Validity of the examination method of occlusal contact pattern relating tomandibular position

Objective: This study was based on the hypothesis that conflicting findings and inconclusive consensus regarding the role of occlusal factors in the m asticatory system are due to the variations in the definitions and methods used to describe and examine the occlusal factors. The object of this study was to determine whether contact patterns during lateral movement vary wit h mandibular positions and whether the contact pattern in lateral positions close to the maximum intercuspation has characteristics distinct from thos e in an edge-to-edge position. Methods: Occlusal contacts of 86 young adults were examined using shim stoc k in regulated lateral positions: 0.5, 1, 2 and 3 mm from the maximum inter cuspation, where the 0.5, 1 and 2 mm positions were defined as lateral posi tions close to the maximum intercuspation and the 3 mm position as an edge- to-edge position. Results: The occlusal contact pattern in the 0.5 mm position showed a marke d prevalence of posterior tooth contacts on the working and the non-working sides, compared with the 1, 2 and 3 mm positions. The occlusal contact pat tern in the 3 mm position predicted the presence or absence of the occlusal contact in the 1 and 2 mm positions (sensitivity > 0.7) but not in the 0.5 mm position (sensitivity < 0.6). Conclusion: The occlusal contact patterns during lateral movement varied gr eatly with mandibular positions. The examination method of the occlusal con tact pattern in one unregulated position will be invalid. It is necessary t o distinguish the occlusal contact patterns between a position close to the maximum intercuspation and an edge-to-edge position when investigating its role in the masticatory system and in oral disease. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.