Hyperdontia

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Classification according to ICD-10
K00.1 Hyperodontia
ICD-10 online (WHO version 2019)

Under hyperdontia (also hyperodontia) (from altgriech. Ὕπέρ "exceed" and ὀδόντος "toothed") refers to a tooth majority. For the human dentition , this means the milk teeth are over 20 or in the permanent dentition are more than 32 teeth available. A special feature is explained in the section on false hyperdontia . Teeth that have already been removed are to be counted. Hyperdontia are rare in the primary dentition.

frequency

Hyperdontia occurs in one to three percent of Europeans and their offspring, more often in Asians . In 86% of the cases there is a single additional tooth, which is mostly located in the upper jaw near the incisors.

Extreme cases

In an operation lasting almost seven hours in 2014, 232 excess teeth were removed from the jawbone of a young person from Mumbai (India).

In 2019, doctors at Saveetha Dental College in Chennai (India) removed a bag-like structure weighing around 200 g from a seven-year-old boy. This contained a total of 526 teeth between 1 mm and 15 mm in size.

causes

The etiology (cause) is not clear. The main causes discussed are overproduction of the tooth ridge , local development disorders , tooth fission or atavism . Occasionally a familial occurrence is observed. Hyperdontia can occur in isolation or together with other diseases: cleidocranial dysostosis , Klippel-Feil syndrome .

Real hyperdontia

morphology

From a morphological point of view, surplus teeth can appear in regular or irregular tooth shape (e.g. mesiodense ), as double or multiple structures, as separate double systems (twin teeth ), as adhesions or as fusions. Tooth adhesions or fusions can go so far that the structure looks like an excessively large tooth. Because such multiple structures mainly occur in the anterior region , aesthetic problems also arise in these cases . The hyperdontia occurs more frequently in cleft lips, jaws and palates .

Hyperdontia (outlined in red in the X-ray)

to form

  • Mesiodentes can occur in families with genetic fixation. This form of hyperdontia makes up almost half of all surplus teeth.
  • Paramolars are additional, mostly single-rooted teeth between the molars that occur predominantly in the upper jaw.
  • Distomolars are additional teeth that grow behind the wisdom teeth.
  • With dysostosis cleidocranialis ( dressocranial dysplasia ) there are multiple excess teeth. In addition, a defect in the collarbones is typical, which enables those affected to move their shoulders forward until they touch.

False hyperdontia

False hyperdontia is when a permanent tooth has erupted but the corresponding milk tooth still exists. The cause of this is usually a displacement of the permanent tooth.

A teratoma is a pluripotent stem cell tumor that often forms teeth.

Therapeutic measures

As with hypodontia ( too few teeth), therapy must be planned individually. In the upper anterior region of the teeth, aesthetic considerations often speak in favor of removing the surplus tooth, especially if it is excessively large or a shift in the midline is to be feared. This removal should be done at an early stage in order to close the gap with the help of orthodontic measures if necessary . On the other hand, a normally formed supernumerary lower incisor often goes unnoticed and can be left in place if this does not result in crowding . A mesiode usually has to be removed because it leads to a diastema (gap between the upper central incisors). Even teeth that are difficult to preserve in the long run must be included in the therapeutic planning, because in individual cases it may be better to remove such a tooth and put the surplus tooth into line.

See also

Individual evidence

  1. ↑ Wilhelm Gemoll : GEMOLL, Greek-German school and hand dictionary , G. Freytag Verlag, Munich
  2. ↑ For the number and names of teeth see also: Tooth scheme
  3. ^ BW Neville et al .: Oral & Maxillofacial Pathology . 2nd Edition. 2002
  4. ↑ Michael A. Kahn: Basic Oral and Maxillofacial Pathology . 2001
  5. ↑ Doctors remove 232 teeth from young people FAZ of July 24, 2014
  6. ↑ "Saveetha'S SURGICAL AND Pathological EXCELLENCE IN Unmasking 526 TEETH FROM A SINGLE SITE IN A CHILD". Retrieved August 23, 2019 (UK English).
  7. ^ Walter Hoffmann-Axthelm: Lexicon of Dentistry , Quintessenz-Verlag, Berlin
  8. ^ Gottfried PF Schmuth: Orthodontics - Basics and Problems , Georg Thieme Verlag, Stuttgart
  9. ↑ a b M. Koch, P. Gängler et al., Anomalies in tooth development  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 1.4 MB), Conservative Dentistry and Periodontology, Georg Thieme Verlag, (2005) ISBN 3-13-593702-X@1@ 2Template: Dead Link / www.thieme.de  

literature

Bernd Merkel : About the number of teeth in the end areas of the toothed bar . Frankfurt, Medical Faculty, dissertation from January 5, 1967