Cusp Inclination Research Articles

Requirements of articulators for lateral movements

The effect that the different location of the guides in the articulator has on the cusp inclines of the posterior teeth has been studied by means of special appliances constructed for this purpose.

Mathematical interpretation of mandibular movements

T HE MOVEMENTS OF THE mandible have been recognized for a long time to be multiple. For the successful construction of complete dentures, these mandibular movements must be registered, reproduced, and intelligently applied to obtain harmony of cusp inclines of the artificial posterior teeth and to obtain a free gliding, efficient, and nontraumatizing occlusion of the dentures in their different excursions. A number of years ago, Gysil presented his theory of the centers of rotation. The theory states that the center of rotation for mandibular movements is found by tracing perpendicular lines to the paths of movement. The point where the perpendicular lines meet is the center of rotation and the cusp inclines of the posterior teeth must be perpendicular to radii from this center. This theory was universally accepted and was used as a basis for educational methods, design of articulators, and the design of occlusal surfaces of artificial posterior teeth. I shall introduce a theory that will help to establish a new approach to these problems.

咬合小面の傾斜角度測定装置

The authors deviced a new type of optical Protoractor, an apparatus for measuring the angle of functional cusp inclination. By the ward of functional cusp inclination the authors mean the slope of small surfaces of occlusal wearing, which harmonizes with mandibular movements.This apparatus consists of two parts, an optical system and a special protoractor. Through the semitranslucent mirror a parallel light beam is thrown vertically upon specimen, which is attached on the circular stage of protoractor. By the angulation of maximum reflection of light, the angle of cusp inclination can be determined three dimensionally. Very small area even 1 mm2 can be measured easily and accurately with this apparatus.Average error of measurements is estimated ±0.5° for the angle of inclination and ±2.0° for that of direction.

The relation of cusp inclination to alveolar integrity

The relation of cusp inclination to alveolar integrity