Hypodontia
| Classification according to ICD-10 | |
|---|---|
| K00.0 | Anodontia, hypodontia, oligodontia |
| ICD-10 online (WHO version 2019) | |
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Hypodontia (from ancient Greek ὕπο hypo "under-" and ὀδόντος odontos "with teeth") is a number of teeth. This is understood to mean the absence of one or more teeth due to a non-predisposition ( agenesis ) . If several teeth are missing (about more than 5 teeth) one speaks of oligodontics (from ancient Greek ὀλίγο- "little") and the absence of all teeth is called anodontics (from ancient Greek ἀ (ν) - "without").
Real hypodontia
True hypodontia is congenital and often hereditary. As a consequence of a developmental disorder, it can occur together with other diseases or anomalies : Down syndrome , Christ-Siemens-Touraine syndrome , anhydrosis hypotrichotica , arachnodactyly , Bloch-Sulzberger syndrome , Curtius syndrome , chondroectodermal dysplasia , acrofacial dysostosis , mandibular dysostosis facialis , orofacio-digital syndrome , hypohidrotic ectodermal dysplasia , ectodermal syndrome , hemolytic anemia , Rutherfurd syndrome or lipoid proteinosis .
Anodontics is found in DDOD syndrome .
Frequency and distribution
Hypodontia is one of the most common abnormalities. 3.5–8.0% of the population (apart from the third molars) are affected. The absence of wisdom teeth can be found in 20–23% of the population.
In humans, the frequency of missing individual teeth in true hypodontia is distributed as follows:
- 3rd molars ( wisdom teeth / 8th)
- Upper lateral incisors (teeth 12 and 22)
- Lower 2nd premolars (teeth 35 and 45)
- Lower central incisors (teeth 31 and 41)
- Remaining premolars and lower lateral incisors
- Relatively rare: Upper central incisors (teeth 11 and 21), canines , (3rd), upper and lower 1st and 2nd molars (6th and 7th)
In the primary dentition Hypodontien are much rarer.
Acquired or fake hypodontia
Traumatic (accident-related) events can lead to premature tooth loss and thus to hypodontia, but also bone marrow inflammation or X-rays and radium radiation . A central dislocation of a milk tooth can damage the tooth germ of the permanent tooth that has already been created, so that it then atrophies. Strictly speaking, of course, the (early) loss of teeth due to caries is also a form of insufficient number of teeth , but here one speaks more of a dentition reduction .
Faked hypodontia (Hypodontia spuria)
If teeth are in place but do not break through, then there is a hypodontia spuria (from Latin : spurius "false, fake"), also called pseudoanodontia , see. GAPO syndrome .
Therapeutic measures
In principle, orthodontic , prosthetic , implantological and oral surgery measures are possible. The treatment must be planned separately for each case because many factors are important: the number of missing teeth, the condition and position of the existing teeth, the size and position of the jaws in relation to one another, general diseases and , last but not least, financial aspects. A complementary combination of several therapeutic measures is often useful and necessary, so that close consultation and cooperation between the above-mentioned dental disciplines is necessary. As far as possible, orthodontic measures will be given priority and only then will surgical (exposure of retained teeth or even implantations or tooth transplants ) or the provision of dentures be included in the therapy as a treatment option. The need for orthodontic treatment in hypodontia is recorded by the Index of Orthodontic Treatment Need (IOTN).
See also
Individual evidence
- ^ A b c Wilhelm Gemoll : GEMOLL, Greek-German school and manual dictionary . G. Freytag Verlag, Munich
- ^ A b Walter Hoffmann-Axthelm : Lexicon of Dentistry , Quintessenz-Verlag, Berlin
- ^ BW Neville et al .: Oral & Maxillofacial Pathology . 2nd Edition. 2002
- ↑ Gottfried PF Schmuth: Orthodontics - Basics and Problems . Georg Thieme Verlag, Stuttgart
- ↑ For the tooth names, see: tooth diagram
- ↑ Joachim Gabka / Herbert Harnisch: Operationskurs for dentists , Georg Thieme Verlag, Stuttgart
