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Underdevelopment of the upper jaw (upper micrognathia, opistognathia): causes, symptoms, diagnosis, treatment
Last reviewed: 19.11.2021
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Underdevelopment of the upper jaw (upper micrognathia, opistognathia) is a type of deformation that is relatively rare and it is very difficult to treat it with a surgical method.
What causes an underdevelopment of the upper jaw (upper micrognathia, opistognathia)?
Underdevelopment of the upper jaw can be caused by endo- and exogenous factors: disruption of the endocrine system, congenital nonunion of the upper lip, alveolar process and palate, disturbances in nasal breathing, harmful habits, inflammatory processes of the maxillary bone (osteomyelitis, sinusitis, noma, syphilis, etc.).
Often, micrognathia develops as a result of early uranoplasty due to congenital non-palatations of the palate.
Symptoms of underdevelopment of the upper jaw (upper micrognathia, opistognathia)
Micrognathia is a kind of so-called "mesial" occlusion, occurring in three forms:
- I - underdevelopment of the upper jaw against a normally developed lower jaw;
- II - normally developed upper jaw against excessive development of the lower jaw;
- III - underdevelopment of the upper jaw, combined with excessive development of the lower jaw.
The surgeon has to differentiate the true micrognathia (I and III form) with the false (II form), in which the upper jaw only seems underdeveloped due to excessive development of the lower jaw.
Externally, the true underdevelopment of the upper jaw is manifested by the occlusion of the upper lip and the sharp forward movement of the nose. There is an impression of hypertrophy of the lower lip and chin ("offended profile").
It is impossible to bite the food, since the lower teeth, not finding themselves antagonists, are shifting anteriorly and upward along with the alveolar process, sometimes causing a picture of a deep back bite.
At the same time, the nasolabial fissures are underlined.
The speech of the patients is somewhat broken, the pronunciation of the dental sounds is unclear.
Where does it hurt?
Treatment of junior development (upper micrognathia, opistognathia)
Similar deformations of the upper jaw were not treated before by the surgical method, but were limited only to the deepening of the vestibule of the mouth and the manufacture of the maxillary prosthesis with a standing frontal department.
Such caution and "passivity" of surgeons is explained by the fact that from time to time in the literature there are reports of complications of various nature both during and after surgery: significant profuse bleeding, sometimes ending with death of the operated; partial necrosis of osteotomized fragments; development of subcutaneous emphysema of the face, neck, mediastinum; occlusions of the internal carotid artery; thrombosis of the carotid artery and cavernous sinus.
Disturbances were frequent relapses of the disease, which, according to different authors, reach 100%. Whitaker and co-authors, summarizing the experience of four centers for the treatment of craniofacial deformities, came to the conclusion that in reconstructive operations more than 40% of cases show some complications.
However, the insistent demands of patients with deformations of the middle zone of the face encourage the surgeons to resort to radical correction of cosmetic and functional deformities of the face (especially in young people and middle-aged patients).
Patients encourage surgeons to work on such complex problems as determining the optimal term of the operation, the method and degree of mobilization of the upper jaw forward; a method for fixing a jaw or a portion of a jaw to be mixed; the choice of grafts for placing them in the resulting cracks after osteotomy of fragments or the entire jaw; elimination of inconsistency of the new function of the displaced upper jaw with the anatomical form of the lower jaw; ensuring the growth of the displaced jaw in a patient with complete development of the entire facial skeleton; determination of the optimal design of the orthodontic apparatus for use after the operation, etc., etc. Gradually these problems are solved by both domestic surgeons and foreigners.
A significant reduction in the risk of complications after surgical reconstructive surgery is facilitated by hyperbaric oxygenation, which increases the patient's resistance.
Currently, sometimes, operations are performed in the form of moving the entire alveolar process and the teeth of the upper jaw, or moving only the frontal portion of the jaw together with the teeth in part.