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Tooth Histology and Morphology. Oral Anatomy, DA102. Succedaneous Teeth. Refer to a permanent tooth that replaces, or succeeds a deciduous tooth in the same position . Succedaneous Teeth. Surface shapes of the facial and lingual. Cusps. Pointed or rounded mound on
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Tooth Histology and Morphology Oral Anatomy, DA102
Succedaneous Teeth Refer to a permanent tooth that replaces, or succeeds a deciduous tooth in the same position.
Cusps • Pointed or rounded mound on the crown of the tooth • Referred to by their position on the tooth Examples: distal cusp mesial cusp distal buccal cusp
Ridges: elevated area of enamel triangular ridge
Pits: Small depressions in surfaces of teeth
Lobes • Separate parts that come together to form a tooth. • In a molar, the lobes often becomes cusps • On lingual surface of maxillary anteriors, lobes are called cingulums
Grooves • Lineal depressions running between cusps; give distinct character to teeth • Fissures: developmental grooves between lobes
Furcations Dividing point of a multi-rooted tooth Two roots = bifurcated Three roots = trifurcated
Contacts and Embrasures Contact: where proximal surfaces of teeth come together and touch Embrasure: triangular space in the gingival direction where two adjacent teeth are in contact
Fossa Shallow rounded or angular depression
Mamelons Three bulges on the incisal edge of newly erupted central incisor. They normally disappear from normal wear. newly erupted teeth
Permanent Teethrefer to Delmar text for illustrations • Maxillary • Anteriors Centrals, Laterals, Canines • 5 surfaces: labial, lingual, mesial, distal, incisal edge • Posterior 1st, 2nd Premolars; 1st, 2nd, 3rd Molars • 5 surfaces buccal, lingual, mesial, distal, occlusal • Mandibular • Anteriors Centrals, Laterals, Canines • 5 surfaces: labial, lingual, mesial, distal, incisal edge • Posteriors: 1st , 2nd Premolars; 1st, 2nd, 3rd Molars • 5 surfaces: buccal, lingual, mesial, distal, occlusal
Maxillary Central Incisor Teeth Numbers: #8 and #9 Sharp incisal edge Largest, widest incisor in mouth Flat labial surface Well-developed cingulum with pit Thumb-nail shape Mesio-incisal edge = sharp corner Disto-incisal edge = rounded Single root Age of eruption: 7 – 8 years
Maxillary Central Incisor Labial Incisal edge Lingual
Maxillary Lateral Incisor Tooth Numbers: #7 and #10 Similar shape to centrals Smaller, shorter, narrower, thinner than centrals More rounded corners on mesio-incisal edge Smaller cingulum than centrals Flat labial surface Definite lingual pit and fossa Single root Age of eruption: 8 – 9 years
Maxillary Lateral Incisor Labial Incisal Edge Lingual
Maxillary Canine Tooth Numbers: #6 and #11 aka “eye-tooth” or cuspid Longest strongest tooth in human dentition Defines mouth and face shape (cornerstone of arch) Incisal edge = rounded and pointed (cusp) Labial surface has prominent curvature labial ridge Lingual surface is concave with marginal ridges Cingulum = bulky Single root Age of eruption: 11 – 12 years
Maxillary Canine Labial Incisal Edge Lingual
Maxillary 1st Premolar • Tooth Numbers: #5 and #12 • 2 cusps: buccal (larger) and lingual • aka: bicuspid • Usually two roots (can be single-rooted) • Buccal and lingual roots • Age of eruption: 10 – 11 years
Maxillary 2nd Premolars Tooth numbers: #4 and #13 Smaller and less bulky than 1st premolar 2 cusps = buccal and lingual Single root Age of eruption: 10 – 12 years
Maxillary 1st Molar • Tooth Numbers: #3 and #14 • aka: 6-year molars • Trifurcated, wide-spread roots • Mesiobuccal, distobuccal, palatal • 4 cusps • mesiolingual, mesiobuccal, distolingual, distobuccal • ML = largest cusp; DL = smallest cusp • Sometimes: 5th cusp (cusp of Carabelli) located on mesiolingual surface, about 1/3 way down from occlusal surface • Age of eruption: 6 – 7 years
