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Excessive development of the upper jaw (upper prognathia): causes, symptoms, diagnosis, treatment
Last reviewed: 20.11.2021
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[Causes of upper prognathia (excessive development of the upper jaw)
Among the endogenous etiologic factors, one should first of all mention rickets and a violation of the respiratory function (for example, on the basis of hypertrophy of the palatine tonsils). Among the exogenous - sucking fingers, artificial feeding with a horn, etc.
Depending on the etiology, the structure of prognathia can be different. Thus, prognathia caused by endogenous factors (for example, a violation of nasal breathing) is combined with lateral compression of the upper jaw, close arrangement of teeth in the anterior part. If it is caused by exogenous factors, there is a significant expansion of the alveolar arch, due to which the teeth in it are located freely, even with intervals (tremes), ie, fan-shaped.
A certain role in the development of maxillary prognathia is played by improper installation of permanent large molars during their eruption. These teeth, when erupted, are installed in a single-tubal closure: the chewing tubercles of the lower major molars are articulated with the same tubercles of the upper molars. Only after erasing the masticatory surfaces of the molar large molars and the medial shift of the lower jaw the upper first molar with its medial-buccal tubercle is set in the inter-tubercle grooves of the lower ones.
If, however, the physiological erosion of the tubercles of the infant teeth is delayed or not at all, the first large molars remain in the position in which they erupted. This is responsible for the delay in the development of the lower jaw, remaining in the distal position; develops the upper prognathia.
Symptoms of upper prognathia (excessive development of the upper jaw)
It is necessary to distinguish true prognathy, in which the lower jaw has a normal shape and dimensions, and a false (apparent) prognathion caused by underdevelopment of the lower jaw. With false expulsion, the size and shape of the upper jaw do not deviate from the norm.
The main symptom of excessive development of the upper jaw is a disfiguring protrusion of it forward; the upper lip is in a forward-shifted position and is not able to cover the frontal part of the dentition, which when exposed to a smile is exposed along with the gum.
The lower part of the face is lengthened by increasing the distance between the base of the septum of the nose and chin. Nasolabial and chin furrows are smoothed.
The lower lip in the region of the red border contacts the palate or the posterior surface of the frontal upper teeth, the incisal edges of which do not contact the lower teeth at all, even with the mandibular extension extended.
The lower front teeth with the cutting edges rest against the mucosa of the palatine surface of the alveolar process or the anterior section of the hard palate, traumatizing it.
The upper dental arch is narrowed and stretched forward; The palatine arch is tall and has a gothic shape.
Often true upper prognathia is combined with underdevelopment of the lower jaw, which aggravates the disfigurement of the face, especially its profile. The face in this case is as though slanted downwards (the "bird's face").
Treatment of upper prognathia (excessive development of the upper jaw)
Upper prognathia should be treated in childhood by using orthodontic devices. If such treatment has not been performed in a timely manner or has proved ineffective, one must resort to surgical methods.
In adults with excessive exaggeration, non-treatable equipment, good results are obtained by removing the anterior teeth and resection of the alveolar process. However, despite the ease of implementation and good cosmetic result, the method can not be called effective, since the functional capacity of the chewing apparatus after such treatment is significantly reduced. Given that the resection of the alveolar process ends with the installation of a non-removable bridge prosthesis, which excludes the possibility of further growth of the upper jaw, this operation is permissible only in adults.
Operation A. Ya. Katz
It is more gentle in this sense, since it presupposes the preservation of teeth: after detachment of the muco-periosteal flap on the lingual surface of the alveolar process within the upper 6-10 teeth, the palatal part of each interdental space is removed by boron. Mucoid-periosteal flap is laid and sewn to the same place.
This intervention weakens the resistance of the alveolar crest to the action of the sliding arch, which is established after the operation. The described operation is shown when the upper teeth are arranged fan-shaped and there are certain gaps between them. Due to these gaps, it is possible to reposition the frontal teeth back and collect them in a close series, achieving contact between the approximal surfaces of their crowns.
Symmetric removal of upper premolars
Symmetric removal of upper teeth in combination with compactosteotomy is performed in those cases when the reposition of all frontal teeth can not be performed by an orthodontic method alone, that is, when each of them contacts two adjacent teeth. In addition, it is indicated with prognathia, combined with lateral narrowing of the upper jaw or with an open bite. In such cases, one (usually the first) small molar tooth is removed from each side, and then the operation is performed as in the treatment of an open bite.
14 days after compactectomy, orthodontic equipment is installed to gradually move the teeth back.
Other ways to treat prognathia
Osteotomy and retrotransposition of the frontal section of the upper jaw according to Yu. I. Vernadsky or according to PF Mazanov is undertaken if rapid (simultaneous) elimination of prognathia is necessary, especially in cases of its combination with an open bite, as discussed above.