Wisdom tooth

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Wisdom tooth
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Wisdom teeth in the human mouth for permanent teeth. There are none in deciduous (children's) teeth.
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Wisdom teeth
Identifiers
MeSH D008964
TA98 A05.1.03.008
TA2 911
FMA 321612
Anatomical terminology

The third molar, commonly called wisdom tooth, is the most posterior of the three molars in each quadrant of the human dentition. The age at which wisdom teeth come through (erupt) is variable, [1] but this generally occurs between late teens and early twenties. [2] Most adults have four wisdom teeth, one in each of the four quadrants, but it is possible to have none, fewer, or more, in which case the extras are called supernumerary teeth. Wisdom teeth may become stuck (impacted) [3] and not erupt fully, if there is not enough space for them to come through normally. Impacted wisdom teeth are still sometimes removed for orthodontic treatment, believing that they move the other teeth and cause crowding, though this is no longer held as true. [4] [5]

Contents

Impacted wisdom teeth may suffer from tooth decay if oral hygiene becomes more difficult. Wisdom teeth which are partially erupted through the gum may also cause inflammation [3] and infection in the surrounding gum tissues, termed pericoronitis. More conservative treatments, such as operculectomies, may be appropriate for some cases. However, impacted wisdom teeth are commonly extracted to treat or prevent these problems. Some sources oppose the prophylactic removal of disease-free impacted wisdom teeth, including the National Institute for Health and Care Excellence in the UK. [4] [6] [7]

History

Although formally known as third molars, the common name is wisdom teeth because they appear so late – much later than the other teeth, at an age where people are presumably "wiser" than as a child, when the other teeth erupt. [8] The term probably came as a translation of the Latin dens sapientiae. Their eruption has been known to cause dental issues for millennia; it was noted at least as far back as Aristotle:

The last teeth to come in man are molars called 'wisdom-teeth', which come at the age of twenty years, in the case of both sexes. Cases have been known in women upwards of eighty years old where at the very close of life the wisdom-teeth have come up, causing great pain in their coming; and cases have been known of the like phenomenon in men too. This happens, when it does happen, in the case of people where the wisdom-teeth have not come up in early years.

— Aristotle, The History of Animals [9]

The oldest known impacted wisdom tooth belonged to a European woman who lived between 13,000 and 11,000 BCE, in the Magdalenian period. [10] Nonetheless, molar impaction was relatively rare prior to the modern era. With the Industrial Revolution, the affliction became ten times more common, owing to the new prevalence of soft, processed foods. [11] [12]

Structure

3D CT of an impacted wisdom tooth near the inferior alveolar nerve 3D CT impacted wisdom tooth.Gif
3D CT of an impacted wisdom tooth near the inferior alveolar nerve

Tooth morphology

Morphology of wisdom teeth can be variable.

Maxillary (upper) third molars commonly have a triangular crown with a deep central fossa from which multiple irregular fissures originate. Their roots are commonly fused together and can be irregular in shape.

Mandibular (lower) third molars are the smallest molar teeth in the permanent dentition. The crown usually takes on a rounded rectangular shape that features four or five cusps with an irregular fissure pattern. Roots are greatly reduced in size and can be fused together. [13]

Dental notation

There are several notation systems used in dentistry to identify teeth.  Under the Palmer/Zsigmondy system, the right and left maxillary wisdom teeth are represented by 8⏌ and ⎿8, while 8⏋ and ⎾8 represent the right and left mandibular wisdom teeth. [14] Under the FDI notational system, the right and left maxillary third molars are numbered 18 and 28, respectively, and the right and left mandibular third molars are numbered 48 and 38. [15] According to the Universal Numbering System the right and left upper wisdom teeth are numbered 1 and 16 and the right and left lower wisdom teeth are 17 and 32. [16]

Variation

Agenesis of wisdom teeth differs by population, ranging from practically zero in Aboriginal Tasmanians to nearly 100% in indigenous Mexicans. [17] [18] The difference is related to the PAX9 and MSX1 genes (and perhaps other genes). [19] [20] [21] [22]

Age of eruption

There is significant variation between the reported age of eruption of wisdom teeth between different populations. [23] For example, wisdom teeth tend to erupt earlier in people with African heritage compared to people of Asian and European heritage. [23]

