1. Developmental disorders
Jan Laco, M.D., Ph.D.

2. Developmental disorders
1. Teeth
2. Jaws
3. Clefts
4. Oral soft tissue

3. Developmental disorders - teeth
1a. Abnormalities of size and form
1b. Abnormalities of number
1c. Defects of structure
1d. Disorders of eruption

4. 1a. Abnormalities of size and form
microdontia …teeth < normal
permanent teeth
absolute x relative
generalized x single (upper 2. I, 3. M)
macrodontia …teeth > normal
generalized x single

5. 1a. Abnormalities of size and form
gemination (schizodontia, twinning)
incomplete division of tooth germ
2 separated crowns on single root
fusion (synodontia)
concrescence
fusion after development of roots (injury)
teeth united by cementum

6. 1a. Abnormalities of size and form
dilaceration
angulation at crown-root junction (injury)
difficult extraction
talon cusp
lingual or palatal aspect of permanent teeth
dens invaginatus (dens in dente)
invagination of enamel into pulp chamber
upper 2. I, bilateral, caries

7. 1a. Abnormalities of size and form
taurodontism (bull tooth)
wide pulp chamber
molars
enamel pearl
ameloblasts below amelocemental junction
mm nodule, upper M

8. Developmental disorders - teeth
1a. Abnormalities of size and form
1b. Abnormalities of number
1c. Defects of structure
1d. Disorders of eruption

9. 1b. Abnormalities of number
Isolated hypodontia – common
hereditary
3. M + 2. P + 2. I
3. M + 2. P: NO effect
2. I: false eruption of C to 1. I
Anodontia – very rare

10. 1b. Abnormalities of number
Anhidrotic ectodermal dysplasia
X-linked inheritance
hypodontia + hypotrichosis + anhidrosis
failure of development of alveolar process
Down´ s syndrome
no 3. M (90% patients)

11. 1b. Abnormalities of number
Hyperdontia (additional teeth) – common
supernumerary: conical
incisor + molar region + midline (mesiodens)
supplemental: normal
excessive growth of l. dentalis
4. M
Cleidocranial dysplasia
Gardner´s syndrome

12. Developmental disorders - teeth
1a. Abnormalities of size and form
1b. Abnormalities of number
1c. Defects of structure
1d. Disorders of eruption

13. 1c. Defects of structure deciduous teeth neonatal jaudice  yellow
congenital porphyria  red
Tetracycline
permanent teeth
periapical infection of d. predeccesor – Turner tooth
systemic diseases

14. 1c. Defects of structure – systemic diseases
genetic
amelogenesis imperfecta
dentinogenesis imperfecta
Ehlers-Danlos syndrome, Gardner´s syndrome
infective – congenital syphilis
metabolic – childhood infections, rickets
drugs – tetracycline, cytotoxic chemotherapy
fluorosis

15. 1c. Defects of structure – systemic diseases
Amelogenesis imperfecta
all teeth + whole enamel x dentine normal
Hereditary enamel hypoplasia
defect of matrix formation – pits, grooves, hard
Hereditary enamel hypocalcification
normal matrix poorly calcified – soft, chalky

16. 1c. Defects of structure – systemic diseases
Dentinogenesis imperfecta
defect of collagen, AD
normal teeth shape
brownish, translucent enamel  chip away
obliteration of pulp
dentine - few tubules + abnormal matrix + incomplete calcification
Dentinal dysplasia
Regional odontodysplasia, Shell teeth

17. 1c. Defects of structure – systemic diseases
Ehlers - Danlos syndrome (floppy joints)
collagen disorder
hypermobile joints + loose skin
small teeth + short roots + pulp stones
Gardner´s syndrome
multiple osteomas (jaws) + skin tumors + colonic polyps  malignant change
impacted teeth, supernumerary teeth

18. 1c. Defects of structure – systemic diseases
Congenital syphilis - Hutchinson
later fetal infection
dental follicle infection by T. pallidum
permanent teeth
upper 1. I (Hutchinson´s incisors) – barrel-shaped
fissure on incisal edge
1. M (Moon´s molar) – pitted occlusal surface

19. 1c. Defects of structure – systemic diseases
Tetracycline (TTC)
calcifying tissues
yellow fluorescence (UV light)
during teeth development – fetus x infancy
dentine
bright yellow  brown  grey
permanent
NOT TTC under 12 years

20. 1c. Defects of structure – systemic diseases
Fluorosis (mottled enamel)
 fluoride in drinking water
paper-white patches  brown
permanent teeth
hydroxyapatite  calcium fluoroapatite
matrix normal

21. Developmental disorders - teeth
1a. Abnormalities of size and form
1b. Abnormalities of number
1c. Defects of structure
1d. Disorders of eruption

22. 1d. Disorders of eruption
deciduous teeth: 6th month – 2nd year
at birth: natal teeth
1st month: neonatal teeth (lower 1. I)
permanent teeth: 6th year – 25th year
loss of space, retention of a dec. predecessor
cretenism, rickets

23. Developmental disorders
1. Teeth
2. Jaws
3. Clefts
4. Oral soft tissue

24. 2. Developmental disorders - jaws
micrognathia x macrognathia
hereditary prognathism
craniofacial anomalies
cherubism
Gardner´s syndrome
osteogenesis imperfecta

25. Developmental disorders
1. Teeth
2. Jaws
3. Clefts
4. Oral soft tissue

26. 3. Developmental disorders - clefts
NOT clefts  non-fusion !!!
? ethiology - genetic component (40%)
cleft lip -  males, inc. 1/1000
cleft palate -  females, inc. 1/2000
lip : lip + palate : palate …22% : 58% : 20%
+ Down´s syndrome

27. 3. Developmental disorders - clefts
cleft lip – cheiloschisis
lateral: unilateral (left side) x bilateral
medial
cleft alveolar ridge – gnathoschisis
hard palate cleft – palatoschisis
soft palate cleft - uranoschisis
uvula cleft - staphyloschisis

28. 3. Developmental disorders - clefts
complications
malformation or absence of teeth in defect
+ other congenital defects
feeding disorder
breathing disorder
speech defect
cosmetic defect

29. Developmental disorders
1. Teeth
2. Jaws
3. Clefts
4. Oral soft tissue

30. 4. Developmental disorders – oral soft tissues
4a. oral mucosa
4b. gingiva and periodontium
4c. tongue

31. 4a. Developmental disorders – oral mucosa
white sponge nevus – AD inheritance
white, soft, thickened area of oral mucosa
Mi: acantosis + hyperkeratosis + intracellular oedema
Fordyce´s granules
heterotopic sebaceous glands
80% adults
soft, creamy spots, papules
symetrical, buccal location

32. 4b. Developmental disorders – gingiva and periodontium
hereditary gingival fibromatosis
AD inheritance
grossly enlarged gingivae - preceding of teeth eruption
Mi: collagen bundles
gingivectomy after puberty
Ehlers-Danlos syndrome

33. 4c. Developmental disorders – tongue
macroglossia
muscle hypertrophy
congenital haemangioma or lymphangioma
Down´s syndrome
lingual thyroid
inc. 10%
nodule, foramen caecum
cleft tongue
ankyloglossia