DENTAL ANOMALIES

Dental anomalies are craniofacial abnormalities of form, function or position of the teeth. These range from missing or stained teeth to expressions of other, more complex disorders. Many dental anomalies are caused by inherited genetic defects or result from spontaneous genetic mutations. Dental deformities may also have environmental, traumatic or nutritional causes; these may develop or become clinically apparent at any time during an individual’s life.

Disturbances in the Eruption of Teeth

Abnormalities in Number of Teeth

Abnormalities in the Shape of the Tooth

Disturbances in Formation

Natal Teeth

These are extra teeth that are present at birth.

Cause: A developmental disturbance creates intracellular activity during the first stage of tooth development (bud stage), which can result in the development of extra teeth. The most common natal teeth are lower incisors.

Treatment: These teeth are defective and their removal is generally recommended, particularly if mobility poses a threat of aspiration. These teeth also make breastfeeding difficult.

These are primary teeth that erupt prematurely (during the first few weeks of life).

Cause: Premature tooth eruption.

Treatment: These teeth are usually normal primary teeth and should be retained. An X-ray will be taken if possible to confirm that these are not extra teeth.

An anomaly associated with eruption of teeth in children. It is an tiny irregular spicule of bone overlying the crown of an erupting permanent molar.

Causes: Normally an erupting tooth is surrounded by bone which resorbs in the course of eruption. When the bony spicule is larger and the resorption process is slower the eruption sequestrum is observed.

Treatment: No treatment is necessary the condition self-correcting.

Retarded or delayed eruption of primary teeth is difficult to establish unless the eruption is grossly overdue. In some instances it is associated with systemic diseases including rickets, cretinism and cleidocranial dysplasia. Local factors such as fibromatosis of the gingiva/ gums also contribute to the condition

Anodontia

A congenital abnormality where some or all of the teeth are missing i.e. the follicles needed to grow the teeth are completely absent.

Anodontia can be divided into

True Anodontia- Complete failure of development of primary as well as permanent teeth.

Partial Anodontia- It is the congenital absence of one or few teeth.

False Anodontia- Teeth are missing due to previous extraction or exfoliation.

Cause: Interferences in tooth development, such as radiation exposure or a hereditary disturbance like ectodermal dysplasia, can result in this rare genetic disorder.

Treatment: Options for children with this condition are limited, treatment includes dentures or implants.

Partial anodontia, known as hypodontia or oligodontia, is the congenital absence of one or more teeth. Congenital absence of all wisdom teeth or third molars, is relatively common.

Cause: Interferences such as radiation exposure or a hereditary disturbance like ectodermal dysplasia or it can be a result of association with diseases like chondroectodermal dysplasia, incontinentiapigmentii, book’s syndrome to name a few.

Treatment: Treatment for missing teeth depends on their location in the mouth.

These are extra teeth that appear in addition to the regular number of teeth.

Cause: A developmental disturbance creating intracellular activity during the first stage of tooth development (bud stage) can result in the development of extra teeth.

Many supernumerary teeth never erupt, but they may delay eruption of nearby teeth or cause other dental problems.

Treatment: The most common treatment is extraction. This often needs to be done by an oral surgeon when the child reaches an appropriate age.

The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary central incisors.

Cause: A developmental disturbance creating intracellular activity during the first stage of tooth development (bud stage) can result in the development of extra teeth.

Treatment: The most common treatment is extraction. This often needs to be done by an oral surgeon when the child reaches the appropriate age.

Concrescence

Concrescence is a condition where the cementum (outer covering of the root) overlying the roots of two teeth, joins together.

Causes: The cause can sometimes be attributed to trauma, crowding of teeth or hypercementosis (excessive deposition of cementum).

Treatment: Surgical separation of the teeth may be necessary if one is to be extracted.

Fusion is where two developing teeth merge into one tooth, at the level of the dentin.

Causes: The phenomenon of tooth fusion arises through union of two normally separated teeth and depends upon the stage of development of the teeth at the time of union, it may be either complete or incomplete fusion.On some occasions, two independent pulp chambers and root canals can be seen. However, fusion can also be the union of a normal tooth bud to a supernumerary tooth germ

In these cases, the number of teeth is fewer if the anomalous tooth is counted as one tooth. Fusion is prevalent in primary dentition, with incisors being affected. These teeth cannot be flossed.

Treatment: There is a groove that runs down the back of the tooth that is prone to decay and may necessitate a filling.It can present a problem if they do not fall out at the right time and interfere with the eruption of the permanent teeth.

Gemination is where partial development of two teeth from a single tooth bud following incomplete division occurs.

