Supernumerary Teeth
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Basis for supernumerary supernumerary permanent tooth formation.
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Supernumerary Teeth
- 1. Supernumerary Teeth ALWALEED ABUSHANAN, BDS PEDIATRIC DENTAL RESIDENT UNIVERSITY OF BRITISH COLUMBIA BC CHILDREN’S HOSPITAL
- 2. Objectives: To explain using drawings, the basis for supernumerary permanent tooth formation.
- 3. Supernumerary Teeth the teeth that form in addition to the normal dental formula. Result from disturbances during the initiation and proliferation stages of dental development If such teeth closely resemble the adjacent teeth, they are classified as supplemental, If they present abnormal shape and size, they are termed rudimentary. Solares, R., Romero, M. I., 2004. Supernumerary premolars: a literature review. Pediatr Dent. 26, 450-8.
- 4. Supernumerary Teeth Maxillary midline supernumeraries Maxillary fourth molars Maxillary paramolars (rudimentary supernumeraries that develop buccally or lingually to the maxillary molars) Mandibular premolars Maxillary lateral incisors Mandibular fourth molars Maxillary premolars Solares, R., Romero, M. I., 2004. Supernumerary premolars: a literature review. Pediatr Dent. 26, 450-8.
- 5. Prevalence 0.2% to 0.8% in the deciduous dentition 0.5% to 5.3% in the permanent dentition Higher in males than in females (1.18:1 to 4.5:1) 1 in every 110 children Maxilla to mandible is 8.2 to 1 • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77. • Solares, R., Romero, M. I., 2004. Supernumerary premolars: a literature review. Pediatr Dent. 26, 450-8.
- 6. Types Based on their morphology, supernumerary teeth are classified into four types Conical type Tuberculate type Supplemental teeth Odontomas • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 7. • http://supernumeraryteeth.com • Eigbobo, J., Osagbemiro, B., 2015 Bilateral tuberculate supernumerary teeth – A rare case report. J Clinics and practice. 1, e30-e30. • http://www.intelligentdental.com/wp-content/uploads/2012/02/supernumerary-tooth-3.jpg • Salgado, Helena; Mesquita, Pedro. Compound odontoma—Case report, rev port estomatol med dent cir maxilofac 2013;54:161-5. Can you identify the type ?
- 8. Theories Atavism (evolutionary throwback). Tooth germ dichotomy. Hyperactivity of the dental lamina. Genetic and environmental factors. • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 9. Atavism or phylogenetic theory Suggested that the occurrence of supernumerary teeth is a regression to the extinct ancestral tissues or anthropoids. Based on the phenomena that ancestor mammals have more teeth with three incisors, one canine, four premolars, and three molars in each quadrant of the jaw. • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 10. Tooth germ dichotomy. Proposed that during early tooth development, the dental lamina was divided into two parts of equal or different size, thus giving rise to two teeth with similar size, or one normal tooth and one dysmorphic tooth • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 12. Hyperactivity of the dental lamina. Once the crown of the permanent tooth has formed, the dental lamina undergoes programmed cell death and degenerates. Residues of un-degenerated dental lamina epithelial cells may cause eruption cysts. Over-proliferation or prolonged survival of dental lamina epithelial cells may cause supernumerary tooth formation. • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 13. Premolar Supernumerary Teeth Solares, R., Romero, M. I., 2004. Supernumerary premolars: a literature review. Pediatr Dent. 26, 450-8.
- 14. Genetic and environmental factors. Supernumerary teeth occur more commonly in the relatives of affected patients than in the general population. They can be transmitted as: An autosomal recessive Autosomal dominant trait with incomplete penetrance May be associated with the X chromosome . Sometimes associated with polydactyly and extra nipples. • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 15. Human Syndromes Associated With Supernumerary Teeth Cobourne, M. T., Sharpe, P. T., 2010. Making up the numbers: The molecular control of mammalian dental formula. Semin Cell Dev Biol.
- 16. Human Syndromes Associated With Supernumerary Teeth • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 17. Modulation of WNT and BMP signaling Cobourne, M. T., Sharpe, P. T., 2010. Making up the numbers: The molecular control of mammalian dental formula. Semin Cell Dev Biol.
- 18. Teeth form a single row through the coordinated restriction of Bmp4 activity Cobourne, M. T., Sharpe, P. T., 2010. Making up the numbers: The molecular control of mammalian dental formula. Semin Cell Dev Biol.