Generally wisdom teeth erupt most commonly between age 17 and 21. [1] Eruption may start as early as age 13 in some groups [23] and typically occurs before the age of 25. [24] If they have not erupted by age 25, oral surgeons generally consider that the tooth will not erupt spontaneously. [2]

Root development can continue for up to three years after eruption occurs. [25]

Function

Anthropologists believe human and primate [12] wisdom teeth may help with chewing tougher foods. [26] [27] After the advent of agriculture over 10,000 years ago, and especially with the industrial revolution in recent centuries, soft human diets became more common through the use of tools (cutting the food) and cooking to make food easier to chew. Compared to hunter-gatherer populations, post-industrial agriculturalist populations are thought to encounter less masticatory stress and consequently have shorter and thicker mandibles, predisposing them to dental crowding and malocclusion. [28]

Clinical significance

Inflamed excess gum flap (inflamed operculum marked by green arrow) over wisdom tooth 38 pericoronitis with pus.jpg
Inflamed excess gum flap (inflamed operculum marked by green arrow) over wisdom tooth

Wisdom teeth (often notated clinically as M3 for third molar) have long been identified as a source of problems and continue to be the most commonly impacted teeth in the human mouth. Impaction of the wisdom teeth results in a risk of periodontal disease and dental cavities. [29] Impacted wisdom teeth lead to pathology in 12% of cases. [30]

Some problems which may or may not occur with third molars: A Mesio-impacted, partially erupted mandibular third molar, B Dental caries and periodontal defects associated with both the third and second molars, caused by food packing and poor access to oral hygiene methods, C Inflamed operculum covering partially erupted lower third molar, with accumulation of food debris and bacteria underneath, D The upper third molar has over-erupted due to lack of opposing tooth contact, and may start to traumatically occlude into the operculum over the lower third molar. Unopposed teeth are usually sharp because they have not been blunted by another tooth. Lower mandibular third molar impaction pericoronitis diagram.jpg
Some problems which may or may not occur with third molars: A Mesio-impacted, partially erupted mandibular third molar, B Dental caries and periodontal defects associated with both the third and second molars, caused by food packing and poor access to oral hygiene methods, C Inflamed operculum covering partially erupted lower third molar, with accumulation of food debris and bacteria underneath, D The upper third molar has over-erupted due to lack of opposing tooth contact, and may start to traumatically occlude into the operculum over the lower third molar. Unopposed teeth are usually sharp because they have not been blunted by another tooth.
Dental x-ray of impacted lower left wisdom tooth with a horizontal orientation Impacted Wisdom Tooth aka Lower Right Third Molar 48 RVG IOPA Xray.jpg
Dental x-ray of impacted lower left wisdom tooth with a horizontal orientation

Impacted wisdom teeth are classified by the direction and depth of impaction, the amount of available space for tooth eruption and the amount of soft tissue or bone that covers them. The classification structure allows clinicians to estimate the probabilities of impaction, infections and complications associated with wisdom teeth removal. [31] Wisdom teeth are also classified by the presence of symptoms and disease. [32]

Treatment of an erupted wisdom tooth is the same as any other tooth in the mouth. If impacted and having a pathology, such as caries or pericoronitis, treatment can be dental restoration for cavities and for pericoronitis, salt water rinses, local treatment to the infected tissue overlying the impaction, [33] : 440–441  oral antibiotics, surgical removal of excess gum flap (operculectomy), or if those failed, extraction or coronectomy.

The National Health Service in the UK recommends people go to dental check-ups every 3–24 months, depending on the state of the teeth and gums and the recommendation of the dentist. [34]

Common pathologies associated with wisdom teeth

Odontogenic infections are a dental complication originating inside the tooth or in close proximity to the surrounding tissues. There are different types of odontogenic infections which may affect impacted wisdom teeth such as periodontitis, pulpitis, dental abscess and pericoronitis.

