Open bite – the violation of okklyuzionny relationship of tooth alignments which is characterized by lack of contact in frontal or side teeth at a smykaniye of jaws. The open bite is shown by existence of a crack between tooth alignments, a nesmykaniye of lips why the mouth of the patient is always half-open or open. Violation of functions of chewing, breath and the speech, dryness of a mucous membrane of an oral cavity is noted. Diagnostics of an open bite is based on data of TRG and the rentgenotsefalometrichesky analysis, an orthopan-tomography, studying of diagnostic models of jaws. The miogimnastika, removable devices (Klammt's activator, Andrezena-Goypl's activator, Gerbst's device, Schwartz's device, etc.), briquettes, surgical methods is applied to treatment of an open bite.
Open bite – a kind of the wrong bite at which there are no contacts between tooth alignments in the forward or side site with formation of a vertical crack. In stomatology the open bite is diagnosed for 1,3-5,7% of patients; its specific weight in structure of zubochelyustny anomalies makes 2%.
Along with a deep bite, the open bite belongs to vertical anomalies of occlusion. The open bite can represent independent violation or be combined with other types of a dizokklyuziya, a thicket with a mezialny and disteel bite. The open bite is followed by a number of esthetic and functional violations which correction demands involvement of experts in the field of orthodontics, surgical stomatology, otolaryngology, logopedics.
The reasons causing formation of an open bite are rather various. Among antenatalny factors the greatest significance is attached to adverse heredity, infectious and somatic diseases of mother during pregnancy, to the toxicoses harmful to the exogenous effects leading to the atypical provision of rudiments of teeth, crevices of a lip, sky and an alveolar shoot, deformations of jaws.
In the post-natal period among the leading reasons of an open bite allocate rickets, disorders of mineral exchange, hypovitaminoses, endokrinopatiya, violation of nasal breath (allergic rhinitis, adenoides, sinusitis, nose polyps, a curvature of a nasal partition). Quite often open bite at children is a direct consequence of such addictions as an obkusyvaniye of nails, sucking of a finger, lip or toys, a language vysovyvaniye between teeth and so forth.
A part in formation of an open bite is played by a retention of teeth, eruption, the edentia caused by early loss of temporary or second teeth, the shortened language bridle, a makroglossiya is later than them.
According to an etiology distinguish the rachitic (true) open bite connected with inferiority of maxillary bones and the traumatic (false) open bite caused by addictions. Taking into account not closed teeth allocate a frontal open and side open bite (unilateral and bilateral). About degree of expressiveness of an open bite judge by crack height between tooth alignments and to the number of not closed teeth:
The I degree – a vertical crack to 5 mm; lack of contact in frontal teeth (cutters and canines);
The II degree - a vertical crack from 5 to 9 mm; lack of contact in frontal teeth and premolyar;
The III degree - a vertical crack more than 9 mm; lack of contact in frontal teeth, premolyar and the first painters.
Also allocate a symmetric and asymmetric open bite; maxillary, mandibular and combined (mixed) forms.
Symptoms of an open bite
The open bite is characterized by distinctive front, intra oral and functional signs. The extended lower third of the face, a half-open or open mouth, a smoothed podborodochny fold, a sloping chin belong to front symptoms of an open bite. The upper lip, as a rule, sluggish and shortened, is not closed from lower; from under it bottom edges of foreteeth and language which covers a slit-like opening between tooth alignments are visible. In other cases the patient tries to squeeze densely lips because of the aspiration to hide the esthetic shortcoming.
Lack of contact of frontal or side teeth with teeth antagonists and existence of a crack of various size between them is the main oral sign of an open bite. At a traumatic open bite the form of a crack repeats the provision of a subject which the child got used to hold in a mouth. Foreteeth at an open bite are usually located densely, often are surprised caries, have signs of a hypoplasia of enamel and an uneven (wavy) contour of a cutting edge, a large number of tooth deposits (a dental plaque and a scale). The puffiness, bleeding and growth of desnevy nipples testifying to a hypertrophic gingivit is quite often noted.
The functional violations accompanying an open bite include difficulties at a nibble, chewing, swallowing of food; violations of the speech (mechanical dislaliya); oral breath. Violation of efficiency of chewing leads to development of dysfunction of VNChS, periodontosis. The main defect of a sound pronunciation at an open bite is the interdental sigmatizm, the pronunciation of lip and lingual phonemes also suffers. Narrowing and asymmetry of tooth arches are followed by change of a form of the top sky, a nose cavity bottom, violation of development of additional bosoms. Oral breath causes dryness of a mucous membrane of an oral cavity.
The diagnosis of an open bite is made by the stomatologist-orthodontist on the basis of clinical and tool inspection. At primary survey of the patient visual assessment of front and oral signs of an open bite is carried out, measured distances between cutters antagonists, the discussion with the patient is led.
Further establishment of a form and degree of an open bite is promoted by a photometric research of the person, performance and studying of results of an orthopan-tomography, diagnostic models of jaws, head TRG with the rentgenotsefalometrichesky analysis and calculation of teleroentgenograms. Patients with defects of the speech need consultation of the logopedist; with violations of nasal breath – the otolaryngologist.
Treatment of an open bite
Tactics of treatment of an open bite during various age periods has the features. In the period of a temporary and early replaceable bite for restoration of miodinamichesky balance the miogimnastika, an elektromiostimulyation, increase in chewing loading due to reception of rigid food are very effective. For breaking of children from pathological habits vestibular plates with an emphasis for language or okklyuzionny overlays for side teeth are used. Orthodontic treatment at this age is carried out by means of removable devices of various designs: Andrezena-Goypl's activator, Klammt's activator, Gerbst's device, Frenkel's device, Schwartz's device, podborodochny prashcha, etc. Sanitation of a nasopharynx is necessary for normalization of nasal breath, according to indications – carrying out plasticity of a bridle of language.
In the period of a late replaceable and constant bite are used a crown or a kappa, raising a bite, the fixed equipment (Engl's device, breket-systems). In certain cases (for example, at an enamel hypoplasia) for simultaneous elimination of cosmetic defect and restoration of okklyuzionny contact prosthetics by means of ceramic-metal crowns is carried out. Particularly complex options of an open bite demand the combined hardware and surgical treatment. The surgical stage can include removal of accessory teeth, a kompaktosteotomiya.
At the speech violations accompanying an open bite, orthodontic treatment has to be combined with logopedic correction of a dislaliya.
Forecast and prevention
The best results of correction of an open bite are achieved at early orthodontic treatment. In this case it is possible to create conditions for normal development of jaws, to improve front signs, to save the patient from psychological experiences at early age. Elimination of a traumatic open bite happens easier and quicker, than true.
Preventive actions are directed to prevention of action of etiologichesky factors - prevention of pathology of pregnancy, the prevention of rickets, disposal of the child of pathological oral habits, ensuring free nasal breath and so forth. It is important to exercise control of a teething, timely treatment of caries of milk teeth and prosthetics at their absence.