- 19. Mice Models for Studying Supernumerary Not an optimal model Only a single primary dentition. Dentition reduced to: One incisor Three molars Separated by a toothless diastema region. Mutant mice exhibited supernumerary diastema teeth with overexpression of Eda or Edar. • Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77.
- 20. Variations in tooth replacement Juuri E., Jussila M., Seidel K., Holmes S., Wu P., Richman J., et al. . (2013). Sox2 marks epithelial competence to generate teeth in mammals and reptiles. Development 140, 1424–1432. 10.1242/dev.089599
- 21. References Solares, R., Romero, M. I., 2004. Supernumerary premolars: a literature review. Pediatr Dent. 26, 450-8. Wang, X. P., Fan, J., 2011. Molecular genetics of supernumerary tooth formation. Genesis. 49, 261-77. Eigbobo, J., Osagbemiro, B., 2015 Bilateral tuberculate supernumerary teeth – A rare case report. J Clinics and practice. 1, e30-e30. Salgado, Helena; Mesquita, Pedro. Compound odontoma—Case report, rev port estomatol med dent cir maxilofac 2013;54:161-5. http://supernumeraryteeth.com http://www.intelligentdental.com/wp-content/uploads/2012/02/supernumerary-tooth-3.jpg https://www.dentalaegis.com/id/2012/05/double-dental-twinning-in-two-children Cobourne, M. T., Sharpe, P. T., 2010. Making up the numbers: The molecular control of mammalian dental formula. Semin Cell Dev Biol. Juuri E., Jussila M., Seidel K., Holmes S., Wu P., Richman J., et al. . (2013). Sox2 marks epithelial competence to generate teeth in mammals and reptiles. Development 140, 1424– 1432. 10.1242/dev.089599
Editor's Notes
- The most common supernumerary teeth, listed in order of frequency are the
- Supernumerary teeth in the deciduous dentition are usually normal or conical shaped, whereas supernumerary teeth in the permanent dentition can exhibit various shapes
- Conical: The most common supernumerary teeth are small conical peg-shaped with root development at the similar stage or ahead of that of adjacent teeth. They usually develop in the anterior maxilla as mesiodens. Tuberculate supernumerary teeth Large barrel- shaped with multiple cusps or tubercles. Their root development is delayed compared to that of adjacent teeth. They are mostly found unerupted in the palatal aspect of the maxillary central incisors Supplemental teeth Duplications of teeth in the normal dentition with essentially normal size and shape, and they are usually found at the end of a tooth series. The most common supplemental tooth is the permanent maxillary lateral incisor, but supplemental premolars and molars were also reported. The majority of supernumerary teeth found in the primary dentition are of the supplemental type. They usually erupt with normal morphology and alignment, and often appear as a supplemental lateral upper incisor Odontomas Contains a mass of dental tissues (enamel, dentin, cementum, pulp tis- sue), and is usually considered to be a hamartomatous (benign and local with disorganized mass) malformation rather than a neoplasm. Compound or Complex
- Conical: The most common supernumerary teeth are small conical peg-shaped with root development at the similar stage or ahead of that of adjacent teeth. They usually develop in the anterior maxilla as mesiodens. Tuberculate supernumerary teeth Large barrel- shaped with multiple cusps or tubercles. Their root development is delayed compared to that of adjacent teeth. They are mostly found unerupted in the palatal aspect of the maxillary central incisors Supplemental teeth Duplications of teeth in the normal dentition with essentially normal size and shape, and they are usually found at the end of a tooth series. The most common supplemental tooth is the permanent maxillary lateral incisor, but supplemental premolars and molars were also reported. The majority of supernumerary teeth found in the primary dentition are of the supplemental type. They usually erupt with normal morphology and alignment, and often appear as a supplemental lateral upper incisor Odontomas Contains a mass of dental tissues (enamel, dentin, cementum, pulp tis- sue), and is usually considered to be a hamartomatous (benign and local with disorganized mass) malformation rather than a neoplasm. Compound or Complex
- Atavism or phylogenetic theory: Suggested that the occurrence of supernumerary teeth is a regression to the extinct ancestral tissues or anthropoids. Based on the phenomena that ancestor mammals have more teeth with three incisors, one canine, four premolars, and three molars in each quadrant of the jaw. Tooth germ dichotomy theory: Proposed that during early tooth development, the dental lamina was divided into two parts of equal or different size, thus giving rise to two teeth with similar size, or one normal tooth and one dysmorphic tooth Hyperactivity of the dental lamina: Primary dental lamina (odontogenic band) is the thickening of oral ectoderm forming during the initiation stage of deciduous teeth and it gives rise to the deciduous dentition. During the cap or bell stage of deciduous tooth development, successional dental lamina forms from the lingual or posterior aspect of deciduous tooth enamel organ. It later elongates under the oral epithelium and buds into the jaw mesenchyme forming the successional (permanent) tooth or the posterior molar teeth. Once the crown of the permanent tooth has formed, the dental lamina undergoes programmed cell death and degenerates. Residues of un-degenerated dental lamina epithelial cells may cause eruption cysts, while over-proliferation or prolonged survival of dental lamina epithelial cells may cause supernumerary tooth formation.
