Developmental Dental Anomalies

Developmental Dental Anomalies

• Alterations in size of teeth = due to problem in morphology stage
• Alterations in shape of teeth = due to problem during appositional (calcification) stage
• Abnormalities on position of teeth = due to problems during stage of eruption

Anodontia:

• Messing clinically + radiographically → true anodontia
• Messing clinically but not radiographically → pseudo-partial anodontia
• Messing clinically & radiographically with history of extraction → false anodontia

Hyperdontia:

• Like normal teeth → supplemental (impacted or normally erupted)
• Abnormal structure→

→    Bt. Ant. Teeth = mesiodens

→    Distal to teeth = distomolar = paramolar (most commonly distal to the wisdom)

→    Buccal or lingual  = paradent (mostly in premolar region)

• Supernumerary tooth may erupt in inverted direction.
• Cleidocranial dysplasia → multiple impacted + supernumerary teeth
• Gardner’s syndrome→ multiple impacted + supernumerary teeth
• Retained = under occlusion
• Submerged = lower level than occlusal plane (of the other teeth)

→    The difference bt. Retained & submerged teeth are ……………….

• Partial anodontia→ found a lot in ectodermal dysplasia (=thertus syndrome << not sure of the spelling) & in papillary –something- syndrome… how to differentiate?

→Ectodermal dysplasia is associated with absence of sweat & sebaceous glands, loss of hair, fragile nails… etc & the partial anodontia is due to the absence of teeth (no formed) .. if he had 2 teeth → these are the only teeth formed

→Papillary –something- syndrome; partial anodontia is associated with continuous shedding of teeth (eruption & shedding), hyperkeratosis in hand & leg

 

Variations are Size:

• Either macro or micro, true or relative:

→True = in comparison to the adjacent teeth, involving 1 tooth

→    Relative = in comparison to the jaw (large jaw →relatively teeth look small), involving all teeth.

• Microdontia is commonly seen in Dwarfism cases, & most common affected teeth = 2^nd & 8^th
• Macrodontia is commonly seen in Gigantism.
• Fusion may lead to macrodontia

Variation of morphology:

• Dilacerations (bending of root near apex)→problem during extraction (fracture)
• Tauradontism;
  • Clinically; same as normal
  • Pulp chamber become rectangular or square
  • Bifurcation is located near apex (in apical 1/3 of the root)
• Fusion;

→ Bt. 2 normal teeth→1 messing tooth clinically

→  Bt. 1 normal tooth + 1 supernumerary tooth→ normal # of teeth clinically.

• Enamel pearl (enameloma);
  • sometimes, it has small pulp chamber (small radiolucency)
  • located in bifurcation areas
• Pulp stone (denticle); causes  problems in RCT
• Turner tooth:  trauma in deciduous tooth affecting the mineralization of the underlying permanent tooth
• Congenital syphilis:  moon (mulberry) molar.
• Dense indente (tooth inside another tooth) → causes problems in RCT
• Concrescence: causes problems during extractions (of u tried to extract a tooth, the other tooth fused to it would be pulled out too)
• Fusion: might happen in the coronal region only or in the entire tooth.
• Gemintaion = 2 germs join together resulting in macrodontia.

Variations on structure:

• Odontome = disarrangement of tooth structure
  • It’s surrounded mostly by radiolucent (fibrous) line.
  • Types:

a)      Compound = denticle or tooth haphazardly distributed… (mostly in upper central incisor & upper & lower 3th molar regions)

b)      Complex = calcified matrix associated with unerupted (impacted) tooth.

• Dentinogenesis imperficta:
  • we’ll find all the following in all teeth:

a)      Bulbous crown

b)      Constriction  CEJ

c)      Short roots

d)     Obliteration in pulp

• Associated sometimes with ……….. (known by blue sclera)
• Enamel is normal, but sometimes it becomes pitted (due to the abnormal dentine beneath)
• Associated with osteogenesis imperficta
• Dentinal dysplasia (type 1), we commonly see:           
  • Rootless teeth (poorly developed roots)
  • Absence of pulp chamber
  • Associated with periapical lesion
• Amelogenesis imperficta:
  • Severe alterations in all teeth
  • Defect in enamel, while dentin is normal.
  • No contour of tooth (e.g. no contact areas)… due to absence of enamel that forms the shape & contour of the crown.
  • Severe attrition
• Odontodysplasia:
  • Resorption, hypocalcification, very thin enamel
• Turner’s hypoplasia: hypomineralization
• Cleidocranial dysplasia:
  • MCQ:  most commonly, dentigerous cysts are associated with Cleidocranial dysplasia
  • Normal deciduous teeth
  • Developmentally formed permanent teeth, but they fail to erupt →clinically messing teeth but seen radiographically → pseudo-partial anodontia.

Tags: Amelogenesis imperficta, Anodontia, Cleidocranial dysplasia, Dentinogenesis imperficta, Hyperdontia, Odontodysplasia, Turner's hypoplasia

Category: Articles, Oral Pathology