A Crown Elevations PDF

A Crown Elevations 1 Lobe It is one of the primary centers of calcification and growth formed during the crown development. Each tooth begins to develop from four lobes or more. -- All anterior teeth and premolars are formed from 4 lobes except- the mandibular 2nd premolar (3 cups type) f...

A Crown Elevations 1 Lobe It is one of the primary centers of calcification and growth formed during the crown development. Each tooth begins to develop from four lobes or more. -- All anterior teeth and premolars are formed from 4 lobes except- the mandibular 2nd premolar (3 cups type) formed from 5 lobes (3 buccal and 2 lingual).-All molars formed from 4 lobes (2 buccal and 2 lingual) except the mandibular 1st molar formed from 5 lobes. 1 2 3 4 5 THE MATURE FORMS OF LOBES ARE: 1. Cusps 2.Cingulum 3. Mamelones 2 Cusps They are pyramidal projections on the incisal portion of the canine and on the occlusal surfaces of the premolars and molars teeth. * Cusp slopes the inclined surfaces, meet at an angle with the cusp tip. also known as cusp arms. * Contact a point or area where one tooth is in contact its neighbor 3.Cingulum It is the enlargement or bulge on the cervical third of lingual surface of the crown in anterior teeth (incisors and canines). It is also called the lingo-cervical ridge 4. Mamelones They are three small round projections of enamel present in the incisal third of newly erupted permanent incisors. After normal use, eventually the mamelones wear down into a flat edge. 5- Tubercle It is a small elevation. It is produced by excessive formation of enamel. Tubercle is noticed at the palatal surface of E & 6 and sometimes at the lingual surface of incisors over the cingulum. M B D P Tubercle differs from cusp as it is formed of enamel only while cusp is formed of pulp horn covered by dentin and enamel 6 Enamel pearl Are very small droplets of enamel present on dentin of the root mostly on the furcation area of permanent molars 7- Ridge It is a linear elevation on the different surfaces of the crown. A- Ridges on the facial surface (Labial and Buccal) B- Ridges on the lingualsurface C- Ridges on the occlusalsurfaceof posterior teeth A- Ridges on the facial surface 1 Labial Ridge : Found on the labial surfaces of (Labial and Buccal) canines. It is the result of greater development of middle labial lobe. 2 Buccal Ridge : Usually found on the buccal surfaces of the premolars. It is the result of greater development of middle buccal lobe. 3 Cervical Ridge : It is found on the cervical one third of the facial surfaces of all the teeth. Cervical ridge are Well developed in deciduous teeth and more pronunced in the (D) followed by (E). B- Ridges on the lingualsurface 1.Incisal Ridge: Linear elevation in lingual surface of incisor 2. Lingual Cusp Ridge: Cusp Slopes Or Cusp Arms DCR MCR NOTE: Usually distal cusp slope is longer than mesial cusp slope in all teeth except C and 4 where the mesial cusp slope is longer than the distal 3.Lingual Ridge : Linear elevation in lingual surface of canine 4.Marginal Ridge: DMR MMR C- Ridges on the occlusal 1.Marginal Ridges MESIAL MARGINAL RIDGE DISTAL MARGINAL RIDGE surface of posterior teeth 2.Triangular Ridges: it descend from the cusp tip of posterior teeth toward The central part of occlusal surface All posterior tooth cusps have a triangular ridge, except the mesiolingual cusp on maxillary molars which has two triangular ridges 3.Transverse ridge the union of directly opposing triangular ridge 4. Oblique Ridge : the union of non opposing triangular ridges of buccal and lingual cusps Found on (E 6 7 may be D , 8 ) Remember that all teeth either anterior or posterior have cervical ridge and two marginal ridges (mesial and distal one)