Dental Anomalies (Unusual Teeth)
Dental defects, or anomolies, are a result from some incident or disease, which occurred during one or more stages of tooth development.
Abnormalities in Quantity of Teeth
Anodontia
Definition:
This is the congenital absence of all primary and permanent teeth.
(Not to be confused with the term Edentulous, which is the clinical absence of all teeth which is seen in patients with dentures)
Cause:
Interferences in tooth development, such as radiation exposure or a hereditary disturbance like ectodermal displaysia, can result in this rare genetic disorder.
Treatment:
Options for children with this condition are limited but treatment does include dentures or implants.
Oligodontia
Definition:
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 displaysia can result in this rare condition.
Treatment:
Treatment for missing teeth depends on their location in the mouth.
Hyperdontia or Supernumerary Teeth
Definition:
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 thedevelopment 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 the appropriate age.
Mesiodens
Definition:
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.
Natal Teeth
Definition:
These are extra teeth that are present at birth.
Cause:
A developmental disturbance creating intracellular activity during the first stage of tooth development (bud stage) 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.
Neonatal Teeth
Definition:
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.
Abnormalities of Size or Form
Concrescence
Definition:
Concrescence is a condition where the cementum (outer covering of the root) overlying the roots of two teeth, joins together.
Cause:
The cause can sometimes be attributed to trauma or crowding of teeth.
Treatment:
Surgical separation of the teeth may be necessary if one is to be extracted.
Fusion
Definition:
Fusion is where two developing teeth merge into one tooth.
Cause:
The phenomenon of tooth fusion arises through union of two normally separated teeth, and depending 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 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.
Gemination
Definition:
Gemination is where a developing tooth splits into two separate teeth.
Cause:
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 would appear to be missing 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
Definition:
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 than any other tooth.
Cause:
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 as a result, and may need root canal treatment.
Talon cusp
Definition:
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 found rarely in primary teeth.
Cause:
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:
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 requires monitoring as the tooth can lose its blood and nerve supply as a result, and may need root canal treatment.
Dens invaginatus/Dens in dente
Definition:
Dens invaginatus or dens in dente, means tooth within a tooth.
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.
The malformation shows a broad spectrum of morphologic variations and frequently results in early pulp necrosis (death).
Treatment:
Root canal therapy may be difficult due to the complex anatomy of the teeth.
Enamel pearl
Definition:
An enamel pearl is a condition of teeth where enamel is found on locations where enamel is not supposed to be, such as on a root surface. It usually forms in a hard, round mass.
Cause:
A developmental disturbance that occurred 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
Definition:
Macrodontia is a condition in which the teeth appear larger than normal.
Cause:
Conditions that have been linked to Macrodont teeth:
Treatment:
There is no standard treatment for macrodont teeth. There are options that can be discussed with Dr. Schroeder.
Microdontia
Definition:
Microdontia is a condition in which the teeth appear smaller than normal.
Cause:
Conditions associated with True Generalized Microdontia:
Maxillary laterals (“peg laterals”) are the most commonly affected teeth.
Treatment:
Build-ups in composite can be done in our office to correct “peg laterals”. This procedure if often requested by orthodontists for proper spacing.
Porcelain Crowns can be done in an adult dental office for a more permanent fix.
Taurodontism
Definition:
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
-
Amelogenesis Imperfecta-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.
Disturbances in Formation
Dilaceration
Definition:
Dilaceration is a developmental disturbance in shape of teeth. It refers to an angulation, or a sharp bend or curve, in the root or crown of a formed tooth.
Cause:
The condition is thought to be due to trauma during the period in which tooth is forming. The result is that the position of the calcified portion of the tooth is changed and the remainder of the tooth is 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.
Such an injury to a permanent tooth, resulting in dilaceration, often follows traumatic injury to the deciduous predecessor in which that 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 more complex.
Regional odontodysplasia (RO)
Definition:
RO is a developmental abnormality of teeth, usually localized to a certain area and nonhereditary. 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.
Turner's hypoplasia
Definition:
Turner’s hypoplasia is a portion of missing or diminished enamel on permanent teeth. Unlike other abnormalities which affect a vast number of teeth, Turner's hypoplasia usually affects only one tooth in the mouth and, it is referred to as a Turner's tooth.
Cause:
If Turner's hypoplasia is found on a canine or a premolar, the most likely cause is an infection that was present when the primary (baby) tooth was still in the mouth. Most likely, the primary tooth was heavily decayed and an area of inflamedtissues around the root of the tooth (called a periapicalinflammation), affecting the development of the permanent tooth. The tooth most likely affected by this cause is the canine tooth. The appearance of the abnormality will depend on the severity and longevity of the infection.
If Turner's hypoplasia is found in the front (anterior) area of the mouth, the most likely cause is a traumatic injury to a primary tooth. The traumatized tooth, which is usually a maxillary central incisor, is pushed into the developing tooth underneath it and consequently affects the formation of enamel. Because of the location of the permanent tooth's developing tooth bud in relation to the primary tooth, the most likely affected area on the permanent tooth is the facial surface (the side closer to the lips or cheek). White or yellow discoloration may accompany Turner's hypoplasia.
Turner's hypoplasia usually affects the tooth enamel if the trauma occurs prior to the third year of life. Injuries occurring after this time are less likely to cause enamel defects since the enamel is already calcified.
Treatment:
Permanent fillings may be placed when the tooth is fully erupted.
If there is discomfort as the tooth erupts, a temporary filling may be placed until the tooth is fully erupted.
Other Hereditary Disturbances is Structure or Formation
Amelogenesis imperfecta
Definition:
Amelogenesis imperfecta is an abnormal formation of the enamel or external layer of teeth. People afflicted with amelogenesis imperfecta have teeth with abnormal color: 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 that is formed and regulated by the proteins in it. Amelogenesis Imperfecta is due to the malfunction of the proteins in the enamel: ameloblastin, enamelin, tuftelin and amelogenin.
Treatment:
Crowns are sometimes being 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.
Dentinogenesis imperfecta (DI)
Definition:
Dentinogenesis imperfecta (hereditary Opalescent Dentin) is a genetic disorder of tooth development. This condition causes teeth to be discolored (most often a blue-gray or yellow-brown color) and 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 Osteogenesis Imperfecta) - Inherited defect in collagen formation resulting in osteoporotic brittle bones. Primary teeth more affected than permanent teeth. Other features include periapical radiolucencies, bulbous crowns, obliteration of pulp chambers, root fractures and amber translucent tooth color.
Shields Type II (Hereditary Opalescent Dentin) - Primary and permanent dentition are equally affected. Features are same as Shields Type I apart from Osteogenesis Imperfecta.
Shields Type III (Brandywine Type) - Teeth have a shell-like appearance with bell-shaped crowns. Occurs exclusively in a isolated group in Maryland called Brandywine population.
Cause:
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Dentinogenesis imperfecta 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 colored 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
Definition:
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.
With 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.
With 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 Dentinogenesis Imperfecta type II.
Radiographic Features:
Type 1 : Roots are short, blunt and conical. In deciduous teeth, pulp chambers and root canals are completely obliterated 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.
Cause:
Dentin dysplasia is an inherited disorder.
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 to have natural teeth as long as possible. Oral rehabilitation of prematurely exfoliated teeth is the treatment of choice in future.