Developmental disorders

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 • absolute x relative • 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

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

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

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

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

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

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

Developmental disorders