Functional Orthodontic Appliances Research Articles

Glycosaminoglycan Synthesis in the Mandibular Condyle during Growth Adaptation

Condylar growth was studied after an operation simulating functional orthodontic appliances. Twenty-five rabbits underwent a surgical operation for the induction of premature synostosis to displace the glenoid fossa posteriorly during growth. Twenty-five control rabbits underwent sham operations. At the age of 15 days, 10 experimental and 10 control animals and, at the age of 20 days, 5 experimental and 5 control animals were killed. Their mandibular condyles were organ-cultured for 3 h in the presence of radiolabelled sulphur. The condyles were used for autoradiographic purposes. Digital image analysis of autoradiograms of histological sections showed synthesis of glycosaminoglycans to have increased from the anterior to the posterior direction. This increase was more marked in experimental animals than in the condyles of control animals. Ten experimental and 10 control animals were killed at the age of 15 days, and mandibular condyles were organ-cultured for 1, 4 and 7 days. Differentiation of proliferating prechondroblasts into hypertrophied chondrocytes continued under organ culture conditions. A marked decrease in the proliferating cell layer was noticed, especially in control condyles. Hypertrophy was faster and came closer to the surface of the condyle in the anterior region of the condyle. This was most marked in the condyles of experimental animals. The results indicate that a procedure carried out on the glenoid fossa with the same effect as functional appliances increases the synthesis of extracellular matrix in the posterosuperior region of the mandibular condyle.

Early Surgical Correction of Unilateral TMJ Ankylosis and Improvement in Mandibular Symmetry with Use of an Orthodontic Functional Appliance—A Case Report

Early ankylosis of the temporomandibular joint (TMJ) can be a deterrent to normal mandibular growth. The frequency of occurrence is rare in the population of young patients who undergo orthodontic treatment. Early diagnosis of TMJ ankylosis is important and early surgical intervention is now an accepted mode of treatment. Ankylosis infers minimal, if any joint function. Caldwell argues that restoration of joint function at an early age is necessary to activate as much growth potential as possible. Laboratory and clinical studies have supported the theory that the mandibular condyle is adaptable under function and perhaps even the most deformed condylar head may exhibit growth when released and placed in function. The purpose of this article is to present a case report of surgical release of TMJ ankylosis followed by radiographic and clinical evidence of unilateral condylar growth. The surgical procedure involved maintenance of the condyle, the disk and majority of fibrocartilage covering the mandibular condyle. Aggressive postoperative physical therapy and the employment of a functional orthodontic appliance appeared to have assisted in a more symmetric growth pattern and maintenance of appropriate function.

Bilateral transverse facial clefts and accessory maxillae—variant or separate entity?

We report an extremely rare case of bilateral transverse facial clefts and accessory maxillae with severe mandibular hypoplasia in a 7-year-old Chinese boy. The transverse facial clefts had been repaired in infancy. The accessory maxillae were excised via a combined temporal and oral approach. Functional orthodontic appliance therapy was not feasible due to restricted protrusive movements of the mandible. Bimaxillary osteotomies were performed one year later due to failure mandibular catch-up growth to occur. The pathogenesis of the accessory maxillae in the presence of lateral facial clefting is postulated to be compensatory mesenchymal growth from the temporal region, and a case is made for this condition to be considered as a possible syndrome rather than a variant of the transverse facial cleft.

Functional orthodontic appliances: K. G. Isaacson, R. T. Reed, and C. D. StephensOxford, England: Blackwell Scientific Publications, 131 pages

Functional orthodontic appliances: K. G. Isaacson, R. T. Reed, and C. D. StephensOxford, England: Blackwell Scientific Publications, 131 pages

Functional orthodontic appliances

Functional orthodontic appliances

Book reviews

The book reviewed are in this article: Functional orthodontic appliances K. G. Isaacson, R. T. Reed and C. D. Stephens A textbook of orthodontics T. D. Foster.

