Dental Anatomy: Lecture 3 Introduction

Anatomical landmarks:
In order to study an individual tooth intelligently, we must be able to recognize all landmarks of importance by name. these include:
?(1)Cusp: it is an elevation or mound on the crown portion of a tooth making up a divisional part of the occlusal surface.
?(2)Cingulum {Latin word for girdle}: it is the lingual lobe of an anterior tooth.
?It makes up the bulk of the cervical third of lingual surface. Its convexity mesiodistally resembles a girdle encircling the lingual surface at the cervical third.
?(3)Tubercle: it is a small elevation on some portion of the crown produced by an extra formation of enamel. Tubercles are deviation from the typical form.
?(4)Ridge : it is any linear elevation on the surface of the tooth and is named according to its location (e.g.buccal ridge,incisal ridge,marginal ridge).
?(a)Marginal ridges: these are rounded borders of the enamel that form the mesial and distal margins of the occlusal surfaces of premolars and molars and the mesial and distal margins of the lingual surfaces of the incisors and canines.
?(b)Triangular ridges: these descends from the tips of the cusps of molars and premolars toward the central part of the occlusal surfaces. they are so named because the slopes of each side of the ridge are inclined to resemble two sides of triangle. They are named after the cusps to which they belong, (e.g.the triangular ridge of the buccal cusp of maxillary first premolar).
(c)Transverse ridge: it is the union of two triangular ridges crossing transversely the surface of posterior tooth.
(d)Oblique ridge: it is a ridge crossing obliquely the occlusal surfaces of maxillary molars.it is formed by the union of the triangular ridge of the distobuccal cusp and the distal cusp ridge of the mesiolingual cusp.