This document discusses various developmental disturbances that can affect the oral cavity. It covers disturbances in size, number, eruption, shape, structure of enamel and dentin. Specific conditions discussed in detail include microdontia, macrodontia, anodontia, hypodontia, supernumerary teeth, impacted teeth, enamel hypoplasia, fluorosis, dentinogenesis imperfecta, dentin dysplasia, regional odontodysplasia and more. Diagrams and radiographs are provided to illustrate features of these different disturbances.

1. DEVELOPMENTAL ORO-FACIAL
DISTURBANCES PART I
Dr. Ali Tahir
B.D.S, R.D.S,
M.Phil Oral Pathology

2. ORAL PATHOLOGY
 It is the speciality of dentistry and pathology that deals
with the nature, identification and management of
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diseases affecting the oral & maxillofacial regions
 It is a science that investigates the causes, processes &
effects of these diseases
 The practice of oral pathology includes research,
diagnosis of disease using clinical, radiographic,
microscopic biochemical or other necessary
examinations & investigations

3. DISTURBANCES IN SIZE
Microdontia
When one or more teeth are smaller than
normal
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Generalized
 True generalized: When all teeth are uniformly smaller
than normal
Cause: Pituitary Dwarfism, Down’s syndrome
 Relative generalized: When mandible or maxilla are
somewhat larger (Macrognathia) but teeth are of normal
size
Localized
 When one tooth is involved
 Maxillary lateral incisors are the most common

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MICRODONTIA

5. DISTURBANCES IN SIZE
Macrodontia
When one or more teeth are larger than normal
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Generalized
 True Generalized: When all teeth are uniformly larger
 Relative Generalized: When maxilla/mandible is smaller
in size (Micrognathia) but teeth are of normal size
Regional
 It is localized e.g; Hemifacial hypertrophy (unilateral),
segmental odontomaxillary dysplasia
 Rhizomegaly :
 When only roots are larger than normal

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MACRODONTIA

7. DISTURBANCES IN NUMBER
Anodontia
 Congenital absence of all teeth
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 Associated with Hereditary Ectodermal Dysplasia
Hypodontia
 Congenital absence of one or more teeth
 Third molars, maxillary lateral incisors are most
commonly absent teeth consecutively

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9. DISTURBANCES IN NUMBER
Supernumerary Teeth
Teeth in excess of normal number
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 More common in maxilla (90%)
 Examples
Maxilla
 Mesiodens
 Paramolars
 Lateral incisors
Mandible
 Premolars
 paramolars
Multiple supernumerary teeth are seen in Cliedocranial dysplasia
and gardner sydrome

10. SUPERNUMERARY TEETH
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11. DISTURBANCES IN ERUPTION
Premature Eruption
 Natal Teeth:
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 Erupted decidous teeth present at time of birth
 Neonatal:
 Deciduous teeth that erupt in first 30 days of life
Premature eruption of entire permanent dentition should
suspect the possibility of hyperthyroidism

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NATAL TEETH

13. DISTURBANCES IN ERUPTION
Delayed Eruption
 Eruption later than the normal age of eruption
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 Usually idiopathic
 Or associated with systemic conditions such as
rickets, cliedocranial dysplasia, cretinism
 Gingival fibromatosis

14. DISTURBANCES IN ERUPTION
Impacted teeth
Teeth with eruption that is impeded by a
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physical barrier
 Causes:
 Dental crowding
 Supernumerary teeth
 Odontogenic cysts
 Odontogenic tumors (odontomas)
 Most common are mandibular and maxillary
third molars followed by maxillary cuspids

15. IMPACTED TEETH
 Classified according to their orientation as
 Mesioangular
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 Distoangular
 Horizontal
 Vertical
 According to their stage of eruption
 Completely impacted (within bone)
 Partially impacted (partly in soft tissue)

16. IMPACTED TEETH
Partially impacted teeth that communicate with the oral
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cavity are more prone to pericoronitis
 Complications
 Root resorption of adjacent normal tooth
 Infection & pain
 Dentigerous cyst
 External resorption of impacted tooth

17. IMPACTED TEETH
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18. DISTURBANCES IN ERUPTION
Eruption Sequestrum
A small spicule of calcified tissue that is extruded
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through the alveolar mucosa that overlies an
erupting molar

19. DISTURBANCES IN SHAPE
Dilaceration
A sharp bend or
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angulation involving the
root of the tooth
Causes:
 Trauma during tooth
formation
 Continued root
formation during a
curved or tortuous path
of eruption

20. DISTURBANCES IN SHAPE
Taurodontism
A molar with an
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elongated crown and
apically placed
furcation of roots
resulting in an enlarged
rectangular pulp
chamber.
Occurs because of late
invagination of
Hertwig’s Epithelial
Root Sheath