Pericoronitis is a common pathology of impacted third molar. [35] It is an acute localized infection of the tissue surrounding the impacted wisdom teeth. Clinically the tissue appears to be red, tender to touch and edematous. The common symptoms the patient’s report are pain ‘that ranges from dull to throbbing to intense’ and often radiates to mouth, ear or floor of the mouth. Moreover, swelling of the cheek, halitosis and trismus can occur. [36]

Odontogenic cysts

Odontogenic cysts are a less common pathology of the impacted wisdom tooth with some estimates of prevalence from 0.64% to 2.24% of impacted wisdom teeth. [37] [38] They are described as ‘cavities filled with liquid, semiliquid or gaseous content with odontogenic epithelial lining and connective tissue on the outside’. However, studies have found cysts to be prevalent in a small percentage of impacted wisdom teeth that are extracted. The most common types associated with impacted third molars are radicular cysts, dentigerous cysts and odontogenic keratocysts. [39] Large cysts take 2–13 years to develop. [38]

The upper left (picture right) and upper right (picture left) wisdom teeth are distoangularly impacted. The lower left wisdom tooth is horizontally impacted. The lower right wisdom tooth is vertically impacted (unidentifiable in orthopantomogram). Impacted wisdom teeth.jpg
The upper left (picture right) and upper right (picture left) wisdom teeth are distoangularly impacted. The lower left wisdom tooth is horizontally impacted. The lower right wisdom tooth is vertically impacted (unidentifiable in orthopantomogram).

Oral hygiene care

Practice and maintenance of good oral hygiene can help prevent and control some wisdom tooth pathologies. In addition to twice daily toothbrushing, interdental cleaning is recommended to ensure plaque build doesn’t occur in interdental areas. There are various products available for this – dental floss and interdental brushes being the most common.

Removal of impacted wisdom teeth

Removal of asymptomatic impacted wisdom teeth with the absence of disease and no evidence of local infection as a prophylactic method has been disputed within the dental community for a long time. There is insufficient reliable scientific evidence for dental health professionals and policy makers to determine if asymptomatic disease-free impacted wisdom teeth should be removed. Therefore, the decision will depend on a combination of clinical expertise and patient preference. If the tooth is retained, regular check-ups to identify any problems that may occur is recommended. Considering the lack of quality evidence at present, more long-term studies need to be undertaken to obtain a reliable scientific conclusion. [40]

Mandibular third molar surgery recovery

Platelet-rich fibrin (PRF) is a postoperative method used to heal the alveolar socket following the removal of the mandibular third molar. PRF is a second generation result of the isolation of platelets, white blood cells, stem cells and growth factors from blood samples. Studies have shown that when used there are improvements in pain sensations, swelling and a decreased risk of developing dry socket. This method was shown to only reduce symptoms and is not completely preventive. To date there is no clear correlation between the use of PRF after a mandibular third molar removal surgery and the recovery of jaw spasms, bone restoration and soft tissue healing. Further studies with larger study samples are needed to validate current theories. [41]

Prognosis

About a third of symptomatic unerupted wisdom teeth have been shown to partially erupt and be non-functional or non-hygienic. Studies have also shown that 30% to 60% of people with previously asymptomatic impacted wisdom teeth will have an extraction of at least one of them in 4 to 12 years from diagnosis. [42]

Risk factors of inferior alveolar nerve damage

Temporary and permanent inferior alveolar nerve (IAN) damage is a known complication of the surgical removal of impacted lower third molars, happening in 1 in 85 patients and 1 in 300 extractions, respectively. Studies have shown that certain risk factors may increase the likelihood of IAN damage. Proximity of the impacted third molar root to the mandibular canal, which can be seen in radiographs, has been shown to be a high-risk factor for IAN damage. Alongside this, the depth of impaction of the tooth, surgical technique and surgeons experience are all contributing risk factors for IAN damage during this procedure. Careful case-by-case consideration is crucial to avoid this risk. [43]

Lower anterior teeth crowding

Lower anterior teeth crowding has been a common discussion among the orthodontic community for decades. In the 1970s it was thought that unerupted wisdom teeth produced a forward directed force which would cause crowding of the anterior segment. Recent research has shown that there is no agreed opinion and that the cause is due to a variety of factors. This includes dental factors such as tooth crown size and primary tooth loss. Skeletal factors which include growth of the maxilla and mandible and the presence of malocclusions. General factors, including the age and gender of the patient. Overall, recent research has suggested that wisdom teeth alone do not cause crowding of teeth. [44]

See also

Related Research Articles

<span class="mw-page-title-main">Toothache</span> Medical condition of the teeth

Toothache, also known as dental pain or tooth pain, is pain in the teeth or their supporting structures, caused by dental diseases or pain referred to the teeth by non-dental diseases. When severe it may impact sleep, eating, and other daily activities.

