Lecture 3 Maxillary Central Incisor 2025 PDF

‫تزول قدما ٍ‬ ‫عبد يوم القيامة‬ ‫قال‪“ :‬ال ُ‬ ‫رسول هللا صلى هللا عليه وسلم َ‬ ‫أن َ‬ ‫َروى َّ‬ ‫حَّت يُسأل عن أرب ٍع عن عُ ُمره فيما أفناهُ وعن جسده فيما أبالهُ وعن علمه‬ ‫ى‬ ‫ماذا عمل فيه وعن ماله من أين ا ْكتسبه...

‫تزول قدما ٍ‬ ‫عبد يوم القيامة‬ ‫قال‪“ :‬ال ُ‬ ‫رسول هللا صلى هللا عليه وسلم َ‬ ‫أن َ‬ ‫َروى َّ‬ ‫حَّت يُسأل عن أرب ٍع عن عُ ُمره فيما أفناهُ وعن جسده فيما أبالهُ وعن علمه‬ ‫ى‬ ‫ماذا عمل فيه وعن ماله من أين ا ْكتسبه وفيما أنفقه “‪(.‬األنبياء ال يسألو َن ه ِ‬ ‫ذه‬ ‫ُ ُ‬ ‫ُ‬ ‫ُ‬ ‫ْ ْ‬ ‫األسئلةَ األربعةَ‪ ،‬يُسألو َن إلظها ِر َشَرفِهم هل بلَّغتم )‪.‬‬  Maxillary Central incisor DR: Eman M. salem Lecturer of oral biology department PUA -The central incisors upper & lower are the only neighboring teeth in the dental arches with mesial surfaces in contact. -The maxillary central incisor is the widest tooth mesiodistally of any of the anterior teeth. Mid line M M D D M D M D  Diastema It is the space between the central incisors Tooth Numbering: Chronology Aspects of maxillary central incisor All teeth have 5 aspects: 1. Labial 2. Lingual 3. Mesial 4. Distal 5. incisal  Labial Surface The Outline Geometrical outline of the crown It is trapezoidal in shape with the shorter of the uneven sides directed cervically. The Mesial outline It is slightly convex, the crest of curvature at the incisal 1/3 near the incisal ridge representing M contact area The mesioincisal angle is sharp. The Distal outline It is more convex, the crest of curvature at the D contact incisal third but in a cervical direction area M contact representing D contact area The distoincisal area angle is rounded. The incisal outline is usually straight and perpendicular to the long axis of the tooth. Root Outline It is cone shaped ends with a blunt apex On the surface There is the cervical outline which is convex root wise Or concave crown wise convex concave Lingual Surface It is the reverse of the labial aspect The tooth converge lingually The tooth converge or taper lingually The lingual surface is narrower than the labial surface. The facial dental arch is larger than the lingual dental arch. Elevations of the lingual surface: Cingulum in cervical 1/3 Mesial & distal marginal ridges Incisal ridge Depressions of the lingual surface: Lingual fossa which is M-Shaped Cingulum Lingual fossa 2 3 4 5  Mesial Surface The Outline Geometrical outline of the crown is wedge shaped or Triangular in shape, with the base of the triangle at the cervix and the apex at the incisal ridge. Mesial Surface -The labial outline: It is convex & the crest of curvature is at the center of the cervical third representing the cervical ridge. -The lingual outline: -The cervical 1/3 is convex & the crest of curvature at the center of the cervical 1/3 representing the cingulum. -Then the outline becomes concave in the other two thirds (lingual fossa) ends with a slight convexity indicating the incisal ridge. The incisal ridge Is on one line with the root apex The root is cone shaped with the labial outline straighter than the lingual outline. The root apex is blunt. the cervical outline which is convex incisally (Its curvature is greater than any other tooth in the mouth). Distal Surface Crown Outline It is the reverse of the mesial aspect The surface anatomy Similar to the mesial aspect but differ in: 1- The crown appear thicker at the incisal 1/3. 2- The cervical line curvature is less than mesial ( by 1 mm).  Mesial Distal  Incisal Aspect -The dimension of the crown is greater mesiodistally than labiolingually. From this aspect the labial outline is flat and broader than the lingual outline as the tooth tapers lingually. -The incisal edge is nearly in the center of this aspect labiolingualy. Incisal Aspect -The fossa is lingual to the incisal edge bordered by well developed mesial and distal marginal ridges. labial labial D M D M cingulum Lingual Lingual Pulp Cavity  Pulp Cavity To study the pulp you have to study the tooth in a longitudinal direction & in cross directional ▪ Pulp Chamber ►Mesio-distal section Trapezoid, wide incisally and narrow cervically. ►3 pulp horns in young teeth corresponding to the mamelons disappeared by age. ►Labio-lingual section Triangular, pointed incisally and wide cervically ▪ Root Canal -Single and straight, tapers apically -Cross Section is Oval