1. Developmental Abnormalities of Teeth
Zhang Qi
Wuhan University School of Stomatology

2. Classification Anomalies of Number Anomalies of Size
Anomalies of Shape
Anomalies of Structure
Anomalies of Color

3. Anomalies of Number Anodontia: a complete absence of
one or both dentition.
2. Hypodontia (partial anodontia):
a deficiency in tooth number.
Hyperdontia (Supernumerary Teeth):
an excess in tooth number.
a. Mesiodens b. Distomolar

4. Mesiodens Anadontia: a complete absence of one or both dentition.
Hypodontia: one or several teeth are missing.
Hyperdontia: There are teeth additional to those of the the normal series.

5. Anomalies of Size
Microdontia
Macrodontia

6. Anomalies of Shape Gemination Fusion Concrescence Dilaceration
Enamel Pearl (enameloma)
Talon Cusp
Taurodontism
Dens in Dente (dens invaginatus)
Dens Evaginatus
Supernumerary Roots
11.Hypercementosis

7. Gemination The partial development of two teeth
from a single tooth bud following
incomplete division.
An incomplete division of a single
tooth bud resulting in a bifid crown
with a single pulp chamber.

8. Gemination

9. Fusion The dentinal union of two embryologically developing teeth.
Fused teeth can contain two separate
pulp chamber, may appear as large bifid
crowns with one chamber.

10. Fusion

11. Concrescence An acquired disorder in which the roots of
one or more teeth are united by cementun
alone after formation of the crowns.

12. Concrescence

13. GEMINATION
FUSION
CONCRESCENCE
One bud
One tooth
One canal
Two buds
Two teeth
Dentin union
Two buds
Two teeth
Cementum union

14. Dens Invaginatus
An extra cusp, usually in the central groove or ridge of a posterior tooth and lateral incisor.

15. Dens in Dente A condition resulting from the
invagination of the inner enamel
epithelium producing the appearance
of a tooth within a tooth.

16. Dens in Dente
(dens invaginatus)

17. Taurodont Taurodont teeth are characterized by
having a significantly elongated pulp
chamber with short stunted roots,
resulting from the failure of the proper
level of horizontal invagination of
Hertwig’s epithelial root sheath..

18. Taurodontism-bull like tooth
The dental chamber has a greater apico-occlusal height than in normal teeth, with no constriction at the level of the amelocemental junction with the result that the chamber extends apically well beyond the cervix.
Taurodontism-bull like tooth

19. Dilaceration Dilaceration refers to an abnormal
bend of the root during its development
and is thought to result from a traumatic
Episode.

20. A deformity in which the crown of the tooth is displaced from its normal alignment with the root, so that the tooth is severely bent along its long axis. Dilaceration is usually the result of acute mechanical trauma and most frequently involves the maxillary incisor.

21. Anomalies of Structure
Enamel hypoplasia caused by
amelogenesis imperfecta (genetic)
Enamel Hypoplasia caused by
febrile Illness or Vitamin Deficiency
Enamel hypoplasia resulting from
local infection or Trauma
a. Turner's Tooth
fluoride Ingestion (dental fluorosis) a. Mottling

22. Anomalies of Structure
Enamel hypoplasia resulting from
congenital syphilis (Treponema pallidum)
a. Hutchinson's incisors b. Mulberry molars
Enamel hypoplasia resulting from birth injury,
premature birth or idiopathic factors
Enamel hypocalcification
Dentinogenesis imperfecta
Dentin dysplasia
10. Regional Odontodysplasia (Ghost teeth)

23. Amelogenesis Imperfecta
Classification of AI
Type I: hypoplastic
TypeII: hypomaturation
TypeIII: hypocalcified
TypeIV: hypomaturation-hypoplastic
with taurodontism

24. Amelogenesis imperfecta

25. enamel hypoplasia

26. enamel hypoplasia

27. Turner Tooth

28. Dental fluorosis

29. Hutchinson teeth

30. Dentinogenesis Imperfecta
Classification of DI
Type I: occures with osteogenesis
imperfecta
TypeII: hereditary opalescent dentin
TypeIII: Brandywine type
a shell-like appearance and
multipe pulp exposures.

31. Dentinogenesis imperfecta

33. — Discoloration of teeth Etiology
Anomalies of Color
— Discoloration of teeth
Etiology
Surface deposits (Extrinsic stains)
Changes in structure or thickness of dental tissues
Diffusion of pigments into dental tissues
Pigments incorporated during formation of dental tissues.

34. Extrinsic stains Substances in the diet
Habitual chewing, betel nut, tobacco
Tobacco smoking
Medicaments
Chromogenic bacteria

35. Changes in structure Enamel hypoplasias, fluorosis
Amelogenesis imperfecta, hypocalcified,
hypomaturation, and hypoplastic types
Enamel opacities
Enamel caries
Dentinogenesis imperfecta
age changes in dental tissues

36. Diffusion of pigments Extrinsic stains Endodontic materials
Products of pulp necrosis

37. Pigments incorporation
Bile pigments
Porphyrins
Tetracycline

38. Tetracycline stained teeth

41. Composite resin restoration

43. Other disorders of teeth

44. Attrition

45. Erosion

46. Toothbrush abrasion