<span class="mw-page-title-main">Alveolar osteitis</span> Inflammation of the alveoli (tooth sockets in the jawbones)

Alveolar osteitis, also known as dry socket, is inflammation of the alveolar bone. Classically, this occurs as a postoperative complication of tooth extraction.

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.

<span class="mw-page-title-main">Cementoblastoma</span> Benign tumor of the teeth roots

Cementoblastoma, or benign cementoblastoma, is a relatively rare benign neoplasm of the cementum of the teeth. It is derived from ectomesenchyme of odontogenic origin. Cementoblastomas represent less than 0.69–8% of all odontogenic tumors.

<span class="mw-page-title-main">Dental follicle</span> Anatomical entity

The dental follicle, also known as dental sac, is made up of mesenchymal cells and fibres surrounding the enamel organ and dental papilla of a developing tooth. It is a vascular fibrous sac containing the developing tooth and its odontogenic organ. The dental follicle (DF) differentiates into the periodontal ligament. In addition, it may be the precursor of other cells of the periodontium, including osteoblasts, cementoblasts and fibroblasts. They develop into the alveolar bone, the cementum with Sharpey's fibers and the periodontal ligament fibers respectively. Similar to dental papilla, the dental follicle provides nutrition to the enamel organ and dental papilla and also have an extremely rich blood supply.

<span class="mw-page-title-main">Dental extraction</span> Operation to remove a tooth

A dental extraction is the removal of teeth from the dental alveolus (socket) in the alveolar bone. Extractions are performed for a wide variety of reasons, but most commonly to remove teeth which have become unrestorable through tooth decay, periodontal disease, or dental trauma, especially when they are associated with toothache. Sometimes impacted wisdom teeth cause recurrent infections of the gum (pericoronitis), and may be removed when other conservative treatments have failed. In orthodontics, if the teeth are crowded, healthy teeth may be extracted to create space so the rest of the teeth can be straightened.

<span class="mw-page-title-main">Pericoronitis</span> Inflammation of the soft tissues surrounding the crown of a partially erupted tooth

Pericoronitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth, including the gingiva (gums) and the dental follicle. The soft tissue covering a partially erupted tooth is known as an operculum, an area which can be difficult to access with normal oral hygiene methods. The hyponym operculitis technically refers to inflammation of the operculum alone.

A dental emergency is an issue involving the teeth and supporting tissues that are of high importance to be treated by the relevant professional. Dental emergencies do not always involve pain, although this is a common signal that something needs to be looked at. Pain can originate from the tooth, surrounding tissues or can have the sensation of originating in the teeth but be caused by an independent source. Depending on the type of pain experienced an experienced clinician can determine the likely cause and can treat the issue as each tissue type gives different messages in a dental emergency.

<span class="mw-page-title-main">Dentigerous cyst</span> Medical condition

A dentigerous cyst, also known as a follicular cyst, is an epithelial-lined developmental cyst formed by accumulation of fluid between the reduced enamel epithelium and the crown of an unerupted tooth. It is formed when there is an alteration in the reduced enamel epithelium and encloses the crown of an unerupted tooth at the cemento-enamel junction. Fluid is accumulated between reduced enamel epithelium and the crown of an unerupted tooth.

<span class="mw-page-title-main">Concrescence</span> Medical condition

Concrescence is an uncommon developmental condition of teeth where the cementum overlying the roots of at least two teeth fuse together without the involvement of dentin. Usually, two teeth are involved with the upper second and third molars being most commonly fused together. The prevalence ranges 0.04–0.8% in permanent teeth, with the incidence being highest in the posterior maxilla.

<span class="mw-page-title-main">Odontogenic keratocyst</span> Medical condition

An odontogenic keratocyst is a rare and benign but locally aggressive developmental cyst. It most often affects the posterior mandible and most commonly presents in the third decade of life. Odontogenic keratocysts make up around 19% of jaw cysts. Despite its more common appearance in the bone region, it can affect soft tissue.

