The Bulletín of Kanagawa Dental College

Vol. 37 No. 1       MARCH- 2009

ISSN: 0385-1443      UBIC: 65

ABSTRACT

Tooth guidance was studied in 5,146 Japanese subjects with complete dentitions, at ages ranging from 10 years to over 60 years. Casts mounted on a SAM articulator with face bow-transfer offered the possibility of measuring the guidance inclination on both sides of the dentition. The functional points F1 and F2, which represent the starting point and end point of the tooth guidance, were recorded by a 3D-digitizer on the maxillary teeth from the central incisor to the second molar. The inclination of the line connecting F1 to F2 with reference to the axis orbital plane was calculated for each tooth. The inclinations of the occlusal plane connecting the F1 points of all teeth from the central incisor to the first molar, the central incisor to the first premolar, and the second premolar to the second molar were also calculated. The values were compared in different age groups and different occlusion groups; Angle Class I, II, and III relationships. The average occlusal guidance sequentially decreased from the anterior to the posterior teeth. Angles from the first molar to the central incisor ranged from 12.0 to 57.2 degrees in natural teeth. Occlusal guidance indicated that the inclinations of the canine and first premolar teeth gradually decreased with age, while those of the molars increased. The occlusal plane measurements showed that although the anterior occlusal plane was relatively unchanged with age, the posterior occlusal plane continuously and gradually flattened from 33.6 to 17.2. The results confirmed the concept of sequential guidance with canine dominance, although the inclinations of guidance between neighboring teeth decreased with age. Key words: Sequential guidance with canine dominance / Sagittal condylar inclination (SCI) / Guidance inclinations / Natural tooth / Occlusal plane.

| Volver |