Dental abnormalities

Dental abnormalities:

Dental abnormalities are craniofacial abnormalities of form, function, or position of

the teeth, bones, and tissues of the jaw and mouth.

Classification:

Dental abnormality can be classified based on 4 types.

(1) Size

(2) Number and Eruption

(3) Shape/Form

(4) Defects of Enamel and Dentin

(1) Size :

According to size Dental abnormality can be divided into 2 types.

1. Microdontia

2. Macrodontia

1. Microdontia :

Microdontia can be classified into 3 types.

(I) True Generalized Microdontia :

➨ All teeth are smaller than normal.

➨ Occur in some cases of pituitary dawrfism.

➨ Exceedingly rare.

➨ Teeth are well formed.

(II) Relative Generalized Microdontia :

➨ Normal or slightly smaller than normal teeth.

➨ Are present in jaws that are somewhat larger than normal.

(III) Focal or Localized Microdontia :

➨ Common condition.

➨ Affects most often maxillary lateral incisior + 3rd molar.

➨ These 2 teeth are most often congenitally missing.

2. Macrodontia :

Macrodontia can be classified into 3 types.

(I) True Generalized Macrodontia :

➨ All teeth are larger than normal.

➨ Associated with pituitary gigantism.

➨ Exceedingly rare.

(II) Relative Generalized Macrodontia :

➨ Normal or slightly larger than normal teeth in small jaws.

➨ Results in crowding of teeth.

➨ Insufficient arch space.

(III) Focal or Localized Macrodontia :

➨ Uncommon condition.

➨ Unknown etiology.

➨ Usually seen with mandibular 3rd molars.

(2) Number and Eruption :

According to number & eruption Dental abnormality can be divided into 3 types.

1. Supernumerary

2. Anodontia

3. Impaction

1. Supernumerary :

➨ Results from continued proliferation of permanent or primary dental lamina to form

third tooth germ.

➨ Teeth may have:

• normal morphology

• rudimentary

• miniature

➨ More often in permanent dentition than primary dentition.

➨ More in the maxilla than in mandible.

➨ may be impacted erupted or impacted.

➨ because of additional tooth bulk, it causes:

• malposition of adjacent teeth

• prevent their eruption

➨ characteristically found in cleidocranial dysostosis.

Supernumerary can be divided into few groups. They are :

i. Mesiodens

ii. Fourth molar

• Maxillary Paramolar

• Distomolar or Distodens

iii. Mandibular Premolar

iv. Maxillary lateral incisors

(I) Mesiodens :

➨ Most common supernumerary tooth.

➨ Tooth situated between maxillary central incisors

• singly

• paired

• erupted or impacted

• inverted

➨ Small tooth.

➨ Cone-shaped crown.

➨ Short root.

(II) Fourth molar :

➨ 2nd most common situated distal to 3rd molar.

➨ Small rudimentary tooth,but may be of normal size.

➨ Mandibular 4th molar also is seen occasionally, but less common than maxillary

molar.

It can be 2 types. They are :

• Maxillary Paramolar

• Distomolar or Distodens

Paramolar :

➨ Small + rudimentary.

➨ Situated bucally or lingually to one of the maxillary molars.

➨ Interproximally between 1st+ 2nd or 2nd + 3rd maxillary molars.

Distomolar or Distodens :

➨ Molar located distal to molar.

2. Anodontia :

➨ Lack of tooth development.

➨ Absence of teeth.

Anodontia can be divided into 4 Types. They are :

i. Complete Anodontia

ii. Partial Anodontia

• Hypodontia

• Oligodontia

iii. Pseudoanodontia

iv. False Anodontia

(I) Complete Anodontia :

➨ When all teeth are missing.

➨ Rare.

➨ Often associated with a syndrome known as hereditary ectodermal dysplasia.

(II) Hypodontia :

➨ Lack of development of one or more teeth.

(II) Oligodontia :

➨ Lack of development of six or more teeth

(III) Pseudoanodontia :

➨ When teeth are absent clinically because of impaction or delayed eruption.

(iv) False Anodontia :

➨ When teeth have been exfoliated or extracted.

3. Impaction :

➨ Most often affects the mandibular 3rd molars + maxillary canines.

➨ Less commonly:

• premolars

• mandibular canines

• second molars

➨ Occurs due to obstruction from crowding.

➨ From some other physical barrier.

➨ Occasionally, may be due to an abnormal eruption path, presumably because of

unusual orientation of tooth germ .

(3) Shape/Form :

According to shape/Form Dental abnormality can be divided into 2 types.They are :

1. Crown

2. Root

Crown can be divided into many types. They are :

★ Fusion

★ Gemination

★ Taurodontism

★ Talon’s Cusp

★ Leong’s Cusp

★ Dens Invaginatus

★ Peg-shaped Lateral

★ Hutchinson Incisor

★ Mulberry Molar

(I) Fusion :

➨ Joining of 2 developing tooth germs.

➨ Resulting in a single large tooth structure.

➨ May involve entire length of teeth.

➨ Or may involve roots only, in which case cementum + dentin are SHARED.

(II) Gemination :

➨ Fusion of 2 teeth from a single enamel organ.

➨ Partial cleavage.

➨ Appearance of 2 crowns that share same root canal.

➨ Trauma has been suggested as possible cause, the cause is still unknown.

Root can be divided into many types. They are :

★ Concresence

★ Enamel Pearl

★ Dilaceration

★ Flexion

★ Ankylosis

(I) Concresence :

➨ 2 fully formed teeth.