“Lateral periodontal cysts (LPCs) are defined as non-keratinised and non-inflammatory developmental cysts located adjacent or lateral to the root of a vital tooth.” LPCs are a rare form of jaw cysts, with the same histopathological characteristics as gingival cysts of adults (GCA). Hence LPCs are regarded as the intraosseous form of the extraosseous GCA. They are commonly found along the lateral periodontium or within the bone between the roots of vital teeth, around mandibular canines and premolars. Standish and Shafer reported the first well-documented case of LPCs in 1958, followed by Holder and Kunkel in the same year although it was called a periodontal cyst. Since then, there has been more than 270 well-documented cases of LPCs in literature.

<span class="mw-page-title-main">Calcifying odontogenic cyst</span> Medical condition

Calcifying odontogenic cyst (COC) is a rare developmental lesion that comes from odontogenic epithelium. It is also known as a calcifying cystic odontogenic tumor, which is a proliferation of odontogenic epithelium and scattered nest of ghost cells and calcifications that may form the lining of a cyst, or present as a solid mass.

<span class="mw-page-title-main">Ameloblastic fibroma</span> Medical condition

An ameloblastic fibroma is a fibroma of the ameloblastic tissue, that is, an odontogenic tumor arising from the enamel organ or dental lamina. It may be either truly neoplastic or merely hamartomatous. In neoplastic cases, it may be labeled an ameloblastic fibrosarcoma in accord with the terminological distinction that reserves the word fibroma for benign tumors and assigns the word fibrosarcoma to malignant ones. It is more common in the first and second decades of life, when odontogenesis is ongoing, than in later decades. In 50% of cases an unerupted tooth is involved.

<span class="mw-page-title-main">Odontoma</span> Benign tumour of dental tissue

An odontoma, also known as an odontome, is a benign tumour linked to tooth development. Specifically, it is a dental hamartoma, meaning that it is composed of normal dental tissue that has grown in an irregular way. It includes both odontogenic hard and soft tissues. As with normal tooth development, odontomas stop growing once mature which makes them benign.

<span class="mw-page-title-main">Tooth impaction</span> Prevention of tooth eruption by a physical barrier

An impacted tooth is one that fails to erupt into the dental arch within the expected developmental window. Because impacted teeth do not erupt, they are retained throughout the individual's lifetime unless extracted or exposed surgically. Teeth may become impacted because of adjacent teeth, dense overlying bone, excessive soft tissue or a genetic abnormality. Most often, the cause of impaction is inadequate arch length and space in which to erupt. That is the total length of the alveolar arch is smaller than the tooth arch. The wisdom teeth are frequently impacted because they are the last teeth to erupt in the oral cavity. Mandibular third molars are more commonly impacted than their maxillary counterparts.

<span class="mw-page-title-main">Cementoma</span> Medical condition

Cementoma is an odontogenic tumor of cementum. It is usually observed as a benign spherical mass of hard tissue fused to the root of a tooth. It is found most commonly in the mandible in the region of the lower molar teeth, occurring between the ages of 8 and 30 in both sexes with equal frequency. It causes distortion of surrounding areas but is usually a painless growth, at least initially. Considerable thickening of the cementum can often be observed. A periapical form is also recognized. Cementoma is not exclusive to the mandible as it can infrequently occur in the maxilla and other parts of the body such as the long bones.

<span class="mw-page-title-main">Odontogenic infection</span> Infection originating in a tooth

An odontogenic infection is an infection that originates within a tooth or in the closely surrounding tissues. The term is derived from odonto- and -genic. The most common causes for odontogenic infection to be established are dental caries, deep fillings, failed root canal treatments, periodontal disease, and pericoronitis. Odontogenic infection starts as localised infection and may remain localised to the region where it started, or spread into adjacent or distant areas.

Cysts of the jaws are cysts—pathological epithelial-lined cavities filled with fluid or soft material—occurring on the bones of the jaws, the mandible and maxilla. Those are the bones with the highest prevalence of cysts in the human body, due to the abundant amount of epithelial remnants that can be left in the bones of the jaws. The enamel of teeth is formed from ectoderm, and so remnants of epithelium can be left in the bone during odontogenesis. The bones of the jaws develop from embryologic processes which fuse, and ectodermal tissue may be trapped along the lines of this fusion. This "resting" epithelium is usually dormant or undergoes atrophy, but, when stimulated, may form a cyst. The reasons why resting epithelium may proliferate and undergo cystic transformation are generally unknown, but inflammation is thought to be a major factor. The high prevalence of tooth impactions and dental infections that occur in the bones of the jaws is also significant to explain why cysts are more common at these sites.

