(牙合)垫与交互牵引联用矫治正锁(牙合)的临床应用体会

正锁(牙合)是上颌后牙被锁结在下颌后牙的颊侧,(牙合)面无咬合接触[1].个别后牙正锁(牙合)及单侧多数后牙的正锁(牙合)在临床上较为多见.锁(牙合)对咀嚼功能、颌面发育及颞下颌关节的健康影响都很大,因此临床上应充分重视、及早矫治锁(牙合)关系.     

Open bite

Summary Although the etiology of the open bite has been often investigated, its treatment is still a great challenge. The open bite can have skeletal or dento-alveolar origins, it can also be caused by habit or dysfunction. In this study, some examples are evaluated in order to find out which of these different factors has the greatest influence on the symptomatology of the open bite. The fundamental question is whether the open bite is caused by function or if there has been a functional adaptation. 250 cases of open bite treated by Dr. Veliskova and 175 own cases are presented in order to show typical variants as they are represented in the lateral remote x-ray picture. The principal criteria are the apparent differences between the direction of growth and the relations of anterior and posterior facial segments. If the treatment is chosen according to the etiologic findings (habitual, functional, or skeletal origin), a desirable result without recurrence can be reached by orthodontic, orthopedic or maxillo-surgical measures. Differential diagnosis is a decisive factor for a succesful treatment.

---

Zusammenfassung Obwohl die Ätiologie des offenen Bisses schon in vielen Arbeiten untersucht wurde, ist seine Behandlung nach wie vor eine große Herausforderung. Ein offener Biß kann sowohl skelettaler oder dentoalveolärer Herkunft sein als auch durch Habits bzw. Fehlfunktion verursacht werden. Deshalb soll an einigen Beispielen herausgearbeitet werden, welcher der verschiedenen Faktoren wohl überwiegend am Krankheitsbild des offenen Bisses beteiligt ist. Grundsätzlich ist die Frage zu stellen, ob die Funktion den offenen Biß verursacht hat, oder ob eine funktionelle Adaptation stattgefunden hat. Anhand von 250 Fällen mit offenem Biß von Dr.Veliskova und anhand von 175 eigenen Fällen sollen typische Varianten, wie sie sich im seitlichen Fernröntgenbild darstellen, aufgezeigt werden. Dabei sind die offensichtlichen Unterschiede zwischen der Wachstumsrichtung und den Beziehungen zwischen den vorderen und hinteren Gesichtsabschnitten die Hauptkriterien. Wenn sich die Therapie nach der Ätiologie (habituell, funktionell oder skelettal) richten soll, so kann mit orthodontischen, orthopädischen oder kieferchirurgischen Maßnahmen ein wünschenswertes Ergebnis ohne Rezidiv erreicht werden. Ausschlaggebend ist die Differentialdiagnostik für eine erfolgreiche Behandlung.

---

Résumée Bien que l'étiologie de la béance vraie ait été étudiée dans de nombreux travaux, son traitement demeure très difficile de nos jours, comme auparavant. La béance peut être squelettique ou dento-alvéolaire ou liée à des dysfonctions. C'est pourquoi il faut dégager parmi différents facteurs, celui qui est prépondérant dans la pathologie de la béance. Il faut principalement poser la question si c'est la fonction qui est la cause de la béance ou si elle n'en représente qu'une adaptation fonctionnelle. A l'aide de la téléradiographie de profil, on présente les variations typiques de 250 cas de béance du Dr.Veliskova et de 175 cas de l'auteur. Les critères de base demeurent les différences évidentes entre la direction de croissance et le relations entre la hauteur antérieure et postérieure de la face. Lorsque la thérapeutique est bien adaptée à l'étiologie (squelettique, fonctionnelle ou habitude néfaste), alors on peut atteindre un résultat désirable sans récidive avec des mesures d'orthodontie, d'orthopédie dento-faciale ou de chirurgie maxillaire. La primauté du succès thérapeutique réside dans le diagnostic différentiel.

     

'The first bite of the cherry' Intra-oral manipulation prior to the first bite in humans

The breakdown of food in the mouth during mastication can be described in terms of two parameters: a breakage function, which describes the fragmentation of food after a bite, and a selection function which defines the probability of particle fracture. The non-zero value of the selection function depends on the manipulation of food particles by the tongue. Little, however, is known about this. As a first step, this study investigated the manipulation of wax sheets of differing sizes and shapes by the tongue after ingestion. It was found that subjects tended to orientate rectangular and square wax wafers so that the long axis of the particle was parallel to the tooth row, independent of the initial orientation given when they were introduced into the mouth. Circular wafers were randomly oriented relative to initial orientation. If this could be extrapolated to the start of mastication, then it suggests that the tongue tends to align food particles so that the post-canines produce close to the greatest surface area possible by fragmenting them along their longest axis.     

The effect of periodontal surgery on bite force, occlusal contact area and bite pressure

BACKGROUND: Tooth mobility resulting from the loss of periodontal support or trauma induced by periodontal surgery may change the amount of bite force (BF) and bite pressure (BP) and number of occlusal contact areas (OCAs). The aim of the authors' study was to compare BF, BP and OCA of teeth with periodontal disease before and after periodontal surgery with similar values of healthy teeth. METHODS: The authors performed quantitative analysis of BF, BP and OCA using a pressure measurement film. Ten patients with periodontitis who needed periodontal surgery served as the test group. The authors took measurements of BF, BP, OCA and mobility (using Miller's Mobility Index) just before surgery and at one, four and 12 weeks after surgery. They also measured clinical attachment levels (CAL) before surgery and 12 weeks after surgery. Ten subjects without periodontitis served as the control group. RESULTS: Although BF and OCA increased the first week after periodontal surgery, analysis of variance (ANOVA) showed no statistically significant differences at a 95 percent confidence interval. There were statistically significant differences between first-week mobility and that at four and 12 weeks (P = .001). A factorial ANOVA showed significant interaction between BF and mobility (P < .05). CONCLUSIONS: The authors' findings suggest that changes in BF, BP and OCA were not affected by periodontal surgery. However, mean mobility values and BF are correlated. Further investigations of this measurement method involving larger study populations and a longer follow-up period are needed. CLINICAL IMPLICATIONS: It seems to be helpful to follow occlusal changes after periodontal surgery using a pressure measurement film. It also may be suggested that this measurement method could be used to evaluate the treatment prognosis.