Acquired and developmental anomalies of teeth.

1. Developmental Anomalies of
teeth
Made by:
Mohamed Ali

2. Abnormalities of Teeth
 Environmental Alterations of Teeth
 Developmental Alterations of Teeth

3. Environmental Alterations of Teeth

4. TURNER’S HYPOPLASIA
 Caused by periapical inflamatory disease or trauma of the overlying deciduous
tooth.
 The altered tooth is called a Turner’s tooth
 The enamel defects vary from focal areas of white, yellow, or brown discoloration
to extensive hypoplasia

6. DENTAL FLUOROSIS
 Caused by the ingestion of excess amounts of fluoride.
 Dentition exhibiting diffuse white and Opaque enamel, with demonstrated
areas Of brown discoloration.

7. Dental fluorosis. Dentition exhibiting lusterless, white,
and opaque enamel.

8. SYPHILITIC HYPOPLASIA
 Congenital syphilis results in a pattern of enamel hypoplasia.
 Anterior teeth altered by syphilis are termed Hutchinson’s incisors.
 Altered posterior teeth are termed mulberry molars

9. Hutchinson’s incisors
Mulberry molars

10. INTERNAL AND EXTERNAL RESORPTION
 Accomplished by cells located in the dental pulp (i.e., internal resorption) or in the
periodontal ligament (PDL) (i.e., external resorption).
 Internal resorption is a relatively rare occurrence, and most cases develop after
injury to pulpal tissues, such as physical trauma or caries-related pulpitis.
 Factors Associated with External Resorption: Cysts ,Dental trauma ,Excessive
mechanical forces (e.g., orthodontic therapy) ,Excessive occlusal forces ,Grafting of
alveolar clefts ,Hormonal imbalances ,Intracoronal bleaching of pulpless teeth,
Local involvement by herpes zoster ,Paget’s disease of bone ,Periodontal treatment
,Periradicular infl ammation ,Pressure from impacted teeth ,Reimplantation of
teeth, Tumors.

11. Internal resorption (pink tooth
of Mummery).
A, Pink discoloration of the
maxillary central incisor.
B, Radiograph of same patient
showing extensive resorption
of both maxillary central incisors.
Internal resorption. Balloonlike
enlargement of
the root canal.
Internal resorption. The
destruction has resulted
in perforation of the lateral root
surface.

12. External resorption. Extensive irregular
destruction of both roots of the
mandibular second molar
associated with chronic periodontitis.
External resorption. Extensive external
resorption of the crown of the impacted
right maxillary
cuspid. Histopathologic examination
revealed resorption
without bacterial contamination or caries.
External resorption. “Moth-eaten”
radiolucent
alteration of the maxillary left central
incisor. The tooth had
been reimplanted after traumatic
avulsion.External resorption.
Diffuse external resorption
of radicular dentin of
maxillary dentition. This
process arose
after initiation of
orthodontics.

13. ANKYLOSIS
 Eruption continues after the emergence of the teeth to compensate for
masticatory wear and the growth of the jaws.
 The cessation of eruption after emergence is termed ankylosis and occurs from
an anatomic fusion of tooth cementum or dentin with the alveolar bone.
 The most commonly involved teeth in order of frequency are the mandibular
primary first molar, the mandibular primary second molar, the maxillary
primary first molar, and the maxillary primary second molar.

14. Ankylosis. Deciduous molar well below the
occlusal plane of the adjacent teeth.
Ankylosis. Radiograph of an ankylosed deciduous
molar. Note the lack of periodontal ligament (PDL)
space.

15. Developmental Alterations
of Teeth

16. DEVELOPMENTAL ALTERATIONS IN
THE NUMBER OF TEETH
 Anodontia
 Hypodontia
 Hyperdontia

17. Anodontia
 Total lack of tooth development.

18. Hypodontia
 The lack of development of one or more teeth.
 oligodontia
 (a subdivision of hypodontia) indicates the lack of development of six or more
teeth.
 increased prevalence of hypodontia is noted in patients with nonsyndromic cleft lip
(CL) or cleft palate (CP).
 It may also be associated with ectodermal dysplasia and down syndrome.

