Maxillary Incisors Dr. Syed Sadatullah Ibn Sina National College Jeddah

Introduction Maxillary incisors are four in number Maxillary central incisor and lateral are similar in anatomy and complement each other in function Their major function is to cut teeth Maxillary central incisor erupts between the age of 7 and 8 and it is the second permanent tooth to erupt Maxillary lateral incisor erupts between the age of 8 and 9

Maxillary Central Incisor Labial aspect The mesial margin is straight and meets the incisal edge at right angle. The distal margin is shorter and more rounded. The distoincisal angle is more rounded than the mesioincisal angle. The labial surface is marked by two developmental groove and has convexity in cervical third. Maxillary central incisor is the widest anterior tooth mesiodistally

Labial aspect

Lingual aspect The crown profile is same as that of labial surface except that there is a broad depression in the central portion called the lingual fossa and a well developed cingulum. The lingual fossa is bordered by mesial and distal marginal ridges on the sides and the cingulum cervically. The cervical line on labial and lingual surface is convex apically.

Lingual aspect

Mesial aspect From the mesial aspect the labial margin is convex The lingual margin is ‘S’ shaped, being convex near cingulum and concave in the middle Mesial curvature of cervical line (3.5mm) is the most pronounced compared to any other tooth. The cervical line on the mesial and distal surface is convex incisally

Mesial aspect

Distal aspect Distal surface is very similar to the mesial surface. Distal aspect

Incisal aspect The crown and incisal margin are centered over root Crown profile is almost bilaterally symmetrical The incisal margin of newly erupted teeth show three elevations called mamelons. They correspond to the developmental lobes Incisal aspect

Root The root is straight and tapers from the cervical line to the apex giving it a conical shape The root ends in a blunt apex. 3.5 2.5 6.0 7.0 8.5 13.0 10.5 Curvature of Cervical Line M D Labiolingual Diameter at Cervical Line Crest of Curvature Mesiodistal Contact Area Root Length Crown Length Average Dimensions in millimeters

Maxillary Lateral Incisor The general shape is similar to maxillary central incisors except that they are shorter and narrower. Next to third molars maxillary lateral incisors are the teeth that show most variation in crown size, shape and form The mesioincisal and distoincisal angles are more rounded than the corresponding angles of the maxillary central incisor On the lingual aspect the marginal ridges and cingulum are more prominent

Labial aspect Lingual aspect Mesial aspect Distal aspect