Tooth Developmental Defects

These flashcards cover essential vocabulary related to tooth developmental defects, providing definitions for key terms from the lecture notes.

Anodontia

Total lack of tooth development.

Hypodontia

A condition where a few teeth are missing, usually 6 or less.

Hyperdontia

Development of an increased number of teeth, commonly known as supernumerary teeth.

Dentinogenesis

The formation of dentin.

Dilaceration

An abnormal bend or curve in the root of a tooth.

Gemination

A single enlarged tooth in which the tooth count is normal when counted as one.

Fusion

A single enlarged tooth created by the joining of two tooth buds, resulting in a missing tooth in the count.

Macrodontia

Abnormally large teeth.

Microdontia

Abnormally small teeth.

Amelogenesis Imperfecta

A genetic condition affecting the enamel of both deciduous and permanent teeth, leading to soft, thin enamel that is easily damaged.

Dentin Dysplasia

A hereditary condition affecting dentin, resulting in abnormal dentin formation.

Regional Odontodysplasia

A non-hereditary developmental anomaly characterized by large pulps with minimal dentin and enamel, often referred to as 'ghost teeth'.

Hypohidrotic Ectodermal Dysplasia

An inherited condition where multiple ectodermally derived anatomic structures fail to develop.

What are some clinical presentations of Hypohidrotic Ectodermal Dysplasia

• Heat intolerance

• Fever

• Hypodontia

• Fine, sparse hair

• Reduced eyebrows and eyelashes

• Periocular skin shows wrinkling and

• hyperpigmentation

Concrescence

Union of two teeth by cementum alone.

Dens Invaginatus

A developmental anomaly where there is an invagination of enamel into the tooth.

Turner’s Hypoplasia

A form of enamel hypoplasia that occurs due to trauma or disease in a primary tooth affecting the permanent tooth beneath.

Cleft Lip and Palate

Congenital deformities resulting from improper fusion of the lip and/or palate during development.

Tetracycline Staining

Color changes in teeth resulting from exposure to tetracycline during tooth development.

Cleidocranial Dysplasia (Cleidocranial Dysostosis)

• Syndrome complex characterized by dental and clavicle abnormalities.

• Autosomal Dominant (AD) inheritance.

• Features:

  • Prolonged retention of deciduous teeth.

  • Delay or failure of eruption of permanent teeth.

  • Abnormally shaped teeth.

  • Numerous unerupted permanent and supernumerary teeth.

Gardner syndrome

• AD / Mutation chromosome # 5 (APC)

• Clinical features:

  • Colorectal (adenoma) polyps which can become malignant ( 100% if not treated)

  • Multiple osteoma

  • Epidermoid cyst of skin

  • 20% have supernumerary teeth

  • Thyroid carcinoma

  • Pigmented ocular fundus (90%)

In which conditions are supernumary teeth found?

Gardner Syndrome and Cleidocranial Dysplasia

Micro vs Macrodontia

Cusp of Carabelli

Accessory cusp on palatal surface of ML cusp of maxillary molars

Talon Cusps

Accessory cusp on lingual of incisor; usually maxillary lateral incisor; usually has pulp tissue inside

Dens Evaginatus (occlusal pearl)

Elongated “cusp” extending from central occlusal surface; mandibular premolars, maybe molars, usually has pulp tissue, problem: occlusal trauma

Dens Invaginatus “dens in dente”

• Deep surface enamel invagination of the crown or root “ tooth within tooth”

• Can be coronal (most frequent) or radicular

  • Type I: Invagination is confined to the crown

  • Type II: Invagination extends below the CEJ

  • Type III: Invagination may extend through the root

Shovel shaped teeth

• Prominent marginal ridges on maxillary incisors (esp centrals)

• Associated with dens evaginatus

• Usually bilateral

• Most common in Asians

Enamel Pearl

• Enamel nodules at furcation of multi-rooted teeth

• Most common site: Maxillary molars

• May have pulp tissue, usually without dentin

• Problem: Perio defect and pulp exposure

Taurodontism

• Enlargement of the body and pulp chamber

• Most common mandibular molars and premolars

• No treatment

• Associated with many syndromes

Dilaceration

• From trauma or infection of tooth bud as root forming

• Tooth vital

• Usually 3rd molars

• No problem unless endo is needed

What are some local factors of hypercementosis

• Abnormal occlusal trauma.

• Adjacent inflammation.

• Unopposed teeth (super eruption).

• Repair of vital root fracture.

