandibular disorders (TMD) patients. It may cause mandibular movement disorders, such as clicking of joint, intermittent closed lock, limitation of mouth opening, etc. These disorders may affect the life qualities of patients. Anterior disc displacement may also cause mandibular malformations, especially among adolescents, which may affect the growth of condyle, therefore may have a correlation with mandibular retrusion or mandibular deviation when grown up. This paper going to review the influences of anterior disc displacement on oral mandibular function and morphology and their biological mechanisms.
Adolescent ; Humans ; Mandible ; abnormalities ; pathology ; Mandibular Condyle ; growth & development ; Mandibular Diseases ; etiology ; Movement ; Retrognathia ; etiology ; Temporomandibular Joint Disorders ; etiology ; physiopathology

OBJECTIVETo investigate the temporomandibular joint (TMJ) function of the condylar hyperplasia patients after condylectomy.

METHODSTwelve patients with condylar hyperplasia were included in this study. Before and after condylectomy, they were examined and the Fricton' s Craniomandibular Index (CMI) was calculated to assess the functional disorder of TMJ.

RESULTS(1) The facial asymmetry was improved after condylectomy. The morphological symmetry of the bilateral condyle and ramus was displayed by X-ray examinations. There was new cortex formed on the surface of the operated condyle. (2) The TMJ function was improved in terms of Fricton's DI and CMI, which decreased from 0.131 and 0.066 to 0.042 and 0.021 respectively (P < 0.05).

CONCLUSIONSCondylectomy is an effective method to remedy facial asymmetry and, at the same time, improve the TMJ function of the condylar hyperplasia patients.

Adolescent ; Adult ; Female ; Follow-Up Studies ; Humans ; Hyperostosis ; surgery ; Male ; Mandibular Condyle ; pathology ; surgery ; Orthopedic Procedures ; Temporomandibular Joint ; pathology ; Temporomandibular Joint Disorders ; etiology ; Young Adult

Animals ; Estrogens ; metabolism ; Gene Expression Regulation ; Humans ; Osteoarthritis ; complications ; genetics ; metabolism ; Pain ; etiology ; Pain Measurement ; Temporomandibular Joint ; pathology ; Temporomandibular Joint Disorders ; complications ; genetics ; metabolism ; Wnt Signaling Pathway

Humans ; Orthodontics, Corrective ; adverse effects ; Risk Factors ; Root Resorption ; etiology ; prevention & control ; Temporomandibular Joint Disorders ; etiology ; prevention & control