Causes: The phenomenon of gemination arises when two teeth develop from one tooth and as a result, the patient has a larger tooth but a normal number of teeth overall, in contrast to fusion, where the patient misses one tooth.In geminated teeth, division is usually incomplete and results in a large tooth crown that has a single root and a single canal. Gemination is prevalent in primary dentition, with incisors being more affected. These teeth cannot be flossed.

Treatment: There is a groove that runs down the back of the tooth that is prone to decay and may necessitate a filling. It can present a problem if they do not fall out at the right time and interfere with the eruption of the permanent teeth.

Dens evaginatus or DE, is a rare dental anomaly involving an extra cusp or tubercle that protrudes from the tooth. Premolars are more likely to be affected.

Causes: The exact etiology of this condition is unknown, but is thought to be a result of genetics or a disruption of the tooth during formation.

Treatment: This condition requires monitoring as the tooth can lose its blood and nerve supply and may need root canal treatment.

A talon cusp is an extra cusp that resembles an eagle’s talon (a talon is the claw of a bird of prey). A talon cusp appears as a projection from the cingulum of incisor teeth. They are rarely found in primary teeth.

Causes: The exact etiology of this condition is unknown but it is linked to genetics or a disruption of the tooth during formation.

Treatment: Large talon cusps can interfere with occlusion however, grinding them down is a hazardous endeavor. Talon cusps often contain a prominent pulp horn which is very susceptible to exposure in the younger patient. This condition also requires monitoring as the tooth can lose its blood and nerve supply and may need root canal treatment.

Dens invaginatus or dens in dente, means tooth within a tooth, i.e a focal area of the tooth is folded or invaginatedpulpally to a variable extent.

Cause: A developmental disturbance in tooth formation resulting from invagination of the epithelium associated with coronal development into the area that was to be pulp space. Teeth most affected are maxillary lateral incisors.

Treatment: The malformation shows a broad spectrum of morphologic variations and frequently results in early pulp necrosis (death). Root canal therapy may be difficult due to the complex anatomy of the teeth.

An enamel pearl is a condition of teeth where enamel is found on locations where it is not supposed to be, such as on a root surface. It usually forms in a hard round mass.

Cause: This is a developmental disturbance that occurs during the formation of the tooth. Enamel pearls are usually found between roots, which is called a furcation. Enamel pearls are not common in teeth with a single root.

Treatment: Clinically, they are only significant when located in a periodontally diseased area, since there is no periodontal attachment to enamel pearls.

Macrodontia is a condition in which the teeth appear larger than normal.

Cause: Conditions that have been linked to Macrodont teeth

Gigantism

47, XYY syndrome

Hemi-hyperplasia

KBG syndrome

Klinefelter syndrome

Oculofaciocardio-dental syndrome

Treatment: There is no standard treatment for macrodont teeth.

Microdontia is a condition in which the teeth appear smaller than normal.

Cause: Conditions associated with True Generalized Microdontia

Down Syndrome (peg laterals)

Ectodermal Dysplasia

Chondroectodermal Dysplasia (Ellis-van Creveld Syndrome)

Maxillary laterals (“peg laterals”) are the most commonly affected teeth.

Treatment: Build-ups in composite can be done to correct “peg laterals”. This procedure if often requested by orthodontists for proper spacing. Porcelain Crowns can be applied for a more permanent fix for adults.

Taurodontism is a morphoanatomical change in the shape of a tooth, which usually occurs in multirooted teeth. An enlarged body and pulp chamber, as well as apical displacement of the pulpal floor, are characteristic features. The term means “bull like” teeth derived from similarity of these teeth to those of ungulate or cud chewing animals. On dental radiograph, the involved tooth looks rectangular in shape without apical taper. The pulp chamber is extremely large and the furcation may be only a few millimeters long at times.

Cause: Conditions associated with taurodontism

Klinefelter’s Syndrome

Trichodento-osseous Syndrome

Oral-facial-digital Syndrome II

Hypohidrotic Ectodermal Dysplasia

AmelogenesisImperfecta-Type IV

Down Syndrome

Treatment: Endodontic treatment of a taurodont tooth is challenging, because it requires special care in handling and identifying the number of root canals.

Dilaceration is a deformation of the tooth’s shape. It refers to an angulation, sharp bend or curve, in the root or crown of a formed tooth.

Cause: The condition occurs due to trauma endured when the tooth was forming. The result is that the position of the tooth’s calcified portion changed and the remainder of the tooth formed at an angle.The curve or bend may occur anywhere along the length of the tooth, sometimes at the cervical portion, at other times midway along the root or even just at the apex of the root, depending upon the amount of root formed when the injury occurred. An injury to a permanent tooth, resulted in dilaceration, this often follows traumatic injury to the deciduous predecessor, so that the tooth is driven apically into the jaw.