What are some systemic factors of hypercementosis

• Acromegaly and pituitary gigantism.

• Arthritis.

• Calcinosis.

• Paget disease of bone*.

• Rheumatic fever.

• Thyroid goiter.

• Gardner syndrome*.

• Vitamin A deficiency (possibly)

What is a supernumerary root?

Increased number of roots

Both deciduous and permanent

Most affected: mand 3rd molars > cuspids and bicuspids

No treatment but detection is important if endo treatment is needed

What is Amelogenesis Imperfecta (AI)

• Autosomal dominant (AD), recessive (AR), X-linked

• Both deciduous and permanent dentition are diffusely involved

• Affects enamel, soft and thin, easily damaged and susceptible to decay

• Dentin is exposed

What do you see in Amelogenesis Imperfecta (AI)

• Yellow-brown to white pitted lesions

• Open bite ,loss of contact

• Types:

  • Hypoplastic (pitted)

  • Hypomaturation /hypocalcification (snow capped)

  • AI with taurodontism

What does hypomaturation amelogenesis imperfecta look like?

Snow capped

What does hypoplastic amelogenesis imperfecta look like?

A pitted pattern

Example of amelogenesis imperfecta: loss of contact

Example of amelogenesis imperfecta: loss of enamel

What is enamel dysplasia?

It can be developmental OR genetic or acquired

What is hypoplasia in enamel dysplasia?

Thickness deficit

What is hypomineralization in enamel dysplasia?

It is a mineral deficit

What categories fall under hypomineralization?

Hypomaturation and hypocalcification

What is hypomaturation

Amelogenin-rich

What is hypocalcification

Amelogenein-poor

What is molar hypomineralization?

A type of hypocalcification of enamel dysplasia that can be

• Albumin-rich

• Amelogenin-poor

• Or an acquired defect

Dentinogenesis Imperfecta (DGI): What is it?

• A hereditary condition affecting dentin.

• Happens without any systemic disease.

• Also known as Hereditary Opalescent Dentin

Dentinogenesis Imperfecta Inheritance Pattern

• Autosomal Dominant (AD) inheritance.

• Passed down from parent to child.

Dentinogenesis Imperfecta vs Osteogenesis Imperfecta (OI)

• DGI and OI have different genetic mutations.

• They are not related, even though they were once thought to be the same condition

Shields Classification: Type 1

• Clinical Presentation: Osteogenesis Imperfecta.

• Features:

  • Opalescent Teeth.

  • Bone fractures

Shields Classification: Type 2

• Isolated opalescent teeth.

• Most common

• Hereditary Opalescent Teeth

Shields Classification: Type 3

• Isolated opalescent teeth.

• Large pulp chambers (Shell teeth).

• Pulp exposure.

• Periapical radiolucencies.

• "Brandywire" appearance of teeth

Important Notes on Dentinogenesis Imperfecta (DGI) and osteogenesis imperfecta (OI)

• DGI is caused by a mutation in Dentin sialophosphoprotein (DSPP).

• OI is caused by a mutation in COL1.

• They are not the same.

What is this an image of?

Dentinogenesis Imperfecta

• Affects both dentition

• Steel-gray/translucent/opalescent crows

• Brittle enamel, breaks off

Radiograph of Dentinogenesis Imperfecta

• Bulbous crown

• Cervical constriction

• Pulp obliteration varies

• Expanded pulp = shell teeth

What is Dentin Dysplasia

A hereditary condition affecting dentin

• Autosomal dominant

• Both dentition affected

• 2 types

  • DD1- radicular

  • DD2- coronal

Dentin Dysplasia type 1 (DD-I)

• 4 types

  • Normal clinical crown

  • Short roots

  • Periapical radiolucencies

  • Chevron pulp chambers

“ROOTLESS”

Dentin Dysplasia type 2 (DD-II)

Primary Dentition

• Blue-amber-brown translucence

• Bulbous crown

• cervical constriction

• thin roots, normal length

• early obliteration of pulp

Permanent Dentition

• Normal color clinically

• Pulp chamber is enlarged = thistle tubs or flames shaped

• Pulp stone

• Normal Root

Regional Odontodysplasia- “ghost teeth”

• Nonhereditary developmental anomaly

  • Most believe it is due to an alteration in vascular supply

• Most commonly involves maxillary anterior teeth

• Usually involves one quadrant; rarely can affect more

• Very large pulps with minimal dentin & enamel

Pano of “Ghost teeth”

Attrition image

Abrasion image

Erosion (chemical) image

Abfraction d/t occlusal stress image

External resorption

Commonly occurs apically/ mid root and is associated with

• Cysts and tumors

• ortho

• excessive occlusal stress

• reimplantation of avulsed tooth

Internal resorption

Rare, injury to pulpal tissue (TRAUMA), when crown is affected known as pink tooth of mummery

Localized Disturbances in Eruption

• Impaction: Tooth is obstructed by a physical barrier.