19. Hypodontia. Developmentally missing maxillary
lateral incisors. Radiographs revealed no underlying
teeth, and there was no history of trauma or
extraction.
Hypodontia. A, Multiple developmentally missing
permanent teeth and several retained deciduous teeth
in a female adult.
B, The panoramic radiograph shows no unerupted
teeth in either jaw.

20. Ectodermal dysplasia

21. Hyperdontia
 Is the development of an increased number of teeth, and the additional teeth are
termed supernumerary.
 Several terms have been used to describe supernumerary teeth, depending on
their location. A supernumerary tooth in the maxillary anterior incisor region
is termed a mesiodens an accessory fourth molar is often called a distomolar
or distodens. A posterior supernumerary tooth situated lingually or buccally
to a molar tooth is termed a paramolar.
 It may be associated with Cleidocranial dysplasia syndrome.
 Aplasia or hypoplasia of clavicles
 Craniofacial malformation
 Supernumerary teeth & impacted permanent teeth

22. Hyperdontia (mesiodens).
Erupted supernumerary,
rudimentary tooth of the
anterior maxilla.
Hyperdontia (mesiodens).
Unilateral supernumerary tooth
of the anterior maxilla, which
has altered the eruption path of
the maxillary right permanent
central incisor.
Hyperdontia (mesiodens).
Bilateral inverted
supernumerary teeth of the
anterior maxilla.

23. Paramolar. A, Rudimentary tooth situated palatal to a maxillary molar in a patient
who also exhibits hypodontia. B, Radiograph of the same patient showing a fully formed tooth
overlying the crown of the adjacent molar.
Hyperdontia. Right mandibular dentition
exhibiting four erupted bicuspids.

24. DEVELOPMENTAL ALTERATIONS IN
THE SIZE OF TEETH
 MICRODONTIA
 MACRODONTIA

25. MICRODONTIA
 The teeth size are physically smaller than usual.
 It may occur as an isolated finding in Down syndrome, in pituitary dwarfism.

26. Diffuse microdontia. Dentition in which the
teeth are smaller than normal and widely spaced
within the arch.
Isolated microdontia (peg shaped lateral).

27. MACRODONTIA
 Teeth size are physically larger than usual.
 It may occur in association with pituitary gigantism.

28. DEVELOPMENTAL ALTERATIONS IN
THE SHAPE OF TEETH
 Gemination
 Fusion
 Concrescence
 Accessory cusps
 Dens invaginatus
 Ectopic enamel
 Taurodontism
 Hypercementosis
 Accessory roots
 Dilaceration

29. GEMINATION
 Is an attempt of a single tooth bud to divide, with the resultant formation of a
tooth with a bifi d crown and, usually, a common root and root canal.
 The tooth count is normal when the anomalous tooth is counted as one.

30. Gemination. Mandibular bicuspid exhibiting
bifid crown.
Gemination. Same patient Note the bifi d crown and shared
root canal.

32. Fusion
 Is the union of two normally separated tooth buds with the resultant
formation of a joined tooth with confluence of dentin.
 The tooth count reveals a missing tooth when the anomalous tooth is counted
as one.
 Occasionally, fusion in the primary dentition is associated with absence of the
underlying permanent successor.

33. Fusion. Double tooth in the place of the
mandibular right lateral incisor and cuspid.
Fusion. Radiographic view of double
tooth in the place of the mandibular
central and lateral incisors. Note
separate root canals.

34. Fusion. Bilateral double teeth in the place of the
mandibular lateral incisors and cuspids.
Fusion. Radiograph of the same
patient Note the bifi d crown overlying
the single root canal; the contralateral
radiograph revealed a similar pattern.

35.  The presence of double teeth (i.e., gemination or fusion) in the
deciduous dentition can result in crowding ,abnormal spacing,
and delayed or ectopic eruption of the underlying permanent
teeth.
 When detected, the progression of eruption of the permanent
teeth should be monitored closely by careful clinical and
radiographic observation. When appropriate, extraction may
be necessary to prevent an abnormality in eruption.

36. Concrescence
 The union of two teeth by cementum without confluence of the dentin.
 The developmental pattern often involves a second molar tooth in which
its roots closely approximate the adjacent impacted third molar

37. Concrescence. Union by cementum of adjacent
maxillary molars.

38. Concrescence. Union by cementum of
maxillary second and third molars. Note
the large carious defect of the
second molar.
Concrescence. Gross photograph of the same
teeth Histopathologic examination revealed
that union occurred in the area of cemental
repair previously damaged by a periapical
inflammatory lesion.

