Dental Anatomy Lec 5 PDF

Course Title: Dental Anatomy I Course Code: BDS021 Topic of Lecture : - Permanent Incisors (Permanent Maxillary Central Incisor) Lecturer: Dr. Tamer Abdelhady Badawy Edited by: Dr. Reham Atef Post : Lecturer P r o...

Course Title: Dental Anatomy I Course Code: BDS021 Topic of Lecture : - Permanent Incisors (Permanent Maxillary Central Incisor) Lecturer: Dr. Tamer Abdelhady Badawy Edited by: Dr. Reham Atef Post : Lecturer P r o g r a m o F D e n t i s t r y T h e F u t u r e S t a r t s H e r e F A L L 2 0 2 4 - 2 0 2 5 Dental Anatomy 1 Lecture 5 Surface Anatomy of Permanent Teeth  Surface Anatomy of Permanent Teeth I, for incisor C, for canine I P, for premolar C P M, for molar M I M P  Incisors There are four Maxillary Incisors and four Mandibular Incisors. - Two central incisors contact with each other in the midline (mesially) and with the lateral incisors (distally). - Two lateral incisors contact with the central incisor mesially and with the canine distally.  Functions 1- Mastication (Incising for incisors and tearing for canine) 2-Esthetic appearance 3- Speaking 4- Growth of the jaws. (The eruption of the teeth is accompanied by alveolar bone formation)  Number of lobes: All anterior teeth (incisors and canines) formed of four lobes, three labially and one lingually. 4 4 1 2 3 1 2 3 3 Labial Lobes 1 Lingual Lobe  Chronology of Permanent Incisors Enamel organ appearance. 5 m.i.u (5 Months Intrauterine Life) Beginning of calcification. 3 – 4 m. except 2 10 – 12 m  Crown completed. 3-4 y Eruption (Crown + Cervical 1/3 of the root). 6–8 y Root completed. 10 – 11 y  Beginning of Crown Eruption Root calc. completed completed (month) (Years) (Years) (Years) 1 3-4 7 1 6 2 10-12 8 2 3-4 7 Dates of Eruption of permanent incisors in years. 7Y 8Y 1 2 Note: Lower teeth erupts before 1 2 Upper opposing teeth. 6Y 7Y  For easy teeth description We have to speak about : Geometric outlines of the teeth crowns are either Geometric outline of the crown. Trapezoid Triangle Rhomboid Outlines of the crown and root. Convex Concave Surface anatomy of the crown and root (anatomical landmarks).  All teeth have 5 aspects 1 D M M D Lab Ling Ling Lab Labial Lingual Mesial Distal Lab Width= mesiodistal dimension Thickness= labiolingual dimension M D Incisal Ling  D M M D 6 B Ling Ling B  Maxillary Central Incisor 1 Maxillary central incisor is the first tooth from the midline. Characteristic features of upper central incisors 1- The two upper centrals are the widest (broadest) of all the incisors. 2- The crown is the longest of all human teeth.  Geometric outline of the crown Facial and lingual aspects have Trapezoidal outline. Smallest uneven side cervically. Largest uneven side incisally. Uneven side Uneven side  Mesial and Distal outlines of the crown M D Cervical outline (convex root wise) Mesial outline Distal outline (more (convex) M D convex) Distal Contact Area Mesial Contact Area At the junction of Middle & In the Incisal 1\ 3 near Incisal 1\ 3. Mesio-incisal angle. Rounded distoincisal angle Sharp mesioincisal angle Incisal (straight and may have mamelons) When?  Outlines of the root The mesial and distal outlines of the root tapered to a blunt apex and has cone shape. The apex is centralized on the long axis so extraction could be done by rotation movement  Surface Anatomy of the Crown and root. Elevations & Depressions Labial aspect Elevations: The crown surface is smooth and convex with maximum convexity at the cervical third (cervical ridge) Depressions: Two shallow developmental grooves could be seen separating mamelons. The root surface is smooth and convex  Lingual aspect Elevations: Marginal ridges (mesial and distal) Distal Marginal Cingulum (cervically) ridge Incisal ridge Mesial Marginal ridge Depressions: Lingual fossa Incisal ridge  You have to notice that the lingual surface of all teeth is smaller in size than the labial due to the Lingual Convergence. This convergence of the teeth is to accommodate the larger arch size facially than lingually (Dental arch resemble horse shoe)  Geometric outline of the crown Proximal (Mesial and Distal) aspects have Triangular outline Base cervically. Apex incisally.  Mesial and distal Outlines It’s Triangular and formed of Labial outline: convex with maximum convexity at the cervical third which represent cervical ridge. Lingual outline: Convex incisally which represent incisal ridge. Concave at the middle which represent lingual fossa. Labial Lingual outline outline Convex cervically which represent cingulum. Cervical outline: Curves incisally. Mesial Dital Aspect Aspect The crown has smooth convex proximal surfaces. Mesial Contact area: Distal Contact area: At the incisal 1/3 Near the junction of I 1/3 & M 1\ 3. Near the MI angle. Cervical line: The curvature is shallower than Curved incisally. mesially.  Outlines of the Root The outlines tapered from the cervical line to a blunt rounded apex Roots They have convex smooth surfaces.  Incisal Aspect Outline and surface anatomy The outline is triangular in shape. The base is placed labially and apex lingually. The mesiodistal dimension (width) is greater than the labiolingual dimension Upper 1 (Thickness). The labial outline is broad and flat in comparison with the lingual surface (Lingual LABIAL Convergence). The crown is tapered lingually. *Incisal edge is centrally situated in relation to the thickness. LINGUAL Note: The elevations and depressions in the crown lingually and labially appeared in this aspect. Developmental groove Cervical Ridge Lingual fossa Incisal Ridge Mesial Marginal Ridge Distal Marginal Ridge Cingulum Identify the tooth, the aspect and the anatomical landmark.?? Scan the QR Code  d a y n i c e ave a n d h ks a Th a n