The effect of bite plane use on terminal hinge axis location

Area of Science:

• Dental Occlusion
• Temporomandibular Joint (TMJ) Disorders

Background:

• The temporomandibular joint (TMJ) is crucial for mastication and speech.
• TMJ dysfunction can significantly impact a patient's quality of life.
• Accurate determination of the hinge axis is essential for effective occlusal analysis and treatment planning.

Purpose of the Study:

• To investigate the effect of bite plane therapy on hinge axis location in normal subjects and patients with TMJ dysfunction.
• To assess the reproducibility of hinge axis determination with bite plane use in normal subjects.
• To understand the influence of muscular patterns on hinge axis location during occlusal adjustments.

Main Methods:

• Comparison of hinge axis location with and without bite plane use in normal subjects.
• Repeated bite plane use in normal subjects to evaluate reproducibility.
• Analysis of hinge axis changes in patients with TMJ dysfunction following bite plane therapy.

Main Results:

• Normal subjects exhibited a mean hinge axis shift of 1.0 mm anteriorly with bite plane use.
• Hinge axis determination showed good reproducibility in normal subjects (mean change of 0.87 mm).
• TMJ dysfunction patients demonstrated a mean posterior hinge axis shift of 1.46 mm after therapy.

Conclusions:

• Bite plane therapy influences hinge axis location, with different directional changes observed in normal versus TMJ dysfunction groups.
• A relaxed, asymptomatic muscular pattern is critical for accurate occlusal adjustments.
• Inaccurate maxillomandibular skeletal relationships can lead to inherent inaccuracies in occlusal equilibration.