Developmental disorders

Jan Laco, M.D., Ph.D.

Developmental disorders

• 1. Teeth

• 2. Jaws

• 3. Clefts

• 4. Oral soft tissue

1. 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

1. 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

1. 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

1. 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