39. ACCESSORY CUSPS
 CUSP OF CARABELLI:
is an accessory cusp located on the palatal surface of the mesiolingual cusp of a maxillary molar.
The cusp is most pronounced on the first molar.
 TALON CUSP:
is a well-delineated additional cusp that is located on the surface of an anterior tooth and extends at
least half the distance from the cementoenamel junction to the incisal edge.
 DENS EVAGINATUS:
is a cusplike elevation of enamel located in the central groove or lingual ridge of the buccal cusp of
premolar or molar teeth.

40. CUSP OF CARABELLI

41. Talon cusp. Accessory cusp present on the
lingual surface of a mandibular lateral incisor.
Talon cusp. Radiograph of same
patient. Note the enamel and dentin
layers within the accessory cusp

42. Dens evaginatus. Cusplike elevation located in
the central groove of mandibular fi rst bicuspid.
Dens evaginatus. Radiograph of teeth Note
the tuberculated occlusal anatomy.
Attrition on the accessory cusp led to pulpal
necrosis and periapical infl ammatory
disease.

43.  Patients with talon cusps on mandibular teeth often require no therapy;
talon cusps on maxillary teeth frequently interfere with occlusion and
should be removed.
 Other complications include compromised aesthetics, displacement of
teeth, caries, periodontal problems, and irritation of the adjacent soft tissue
(e.g., tongue or labial mucosa)
 Dens evaginatus typically results in occlusal problems and often leads to
pulpal death.
 In affected teeth, removal of the cusp often is indicated, but attempts to
maintain vitality have met with only partial success.

44. DENS INVAGINATUS (DENS IN DENTE)
 A deep surface invagination of the crown or root that is lined by enamel.
 coronal dens invaginatus has been classified into three major types:
 Type I exhibits an invagination that is confined to the crown.
 The invagination in type II extends below the cementoenamel junction
and ends in a blind sac that may or may not communicate with the
adjacent dental pulp
 Type III extends through the root and perforates in the apical or lateral
radicular area without any immediate communication with the pulp.

45. Coronal dens invaginatus type II.
Maxillary lateral incisor exhibiting
invagination of the surface enamel
that extends below the
cementoenamel junction.
Coronal dens invaginatus
type II. Bulbous
maxillary cuspid exhibiting a
dilated invagination lined by
enamel.
Coronal dens invaginatus type II. Gross
photograph of a sectioned tooth. Note the
dilated invagination with apical
accumulation of dystrophic enamel.

46. Coronal dens invaginatus type III. Parulis
overlying vital maxillary cuspid and lateral incisor. The
cuspid contained a dens invaginatus that perforated the
mesial surface of its root. Coronal dens invaginatus type III.
Maxillary cuspid exhibiting an enamel
invagination that parallels the pulp canal
and perforates the lateral root surface

47. ECTOPIC ENAMEL
 The presence of enamel in unusual locations, mainly the tooth root.
 The most widely known are enamel pearls.
 These are hemispheric structures that may consist entirely of enamel or
contain underlying dentin and pulp tissue.
 The majority occur on the roots at the furcation area or near the
cementoenamel junction

48. Enamel pearl. Mass of ectopic enamel
located in the furcation area of a molar
tooth.
Enamel pearl. Radiopaque nodule on the mesial surface of
the root of the maxillary third molar. Another less
distinct enamel pearl is present on the distal root of the
second molar.

49. TAURODONTISM
 Is an enlargement of the body and pulp chamber of a multirooted tooth,
with apical displacement of the pulpal floor and bifurcation of the roots.
 Affected teeth tend to be rectangular and exhibit pulp chambers with a
dramatically increased apicoocclusal height and a bifurcation close to the
apex.

51. HYPERCEMENTOSIS
 Hypercementosis (cemental hyperplasia) is a nonneoplastic
deposition of excessive cementum that is continuous with the normal
radicular cementum.
 Radiographically, affected teeth demonstrate a thickening or blunting
of the root.