• Embedded: Tooth lacks eruptive force to emerge.

• Rarely occurs in deciduous teeth

Ankylosis: What is it?

• Cessation of eruption after the tooth emerges.

• Fusion of cementum with bone.

• Unknown pathogenesis (cause not fully understood)

Turner’s Hypoplasia

Common causes:

• Fever

• Periapical inflammatory disease of overlying deciduous tooth

• Trauma

Clinical: Enamel can be white, yellow, brown and/or have different degrees of hypoplasia

Location: Most common in bicuspids because of their relationship with the deciduous molars

What are some other names for Congenital Syphilis?

hutchinson’s incisors and mulberry molars

How is congenital syphilis transmitted:

From active syphilis in mother during last trimester

What are the intraoral clinical manifestations of congenital syphillis?

• Hutchinson’s incisor (screwdrivers)

• Mulberry molars (1st molars develop irregular nodules of enamel on occlusal surface)

What are the health and neck effects of congenital syphilis?

Mental degeneration, cartilage septal destruction of nose (saddle nose), blindness and deafness d/t nerve 8

What is the hutchinson triad?

1. Hutchinson teeth

2. Ocular

3. 8th nerve deafness

What is fluorosis?

Mottled enamel; hypomineralization- creating chalky white areas; severity is dose dependent; ingestion of excess amount of fluoride; retention of amelogenin protein in enamel

What are the clinical manifestations of fluorosis?

Must be bilateral symmetrical distribution with previous exposure to Fl

Trauma of a non-vital tooth

• Pulp death after RCT

• Age

• Gets darker with time

• Tooth is brittle

• cannot bleach enamel

• color doesn’t change with new RCT

• Post and crown

Trauma: internal resorption

• Rare

• Injury to pulpal tissue

• When crown is affected known as Pink tooth of mummery

What is the cause of tetracycline staining?

From use of tetracycline during tooth development

How does tetracycline work cellularly?

• Minocycline (a type of tetracycline) binds to collagen in:

  • Dental tissues

  • Pulp

  • Dentin

  • Bone

• May also discolor skin, sclera, and thyroid

Tetracycline Staining: Uses and Precautions

• Rx: Often prescribed for:

  • Acne

  • Cystic fibrosis

  • Rheumatoid arthritis (RA)

• Precaution: Avoid tetracycline use during:

  • Pregnancy

  • Up to 8 years of age (due to risk of staining developing teeth).

What is a clinical feature you see in Hypohidrotic Ectodermal Dysplasia?

Screw driver teeth

What is the mode of inhertance in Hypohidrotic ectodermal dysplasisa?

Autosomal dominant, autosomal recessive, and x-linked

In hypohidrotic ectodermal dysplasia, what structures fail to develop?

2+ ectodermally derived anatomic structures like skin, ahir, nails, teeth and sweat glands

What does paramolar mean?

Situated lingually or bucally to a molar

What is the order in which you’d see hyperdontia?

Max incisor, max 4th molar, mandibular 4th molar

What is the mode of inheritance for cleidocranial dysplasia?

Autosomal dominant

What is the most of inheritance for gardner syndrome?

Autosomal dominant

What is a peg lateral?

A small lateral incisor associated with microdontia

What are the conditions you see in microdontia?

Down syndrome, hypopituitarism

What features do you see in macrodontia

Isolated macrodontia (only 1 tooth is larger than the rest)

Generalized macrodontia is rare but could happen

Where do you commonly see a talon cusp?

Maxiallary lateral incisor linguallyW

WHere do you normally see dens evaginatus (occlusal pearl)

mandibular premolars

What is type 1 dens invaginatus

Confined to crown

What is type 2 dens invaginatus

Extended below the CEJ

What is type 3 dens invaginatus

Extended through root

What condition is associated with shovel shaped teeth?

Dens evaginatus

Paget disease of bone and Garder syndrome are associated with this

Systemic hypercementosis

Where would you most commonly see a supernumeray root?

Mandibular 3rd molar