21. DISTURBANCES IN SHAPE
Dens Invaginatus
Developmental
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anomaly characterized
by a deep enamel lined
pit that extends for
varying depths into the
underlying dentin
displacing the pulp
chamber

22. DENS IN DENT AND SUPERNUMERARY
CUSP
Supernumerary
cusps
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Teeth containing
additional cusp
Example: Cusp of
caribili, Talon cusp

23. DISTURBANCES IN SHAPE
Dens Evaginatus
Characterized by
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cusp like
supernumerary
enamel protrusion
on occlusal or
lingual surface of
crown

24. Gemination
Single rooted tooth with
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unusual wide, partly
divided crown or two
separate crowns.
Cause: Because of
partial division of a
single tooth gem
 Teeth count is normal

25. DISTURBANCES IN SHAPE
Fusion
Abnormally shaped
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tooth with wide crown
or a normal crown with
additional root(s)
Cause: Results from
the union of two tooth
germs

26. DISTURBANCES IN SHAPE
Concrescence
Union of the roots of
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two or more normal
teeth by confluence of
their cementum.
Cause: Trauma, Inter-
septal bone loss

27. DISTURBANCES IN SHAPE
Hypercementosis
One or more teeth with excessive deposition of
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cementum of roots
Causes: Increase/Decreased occlusal forces,
Paget’s disease, hyperpituitarism, chronic
inflammation

28. Cervical Enamel
Projections
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Apical extension of
coronal enamel beyond
the smooth cervical
margin

29.  Hemispheric structures
that may consist
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entirely of enamel or
may contain underlying
dentin & pulp
 Mostly present in roots
of maxillary or
mandibular molars

30. DISTURBANCES IN STRUCTURE OF ENAMEL
 Acquired
Environmental factors
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 Bacterial (syphilis), viral infections
 Inflammation
 Nutritional deficiencies
 Chemical injuries
 Trauma
 Genetic
 Amelogenesis Imperfecta

31. ACQUIRED DISTURBANCES
Focal enamel hypoplasia
 Localized enamel hypoplasia involving one or two
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teeth
 Example: Turner tooth, results from localized
inflammation or trauma during tooth development
 Enamel has pitting areas or deformed with
yellowish or brownish discoloration

32. ACQUIRED DISTURBANCES
Generalized Enamel Hypoplasia
 Systemic or Environmental factors inhibit
functioning ameloblasts.
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 Enamel has horizontal lines of small pits or
grooves
 Example:
 Hutchinson’s incisors and mulberry molars due to
congenital syphilis
 Neonatal line
 Flourosis
 Can also be seen in hypocalcemia (Vit. D
deficiency), measles, chicken pox, scarlet fever, Vit
A & C deficiency

33. GENERALIZED ENAMEL HYPOPLASIA
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34. ACQUIRED DISTURBANCES
Flourosis (Flouride mottling)
 Minimal Flourosis:
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Smooth enamel surface with white flecks
 Mild Flourosis:
Smooth enamel surface with white opaque areas
 Moderate to severe:
Pitting and brownish discoloration
 Severe:
Enamel is softer and weaker than normal, resulting
in excessive wear
Teeth are largely resistant to caries

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36. HEREDITARY DISTURBANCES
Amelogenesis Imperfecta
A heterogeneous group of genetic disorders
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exhibiting faulty enamel formation (affects both
primary & permanent dentition)
Normal enamel formation:
1. Enamel matrix formation
2. Mineralization of enamel
3. Enamel maturation (secondary mineralization)
Accordingly three types of AI is identified

37. TYPES
Clinical Features:
 Hypoplastic (focal or generalized)
 Decreased enamel formation by disturbance in function of
ameloblasts
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 Enamel is thinner than normal
 Radiodensity is greater than that of dentin
 Hypocalcified
 Defect in mineralization of enamel
 Enamel is off normal thickness but softer than normal
 Can be easily removed with a blunt instrument
 Radiodensity is lesser than that of dentin
 Haypomaturation
 Focal or generalized areas of immature enamel
crystallites
 Enamel of normal thickness, but less harder and is
radiolucent e.g. snow capped teeth

38. WITKOP/SAUK CLASSIFICATION
 Hypoplastic
 Pitted, autosomal dominant
 Local, autosomal dominant
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 Smooth, autosomal dominant
 Rough, autosomal dominant
 Rough, autosomal recessive
 Smooth, X-linked
 Hypocalcified
 Autosomal dominant
 Autosomal recessive
 Hypomaturation
 Autosomal dominant (with taurodontism)
 X-linked recessive
 Pigmented, autosomal recessive
 Snow-capped teeth

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40. DISTURBANCES IN STRUCTURE OF DENTIN
Acquired
 Turner tooth
 Regional odontodysplasia
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Genetic
 Dentinogenesis Imperfecta
 Type I
 Type II
 Type III
 Dentin Dysplasia
 Type I
 Type II
 Familial hypophosphatemia (Vit. D resistant rickets)

