Variability of passively recorded centric relation

Area of Science:

• Dental occlusion and biomechanics.
• Temporomandibular joint (TMJ) function.

Background:

• Understanding centric relation is crucial for prosthodontic and orthodontic treatments.
• Accurate determination of centric relation minimizes occlusal discrepancies and TMJ issues.

Purpose of the Study:

• To quantify the range of mandibular positions defining centric relation in individuals without signs of mandibular dysfunction.
• To compare the reliability of different methods for recording centric relation.

Main Methods:

• Five subjects without clinical signs of mandibular dysfunction were included.
• Mandibular positions were recorded using three techniques: chin-point guidance, chin-point guidance with ramus support, and bimanual manipulation.
• The range of mandibular shift was measured mediolaterally and anteroposteriorly.

Main Results:

• Centric relation was found to be a small range of mandibular positions.
• The average range of mandibular shift was 0.302 mm mediolaterally and 0.278 mm anteroposteriorly.
• No significant differences were observed between the three recording techniques.

Conclusions:

• The determined range of centric relation is minimal in healthy individuals.
• The tested techniques for recording centric relation exhibit comparable reliability.
• The methodology is sensitive enough to detect minor biologic variations in mandibular positioning.