Dental Anomalies: Number, Size, and Shape

• Dental anomalies can be classified based on alterations in the number, size, shape, and position of teeth, as well as abnormalities of the dental pulp and tooth structure.
• Identifying dental anomalies and deviations from the normal is crucial for proper clinical and radiographic assessment.
• Understanding treatment options is important for managing patients with dental anomalies, and appropriate referrals should be made when necessary.
• Dental anomalies can arise from issues during tooth formation (genetics), disruptions (secondary factors), or problems with eruption.

Alterations in Tooth Number

• Hypodontia involves having fewer teeth than normal.
• Anodontia is the complete absence of teeth and is linked to genetics and syndromes.
• Hyperdontia/supernumerary refers to having extra teeth.
• Supplemental teeth represent extra teeth that resemble normal teeth.
• Mesiodens are supernumerary teeth located in the midline of the maxilla.
• Tuberculate teeth are supernumerary teeth with a tubercle.
• Conical teeth are cone shaped supernumerary teeth.

Alterations in Tooth Size

• Macrodontia refers to abnormally large teeth.
• Microdontia refers to abnormally small teeth, which can be generalized or localized.

Alterations in Tooth Shape

• Concrescence is the fusion of teeth by cementum.
• Fusion is the joining of two developing tooth germs, resulting in a single large tooth structure.
• Germination is the incomplete splitting of a single tooth germ, resulting in a bifid crown with a single root.
• Dens in dente (dens invaginatus) is a tooth within a tooth, caused by invagination of the enamel organ during development.
• Dens evaginatus is an accessory cusp-like elevation on the occlusal surface
• Talon cusps are extra cusps, typically on the lingual surface of anterior teeth.
• Taurodontism involves teeth with elongated bodies and short roots.
• Hypercementosis is the excessive buildup of cementum on the tooth roots.
• Dilaceration is an abnormal bend or curve in the root or crown of a tooth.
• Enamel pearls are small, round nodules of enamel found on the roots of teeth.

Abnormalities of the Dental Pulp

• Resorption is the process where tooth structure is lost due to the action of cells.
• Internal or external resorption can be physiological, idiopathic, or pathological.
• Pulp calcification involves the formation of pulp stones.
• Secondary or reparative dentine represents dentine formed in response to stimuli.
• Pulp obliteration is the complete or partial filling of the pulp chamber and root canal with hard tissue.

Abnormalities in Tooth Position

• Submerged teeth are teeth that have become ankylosed and are infraoccluded.
• Impacted teeth are teeth that are blocked from erupting normally.
• Transposed teeth are teeth that have exchanged positions.
• Ankylosed teeth are fused to the bone, preventing eruption.

Abnormalities in Tooth Structure

• Hypoplasia is a defect in enamel formation, resulting in thin or deficient enamel.
• Molar incisal hypoplasia (MIH) affects the molars and incisors
• Hypomineralization is a defect in enamel mineralization, resulting in soft, porous enamel.
• Turner tooth/hypoplasia affects teeth that have been subject to trauma.
• Dentinogenesis imperfecta affects dentine formation, types I, II and III.
• Amelogenesis imperfecta affects enamel formation, including hypoplastic, hypocalcified, hypomaturation, and hypomaturation-hypoplasia types.
• Staining such as tetracycline staining can cause discoloration.

Management of Conditions

• Management of these conditions should be done on a case by case basis.
• Options include doing nothing and reviewing the condition if there are no aesthetic or functional concerns.
• Specialist referral may be necessary for complicated conditions requiring multidisciplinary care in secondary settings.
• Restoration theth with materials such as composite resin or pre-formed metal crowns.