Maximum mandibular mobility in patients with temporomandibular disorders

Area of Science:

• Dentistry
• Orthodontics
• Biomechanics

Background:

• Mandibular mobility assessment is crucial in dental exams.
• Limited data exists on maximum mandibular motion in large temporomandibular disorders (TMD) patient groups.

Purpose of the Study:

• To analyze mandibular mobility data from 500 TMD patients.
• To propose new, lower threshold values for impaired mandibular function.
• To reduce medicalization and overtreatment by adjusting traditional thresholds.

Main Methods:

• Analysis of recorded mandibular motion data from 500 TMD patients.
• Measurements included unassisted jaw opening, protrusion, and lateral movements.
• Data was collected by a single examiner at the University Center for Dental Medicine Basel.

Main Results:

• Average maximal unassisted jaw opening: 49.3 mm.
• Average maximal protrusion: 8.8 mm; lateral movement (right/left): 9.4 mm / 11.8 mm.
• Proposed thresholds for impaired function: interincisal distance < 30 mm; laterotrusion/protrusion < 5 mm.

Conclusions:

• Lowered thresholds for mandibular mobility (interincisal distance < 30 mm, laterotrusion/protrusion < 5 mm) are sufficient for functionally undisturbed movements.
• These revised values account for greater anatomical and functional variability.
• The proposed thresholds aim to prevent overdiagnosis and overtreatment in TMD patients.