<span class="mw-page-title-main">Impacted wisdom teeth</span> Teeth that do not fully grow out of the gums due to being blocked by other teeth

Impacted wisdom teeth is a condition where the third molars are prevented from erupting into the mouth. This can be caused by a physical barrier, such as other teeth, or when the tooth is angled away from a vertical position. Completely unerupted wisdom teeth usually result in no symptoms, although they can sometimes develop cysts or neoplasms. Partially erupted wisdom teeth or wisdom teeth that are not erupted but are exposed to oral bacteria through deep periodontal pocket, can develop cavities or pericoronitis. Removal of impacted wisdom teeth is advised for the future prevention of or in the current presence of certain pathologies, such as caries, periodontal disease or cysts. Prophylactic (preventative) extraction of wisdom teeth is preferred to be done at a younger age to take advantage of incomplete root development, which is associated with an easier surgical procedure and less probability of complications.

References

  1. 1 2 McCoy JM (September 2012). "Complications of retention: pathology associated with retained third molars". Atlas of the Oral and Maxillofacial Surgery Clinics of North America. 20 (2): 177–195. doi:10.1016/j.cxom.2012.06.002. ISBN   978-1455747887. PMID   23021395.
  2. 1 2 Swift JQ, Nelson WJ (September 2012). "The nature of third molars: are third molars different than other teeth?". Atlas of the Oral and Maxillofacial Surgery Clinics of North America. 20 (2): 159–162. doi:10.1016/j.cxom.2012.07.003. PMID   23021392.
  3. 1 2 "Wisdom Teeth And Orthodontic Treatment: Should I be worried?". Orthodontics Australia. 2020-01-25. Retrieved 2020-11-19.
  4. 1 2 Friedman JW (September 2007). "The prophylactic extraction of third molars: a public health hazard". American Journal of Public Health. 97 (9): 1554–1559. doi:10.2105/AJPH.2006.100271. PMC   1963310 . PMID   17666691.
  5. ↑ Lyros, Ioannis; Vasoglou, Georgios; Lykogeorgos, Theodoros; Tsolakis, Ioannis A.; Maroulakos, Michael P.; Fora, Eleni; Tsolakis, Apostolos I. (May 2023). "The Effect of Third Molars on the Mandibular Anterior Crowding Relapse—A Systematic Review". Dentistry Journal. 11 (5): 131. doi: 10.3390/dj11050131 . ISSN   2304-6767. PMC   10217727 . PMID   37232782.
  6. ↑ "1 Guidance | Guidance on the Extraction of Wisdom Teeth | Guidance | NICE". www.nice.org.uk. 27 March 2000. Retrieved 2019-12-03.
  7. ↑ "Opposition to Prophylactic Removal of Third Molars (Wisdom Teeth)". www.apha.org. Retrieved 2019-12-02.
  8. ↑ "Wisdom tooth". Oxford English Dictionary. Oxford: Oxford University Press. 1989. ISBN   0-19-861186-2.
  9. ↑ Aristotle (2015). The History of Animals. Translated by D'Arcy Wentworth Thompson. Aeterna Press. p. 49.
  10. ↑ "Magdalenian Girl is a woman and therefore has oldest recorded case of impacted wisdom teeth" (Press release). Field Museum of Natural History. March 7, 2006. Retrieved February 15, 2013.
  11. ↑ "What teeth reveal about the lives of modern humans". Ohio State News. The Ohio State University. 9 January 2017. Retrieved 2018-10-22.
  12. 1 2 Boughner J (9 November 2018). "Bad molars? The origins of wisdom teeth". The Conversation. Retrieved 2023-03-13.
  13. ↑ Berkovitz BK, Holland GR, Moxham BJ (2017). Oral Anatomy, Histology and Embryology (fifth ed.). Elsevier. pp. 25–26.
