Related Research Articles
Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla or the mandible and are covered by gums. Teeth are made of multiple tissues of varying density and hardness.
Hyperdontia is the condition of having supernumerary teeth, or teeth that appear in addition to the regular number of teeth. They can appear in any area of the dental arch and can affect any dental organ. The opposite of hyperdontia is hypodontia, where there is a congenital lack of teeth, which is a condition seen more commonly than hyperdontia. The scientific definition of hyperdontia is "any tooth or odontogenic structure that is formed from tooth germ in excess of usual number for any given region of the dental arch." The additional teeth, which may be few or many, can occur on any place in the dental arch. Their arrangement may be symmetrical or non-symmetrical.
Hypodontia is defined as the developmental absence of one or more teeth excluding the third molars. It is one of the most common dental anomalies, and can have a negative impact on function, and also appearance. It rarely occurs in primary teeth and the most commonly affected are the adult second premolars and the upper lateral incisors. It usually occurs as part of a syndrome that involves other abnormalities and requires multidisciplinary treatment.
The cusp of Carabelli, Carabelli's tubercle, or tuberculum anomale of Georg Carabelli is a small additional cusp at the mesiopalatal line angle of maxillary first molars. This extra cusp is usually found on the secondary maxillary first molars and is rarely seen on primary maxillary second molars even less likely on other molars. This cusp is entirely absent in some individuals and present in others in a variety of forms. In some cases, the cusp of Carabelli may rival the main cusps in size. Other related forms include ridges, pits, or furrows. This additional cusp was first described in 1842 by the Hungarian Georg Carabelli, the court dentist of the Austrian Emperor Franz.
Acid erosion is a type of tooth wear. It is defined as the irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin. Dental erosion is the most common chronic condition of children ages 5–17, although it is only relatively recently that it has been recognised as a dental health problem. There is widespread ignorance of the damaging effects of acid erosion; this is particularly the case with erosion due to consumption of fruit juices because they tend to be seen as healthy. Acid erosion begins initially in the enamel, causing it to become thin, and can progress into dentin, giving the tooth a dull yellow appearance and leading to dentin hypersensitivity.
The dental lamina is a band of epithelial tissue seen in histologic sections of a developing tooth. The dental lamina is first evidence of tooth development and begins at the sixth week in utero or three weeks after the rupture of the buccopharyngeal membrane. It is formed when cells of the oral ectoderm proliferate faster than cells of other areas. Best described as an in-growth of oral ectoderm, the dental lamina is frequently distinguished from the vestibular lamina, which develops concurrently. This dividing tissue is surrounded by and, some would argue, stimulated by ectomesenchymal growth. When it is present, the dental lamina connects the developing tooth bud to the epithelium of the oral cavity. Eventually, the dental lamina disintegrates into small clusters of epithelium and is resorbed. In situations when the clusters are not resorbed, eruption cysts are formed over the developing tooth and delay its eruption into the oral cavity. This invagination of ectodermal tissues is the progenitor to the later ameloblasts and enamel while the ectomesenchyme is responsible for the dental papilla and later odontoblasts.
Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. For human teeth to have a healthy oral environment, all parts of the tooth must develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth week of prenatal development, and permanent teeth begin to form in the twentieth week. If teeth do not start to develop at or near these times, they will not develop at all, resulting in hypodontia or anodontia.
Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. It is inherited in an autosomal dominant pattern, as a result of mutations on chromosome 4q21, in the dentine sialophosphoprotein gene (DSPP). It is one of the most frequently occurring autosomal dominant features in humans. Dentinogenesis imperfecta affects an estimated 1 in 6,000-8,000 people.
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. This disturbance is more likely to affect the maxillary incisors and occurs in permanent dentition. Although this may seem more of an aesthetics issue, an impacted maxillary incisor will cause issues related to occlusion, phonetics, mastication, and psychology on young patients.
Tooth fusion [also known as syndontia or double teeth] occurs when two separate tooth germs fuse to form one tooth. The fusion may be complete or partial, depending on the stage of tooth development when the teeth started to fuse. Tooth fusion is difficult to distinguish from tooth gemination, thus, both conditions are often referred to together as “double teeth”.
Macrodontia is a type of localized gigantism in which teeth are larger than normal. Macrodontia seen in permanent teeth is thought to affect around 0.03 to 1.9 percent of the worldwide population. Generally, patients with macrodontia have one or two teeth in their mouth that is abnormally large; however, single tooth growth is seen in a number of cases as well.
Dens evaginatus is a rare odontogenic developmental anomaly that is found in teeth where the outer surface appears to form an extra bump or cusp.
Talon cusp is a rare dental anomaly resulting in an extra cusp or cusp-like projection on an anterior tooth, located on the inside surface of the affected tooth. Sometimes it can also be found on the facial surface of the anterior tooth.
