Dental Anomalies II

Bulimia nervosa can lead to a characteristic pattern of palatal erosion of the maxillary anterior teeth due to repeated exposure to stomach acid during purging.

Patients with Down syndrome often present with a Class III malocclusion and open bite tendency.

Patients with cleft lip and palate commonly present with missing or malformed lateral incisors in the area of the cleft.

Children with hemophilia or other bleeding disorders are prone to spontaneous gingival bleeding.

Tetracycline staining of the dentition can occur with use during the calcification stage of tooth development.

Dens invaginatus, also known as dens in dente, is characterized by a deep invagination of enamel and dentin into the pulp chamber.

Regional odontodysplasia typically affects a localized group of contiguous teeth in one quadrant of a dental arch.

Molar incisor hypomineralization (MIH) most commonly affects the permanent first molars and incisors.

Supernumerary teeth in the anterior maxilla are referred to as mesiodens.

Internal inflammatory resorption is most commonly associated with chronic pulpal inflammation, as the resorptive process begins on the internal aspect of the root canal wall and progresses outward.

External apical resorption is the most common type of resorption seen following orthodontic tooth movement, as the mechanical forces applied to the teeth can lead to resorption of the apical root surface.

Dentinogenesis imperfecta (DI) is an inherited disorder that affects the dentin, leading to discolored (blue-gray or brown) and brittle teeth, often with obliterated pulp chambers and shortened, narrow roots. This condition is genetically inherited in an autosomal dominant manner and can vary in severity. DI is divided into three types: Type I (associated with osteogenesis imperfecta), Type II (most common form, not associated with osteogenesis imperfecta), and Type III (Brandywine type, with very severe dental manifestations). The primary defect in DI involves the dentin matrix, which leads to weak, fragile teeth that are prone to fractures and pulp obliteration.

High fever in infancy can lead to enamel hypoplasia, often resulting in pitted or discolored enamel, especially during the first year of life.

Fusion may result in two distinct pulp chambers but the teeth are fused at the root level, often seen in the anterior dentition.

Dens evaginatus is characterized by an extra cusp on the tooth’s surface, often involving both enamel and dentin.

Dentinogenesis imperfecta (Type III) presents with shell-like teeth and large pulp chambers, often seen in the Brandywine population.

Dentinogenesis imperfecta is characterized by weak, brittle teeth, pulp chamber obliteration, and high susceptibility to fractures.

Amelogenesis imperfecta often leads to hypoplastic or hypocalcified enamel, causing discolored, brittle, or absent enamel in both primary and permanent teeth.

Gemination is when a tooth splits to form two teeth, which may appear as one large crown. Fusion occurs when two tooth buds fuse during development, leading to a single large tooth with one pulp chamber. Fusion will result in teeth missing from the dentition. Since there are no missing teeth, this is a case of Gemination.

Dentinogenesis imperfecta is characterized by these findings, including translucent enamel, obliterated pulp chambers, and fragile teeth.
Dentinogenesis Imperfecta (DI) is a genetic disorder that primarily affects the dentin of teeth, leading to defective dentin formation. This results in various clinical manifestations such as:

Discoloration: Teeth may appear blue-gray, amber, or brown depending on the severity and type of DI.
Pulp obliteration: Radiographs often show obliterated pulp chambers due to secondary dentin formation. This is a hallmark feature of DI.
Short, narrow roots: The roots of affected teeth are often shortened and narrower, which can increase the risk of fractures and result in teeth that are more prone to wear.
Brittle teeth: DI leads to brittle teeth that are prone to chipping or breaking due to the defect in the dentin matrix.
There are three types of Dentinogenesis Imperfecta:

Type I (Osteogenesis Imperfecta-related DI): This type is associated with osteogenesis imperfecta (a condition characterized by brittle bones) and presents with severe bone fragility, short stature, and frequent fractures in addition to dental issues.
Type II (Classic DI): This is the most common form of DI and is not associated with osteogenesis imperfecta. It is typically characterized by blue-gray or brown teeth and pulp chamber obliteration.
Type III (Brandywine DI): This form is very severe, typically presenting with extreme dental manifestations like shell teeth (thin enamel and large pulp chambers) and a high incidence of dental fractures. This type is most common in the Brandywine population.
Management of DI includes preventive care to avoid dental fractures, restorative treatments such as crowns to protect weakened teeth, and regular dental checkups to monitor pulp health and prevent further complications.

Dens in dente (also known as dens invaginatus) causes the appearance of a “tooth within a tooth” due to invagination of the enamel organ into the dentin.

Taurodontism is characterized by elongated pulp chambers and shortened roots, often affecting molars and is associated with genetic syndromes. Taurodontism typically affects molars—particularly permanent molars—and can be observed in both primary and permanent teeth.
Taurodontism is frequently observed in certain genetic syndromes, including:
Klinefelter syndrome (XXY chromosomal pattern)
Down syndrome
Amelogenesis imperfecta
It can also appear as a primary dental anomaly (isolated taurodontism) in individuals without any syndromic conditions.

Enamel hypoplasia results from factors like childhood infections, malnutrition, or fever, leading to defects in enamel formation.

Dens in dente affects maxillary lateral incisors and creates grooves susceptible to caries.

Dentinogenesis imperfecta leads to these features, often associated with brittle teeth that fracture easily.

Enamel hypoplasia can be caused by systemic or environmental disturbances affecting enamel formation.

These radiographic features characterize taurodontism and is commonly seen in syndromes like Down syndrome, tricho-dento-osseous syndrome, otodental dysplasia, ectodermal dysplasia, tooth and nail syndrome, AI, Mohr syndrome, and Klinefelter syndrome.

Turner’s hypoplasia results from trauma or infection affecting the primary tooth, disrupting enamel formation of the underlying permanent tooth.

Concrescence occurs when two teeth are joined by cementum, typically from trauma or crowding.

Dentinogenesis imperfecta (Type III) presents with this characteristic, particularly in Brandywine populations.

Hypocalcification is a subtype of amelogenesis imperfecta where enamel lacks proper mineralization.

Conditions like syphilis, high fever during childhood, or malnutrition can lead to enamel hypoplasia.

Amelogenesis imperfecta results from genetic mutations affecting enamel quantity and quality.

Amelogenesis imperfecta (AI) is a genetic disorder affecting the enamel formation of teeth. It leads to hypoplastic, hypocalcified, or hypomatured enamel, which may be discolored, brittle, or missing entirely.

Types of Amelogenesis Imperfecta:
Type I (Hypoplastic): Thin enamel that is underdeveloped, leading to small, discolored teeth with normal mineralization.
Type II (Hypocalcified): Normal enamel thickness, but it is poorly mineralized, causing it to be soft, prone to decay, and easily wear away.
Type III (Hypomatured): Enamel has normal thickness and mineralization, but it is softer and prone to surface pitting or mottling.
Type IV (Hypoplastic-Hypomatured): A combination of hypoplastic and hypomatured features, resulting in enamel that is both thin and poorly mineralized.
Inheritance Pattern:

Autosomal dominant: Most common inheritance pattern (Type I, II, IV).
Autosomal recessive: Seen in some forms of AI (Type III).
X-linked: A rare pattern seen in some cases (primarily affects males).
Clinical Features:
Enamel defects: The enamel can range from thin, discolored, and pitted to completely absent.
Tooth discoloration: Teeth may appear yellow, brown, or blue-gray depending on the type.
Brittle enamel: The enamel may be prone to chipping, wear, and fracture, leading to tooth sensitivity.