Bibliothek

Kurzfassung: Synopsis All around the tooth retained in its new position, the alveolar bone builds itself up to meet the new static demands. Here the retaining appliance itself represents an important static factor, and after its removal the neighbourhood of the tooth may be brought under the influence of new reconstruction stimuli which may help bring about a relapse. The most important biological moment for production of a relapse is the tendancy of alveolar tissues to regenerate. The principal path for this tendancy passes through the interdental vasculo-nervous bundles. Another biological factor in producing relapses lies in the displacement of the soft tissues of the alveolus, which brings about long enduring traction-forces. Septotomy and gingivotomy applied together produce: 1. a destruction of the regeneration paths 2. the formation of an active union with the bony scar 3. the arrest of the greatest traction-forces of the soft tissues. From a biological stand-point the combination of orthodontic measures and of the described surgical means during the period of retention constitutes one of the principal advances in the struggle against relapses.

Kurzfassung: Synopsis The analysis of these cases, which are not rare in practice, shows us that we must not keep entirely to the biometric treatment diagram, in treating distal occlusion cases in the permanent denture. Even so, the general refusal to extract in such cases is proved to be a mistake. For the proper treatment, the development of the “apical base” of the upper jaw is decisive. It depends upon the position of the dental follicles. If the incisor follicles are in protrusion, the apical base is often tardy in its development, whereas if the incisor follicles slant backwards (close-bite type) the apical base is prematurely developed to a great extent. This biological factor determines the treatment: if the apical base is too small we must extract, and move the upper front teeth backwards, even if the analysis of the profile (gnathostat) shows that the lower jaw should be moved forwards. If the apical base is large we dare not extract, but we must move the lower jaw forward, even if, according to the profile analysis (biometrically considered), the upper jaw is too far forward. In the interest of a favorable and lasting result, the biometric necessities should come after the biological.

Kurzfassung: Synopsis Clinical division of lower prognathy: a) according to its form: with close-bite character of incisor teeth; without close-bite character of incisor teeth. b) according to its degree: first degree: reversed incisor articulation with neutroclusion; second degree: mesioclusion and locked-bite; third degree: anatomically fixed mesioclusion. c) according to the responsible part of the jaw, or according to the cranial relation: d) mesioclusion with lower jaw foreward; e) mesioclusion with upper jaw backward; f) mixed forms. Genesis: A. Inferior prognathy with the over-bite character (mesioclusion) may be ushered in, without dysharmony either in the size of the maxillae or their position, through the fact that the upper incisors erupt in a strongly lingual position, later than the lowers, and so remain held in their lingual position (locked bite). By reason of the abnormal guidance and function of the jaw, a secondary mesioclusion, anatomically fixed, may develop. But on the other hand, the locked-bite may remain in existance until the replacement of the teeth, and when the false guidance naturally ceases it may be cured spontaneously. B. Lower prognathy without the close-bite character is assumed to due to a dysharmony in the relative size or position of the maxillae. This dysharmony may be produced by: 1. Hereditary forward growth of the mandible during the suckling period (mesioclusion with lower jaw foreward); 2. Insufficient development of the maxilla through lack of functional activity (impaired nasal breathing, adenoids) during the suckling period and temporary denture period (mesioclusion with upper jaw backward); 3. Forward displacement of the mandible as a postural habit due to enlarged tonsils; 4. Possible persistance of the embryonal lower prognathy until the period of eruption of the temporary teeth. 5. Habitual sleeping posture with head sharply inclined towards the chest. In cases of lower prognathy with the close-bite character, the above dysharmonies may come in addition to the primary agent, the position of the tooth germs and so bring about mixed forms. Prophylaxis: Practically powerless considering the overbalancing importance of inherited factors. Care for normal nasal function during the suckling period and the temporary denture period; early removal of enlarged adenoids and tonsils, prevention of sleeping with head in strongly flexed ventral posture. Early treatment: Three age periods: 1. Until the fifth year of age, anterior-bite plane and chin-cap. 2. Up to and during the period of replacement of the incisors, unlocking the occlusal guiding planes (by grinding or opening the bite) and chin-cap. In cases of lower prognathy with upper jaw backward, add early expansion of the maxilla; control for pseudo-relapse. 3. Until the end of the replacement of the temporary teeth, anterior splint and chin-cap.; in cases of lower prognathy with upper jaw backward, and in cases of pseudo-relapse, lingual arch for restoration of the upper dental arch dimensions; eventually intermaxillary block just as for treatment of the permanent denture. In every age period, watch carefully over normal nasal function, treatment by exercises of muscles.