Max Canines - Dr. Gihan Hassan - 11 2024 Final - PDF

 4 maxillary and mandibular permanent canines one on each side of each jaw.  called cornerstones of the arches as they are located at the corners of the mouth.  Their location in this area requires extra anchorage in the alveolar bones.  The positions and forms of the canines have a...

 4 maxillary and mandibular permanent canines one on each side of each jaw.  called cornerstones of the arches as they are located at the corners of the mouth.  Their location in this area requires extra anchorage in the alveolar bones.  The positions and forms of the canines have a cosmetic value, they help in maintaining natural facial expression.  The canine has a single long root which has a special projection of bone called the canine eminence.  In function, the canines act as tearing tools and assist both the incisors and premolars.  The maxillary canine resembles the incisor  developed from 4 developmental lobes  (3 facial and 1 lingual)  3 labial lobes  middle lobe extension results in the formation of a single cusp.  The lingual lobe of the canine is much larger and thicker than the lingual lobe of an incisor.  Canine  wider lobiolingually than in maxillary incisor.  narrower mesiodistally than those of maxillary central incisor.  Beginning of calcification. 4 – 5m Crown completed. 6 – 7y Eruption. 11 – 12 y 9 – 10y Root completed. 13-15y 12- 14 y Labial Lingual Mesial Distal Incisal GEOMETRIC OUTLINE OF THE CROWN Distal mesial Trapezoid outline Smallest uneven side cervically Mesial outline: convex from the cervix till the contact area (at the junction of I 1/3 and M 1/3) then Distal Mesial continues as concave till the cusp tip. Distal outline: concave till the contact area (at the middle third) then continues as convex till the cusp tip. Cervical outline: convex root wise. Cusp Slopes: Distal Mesial The mesial slope is shorter than the distal slope. Cusp Tip :  pointed  on line with the long axis  The middle labial lobe shows much greater Distal mesial development than the other lobes………. labial ridge  It has shallow depressions mesially and distally, dividing the labial surface into three labial lobes.  convexity at cervical third. Root: The mesial and distal outlines of the root…….. Tapered to a pointed apex  Crown & root narrower lingually than labially.  The cervical line is more convex than labially  The cingulum is large and pointed like small cusp.  Lingual Ridge well developed extend from the cusp tip to a point near the cingulum that divides the lingual fossa into two shallow concavities (lingual fossae).  The mesial and distal marginal ridges  The mesial and distal outlines are similar to the labial aspect.  The Root:  The lingual portion of the root is narrower than the labial portion.  Developmental depressions  mesial and distal  extending most of the root length.  Geometric outline of the crown Proximal aspects have triangular outline The base cervically. Note: the cusp tip of upper canine centralized on the long axis Apex of the or triangle inclined labially. incisally. Labial Outline: is convex with the crest of curvature at the cervical third represent…… Lingual Outline: is convex cervically represent... In the middle it’s straight due to presence of ridge …….. In the incisal third it’s convex again represent…… Cervical Outline: curved incisally Mesial Surface:  The mesial contact area is oval in shape, centered labiolingually and located at the junction of incisal and middle thirds.  Concave area between the cervical line and the contact area. ROOT  Conical in shape. The outlines tapered from the cervical line to tapered apex  Broad with shallow depression for a part of its length  help in anchoring the tooth to the alveoli and in preventing rotation and displacement.  The distal aspect shows the same form as the mesial aspect, with the following variations: - 1- Cervical Line exhibits less curvature 2- Distal Marginal Ridge is heavier and more irregular in outline. 3- Distal Contact Area is more cervical in its level than the mesial contact 4- Surface displays more concavity above the contact area. 5- Developmental Depression…more pronounced.  The labiolingual dimension is greater than the mesiodistal.  The labial surface appeared convex and even more than the incisors  The labial ridge is very noticeable  The cingulum forms a short arc. Pulp cavity is formed of pulp chamber and a single root canal Labiolingul section:  Shows a large pulp chamber that points incisally.  The root canal is wide in the cervical half of the root than any tooth, then it narrows down to average width on its way to apical end of the root. Mesiodistal section  The pulp cavity is much narrower and similar to those of the incisors.  It has a much longer tapered root canal.  A mesial or distal curve of the apical root may be present Cervical cross section  The pulp cavity seems much narrower from this view.  The shape of the root canal is elliptical rather than round and it is centered over the root.  It is wider labiolingually than mesio-distally.