Tooth eruption is a process in tooth development in which the teeth enter the mouth and become visible. It is currently believed that the periodontal ligament plays an important role in tooth eruption. The first human teeth to appear, the deciduous (primary) teeth, erupt into the mouth from around 6 months until 2 years of age, in a process known as "teething". These teeth are the only ones in the mouth until a person is about 6 years old creating the primary dentition stage. At that time, the first permanent tooth erupts and begins a time in which there is a combination of primary and permanent teeth, known as the mixed dentition stage, which lasts until the last primary tooth is lost. Then, the remaining permanent teeth erupt into the mouth during the permanent dentition stage.
Dental radiographs, commonly known as X-rays, are radiographs used to diagnose hidden dental structures, malignant or benign masses, bone loss, and cavities.
Dental pertains to the teeth, including dentistry. Topics related to the dentistry, the human mouth and teeth include:
Restorative dentistry is the study, diagnosis and integrated management of diseases of the teeth and their supporting structures and the rehabilitation of the dentition to functional and aesthetic requirements of the individual. Restorative dentistry encompasses the dental specialties of endodontics, periodontics and prosthodontics and its foundation is based upon how these interact in cases requiring multifaceted care. This may require the close input from other dental specialties such as orthodontics, paediatric dentistry and special care dentistry, as well as surgical specialties such as oral and maxillofacial surgery.
Enamel hypoplasia is a defect of the teeth in which the enamel is deficient in quantity, caused by defective enamel matrix formation during enamel development, as a result of inherited and acquired systemic condition(s). It can be identified as missing tooth structure and may manifest as pits or grooves in the crown of the affected teeth, and in extreme cases, some portions of the crown of the tooth may have no enamel, exposing the dentin. It may be generalized across the dentition or localized to a few teeth. Defects are categorized by shape or location. Common categories are pit-form, plane-form, linear-form, and localised enamel hypoplasia. Hypoplastic lesions are found in areas of the teeth where the enamel was being actively formed during a systemic or local disturbance. Since the formation of enamel extends over a long period of time, defects may be confined to one well-defined area of the affected teeth. Knowledge of chronological development of deciduous and permanent teeth makes it possible to determine the approximate time at which the developmental disturbance occurred. Enamel hypoplasia varies substantially among populations and can be used to infer health and behavioural impacts from the past. Defects have also been found in a variety of non-human animals.
Dental trauma refers to trauma (injury) to the teeth and/or periodontium, and nearby soft tissues such as the lips, tongue, etc. The study of dental trauma is called dental traumatology.
Tooth ankylosis refers to a fusion between a tooth and underlying bony support tissues. In some species, this is a normal process that occurs during the formation or maintenance of the dentition. By contrast, in humans tooth ankylosis is pathological, whereby a fusion between alveolar bone and the cementum of a tooth occurs.
References
- ↑ Mamdani, Sajida; Pathak, Divya; Harrison, Mike; Bhujel, Nabina (March 2023). "Macrodontia and double teeth: a review and case series". British Dental Journal. 234 (5): 315–321. doi:10.1038/s41415-023-5571-9. ISSN 1476-5373. PMID 36899237.
- 1 2 3 Süha Türkaslan, Hasan Suat Gökçe and Mehmet Dalkız (July 2017). "Esthetic Rehabilitation of Bilateral Geminated Teeth: A Case Report". European Journal of Dentistry. 1 (3): 188–191. PMC 2638247 . PMID 19212565.
- 1 2 Nandini DB, Deepak BS, Selvamani M, Puneeth HK (2014). "Diagnostic dilemma of a double tooth: a rare case report and review". Journal of Clinical and Diagnostic Research. 8 (1): 271–2. doi:10.7860/JCDR/2014/6556.3928. PMC 3939503 . PMID 24596793.
- 1 2 3 4 5 6 "Tooth gemination in dentistry". DentaGama Dental Social Network. DentaGama. Retrieved 1 December 2017.
Hattab, FN. (2014). Double talon cusps on supernumerary tooth fused to maxillary central incisor: Review of literature and report of Case. Journal of Clinical and Experimental Dentistry. https://doi.org/10.4317/jced.51428
Hülsmann, M., Bahr, R., & Grohmann, U. (1997). Hemisection and vital treatment of a fused tooth – literature review and Case report. Dental Traumatology, 13(6), 253–258. https://doi.org/10.1111/j.1600-9657.1997.tb00051.x
Mamdani, S., Pathak, D., Harrison, M., & Bhujel, N. (2023). Macrodontia and double teeth: A review and Case series. British Dental Journal, 234(5), 315–321. https://doi.org/10.1038/s41415-023-5571-9
Nandini, D. B. (2014). Diagnostic dilemma of a double tooth: A rare case report and Review. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH. https://doi.org/10.7860/jcdr/2014/6556.3928
Neville, B. W., Damm, D. D., Allen, C. M., & Chi, A. C. (2016). Oral and maxillofacial pathology (Fourth edition.). Elsevier. Chapter 2
Scheid, R. C., & Weiss, G. (2017). Woelfel’s dental anatomy (Enhanced ninth edition.). Jones & Bartlett Learning. Chapter 11
White, S. C., & Pharoah, M. J. (Eds.). (2014). Oral radiology : principles and interpretation (8th ed.). Elsevier. Chapter 21