Treatment: There is no treatment for a tooth with a dilacerated root. However, teeth with these types of roots make extractions complex

Regional Odontodysplasia (RO)

RO is a developmental abnormality of teeth, usually localized to a certain area and are non-hereditary. The enamel, dentin and pulp of teeth are affected and on radiographs the teeth are described as “ghost teeth”.

Cause: The etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia and hyperpyrexia. It most commonly affects the maxillary anterior teeth of both the permanent and primary dentitions.

Treatment: Most dentists will advocate extracting the affected teeth as soon as possible and inserting a prosthetic replacement.

is an abnormal formation of the enamel or external layer of teeth. People afflicted with amelogenesisimperfecta have teeth with abnormal colour: yellow, brown or grey. The teeth have a higher risk for dental cavities and are hypersensitive to temperature changes. This disorder can afflict any number of teeth.

Cause: Enamel is composed mostly of mineral and regulated by the proteins in it. AmelogenesisImperfecta is due to the malfunction of the proteins in the enamel: ameloblastin, enamelin, tuftelin and amelogenin.

Treatment: Crowns are sometimes used to compensate for the soft enamel. Usually stainless steel crowns are used in children, which may be replaced by porcelain once they reach adulthood. In the worst case scenario, the teeth may have to be extracted and implants or dentures are required.

Dentinogenesisimperfecta (Hereditary Opalescent Dentin) is a genetic disorder of tooth development. This condition causes teeth to be discoloured (most often a blue-gray or yellow-brown colour) and turn translucent. Teeth are also weaker than normal, making them prone to rapid wear, breakage and loss. These problems can affect both primary (baby) teeth and permanent teeth.Classified into three basic types:

Shields Type I (associated with OsteogenesisImperfecta) – Inherited defect in collagen formation resulting in osteoporotic brittle bones. Primary teeth are more affected than permanent teeth. Other features include periapicalradiolucencies, bulbous crowns, obliteration of pulp chambers, root fractures and amber translucent tooth colour.

Shields Type II (Hereditary Opalescent Dentin) – Primary and permanent dentition are equally affected. Features are same as Shields Type I apart from OsteogenesisImperfecta.

Shields Type III (Brandywine Type) – Teeth have a shell-like appearance with bell-shaped crowns. The condition occurs exclusively in an isolated group in Maryland called Brandywine population.

Cause: DI is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Dentinogenesisimperfecta affects an estimated 1 in 6,000 to 8,000 people.

Treatment: Treatment for this condition usually involves placement of crowns on the teeth, at least in the posterior region. This helps decrease the wear on the teeth and maintains proper vertical dimension between the upper and lower jaws. For primary teeth, this may mean placement of stainless steel crowns on the posterior teeth and composite resin (tooth coloured filling material) for anterior teeth. Crowns may be necessary for all permanent teeth. Stainless steel crowns and/or composite resin may be used to maintain vertical dimension in the posterior region during maturation. In general, fillings are not a successful long-term solution because the dentin is so soft. If tooth loss should occur, care should be taken in the fabrication of appliances which may exert pressure on remaining teeth because the roots fracture easily. With severe cases of DI, the placement of a complete denture over the worn teeth (an overdenture) may be beneficial.

Dentin dysplasia is a genetic disorder of teeth, commonly exhibiting an autosomal dominant inheritance. It is characterized by presence of normal enamel but atypical dentin with abnormal pulpal morphology.

There are two types: Type I is the radicular type and Type II is the coronal type.

Type I: the roots of teeth are shorter than normal and the pulp chamber may be nearly gone. The pulp chamber is sometimes described as having a “crescent shaped” appearance.

Type II: the pulps are enlarged and are described as having a “thistle tube” appearance, in permanent dentition. In the deciduous dentition, coronal dentin dysplasia bears a resemblance to DentinogenesisImperfecta type II.

Type 1: Roots are short, blunt and conical. In deciduous teeth, pulp chambers and root canals are completely obliterated and in permanent they may be crescent shaped.Type 2: The pulp chamber of the deciduous teeth becomes obliterated in deciduous teeth. While in permanent teeth, large pulp chamber is seen in coronal portion of the tooth referred to as thistle tube appearance. Pulp stones may be found.

Treatment: Treatment for children with dentin dysplasia type I is aimed at preventive care. As a result of shortened roots, early loss from periodontitis is frequent. So, meticulous oral hygiene must be established and maintained for the retention of teeth to help children retain natural teeth as long as possible. Oral rehabilitation of prematurely exfoliated teeth is the treatment of choice in future.