41. DENTINOGENESIS IMPERFECTA
A hereditary (autosomal dominant) defect
consisting of opalescent teeth composed of
irregularly formed & undermineralized dentin
that obliterates the pulp chambers & canals
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Types:
 Type 1
 Associated with osteogenesis imperfecta.
 Characterized by bluish tint to sclera
 Type 2
 Hereditary opalescent dentin
 Most common type
 Type 3
 Also called brandywine type
 Clinically the same as type 1 & II
 Multiple pulpal exposures of decidous dentition

42. DENTINOGENESIS IMPERFECTA
Clinical Features
 Both dentitions are affected
 Oplaescent teeth with bluish grey to brownish
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or yellowish discoloration
 Abnormally soft dentin, enamel easily chipped
off
 Despite the exposure of dentin, teeth are not
prone to caries
Histopathology
 The mantle dentin is normal whereas remaining
dentin is severely dysplastic
 Amorphous matrix with globular & inter-globular
areas of mineralization
 Irregularly widely spaced disoriented dentinal
tubules

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44. RADIOGRAPHICALLY
 Type I & II
 Bulb shaped crowns
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 Constricted cemento-enamel junction
 Thin roots
 Varying degrees of obliteration of pulp chamber &
canals
 Type III
 Same features or may show extremely large pulp
chambers surrounded by thin shell of dentin

45. DENTIN DYSPLASIA
A hereditary defect in dentin formation where root
dentin is abnormal & gnarled, roots are
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shortened & tapered
 Also called Rootless teeth
 Autosomal dominant
 Two types
 Type I (radicular)
 Type II (coronal)

46. DENTIN DYSPLASIA
Types:
1) Radicular Dentin Dysplaisa:
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 Brownish or bluish translucency in cervical region
 More common than type II
 All teeth in both dentitions are affected
 Teeth often show increased mobility & exfoliate prematurely
Histopathology:
 Enamel and mantle dentin is normal
 Remaining coronal and root dentin consists of nodular
masses composed of tubular dentin and osteo-dentin
 Slit-like pulp remnants may be seen between nodular masses
 Gives an appearance of ‘lava flowing around boulders’

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48. RADIOGRAPHICAL FEATURES
 Short blunt roots, may
be absent entirely
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 Mandibular molars
have W-shaped roots
 Dentition may show
obliteration of pulp
chambers & canals
 Crescent shaped
remnants of pulp may
be seen

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50. DENTIN DYSPLASIA TYPE II (CORONAL)
 Both dentitions affected
 Deciduous teeth with bluish-grey, brownish or
yellowish discoloration
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 Same translucent, opalescent appearance as in DI
 Permanent teeth have normal clinical appearance
Histopathology:
 Deciduous teeth
 Normal zone of mantle dentin that changes abruptly into
dense amorphous dentin with irregular arrangement of
tubules.
 Permanent teeth
 Globular and inter-globular areas of dentin in pulpal third
of dentin with atubular root dentin
 Has pulp stones in pulp chamber
 Narrow pulp canals

51. RADIOGRAPHIC FEATURES
 Deciduous teeth show
obliteration of pulp
chambers & canals as
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seen in DD type I & DI
 Roots are normal
 Pulp chambers of
permanent teeth are
enlarged
 Thistle-tube or flame
shaped pulp chamber
 Pulpal calcifications in
coronal pulp chamber

52. REGIONAL ODONTODYSPLASIA (GHOST
TEETH)
Defective formation of enamel and dentin with
abnormal pulp and follicle calcifications with
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surrounding soft tissue hyperplaisa along-
with accumulations of spherical
calcifications and odontogenic rests

53. CLINICAL FEATURES
 More common in maxilla
 Affects several adjacent teeth in the same quadrant
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 Mostly in permanent dentition
 Deformed teeth with soft, leathery surface
 Discolored, yellowish brown
Histopathology
 Dysplastic, globular and interglobular dentin
 Widened predentin layer
 Enlarged pulp chamber with pulp stones

54. RADIOGRAPHIC FEATURES
 Ghost teeth
 Decreased
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radiodensity
 Enamel & dentin are
very thin
 Large pulp chambers
 Pulp stones

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56. DISTURBANCES IN STRUCTURE OF
CEMENTUM
Hypophosphatasia
 Disorder of bone mineralization caused by
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deficiency in alkaline phosphatase in serum and
tissues
 Autosomal recessive/dominant
 Delayed formation and eruption of dentition
 Premature loss of primary teeth
 Spontaneous loss of permanent teeth
Radiographically
 Enlarged pulp chambers & pulp canals
Histopathology
 Absence or marked reduction of cementum

57. HYPOPHOSPHATASIA
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