- It is generally thought that during evolution, the total number of teeth per dentition decreased (from polyodonty to oligodonty). The generations of teeth were also reduced (from polyphyodonty to diphyodonty or monophyodonty) Whereas the morphology of teeth became more complex (from homodonty to heterodonty). Over the course of evolution, the teeth in placental mammals tend to disappear in an order that is opposite to the order of their eruption
- Tooth germ dichotomy theory: Proposed that during early tooth development, the dental lamina was divided into two parts of equal or different size, thus giving rise to two teeth with similar size, or one normal tooth and one dysmorphic tooth Development of deciduous upper lateral incisor in human embryos (3D reconstructions) discovered that it forms the fusion of two dental epithelial thickenings separated by a groove at the formal fusion site of the medial nasal and maxillary processes epithelial thickenings fused later and formed a continuous dental lamina (Hovorakova et al ., 2006)
- Gemination is thought to be when one enlarged tooth appears as if the clinical crown has two portions; that is, the crown of one tooth has twinned. Twinning tooth formation, also known as double teeth, is defined when 2 teeth are joined together and is most often observed in the mandibular incisors of the primary dentition. A twinning anomaly can present as gemination, fusion, or concrescence.3 Gemination occurs when there is partial development of 2 teeth from 1 sin- gle tooth germ.4 In the case of fusion, 2 adjacent teeth are connected with each other by enamel or dentin, and fusion may be complete over the full length or incom- plete as seen in our patient.4 Concrescence is defined as 2 teeth being joined by cementum only, is usually the result of trauma or adjacent tooth malposition and is technically not a developmental anomaly.3 The distinc- tion between fusion and gemination is established by counting teeth. Fusion will result in the patient having one less tooth (19, rather than 20).
- Most widely accepted. Hyperactivity of the dental lamina: Primary dental lamina (odontogenic band) is the thickening of oral ectoderm forming during the initiation stage of deciduous teeth and it gives rise to the deciduous dentition. During the cap or bell stage of deciduous tooth development, successional dental lamina forms from the lingual or posterior aspect of deciduous tooth enamel organ. It later elongates under the oral epithelium and buds into the jaw mesenchyme forming the successional (permanent) tooth or the posterior molar teeth. Once the crown of the permanent tooth has formed, the dental lamina undergoes programmed cell death and degenerates. Residues of un-degenerated dental lamina epithelial cells may cause eruption cysts, while over-proliferation or prolonged survival of dental lamina epithelial cells may cause supernumerary tooth formation.
- Gardiner discussed 3 possible mechanisms that can give rise to supernumerary teeth in the premolar region: An abnormal proliferation of the dental lamina can be observed at A, that can give rise to a predeciduous type of supernumerary tooth. Although this may be a possible scenario, only one case was found in the literature reporting a supernumerary first primary molar together with a supernumerary first premolar. A more frequent type of situation can be seen in B. Before development of the permanent tooth takes place, the dental lamina provides an additional follicle that gives rise to a supernumerary tooth. On the other hand, an extra tooth can develop from an extension of the dental lamina after the deciduous as well as the permanent follicles have been formed. This has been termed a postpermanent type of supernumerary tooth and can be seen in C.
- Heredity is also believed to be an important factor. Supernumerary teeth occur more commonly in the relatives of affected patients than in the general population. They can be transmitted as an autosomal recessive or autosomal dominant trait with incomplete penetrance, or may be associated with the X chromosome . There are also reports that supernumerary teeth are sometimes associated with polydactyly and extra nipples. The etiology of odontomas is still unknown. It is usually thought to be hereditary or due to a disturbance during tooth development triggered by trauma or infection
- Supernumerary teeth, which form in addition to the normal complement found within a dentition, can occur. In humans, these teeth are relatively common, occurring as an isolated finding in up to 3% of the population or less commonly, presenting as a feature of a wider developmental disorder The conditions commonly associated with an increased prevalence of supernumerary teeth include cleft lip and palate, cleidocranial dysplasia (Fig. 1), and Gardner syndrome. 22.2% of patients with cleft lip and/or palate develop supernumerary teeth on the affected area.
