2. • There are many developmental abnormalities
that can affect the teeth and facial skeleton. In
most cases, clinicians need little more than to
be able to recognize these abnormalities
ikassem@dr.com
10. Missing teeth
• Localized anodontia or hypodontia — usually
third molars, upper lateral incisors or second
premolars.
• Anodontia or hypodontia associated with
systemic disease — e.g. Down's syndrome,
ectodermal dysplasia.
ikassem@dr.com
23. Acquired defects
• Turner teeth — enamel defects caused by
infection from overlying deciduous predecessor
• Congenital syphilis — enamel hypoplastic and
altered in shape (see below)
• Severe childhood fevers, e.g. measles — linear
enamel defects
Fluorosis — discolouration or pitting of the
enamel
• Discolouration — e.g. tetracycline staining.
ikassem@dr.com
31. Anomalies affecting -whole teeth
• Fusion — two teeth joined together from the
fusion of adjacent tooth germs
• Gemination — two teeth joined together but
arising from a single tooth germ
• Concrescence — two teeth joined together by
cementum
• Dens-in-dente (invaginated odontome) — in
folding of the outer surface of a tooth into the
interior usually in the cingulum pit region of
maxillary lateral incisors.
ikassem@dr.com
39. Anomalies affecting roots and or pulp
canals
• Number — additional roots, e.g. two-rooted
incisors, three-rooted premolars or four-rooted
molars
• Morphology, including:
— Bifid roots
— Excessively curved roots
— Dilaceration — sharp bend in the root
direction
— Taurodontism — short, stumpy roots and
longitudinally enlarged pulp chambers
Pulp stones — localized or associated with
specific syndromes, e.g. Ehlers-Danlos (floppy
joint syndrome).
ikassem@dr.com
45. Odontomes
• Enameloma/enamel pearl
• Cementoma (see fibro-cemento-osseousmesions in
— Benign cementoblastoma (true cementoma)
— Periapical cemento-osseous dysplasia
— Focal cemento-osseous dysplasia
— Florid cemento-osseous dysplasia
(gigantiform cementoma)
• Composite
— Compound odontome — made up of one or more small
tooth-like denticles
— Complex odontome — complex mass of disorganized dental
tissue.
ikassem@dr.com
51. Delayed eruption
• Local causes
— Loss of space
— Abnormal crypt position — especially 8/8 and 3/3
— Overcrowding
— Additional teeth
— Retention of deciduous predecessor
— Dentigerous and eruption cysts
• Systemic causes
— Metabolic diseases, e.g. cretinism and rickets
— Developmental disturbances, e.g. cleidocranial dysplasia
— Hereditary conditions, e.g. gingival fibromatosis and
cherubism.
ikassem@dr.com
52. Other positional anomalies
• Transposition two teeth occupying exchanged positions
• Wandering teeth, movement of unerupted
teeth for no apparent reason (distal drift)
• Submersion, second deciduous molars apparently descend into the
jaws. Since these teeth do not in fact submerge, but rather remain in
their original position while the adjacent Other positional anomalies
• Transposition, two teeth occupying exchanged positions
• Wandering teeth, movement of unerupted teeth for no apparent
reason (distal drift)
• Submersion, second deciduous molars apparently descend into the
jaws. Since these teeth do not in fact submerge, but rather remain
in their original position while the adjacent
ikassem@dr.com
57. Abnormalities of the mandible or
maxilla
• Micrognathia
• Macrognathia (prognathism)
• Other mandibular anomalies
ikassem@dr.com
58. Micrognathia
• True micrognathia — usually caused by bilateral
hypoplasia of the jaw or agenesis of the condyles
• Acquired micrognathia — usually caused by unilateral
early ankylosis of the temporomandibular joint.
ikassem@dr.com
64. Cleft lip and palate
• Cleft lip
— Unilateral, with or without alveolar ridge
— Bilateral, with or without alveolar ridge
• Cleft palate
— Bifid uvula
— Soft palate only
— Soft and hard palate
• Clefts of lip and palate (combined defects)
— Unilateral (left or right)
— Cleft palate with bilateral cleft lip.
ikassem@dr.com
