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

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

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

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

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

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

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

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

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

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)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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