  14. ↑ Edward F. Harris (2005). "Tooth-Coding Systems in the Clinical Dental Setting" (PDF). Dental Anthropology. 18 (2): 44. ISSN   1096-9411. Archived from the original (PDF) on 2012-01-06.
  15. ↑ ISO (International Organization for Standardization). "ISO 3950:2016". ISO 3950:2016 Dentistry — Designation system for teeth and areas of the oral cavity. Retrieved 2023-03-10.
  16. ↑ American Dental Association (August 2022). "Universal Tooth Designation System" (PDF). ValueSet - Universal Tooth Designation System ada.org. Archived (PDF) from the original on 2023-03-06. Retrieved 2023-03-10.
  17. ↑ Rozkovcová E, Marková M, Dolejsí J (1999). "Studies on agenesis of third molars amongst populations of different origin". Sbornik Lekarsky. 100 (2): 71–84. PMID   11220165.
  18. ↑ Sujon, Mamun Khan; Alam, Mohammad Khursheed; Rahman, Shaifulizan Abdul (31 August 2016). "Prevalence of Third Molar Agenesis: Associated Dental Anomalies in Non-Syndromic 5923 Patients". PLoS ONE. 11 (8).
  19. ↑ Pereira TV, Salzano FM, Mostowska A, Trzeciak WH, Ruiz-Linares A, Chies JA, et al. (April 2006). "Natural selection and molecular evolution in primate PAX9 gene, a major determinant of tooth development". Proceedings of the National Academy of Sciences of the United States of America. 103 (15): 5676–5681. Bibcode:2006PNAS..103.5676P. doi: 10.1073/pnas.0509562103 . JSTOR   30050159. PMC   1458632 . PMID   16585527.
  20. ↑ Bonczek O, Balcar VJ, Šerý O (November 2017). "PAX9 gene mutations and tooth agenesis: A review". Clinical Genetics. 92 (5): 467–476. doi:10.1111/cge.12986. PMID   28155232. S2CID   29589974.
  21. ↑ Lidral AC, Reising BC (April 2002). "The role of MSX1 in human tooth agenesis". Journal of Dental Research. 81 (4): 274–278. doi:10.1177/154405910208100410. PMC   2731714 . PMID   12097313.
  22. ↑ Tallón-Walton V, Manzanares-Céspedes MC, Carvalho-Lobato P, Valdivia-Gandur I, Arte S, Nieminen P (May 2014). "Exclusion of PAX9 and MSX1 mutation in six families affected by tooth agenesis. A genetic study and literature review". Medicina Oral, Patologia Oral y Cirugia Bucal. 19 (3): e248–e254. doi:10.4317/medoral.19173. PMC   4048113 . PMID   24316698.
  23. 1 2 3 Tsokos M (2008). Forensic Pathology Reviews 5. Springer Science & Business Media. p. 281. ISBN   9781597451109.
  24. ↑ "Wisdom Teeth". American Association of Oral and Maxillofacial Surgeons. Retrieved 2019-11-19. They come in between the ages of 17 and 25, a time of life that has been called the "Age of Wisdom."
  25. ↑ Kaveri GS, Prakash S (June 2012). "Third molars: a threat to periodontal health??". Journal of Maxillofacial and Oral Surgery. 11 (2): 220–223. doi:10.1007/s12663-011-0286-x. PMC   3386422 . PMID   23730073.
  26. ↑ Cooper R (February 5, 2007). "Why Do We Have Wisdom Teeth?". Scienceline.org. Archived from the original on 2016-05-03.
  27. ↑ "A grassy trend in human ancestors' diets". ScienceDaily. Retrieved 2023-03-13.
  28. ↑ von Cramon-Taubadel N (December 2011). "Global human mandibular variation reflects differences in agricultural and hunter-gatherer subsistence strategies". Proceedings of the National Academy of Sciences of the United States of America. 108 (49): 19546–19551. Bibcode:2011PNAS..10819546V. doi: 10.1073/pnas.1113050108 . PMC   3241821 . PMID   22106280.
  29. ↑ "Dental cavities: MedlinePlus Medical Encyclopedia". MedlinePlus. U.S. National Library of Medicine. Retrieved 2022-10-31.
