Maxillary Central Incisor Anatomy PDF

 DENTAL ANATOMY Dr. Hagar Sherif (BDS, MSc, Phd) Lecturer of Oral Biology, Faculty of Dentistry, Alexandria University. “ MORPHOLOGY OF PERMANENT ANTERIOR TEETH ”  ANTERIOR TEETH They are divided into: Incisors...

 DENTAL ANATOMY Dr. Hagar Sherif (BDS, MSc, Phd) Lecturer of Oral Biology, Faculty of Dentistry, Alexandria University. “ MORPHOLOGY OF PERMANENT ANTERIOR TEETH ”  ANTERIOR TEETH They are divided into: Incisors + Canines  INCISORS There are four maxillary incisors and four mandibular incisors. ✓ Two central incisors are centered in the maxilla , one on either side of the median line. ✓ The central incisors are the only neighboring teeth with the mesial surfaces in contact. ✓ Two lateral incisors are distal to the central incisors.  PERMANENT MAXILLARY CENTRAL INCISOR  MAXILLARY CENTRAL INCISOR The maxillary central incisors are larger than the lateral incisors and are the widest mesiodistally of all anterior teeth. A space between the central incisors or other teeth is called “Diastema”.  Chronology: First evidence of calcification. Crown completed. Eruption. Root completed. ❑1st Evidence of Calcification 3 to 4 Months ❑Enamel Completed 4 to 5 Years ❑Eruption 7 to 8 Years ❑Root Completed 10 Years  ALL TEETH HAVE 5 ASPECTS Labial Lingual Mesial Distal Incisal Labial Aspect The Geometric outline of the crown is trapezoidal with the shortest uneven side cervically. This outline is characteristic for all teeth facially and lingually The Crown outline: Labial aspect - Mesial outline is slightly convex. - Distal outline is more convex. - Incisal outline is regular and straight. - In newly erupted teeth, mamelons are seen on the incisal ridge D M - The labial surface is smooth and convex. - It shows developmental lines which divide the surface into 3 parts. (lobes) CONTACT AREAS The mesial contact area is near the incisal edge. The distal contact area is at the junction between incisal and middle thirds. D M  -The mesio-incisal angle is sharp - The disto-incisal angle is rounded. ❖The cervical line is convex root wise. The root: D M - It has a single root. - It is cone shape with blunt apex. Disto- Mesio- - The root is 2-3 mm longer than the incisal incisal crown angle angle Labial aspect Labial Aspect Lingual Aspect The outline is a mirror image of that of the labial - It has the same geometric outline and Lingual aspect outline of the crown. - The crown and root tapers lingually making the lingual surface narrower than the labial. - This convergence to accommodate with the horseshoe shaped of the alveolar process. M D A cross section of the root at the cervix is triangular with rounded angles ; its base at the labial.  The lingual surface shows elevations and a concavity The elevations: 1- The cingulum ( present at cervical 1/3. 2- Mesial and distal Marginal ridges. (MMR and DMR ) M D 3- Incisal ridge. Cingulum ✓ Incisal ridge is present in newly erupted teeth, the MMR DMR incisal edge is created after incisal wear due to forces of mastication.  Lingual Aspect Depression (Concavity): Lingual fossa Below the cingulum and between the ridges is a shallow concavity known as lingual fossa. Triangular or M shaped.  PROXIMAL ASPECTS Mesial Distal  Mesial aspect The Geometric outline of the crown: - Wedge in shape or triangular; the base cervically and the apex incisally. The apex of the root and the incisal ridge are centered on the midline The outline: - The labial outline is convex. - The lingual outline is convex at cervical 1/3 (cingulum). - Then concave at the lingual fossa. - Then slightly convex for the incisal ridge. The labial crest of curvature is at center of cervical third and at the same level on the lingual. The mesial cervical line is concave root wise. The root: It is cone shape with a rounded blunt apex.  Distal aspect There is a little difference between the mesial and distal aspects. -The crown appears thicker. -The cervical line curvature is shallower than mesial ( by 1 mm). M D  Incisal aspect -The dimensions of the crown are greater mesiodistally than labiolingually - The labial surface is broad and flat. - The tooth tapers lingually. - The cingulum makes up the cervical portion of the lingual surface. -The fossa is bordered by the cingulum , 2 well developed mesial and distal marginal ridges and the incisal ridge.  Any Questions ?