- Supernumerary teeth, which form in addition to the normal complement found within a dentition, can occur. In humans, these teeth are relatively common, occurring as an isolated finding in up to 3% of the population or less commonly, presenting as a feature of a wider developmental disorder
- Supernumerary teeth in mice. The upper panels show the gross appearance of wild type (WT) adult mandibular incisor teeth and supernumerary teeth (red arrows) seen in Lrp4 and Ectodin mutant mice. The lower panels show three-dimensional reconstructions from micro-CT scans of the newborn mouse molar dentition. There are supernumerary premolar teeth mesial to the first molar in the Lrp4 and Gas1 mutants. M1, first molar; M2, second molar; M3, third molar; S, supernumerary.
- Msx1 (Blue) Osr2 (Purple) Bmp4 (Red) Control of tooth number across buccal–lingual dental axis. Left panel: In the wild type mouse, Osr2 is expressed in a lingual-to-buccal gradient across the jaw axis and restricts Bmp4–Msx1 pathway activity in the lingual region. Right panel: In the absence of Osr2 function Bmp4–Msx1 activity is unrestricted and propagates mesenchymal activation for sequential tooth induction in the lingual region, with supernumerary teeth developing directly from the oral epithelium. Therefore, Osr2 is an important determinant for patterning the mammalian dentition into a single row across the jaw. Mice lacking the function of Osr2 have a unique tooth phenotype, involving the development of supernumerary molar teeth on the lingual side of the dental arch. These teeth are interesting because they develop directly from thickenings of the oral epithelium in this region and not from vestigial tooth germs In the absence of Osr2, this restriction is lost and Bmp4–Msx1 is upregulated in lingual regions of the developing jaw—an activity that is sufficient to induce supernumerary tooth formation in this region. Protein odd-skipped-related 2 is a protein that in humans is encoded by the OSR2 gene. In mice, it is involved in the development of the palate and in suppressing the formation of teeth after the eruption of adult teeth.
- Mice have been used for a long time as the predominant model for studying tooth development. However, mouse dentition is highly reduced with only one incisor and three molars, separated by a toothless diastema region, in each quadrant of the jaw. In addition, mice have only a single primary dentition and their teeth are not replaced. Therefore, the mice may not be an optimal model for studying tooth replacement and supernumerary tooth formation Most of reported mouse supernumerary teeth located in the diastema region in front of the first molars A number of mutant mouse stains have been reported exhibiting supernumerary diastema teeth, including mice with overexpression of Eda or Edar Tabby mice with mutation of Eda, Sprouty2 or Sprouty4 Null mutant mice affecting Fgf, hypomorphic Polaris mice and Wnt1-Cre Polaris conditional mutant mice affecting Shh Pax6 mutant mice Gas1 null mutant mice Hypomorphic mice present supernumerary teeth in both incisors and molar regions. Hypomorphic describes a mutation that causes a partial loss of gene function. A hypomorph is a reduction in gene function through reduced (protein, RNA) expression or reduced functional performance, but not a complete loss.
- Variations in tooth replacement in reptiles and mammals, and serial addition of molars in mammals. (A) Schematics of dentitions of different vertebrates showing the left half of the lower jaws. Replacement teeth form at the lingual side of the dental arch. Mammalian molars are added serially in the posterior direction. Most reptiles have a homodont dentition, which is continuously replaced. Humans and ferrets represent typical mammals with a heterodont dentition composed of incisors, one canine, premolars and molars, and all teeth except molars are replaced once. Mice have one continuously growing incisor, a toothless diastema region and three molars. Mouse teeth are not replaced. (B) Reconstruction of human deciduous tooth germs illustrating: Their connection by the continuous dental lamina and the initiation of replacement tooth formation by budding of the successional dental lamina. Lingual view of anterior tooth germs in the lower jaw. A similar dental lamina is present in most other mammals and squamate reptiles. C, permanent canine; dC, deciduous canine; dI, deciduous incisor; dP, deciduous premolar; I, permanent incisor; M, molar; P, permanent premolar.
- Indications for Supernumerary Removal Central incisor eruption has been delayed or inhibited; Altered eruption or displacement of central incisors is evident; There is associated pathology; Active orthodontic alignment of an incisor in close proximity to the supernumerary is envisaged; Its presence would compromise secondary alveolar bone grafting in cleft lip and palate patients; The tooth is present in bone designated for implant placement; Spontaneous eruption of the supernumerary has occurred.