53. DILACERATION
 Dilaceration is an abnormal angulation or bend in the root or, less frequently,
the crown of a tooth.
 The damage frequently follows avulsion or intrusion of the overlying primary
predecessor.
 Altered deciduous teeth often demonstrate inappropriate resorption and
result in delayed eruption of the permanent teeth.

54. Dilaceration. Sharp curvature of the root of a
maxillary central incisor.
Dilaceration. Maxillary second bicuspid
exhibiting mesial inclination of the root. The patient
reported no history of injury to this area.

55. SUPERNUMERARY ROOTS
The term supernumerary roots refers to the deve lopment of an increased number of roots on a
tooth compared with that classically described in dental anatomy.
The most frequently affected teeth are the permanent molars (especially third molars) from either
arch.

56. DEVELOPMENTAL ALTERATIONS IN
THE STRUCTURE OF TEETH
 AMELOGENESIS IMPERFECTA
 DENTINOGENESIS IMPERFECTA

57. AMELOGENESIS IMPERFECTA
 Developmental alterations in the structure of the enamel in the absence of a
systemic disorder.
 The hereditary defects of the formation of enamel also are divided into :
hypoplastic, hypocalcified, and hypomaturation.
 the main problems are aesthetics, dental sensitivity, and loss of vertical
dimension. In addition, in some types of amelogenesis imperfecta there is an
increased prevalence of caries, anterior open bite, delayed eruption, tooth
impaction, or associated gingival inflammation.

58. Hypoplastic amelogenesis imperfecta, generalized pitted pattern. A, Note the
numerous pinpoint pits scattered across the surface of the teeth. The enamel between the pits
is of normal thickness, hardness, and coloration. B, Occlusal view of same patient showing
diffuse involvement of all maxillary teeth,

59. Hypoplastic amelogenesis imperfecta, autosomal dominant smooth pattern
(generalized thin pattern). A, Small, yellowish teeth exhibiting hard, glossy enamel with
numerous open contact points and anterior open bite. B, Radiograph of the same patient
demonstrating thin peripheral outline of radiopaque enamel.

60. Hypoplastic amelogenesis imperfecta, rough pattern (generalized thin pattern).
A, Small, yellow teeth with rough enamel surface, open contact points, signifi cant attrition,
and anterior open bite. B, Radiograph of the same patient. Note the impacted tooth and the
thin peripheral outline of radiodense enamel.

61. Hypomaturation amelogenesis imperfecta,
X-linked. A, Male patient exhibiting diffuse
yellow-white dentition. B, The patient’s
mother exhibits vertical bands of
white, opaque enamel and translucent
enamel.

62. Hypocalcified amelogenesis imperfecta. A, Dentition exhibiting diffuse yellowbrown
discoloration. Note numerous teeth with loss of coronal enamel except for the cervical
portion. B, Radiograph of the same patient. Note the extensive loss of coronal enamel and the
similar density of enamel and dentin.

63. DENTINOGENESIS IMPERFECTA
 Dentinogenesis imperfecta is a hereditary developmental disturbance of the
dentin in the absence of any systemic disorder.
 The dentitions have a blue-to-brown discoloration, often with a distinctive
translucence.
 Radiographically, the teeth have bulbous crowns, cervical constriction, thin
roots, and early obliteration of the root canals and pulp chambers.
 Shell teeth demonstrate normal-thickness enamel in association with
extremely thin dentin and dramatically enlarged pulps

64. Dentinogenesis imperfecta.
Dentition exhibiting
diffuse brownish
discoloration and slight
translucence.
Dentinogenesis imperfecta.
Dentition exhibiting
grayish discoloration with signifi
cant enamel loss and
attrition.
Dentinogenesis imperfecta.
Radiograph of
dentition exhibiting bulbous
crowns, cervical constriction,
and obliterated pulp canals
and chambers.

65. Shell teeth. Dentition exhibiting normal
thickness enamel, extremely thin dentin, and dramatically
enlarged pulps.

66. Reference
1. Neville B., Damm D., Allen C and Bouquot J: (2016) Oral and
Maxillofacial Pathology, 4th edition, Saunders Elsevier. ISBN-
9788131215708.
2. Differential diagnosis of dental diseases ,Priya Verma Gupta
,JAYPEE (2008) First edition.