Vertikale Veränderungen am Fernröntgenseitenbild nach funktions-kieferorthopädischer Therapie

We looked for vertical changes in lateral cephalometric X-rays of patients who had been treated with Andresen and Häupl appliances to correct distal occlusion. Thus, a therapy using functional appliances for orthodontic correction has the following effects on the vertical proportions of the visceral cranium. 1. The alveolar processes show additional vertical growth in the area of the incisors of the upper jaw and the molars of the lower jaw. 2. In conjunction with 1, increased vertical growth of the anterior facial heights compared to the posterior facial height causes an opening of the bite which, however, is not significant in terms of the Jarabak ratio. 3. Functional therapy has an effect on the spina plane, and, in addition, causes active vertical growth in the area of both upper facial heights, i.e., of the entire nasomaxillary complex. This additional growth is a little bit more pronounced anteriorly than posteriorly. Therefore the effect of functional orthodontic appliances on the nasomaxillary complex seems to be more complex than previously believed. 4. We did not observe any additional growth in the area of the ascending rami and/or condyles of the lower jaw during activator treatment. Our studies showed that the influence of functional orthodontic therapy on the vertical growth of the lower jaw is rather insignificant; the significant vertical changes were seen in the area of the mandibular molars and of the anterior facial heights. 5. Our findings thus support the assumption that the main vertical effect of the activator can be described as a relative inhibition of the development of the nasomaxillary complex with simultaneous normal progression of mandibular growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemifacial microsomia.

Hemifacial microsomia is variable with respect to the degree of the deformity it presents, thus, treatment varies. Mild degrees of the condition are usually treated adequately by waiting until adolescence, when definitive surgical correction of any skeletal or soft tissue asymmetry can be dealt with. Some mild and moderate cases may benefit from orthodontic functional appliance therapy during growth, but orthodontic opinion is divided on the value of such therapy. Children with severe forms of hemifacial microsomia are improved in appearance during their school years by early surgery performed in the preschool period. A number of surgical approaches have been used at this stage. The technique currently being used by the author involves composite transfer of vascularized soft tissue for contouring, together with a vascularized costochondral strut to lengthen the affected side of the mandible. Early results using this method are satisfactory, but further work is required to assess the advantages of this over other techniques.

Patient age as a limit in the use of functional orthodontic appliances

Breite Anwendungsmoglichkeiten der FKO-Gerate, die besonders gunstig die allgemeinen und die lokalen physiologischen Merkmale der Entwicklungsperiode beeinflussen, bedeuten, das gewisse Altersgrenzen fur diese Methoden zu beachten sind. Auf Grund klinischer Erfahrungen liegt die untere Grenze im 3. bis 4. Lebensjahr, wofur das reifende neuromuskulare System und das vollgestaltete Milchgebis charakteristisch sind. Die reziproke Wirkung aller Glieder der stomatognathen Kette beeinflust in diesem Alter besonderer psychosomatischer Plastizitat die Form und die Funktion des sich entwickelnden Systems. Die obere Grenze wird durch die vorangehenden Anzeichen der Pubertatsperiode bestimmt. Die Adaptationsfahigkeit einzelner anatomischer und physiologischer Strukturen wird allmahlich geringer; infolge zunehmender Umweltanforderungen wird eine Minderung der fur den Erfolg der FKO-Behandlung unerlaslichen Beteiligung des Patienten beobachtet. Diese individuellen Reaktivitatswandlungen wie auch die Umwelteinflusse bestimmen in diesem Alter oft die Wahl der Behandlungsmethode.

Controlled results of treatment of posterior occlusion by means of functional orthodontic appliances

Die vorliegende Arbeit schaltet sich in die vielfachen Bemuhungen ein, einen Nachweis fur die artikularen und alveolaren Veranderungen bei einer Distalbisbehandlung mit funktions-kieferorthopadischen Geraten zu liefern. Der Verfasser geht vom Fernrontgenbild aus. Er untersucht seine Falle, bei denen es gelungen war, eine klinisch und im Modellbefund nahezu fehlerfreie neutrale Verzahnung im bleibenden Gebis zu erreichen. Das Lot von der knochernen Kinnrundung auf die Oberkiefer-Grundebene in der Relation zu A und der Neigungswinkel der Zahnachsen der oberen und unteren Schneidezahne haben erkennen lassen, das 1. es in der Tat eine mandibulare Nachentwicklung gibt, 2. aber die untere Front fast immer im Sinne einer Mesialkippung gefahrdet ist, 3. im Einzelfall nicht vorausgesehen werden kann, ob er mit mandibularem Vorsprung reagiert, 4. haufig ein Kompromis zwischen mandibularem und alveolarem Umbaugeschehen zu beobachten ist.