1. Developmental disorders
Assoc. Professor Jan Laco, MD, PhD

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 I2, M3)
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, upper I1
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 I2, bilateral, caries

7. 1a. Abnormalities of size and form
taurodontism (bull tooth)
wide pulp chamber
molars
enamel pearl
displaced 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
M3 + P2 + I2
M3 + P2: NO effect
I2: false eruption of C to I1
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 M3 (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 M4
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
AD inheritance
defect of matrix formation – pits, grooves, hard
Hereditary enamel hypocalcification
AD + AR inheritance
normal matrix poorly calcified – soft, chalky

16. 1c. Defects of structure – systemic diseases
Chronological hypoplasia
transient impairment of enamel formation in case of severe illness
severe fever, gastroenteritis, measles in the past
horizontál bands of pits, grooves, defects
Molar-incisor hypomineralisation
all M1 a I1 a I2
enamel - hard surface, but soft beneath
yellow brown discoloration, ↑ caries

17. 1c. Defects of structure – systemic diseases
Dentinogenesis imperfecta
defect of collagen/sialoprotein, AD
normal teeth shape
brownish, translucent enamel  chip away
obliteration of pulp
dentine - few tubules + abnormal matrix + incomplete calcification
“shell teeth“ – thin mantle of dentine covers abnormal dentine, few odontoblasts, no roots
Dentinal dysplasia
very short and conical roots, teeth are lost early
Regional odontodysplasia (ghost teeth (radiolucent on RTG))
hypoplastic / hypomineralised enamel + thin dentine

18. 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

19. 1c. Defects of structure – systemic diseases
Congenital syphilis – Hutchinson (1858)
later fetal infection
dental follicle infection by T. pallidum
chronic inflammation  fibrosis of tooth sac  compression of developing tooth  distortion of ameloblasts
permanent teeth
upper I1 (Hutchinson´s incisors) – barrel-shaped,
fissure on incisal edge
M1 (Moon´s molars) – dome-shaped,
pitted occlusal surface (“mulbery molar“)

20. 1c. Defects of structure – systemic diseases
Tetracycline (TTC)
taken up calcifying tissues
yellow fluorescence (UV light)
during teeth development – fetus x infancy
dentine
bright yellow  brown  grey
permanent teeth
Avoid TTC under 12 years

21. 1c. Defects of structure – systemic diseases
Fluorosis (mottled enamel)
 fluoride in drinking water, India
during dental development
paper-white patches  brown
permanent teeth
hydroxyapatite  calcium fluoroapatite
patches of incomplete calcification with high organic and water content
enamel matrix usualy normal

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

23. 1d. Disorders of eruption
deciduous teeth: 6th – 30th month
at birth: natal teeth
1st month: neonatal teeth (lower I1)
permanent teeth: 6th – 13th y (M3: 18th – 30th y)
loss of space, retention of a dec. predecessor
cretenism, rickets

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

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

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

27. 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 (1 in 200 pts.)
van der Woude syndrome (AD, IRF6 gene)
clefts + pits on lower lips + hypodontia

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

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

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

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

32. 4a. Developmental disorders – oral mucosa
white sponge nevus – AD inheritance
white, soft, thickened area of oral mucosa
Mi: acantosis + hyperkeratosis + intracellular edema
Fordyce´s granules
heterotopic sebaceous glands
80% adults
soft yellowish spots or papules
symmetrical, buccal location

33. 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

34. 4c. Developmental disorders – tongue
macroglossia
muscle hypertrophy
congenital hemangioma or lymphangioma
Down´s syndrome
lingual thyroid
incidence 10%
nodule, foramen caecum
cleft tongue
ankyloglossia

35. 4c. Tongue Lingua plicata
cerebelli-, cerebriformis, fissurata, gyrata, scrotalis
fissured dorsal aspect of tongue
children x adults
asymptomatic x pain during eating, hygiene
+ geographical tongue
+ Cowden syndrome
+ Melkersson-Rosenthal syndrome

36. 4c. Jazyk Lingua geographica geographical tongue, glossitis migrans
+ lingua plicata; ± psoriasis
asymptomatic x pain during eating
irregular smooth red area  healing (hours / days)  another red area appears
centre – epithelium thinning; periphery – hyperplasia + keratinization; mild inflammation