Odontogenesis- Clinical considerations Flashcards by Faye Sitron

What are some initiation stage disturbances? Where do they occur?

Occur in the dental lamina

Anodontia (hypodontia)

Supernumerary Teeth (hyperdontia)

How well did you know this?

Not at all

Perfectly

What is anodontia?

Absence of one or more teeth
Max laterals and third molars most often affected

Complete anodontia= rare, absence of all teeth

How well did you know this?

Not at all

Perfectly

What are supernumerary teeth?

Extra teeth in the permanent dentition

More than 32 teeth, often smaller in size

How well did you know this?

Not at all

Perfectly

What are some bud stage disturbances?

Microdontia (partial or complete)

Macrodontia (partial or comeplete)

How well did you know this?

Not at all

Perfectly

What is microdontia?

Teeth are smaller in size

affects permanent max lateral incisors/ 3rd molars w/ partial microdontia

How well did you know this?

Not at all

Perfectly

What is macrodontia?

Teeth are larger in size

How well did you know this?

Not at all

Perfectly

What are some cap stage disturbances?

Dens in Dente

Germination

Fusion

Tubercle

How well did you know this?

Not at all

Perfectly

What is dens in dente?

Enamel organ invaginates into the dental papilla

Forms a tooth within a tooth

Affects permanent anteriors

How well did you know this?

Not at all

Perfectly

What is germination?

Forming tooth germ tries to divide causing incomplete formation of 2 teeth

Large crown with twinning and one large root

Affects permanent and primary anteriors

How well did you know this?

Not at all

Perfectly

What is fusion?

Union of 2 separate teeth. Common in primary anteriors

Pressure or physical force produces contact between forming tooth germs

Complete= one large single tooth
Incomplete= Union of ROOTS ONLY (2 crown)

How well did you know this?

Not at all

Perfectly

What is a tubercle?

Enamel extension forming an extra cusp

Found on facial/lingual anteriors and buccal/occlusal posteriors

How well did you know this?

Not at all

Perfectly

What are some apposition & maturation disturbances?

Enamel dysplasia
Concrescence
Supernumerary root
Accessory canals
Dilaceration
Enamel pearls

How well did you know this?

Not at all

Perfectly

What is enamel dysplasia?

Faulty enamel development ameloblasts
Enamel pitting (hypoplasia)
Intrinsic color changes (hypocalcification) w/ changes in enamel thickness

How well did you know this?

Not at all

Perfectly

What is concrescence?

A form of fusion that occurs after root formation is complete

Caused by trauma/crowding, causing roots to contract

Roots united by cementum only- two crowns, one large root

How well did you know this?

Not at all

Perfectly

What are supernumerary roots?

Additional roots, usually with 3rd molars

How well did you know this?

Not at all

Perfectly

What are accessory canals?

Additional pulp canals that form when parts of HERS breaks down before dentin formation is complete.

Canals become innervated with blood vessels and sensory nerves

Apical 3rd of root

How well did you know this?

Not at all

Perfectly

What is dilaceration?

Occurs in the molars

Sever, sharp curving or bending of the roots

Caused by trauma– difficult to perform root canal or do extractions

What are enamel pearls?

Ectodermal disturbance

HERS does not break down. Cementoblasts cannot pass through, causing ameloblasts to form from IEE layer of HERS, producing enamel instead of cementum

Found at CEJ & in furcation areas

What type of tissue is affected by amelogenesis imperfecta? Which cells are disturbed?

Affects enamel. Ectodermal disturbance

What are the different types of amelogenesis imperfecta?

Hypoplastic
Hypocalcification
Hypomaturation
Hypoplasia/taurodontism

What is hypoplastic amelogenesis imperfecta?

Affects the matrix- enamel is thin to absent

Hypo-calcification amelogenesis imperfecta

Affects mineralization of matrix

Enamel is soft and wears away easily (may abrade easily by prophy)

Hypo-maturation amelogenesis imperfecta

Causes incomplete crystallization

Enamel may be easily pierced w/ an explorer and/or chipped away

Hypoplasia/taurodontism amelogenesis imperfecta

Enamel is slightly thin w. LARGE PULP CHAMBERS and enamel is hyper-mineralized

Appearance of amelogenesis imperfecta

May/may not show discoloration Texture is chalky to cheesy (very soft to relatively hard) Open contacts w/ severely abraded occlusal and incisal edges Open anterior bite common

What type of tissue is affected by dentinogenesis imperfecta? Which cells are disturbed?

Affects the dentin. Ectomesenchymal disturbance

How many types of dentinogenesis imperfecta are there? What are they?

3 types Type 1: W/ osteogenesis imperfecta Type2: Hereditary opalescent dentin (MOST COMMON) Type 3: Brandywine type- rare & isolated to MD

What is the appearance of dentinogenesis imperfecta?

Gray to brownish violet- translucent opalescent hue Enamel may chip away- abnormal interlocking between enamel and dentin Exposed dentin wears away, especially on incisal and occlusal surfaces

What is dentin dysplasia?

Hereditary, ectomesenchymal disorder Normal enamel w/ atypical dentin and abnormal pulp morphology 2 types

Characteristic appearance of dentin dysplasia type 1

Radicular- "w" pattern in roots that is lost early on- pulp chamber is obliterated "Rootless teeth" Abnormally short roots, blunt shape, conical or malformed

Characteristic appearance of dentin dysplasia type 2

Coronal- relatively normal roots/pulp chambers but pulp chambers can be large and contain an increased # of generalized pulp stones

Appearance of dentin dysplasia

Crowns appear normal, may have an amber color Normal eruption Increased mobility, early exfoliation & high incidence of tooth loss due to trauma

What are dentigerous cysts?

A developmental cyst that forms over an unerupted tooth. Ectodermally derived from cell rests of Serres, Malassez or reduced enamel epithelium

Cellular characteristics of dentigerous cysts

Cysts are lined with non-keratinized squamous epithelium Fluid forms between the reduced enamel epithelium and the formed enamel

Appearance of dentigerous cysts

Varying sizes, and may be asymptomatic Clinically may exhibit a palpable mass w/ displaced teeth Often found on routine radiographs- radiolucency surrounding unerupted tooth

What is the treatment for dentigerous cysts?

Complete removal of the cyst and involved tooth Marsupialization: drain fluid, allow bone growth, then enucleate cyst. This may be used to allow the tooth to erupt

What are eruption cysts?

Less serious dentigerous cyst. Associated with erupting primary and permanent teeth Forms over the crown, resolves w/ eruption

What is an ameloblastoma and what do they originate from?

Large ectodermal tumor of odontogenic origin that forms in the jaw near the molars and is usually associated with impacted teeth and dentigerous cysts Forms from cell rests; Serres, Malassez, REE Central bone lesion

What is the appearance and treatment of an ameloblastoma?

Expands the alveolar ridge causing asymmetry Asymptomatic On radiographs will have a translucent, compartmentalized appearance. Treatment is complete surgical removal of the lesion and involved teeth

What is an odontoma?

Tumor of odontogenic origin Contains mixed tissues- enamel, dentin, pulp, cementum Associated with impacted teeth and unerupted teeth Causes are unknown but may be from localized trauma, infection, inheritance, or genetic mutation

What are the two types of odontomas?

Compound: calcified dental tissues, resemble teeth Complex: Calcified dental tissues; amorphous

Appearance and treatment of odontomas

Expansion of alveolar ridge Found in both arches Asymptomatic Situated btw roots of teeth, usually does not cause resorption Treatment is surgical excision