Mandibular retrognathy

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Classification according to ICD-10
K07.1 Anomalies in the relationship between the base of the jaw and the base of the skull
ICD-10 online (WHO version 2019)

A mandibular retrognathia (from Latin mandibula " lower jaw ", Latin retro "backwards" and Greek γνάϑος " jaw "), more rarely retromandibulia , refers to a displacement of the lower jaw in relation to the base of the skull . It is therefore a description of the position of the lower jaw, but not its size. In addition, the term does not include a description of the position of the jaws in relation to one another. There are a number of terms that are often used interchangeably, which must be correctly distinguished as follows:

  • Mandibular opisthognathy - (Gr. Ópisthen - "backwards", γνάϑος - "jaw") Synonym, which is hardly used in the dental literature .
  • Mandibular micrognathia - (Gr. "Small" γνάϑος - "jaw") describes a pronounced hypoplasia of the lower jaw with shortening of the lower jaw base, which leads to an apparent displacement of the lower jaw with a corresponding horizontal overbite . Micrognathy is also known as the bird's face .
  • Retrogeny (Latin: retro "backwards" and Greek γενειον " chin "), opisthogeny (Greek ópisthen - "backwards", γενειον "chin") - these terms are out of date and misleading. Strictly speaking, they describe a back shift of the chin. It does not differentiate whether the cause is mandibular retrognathia, micrognathia or an underdevelopment of the bony parts of the chin.

The term mandibular retrognathy alone does not describe a complete diagnosis . In particular, the position in relation to the maxilla and its position in relation to the base of the skull are decisive for therapy planning. This results in a large number of possible diagnoses that belong to the retrospective form . In the Anglo-Saxon literature , one speaks of mandibular retrognathism or mandibular retrognathia .

If not only the lower jaw is shortened, but the mouth gap is too small overall, this is called a microstomy .

etiology

Mandibular retrognathy is very often hereditary. In addition, disorders of the growth of the jaw, for example due to osteomyelitis (inflammation of the bone marrow), a joint process fracture or ankylosis , can lead to the symptom. Also inflammation to the growth plates in the jaw can lead to retrognathia.

Symptoms

Affected patients have a "receding chin " and a protruding upper lip . The mandibular retrognathia usually occurs on both sides, but in the non-congenital case it can also occur on one side. It is characterized by a significant underdevelopment (hypoplasia) of the lower jaw, which causes the chin to recline and thus a distal bite (overbite). In individual cases, mandibular retrognathy can also occur together with a maxillary prognathy (misalignment of the teeth in the upper jaw). Opening the mouth is usually restricted in the case of joint fractures or ankyloses. The incisors are very often elongated because they did not have natural resistance in the form of the upper row of teeth as they grew. When the final bite occurs , the lower incisors meet the palatal mucosa . Other syndromes, such as sleep apnea syndrome, are often associated with mandibular retrognathia .

While most patients with retrogeny are otherwise completely healthy, in some cases the symptom can be associated with some genetic syndromes, such as trisomy 9 , Zellweger syndrome , Pierre Robin sequence or De Grouchy syndrome .

therapy

If the misalignment of the lower jaw is not treated in time, the likelihood of damage to the teeth and the tooth support system increases . Both can lead to premature tooth loss.

The forward displacement of the lower jaw can only be achieved by lengthening the ascending branches of the lower jaw bone. This can be achieved by oral surgery by means of a bone transplant or a callus distraction (gradually pulling apart the previously separated bone fragments, see lengthening osteotomy ).

Individual evidence

  1. ↑ Peter Reuter: Springer Lexicon Medicine. Springer, Berlin a. a. 2004, ISBN 3-540-20412-1 (Lemma Mikrostomie).
  2. ↑ W. Stelzenmüller, J. Wiesner: Therapy of temporomandibular joint pain. Georg Thieme, Munich 2004, pp. 103-104. ISBN 3-13-131381-1
  3. ↑ DN Faircloth et al .: Pulmonary dysfunction secondary to mandibular retrognathia in Marfan's syndrome. In: Chest. Northbrook 105.1994, pp. 1610-1613. PMID 8181376 .
  4. ↑ RM Berger: Mandibular Retrognathia and sleep apnea. In: The journal of the American Medical Association (JAMA). Chicago 247.1982, p. 2234. PMID 7069876 .

See also

literature

Reference books
  • S. Schamsawary: Dysgnathias . Urban & Fischer, Munich 2007, ISBN 3-437-05620-4 .
  • HH Horch, J. Bier: Oral and maxillofacial surgery. Urban & Fischer, Munich 2007, ISBN 3-437-05417-1 .
  • A. Kübler, J. Mühling: Guidelines for oral and maxillofacial surgery. Springer, Berlin 1997, ISBN 3-540-63566-1 .
Technical article
  • DA Walker: Management of severe mandibular retrognathia in the adult patient using distraction osteogenesis. In: Journal of oral and maxillofacial surgery. Orlando Fa 60.2002, pp. 1341-1346. PMID 12420271 .
  • MR Tucker: Management of severe mandibular retrognathia in the adult patient using traditional orthognathic surgery. In: Journal of oral and maxillofacial surgery Orlando Fa 60.2002, pp. 1334-1340. PMID 12420270 .
  • R. Schwestka-Polly et al .: Harmonization of free mandibular movements by orthodontic-surgical treatment of patients with mandibular retrognathism. In: The international journal of adult orthodontics and orthognathic surgery. Chicago 15.2000, pp. 205-231. PMID 11307200 .
  • JI Leira, OT Gilhuss-Moe: Sensory impairment following sagittal split osteotomy for correction of mandibular retrognathism. In: The international journal of adult orthodontics and orthognathic surgery. Chicago 6.1991, pp. 161-167. PMID 1812181 .
  • RP Harper et al .: Lateral pterygoid muscle activity in mandibular retrognathism and response to mandibular advancement surgery. In: American journal of orthodontics and dentofacial orthopedic. St. Louis 91.1987, pp. 70-76. PMID 3467583 .
  • RW McNeill, RA West: Severe mandibular retrognathism: orthodontic versus surgical orthodontic treatment. In: American journal of orthodontics. St. Louis 72.1977, pp. 176-182. PMID 268148 .
  • WH Bell: Surgical correction of mandibular retrognathism. In: American journal of orthodontics. St. Louis 52.1966, pp. 518-528. PMID 5220417 .

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