Tooth Morphology

Dentition Dentition Arch Natural teeth in position in the dental arch. One row of teeth in the mouth. Maxillary Upper teeth Mandibular Lower teeth

Numbers of teeth Permanent Primary 32 total 20 total 16 each arch 20 succedaneous Replace baby teeth! Primary 20 total 10 each arch NO pre-molars NO 3rd molars

Quadrants Each arch is divided into R + L. Max. R. quadrant Midline Max. R. quadrant URQ Max. L. quadrant ULQ Man. L quadrant LLQ Man. R quadrant LRQ

Sextants 6 sections of the mouth Maxillary Mandibular 3 of each arch Maxillary Max. R. Post. Sextant Max. Anterior Sextant Max. L. Post. Sextant Mandibular Mand. L. Post. Sextant Mand. Anterior Sextant Mand. R. Post. Sextant

Tooth surfaces Anterior Posterior Proximal surfaces? Example Facial / Labial Lingual Mesial Distal Incisal edge Posterior Facial / Buccal Occlusal Proximal surfaces? Surfaces of adjacent teeth closest to each other. Mesial / Distal Midline Mesial / Mesial Example You floss the proximal surfaces of a tooth. Your floss would be interproximal. Between the proximal surfaces.

Tooth Relationships Antagonistic (Antagonists) Adjacent Teeth that work together to chew Same tooth in the opposite arch. #1 and #32 #14 and #19 Adjacent Teeth next to each other in the same arch. #17 and #18

Tooth descriptions Convex Concave Outward curve Bulge Rounded projection Concave Inward curve Recessed area Opposite of convex  convex Concave 

Tooth Morphology Contact point Diastema Where adjacent teeth touch each other. Diastema Aka open contact Naturally occurring ‘gap’ between teeth Common #8 #9 Any 2 teeth/arch 

Tooth Morphology Embrasure Cingulum Triangular space between the contact and the gingiva. Cingulum Lump of enamel Lingual surface @ the gum line. Maxillary incisors

Tooth Morphology Lobes Cusp Underdeveloped cusps. Pointed or round mound of enamel. Form the ‘bumps’ on the chewing surface of molars and premolars. “cuspid”!

Tooth Morphology Fossa Developmental groove. Round Triangular Linear “low spot” / recessed area On a surface Between cusps or ridges. Developmental groove. Linear “low spot” / recessed area Usually occlusal surface Between cusps

Tooth Morphology Fissure Pit Imperfect union of cusps Appears as a small “crack” Located at the bottom of a developmental groove Pit Where fissures cross or end. Sealants are placed in pits and fissures to prevent decay.

Tooth Morphology Mamelons Cusp of Carabelli 3 small cusps Incisal edge Newly erupted incisors. Wear down w/ use. Cusp of Carabelli 5th/ additional cusp Lingual surface Maxillary 1st molars #3 + #14

Tooth Morphology Ridges Marginal ridges Elevated lines of enamel between cusps. Many examples Marginal ridges Form the mesial + distal borders of the tooth. Extend between the buccal and lingual cusps

Tooth Morphology Crown Root(s) Apex Apical foramen Top of the tooth Covered w/ enamel Root(s) Bottom of the tooth Covered w/ cementum Apex End of the root Apical foramen Hole @ apex

Tooth Morphology Furcation Dividing point of roots Bifurcation Of a multi-rooted tooth Bifurcation 2 roots Trifurcation 3 roots Furcation 

Tooth tissue junctions CEJ Cementoenamel junction Where enamel meets cementum. Around the outside of the tooth. DEJ Dentinoenamel junction Where enamel meets the dentin. Under the enamel

Permanent Tooth descriptions! Max. Cent. Incisors Numbers: 8, 9 # of roots: 1 Nerve: ASA Type of injection: Infiltration Succedaneous: yes Replaces E and F Function Cut Max. Lat. Incisors 7, 10 1 roots ASA Infiltration Succedaneous: yes Replaces: D, G Most anomalies. Function Cut

Permanent Tooth Descriptions! Max. Cuspid / canine 6 + 11 1 root (Longest) “cornerstone” of the mouth ASA Infiltration Succedaneous: yes Replace C, H Function Tear / cut Max 1st premolar / bicuspid 5 + 12 2 roots Only premolar w/ 2 roots Removed for ortho MSA Infiltration Succedaneous: yes Replace B, I Function Chew

Permanent Tooth Descriptions! Max 2nd Premolar 4 + 13 1 root MSA Infiltration Succedaneous: yes Replace A , J Function Chew Max 1st Molars 3 + 14 6 year molars Cusp of carabelli 3 roots PSA MSA MB root Infiltration Not Succedaneous Function Grind Chew

Permanent Tooth Descriptions! Max 2nd Molars 2 + 15 (12 year molars) 3 roots PSA Infiltration Not succedaneous Function Grind Chew Max 3rd Molars 1 + 16 (wisdom teeth) 3 roots PSA Infiltration Not succedaneous Function Grind Chew

Permanent Tooth descriptions! Mandibular Central Incisors 24 + 25 1 root Incisive nerve Infiltration Succedaneous: yes Replaces O + P Function cut Mandibular lateral Incisors 23 + 26 1 root Incisive nerve Infiltration Succedaneous: yes Replaces N + Q Function cut

Permanent Tooth Descriptions! Mandibular Cuspid / Canine 22 + 27 1 root Incisive nerve Infiltration Succedaneous: yes Replaces M + R Function Tear / cut Mandibular 1st Premolar / bicuspid 21 + 28 1 root IA (inferior alveolar) Block injection @? Mandibular foramen Succedaneous: yes Replaces L + S Function chew

Permanent Tooth Descriptions! Mandibular 2nd Premolar / bicuspid 20 + 29 1 root IA nerve Block Succedaneous: yes Replaces K + T Function Chew Mandibular 1st Molars 19 + 30 2 roots IA nerve Block Not Succedaneous Function Chew, grind, pulverize

Permanent Tooth descriptions! Mandibular 2nd Molars 18 + 31 2 roots IA nerve Block Not succedaneous Function Grind, chew, pulverize Mandibular 3rd Molars (wisdom teeth) 17 + 32 2 roots IA nerve Block Not succedaneous Function (if in occlusion) Grind, chew, pulverize

Primary Tooth Descriptions Aka Deciduous Baby Milk Denoted / Labeled A – T ABC’s Alphabetically Letters not numbers No Premolars 3rd molars Roots Max molars 3 roots Mand molars 2 roots Cuspid / canine and incisors All 1 root.

Naming a Tooth! Arch 1st Side 2nd Position 3rd Type of tooth 4th Max or Mand Side 2nd Right / left Position 3rd Central / Lateral 1st / 2nd / 3rd Type of tooth 4th Molar / premolar / cuspid / incisor Examples Permanent teeth #2 Max R. 2nd Molar #21 Mand L. 1st Premolar Primary teeth #B Max R. 1st primary molar

Conclusion Knowing your tooth names and numbers is critical to being a successful dental assistant. Understanding morphology terminology will make it easier to communicate with your dentist. Do you have any questions?