Maxillary 1st Molar BuccalOcclusal Lingual Cusp of Carabelli
Maxillary 2nd Molar • Tooth Numbers: #2 and #15 • aka: 12 year molars • Slightly shorter and smaller than 1st molars • Roots are usually longer than 1st molars • Trifurcated roots, not as widespread as 1st molar • Mesiobuccal, distobuccal, palatal • 4 cusps: • Mesiolingual, mesiobuccal, distolingual, distobuccal • No cusp of Carabelli • Age of eruption: 12 – 13 years
Maxillary 2nd Molar BuccalOcclusal Lingual
Maxillary 3rd molars Tooth Numbers: #1 and #16 aka: wisdom teeth Size, shape, and contour differs greatly; may be distorted Smaller than 1st and 2nd molars Possibility of 1, 2, or 3 roots; often fused together Age of eruption: 17 – 21 years
Maxillary 3rd Molar BuccalOcclusal Lingual
Maxillary Molar Comparison 3rd 2nd 1st 3rd 2nd 1st
Mandibular Central Incisor Tooth Numbers: # 24 and # 25 Smallest incisor in mouth; smallest tooth in mouth Smaller than mandibular lateral Lingual surface is concave with a flat cingulum Incisal edge is right angles with mesial and distal First primary tooth to exfoliate and be replaced by succedaneous tooth Single root Age of eruption: 6-7 years
Mandibular Lateral Incisor Tooth numbers: # 23 and # 26 Larger than central incisors Distal-incisal edge slops apically (toward root) Cingulum positioned slightly to the distal Single root Age of eruption: 7 – 8 years
Mandibular Canine Tooth Numbers: # 22 and # 27 AKA: cuspid or eye-tooth Smaller and more slender than maxillary canine Smooth lingual surface; cingulum rarely present Cusp ridge: distal ridge is longer than mesial ridge Labial is rounded and prominent Single root Age of eruption: 9 – 10 years
Mandibular Canine Facial Incisal Lingual
Mandibular First Premolar Tooth Numbers: # 21 and # 28 AKA: 1st bicuspid Smaller than 2nd premolars Large buccal cusp with smaller, non-functional lingual cusp Transverse ridge across occlusal surface Rounded buccal surface Single root Age of eruption: 10 – 12 years
Mandibular First Premolar Facial Occlusal Lingual
Mandibular Second Premolar Tooth Numbers: # 20 and # 29 AKA: 2nd bicuspid Single buccal cusp with 1 or 2 smaller lingual cusps Lingual cusps are more prominent than on 1st premolar Larger and longer root than 1st premolar Single root Age of eruption: 11 – 12 years
Mandibular Second Premolar Facial Occlusal Lingual
Mandibular First Molar • Tooth Numbers: # 19 and # 30 • AKA: 6 year molar • First permanent tooth to erupt in the mouth • Usually largest mandibular tooth • 5 well-developed cusps: • Mesiobuccal, distobuccal, mesiolingual, distolingual, distal • 5th cusp is the distal cusp • All cusps are on the lingual surface • 2 buccal grooves; 1 lingual groove • Crown shape is somewhat rectangular • 2 roots: mesial and distal; spaced wide apart • Age of eruption: 6 – 7 years
Mandibular First Molar Facial Occlusal Lingual
Mandibular Second Molar • Tooth Numbers: # 18 and # 31 • AKA: 12 year molar • 4 cusps: • Mesiobuccal, distobuccal, mesiolingual, distolingual • All located on occlusal surface • Lingual cusps are more pointed and longer than buccal cusps • 1 buccal groove; 1 lingual groove • 2 roots: mesial and distal; not as wide-spread as 1st molars • Age of eruption: 11 – 13 years
Mandibular Second Molar Facial Occlusal Lingual
Mandibular Third Molar • Tooth Numbers: # 17 and # 32 • AKA: wisdom tooth • Size, shape, contour differ widely: • Smaller than 1st and 2nd molars • More grooves • 4-5 cusps, not as defined as 1st and 2nd molars • 2 roots: usually fused together • Age of eruption: 17 – 21 years
Mandibular Third Molars Facial Occlusal Lingual