The relationship between temporomandibular joint mobility and peripheral joint mobility reconsidered

Area of Science:

• Orthopedics
• Oral and Maxillofacial Surgery
• Human Anatomy

Background:

• The temporomandibular joint (TMJ) is crucial for jaw function.
• Understanding TMJ mobility in relation to overall joint mobility is important for diagnosing and treating related disorders.
• Previous research has not fully elucidated the correlations between TMJ mobility and peripheral joint mobility.

Purpose of the Study:

• To investigate the relationship between temporomandibular joint (TMJ) mobility and the mobility of peripheral joints.
• To assess the general characteristics of joint mobility across various body joints.
• To determine the predictive power of peripheral joint mobility, age, and sex on TMJ maximal mouth opening.

Main Methods:

• Eighty-three healthy subjects (55 female, 28 male) without TMJ disorders were recruited.
• Maximal mouth opening (angular displacement of the mandible) was measured.
• Range of motion for passive digit hyperextension, thumb apposition, active elbow and knee hyperextension, active ankle dorsal flexion, and trunk flexion were measured bilaterally where applicable.

Main Results:

• Weak correlations (r < 0.4) were found between maximal mouth opening and mobility of digit five and elbows.
• Multiple regression analysis indicated that peripheral joint mobility, age, and sex explained only 25.9% of the variance in maximal mouth opening.
• Correlations between different peripheral joints were generally weak, except for paired joints, suggesting limited general joint mobility.

Conclusions:

• Temporomandibular joint (TMJ) mobility exhibits a weak association with the mobility of peripheral joints.
• Peripheral joint mobility, age, and sex are poor predictors of individual TMJ maximal mouth opening.
• The general character of joint mobility is weak, indicating that mobility in one joint does not strongly predict mobility in others.