  30. ↑ Stanley HR, Alattar M, Collett WK, Stringfellow HR, Spiegel EH (March 1988). "Pathological sequelae of "neglected" impacted third molars". Journal of Oral Pathology. 17 (3): 113–117. doi:10.1111/j.1600-0714.1988.tb01896.x. PMID   3135372.
  31. ↑ Juodzbalys G, Daugela P (July 2013). "Mandibular third molar impaction: review of literature and a proposal of a classification". Journal of Oral & Maxillofacial Research. 4 (2): e1. doi:10.5037/jomr.2013.4201. PMC   3886113 . PMID   24422029.
  32. ↑ Dodson TB (September 2012). "The management of the asymptomatic, disease-free wisdom tooth: removal versus retention". Atlas of the Oral and Maxillofacial Surgery Clinics of North America. 20 (2): 169–176. doi:10.1016/j.cxom.2012.06.005. PMID   23021394.
  33. ↑ Newman MG, Takei HH, Klokkevold PR, Carranza FA (2012). Carranza's Clinical Periodontology. Elsevier Saunders. ISBN   978-1-4377-0416-7.
  34. ↑ "Dental check-ups". nhs.uk. 2022-01-18. Retrieved 2023-10-04.
  35. ↑ López-Píriz R, Aguilar L, Giménez MJ (March 2007). "Management of odontogenic infection of pulpal and periodontal origin". Medicina Oral, Patologia Oral y Cirugia Bucal. 12 (2): E154–E159. PMID   17322806.
  36. ↑ López-Píriz R, Aguilar L, Giménez MJ (March 2007). "Management of odontogenic infection of pulpal and periodontal origin". Medicina Oral, Patologia Oral y Cirugia Bucal. 12 (2): E154–E159. PMID   17322806.
  37. ↑ Shin SM, Choi EJ, Moon SY (2016-06-29). "Prevalence of pathologies related to impacted mandibular third molars". SpringerPlus. 5 (1): 915. doi: 10.1186/s40064-016-2640-4 . PMC   4927556 . PMID   27386359.
  38. 1 2 Patil S, Halgatti V, Khandelwal S, Santosh BS, Maheshwari S (2014). "Prevalence of cysts and tumors around the retained and unerupted third molars in the Indian population". Journal of Oral Biology and Craniofacial Research. 4 (2): 82–87. doi:10.1016/j.jobcr.2014.07.003. PMC   4252379 . PMID   25737923.
  39. ↑ Borrás-Ferreres J, Sánchez-Torres A, Gay-Escoda C (December 2016). "Malignant changes developing from odontogenic cysts: A systematic review". Journal of Clinical and Experimental Dentistry. 8 (5): e622–e628. doi:10.4317/jced.53256. PMC   5149102 . PMID   27957281.
  40. ↑ Ghaeminia H, Nienhuijs ME, Toedtling V, Perry J, Tummers M, Hoppenreijs TJ, et al. (May 2020). "Surgical removal versus retention for the management of asymptomatic disease-free impacted wisdom teeth". The Cochrane Database of Systematic Reviews. 2020 (5): CD003879. doi:10.1002/14651858.CD003879.pub5. PMC   7199383 . PMID   32368796.
  41. ↑ Xiang X, Shi P, Zhang P, Shen J, Kang J (July 2019). "Impact of platelet-rich fibrin on mandibular third molar surgery recovery: a systematic review and meta-analysis". BMC Oral Health. 19 (1): 163. doi: 10.1186/s12903-019-0824-3 . PMC   6659259 . PMID   31345203.
  42. ↑ Dodson TB, Susarla SM (August 2014). "Impacted wisdom teeth". BMJ Clinical Evidence. 2014: 1302. PMC   4148832 . PMID   25170946.
  43. ↑ Kang F, Sah MK, Fei G (February 2020). "Determining the risk relationship associated with inferior alveolar nerve injury following removal of mandibular third molar teeth: A systematic review". Journal of Stomatology, Oral and Maxillofacial Surgery. 121 (1): 63–69. doi:10.1016/j.jormas.2019.06.010. PMID   31476533. S2CID   201805670.
  44. ↑ Stanaitytė R, Trakinienė G, Gervickas A (2014). "Do wisdom teeth induce lower anterior teeth crowding? A systematic literature review". Stomatologija. 16 (1): 15–18. PMID   24824055.
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