Anatomy of Maxillary incisors PDF

Preview

Summary

anatomy maxillary teeth ...

Description

Anatomy of Maxillary incisors Maxillary Central incisors Function: Shearing or cutting teetj. Major function is to cut and punch the food during mastication buccal surface the vestibular SURFACE of the molars and premolars, which faces the cheek. contact surface proximal surface. distal surface the surface of a tooth that is farthest from the midline of the dental arch, oppos ite to its mesial SURFACE. facial surface vestibular surface. incisal surface the cutting edges of the anterior teeth, the incisors and canines, which come i nto contact with those of theopposite teeth during protrusive occlusion. See also occlusal SU RFACE. labial surface the vestibular SURFACE of the incisors and canines, which faces the lips. lingual surface the surface of a tooth that faces inward toward the tongue and oral cavity, op posite the vestibularSURFACE; called also oral surface. masticatory surface occlusal surface. mesial surface the surface of a tooth that is closest to the midline of the dental arch, opposit e to its distal SURFACE. occlusal surface the surface of the teeth that comes in contact with those of the opposite jaw during OCCLUSION; calledalso masticatory surface. oral surface lingual surface. proximal surface (proximate surface) the area where the mesial SURFACE of one tooth touc hes the distal SURFACE ofanother; called also contact area or surface. vestibular surface the surface of a tooth that is directed outward toward the VESTIBULE OF THEMOUTH, opposite to thelingual SURFACE; see also buccal SURFACE and labial SURFACE. Ca lled also facial surface.

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 grove and has convexity in cervical third

 

Maxillary central incisor is the widest anteriorly tooth mesiodistaly. Cervical line on labial and lingual surface is convex apically

Lingual aspect 

The crown profile is same as labial surface exept the broad depssion in central portion called Lingual Fossa and well developed Cingulum



Lingual fossa is bordered by mesial and distal marginal ridges on the sides, and the cingulum cervically



Cervical line on labial and lingual surface is convex apically

Mesial aspect 

From the mesial aspect the labial margin is convex



The lingual margin is ’S’ shaped, being conmvex near cingulum and concave in the middle.



Mesial curvature of cervial line (3.5) is the ost pronounced compared toa ny other tooth. The cervical line on the mesial and distal surface is convex incissaly.



Distal aspect 

Very similiar to mesial 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 threee elevations called mamelons. They correspond to the development groove.

Root   Crown length

The root is straight and tapers from the cervical linet o the apex giving it a conical shape The root ends in a blunt apex Root lenght

Mesiodistal diameter at contact area

Mesiodistal diameter at Cervical line

Labiolingual diameter at crest of curvatura

Labiolingual diameter at cervical line

Curvature at cervical line M D 3.5

Maxillary Lateral incisors 

General shape is similar to maxillary central incisors exept that they are shorter and narrower



After 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 incisors. On the lingual aspect the marginal ridges and cingulum are more prominent



Mandibular Incisors 

Four in number



Central and lateral are similiar in anatomy and complement each other in function

 

They are smaller than maxillary incisors Central erupts between the age 6-7



Lateral erupts between the age 7-8

Central incisors Labial aspect  Labial surface is very small and inclined towards lingually  Narrowest tooth mesiodistally of all permanent teeths  Bilaterally symmetrical  Central Mandibular Incisors has both mesio and distoincisal angles sharp and at right angles

Lingual aspect  Convage from incisal edge to the cervical line  Shallow lingual fossa  Cingulum is smooth and barely visible  Surface is smooth and shows the least developmental line and groves of all teeths

Mesial aspect  Labial outline is almost straight, except near cervical third, where it is  

convex Lingual margin is ”S” shaped Cervicalline of mesial and distal surface is convex incisally

Distal aspect 

Very similiar to mesial surface



Cervical line less curved

Incisal aspect  This aspect illustrates bilateral symmetry of this tooth  Labiolingual diameter is greater than mesiodistal diameter Root 

Normally single and straight



From labial or lingual view, root is generally symetrical & tapers gradually to a relatively sharp apex



From mesial or distal view, root is much wider & it is slightly convex cervico-apically on both labial & lingual margins Central portions of mesial and distal surfaces is usually flattened, or



concave.

Distinguish between Maxillary and Mandibular central incisors. (Traits) Maxillary Central incisor 1. Crown wider mesiodistaly than labiolingually 2. Lingual fossa pronounces often with lingual pit

Mandibular central incisor

FIGURE 6-1 Maxillary right central incisor Lingual and incisal aspects. The labioincisal edge [LIE (1)] and linguoincisal edge [LIE (2)] border the incisal ridge. CL, Cervical line; C, cingulum; MMR, mesial marginal ridge; LF, lingual fossa; DMR, distal marginal ridge....