➨ Joined along the root surfaces by cementum.

➨ Noted more frequently in posterior and maxillary regions.

➨ Often involves a 2nd molar tooth in which its roots closely approximate the adjacent

impacted 3rd molar.

➨ May occur before or after the teeth have erupted.

➨ Usually involves only 2 teeth.

(III) Enamel Pearl :

➨ Droplets of ectopic enamel.

➨ Or so called enamel pearls.

➨ May occasionally be found on roots of teeth.

➨ Uncommon, minor abnormalities, which are formed on normal teeth.

➨ Occur most commonly in bifurcation or trifurcation of teeth.

➨ May occur on single-rooted premolar as well.

➨ Maxillary molars are commonly affected than mandibular molars.

➨ Consist of only a nodule of enamel attached to dentin.

➨ May have a core of dentin containing pulp horn.

➨ May be detected on radiographic examination.

(4) Defects of Enamel and Dentin :

According to enamel & dentin Dental abnormality can be divided into 4 types.

1. Amelogenesis Imperfecta

2. Dentinogenesis Imperfecta

3. Dentinal Dysplasia

4. Odontodysplasia

1. Amelogenesis Imperfecta :

It is also known as:

Hereditary Enamel Dysplasia

Hereditary Brown Enamel

Hereditary Brow Opalescent Teeth

➨ Disturbance in the ectodermal layers of developing teeth.

➨ Hereditary abnormality.

➨ Affect either the primary or the permanent dentition.

➨ Soft enamel starts to fracture.

➨ Dark brown color.

➨ Enamel has the same radiopacity as the dentin, and the two cannot be

differentiated on a radiograph.

It can be classified based on pattern of inheritance:

★ hypoplasia

★ hypomaturation

★ hypocalcified

2. Dentinogenesis Imperfecta :

➨ A hereditary abnormality in the formation of dentin.

➨ Teeth varies from gray to brownish violet to yellowish brown color.

➨ Crown fractures easily because of abnormal DEJ.

➨ Pulp chambers and root canals may be partially or completely obliterated.

➨ Radiographically, the teeth exhibit thin, short roots.

It can be classified into 3 types. They are :

★ Type I

★ Type II

★ Type III

3. Dentinal Dysplasia :

➨ Also known as “Rootless Teeth”.

➨ Rare disturbance of dentin formation.

➨ Normal enamel.

➨ A typical dentin formation.

➨ Abnormal pulpal morphology.

➨ Hereditary disease.

It can be classified into 2 types. They are :

★ Type I (Radicular Type)

★ Type II (Coronal Type)

type I or radicular type :

(also known as rootless teeth)

● Affects primarily the root portion.

● On a radiograph, short conical roots.

● Periapical lesions without any obvious cause.

● Premature tooth loss may occur because of short roots.

type II or coronal type :

(also known as coronal dysplasia)

•affects primarily the pulp chambers

•frequently contain pulp stones

4. Odontodysplasia :

It is also known as:

★ Odontogenic Dysplasia

★ Odontogenesis Imperfecta

★ Ghost Teeth

➨ One or several teeth in a localized area are affected.

➨ Maxillary teeth are involved more frequently than mandibular area.

➨ Etiology is unknown.

➨ Teeth affected may exhibit a delay or total failure in eruption.

➨ Shape is altered, irregular in appearance.

Other Causes :

Except those mentioned abnormality dental abnormality can be caused due to

different environmental reasons. It could be :

a. Tetracycline

b. Fluorosis

Also in some cases humans are also responsible for dental abnormalities. Dental

abnormality might be caused by:

a. Coffee, tea, and red wine

b. Scurvy (vit.c def)

TREATMENT : Abrasion :

• Restorative dental techniques • Correction of habits, occlusal force discrepancies

Amelogenesis Imperfecta :

• Full-crown restorations for esthetics • Regular periodic examinations

• Meticulous oral hygiene, calculus removal, and oral rinses

• Use of Fluoride applications and desensitizing agents • Genetic counseling

Attrition :

• Usually does not require specific management • Elective restoration of occlusal/incisal surfaces to prevent over-closure of jaws in

function

Bulimia :

Combined aggressive medical management, psychotherapy, behavioral management,

food intake management, and nutritional counseling

Dentinal Dysplasia :

• Teeth usually unsalvageable (type I) • Regular periodic examinations

• Prosthetic replacement including dentures, overdentures, partial dentures or dental implants

• For esthetics restorations- discolored teeth can be improved with resin bonding or

veneering • Genetic counseling

• Endodontic therapy like negotiating around pulp stones and through whorls of tubular dentin

• Peri-apical curettage and retrograde amalgam seals in teeth with short roots

Dentinogenesis Imperfecta :

• Functional and esthetic restorations (full crowns) by different types of veneers and

by masking the opalescent blue-gray discoloration of the anterior teeth • Meticulous oral hygiene, calculus removal, and oral rinses

• Use of Fluoride applications and desensitizing agents

• Genetic counseling • Apical surgery may be required to maintain the abscessed teeth

Erosion :

• Identification and elimination of cause • Treatment of underlying etiology

• Dental restorative treatment subsequent to complete functional evaluation, vertical

dimension, and esthetics

Fluorosis: Chronic Endemic :

• Restorative dental treatment • Cosmetic bleaching

Fusion :

• If esthetics demand, removal and replacement

Natal Teeth :

• If mobile, extraction

• Possible retention for functional, esthetic reasons