Developmental anomalies of tooth - Diagram

Mesiodens:  A small supernumerary tooth that forms between the central incisors (.15-1.9% occurrence)

Distomolars, paramolars, 4^th molars: extra molars

Gemination or twinning:  results from the splitting of a single forming tooth bud, separation is incomplete (larger crown, one normal root).

Fusion: joining of 2 root buds and involves dentin (larger crown, 2 separate roots).

Hutchinson’s teeth: screwdriver shaped, taper from cervical to incisal edge. From prenatal syphilis (also cause of mulberry molars).

Concrescent:  After development 2 teeth fuse by Cementum only, usually due to close proximity of root during eruption (usually affects Mx incisors).

Tuberculum intermedium: extra cusp in middle in tooth

Tuberculum sextum: extra cusp on distal side of tooth

Taurodontism: no tapering of root, block shaped

Shovel-shaped incisors: pronounced cingulum

Dens in dente: “tooth within a tooth” usually Mx lateral incisors (in cingulum), a mass of enamel in dentin.  Often peg shaped.

Ankylosis: outside of occlusion, fused directly to alveolar bone, breaking down of periodontal ligaments.

Transposition: 2 teeth switched

Abfraction: results from tooth bending, lesions from separation of enamel rods.

Enamel pearl:  small, rounded formation of extra enamel on tooth

Micro vs macro dentia:  abnormally small or large teeth

Hypercementosis:  An overgrowth of cementum on the root of a tooth possibly caused by localized trauma or inflammation, metabolic dysfunction, or developmental defects.