Craniofacial changes in patients with skeletal class II treated with appliance with screws for mesial shift of the lower jaw

Abstract

Introduction. Biological most appropriate method of treatment class II is a modification of the growth with functional appliances. The machine screw in the mesial direction of the mandible (M block) due to design has features of both functional and active orthodontic appliances. Objective. The aim of the study was to evaluate the skeletal and dentoalveolar changes as well as changes in soft tissue profile after treatment with M block compared with Frankel's function regulator type I and Balters’ bionator type I. Methods. The study included 70 patients divided into 3 groups according to the type of device used (M block, Frankel's function regulator type I, Balters’ bionator type I). Before the therapy each patient's medical history was taken and the clinical examination was performed. At the beginning of the therapy orthopantomographic and profile cephalograph were shot and impressions were taken for study models. At the end of treatment, the changes in the position and development of both the upper and lower jaw, intermaxillary relationships, changes in the cranial base and soft tissue facial profile, as well as changes in the position of the incisors and TMJ. Results. Statistically significant differences were found when using the M block in the analysis of the development and position of the maxilla and mandible, intermaxillary angles, length of anterior and posterior cranial base, the direction of facial growth, length of anterior and posterior face height, the position of the upper lip in relation to the aesthetic line and position of the upper and lower incisors and TMJ. Conclusion. M block leads to redirection of the position of the upper and lower jaw and corrections of class II into class I.

Uvod. Biološki najprihvatljivija metoda lečenja druge klase je modifikacija rasta funkcionalnim aparatima. Aparat sa zavrtnjem za mezijalno usmeravanje donje vilice (M blok) zahvaljujući svojoj konstrukciji ima osobine i funkcionalnog i aktivnog ortodontskog aparata. Cilj rada. Cilj istraživanja bio je utvrđivanje skeletnih i dentoalveolarnih promena, kao i promena na mekotkivnom profilu nakon terapije M blokom u poređenju sa Frankel-ovim regulatorom funkcije tip I i bionatorom po Balters-u tip I. Metode rada. Istraživanjem je obuhvaćeno 70 pacijenata podeljenih u 3 grupe prema vrsti korišćenog aparata (M blok, Frankel-ov regulator funkcije tip I, bionator po Balters-u tip I). Pre terapije svakom od pacijenata uzeta je anamneza i urađen klinički pregled. Pre početka, kao i na kraju terapije, urađen je ortopantomografski i profilni teleradiografski snimak i uzeti su otisci za studijske modele. Na kraju terapije analizirane su promene u položaju i razvijenosti kako gornje, tako i donje vilice, međuviličnih odnosa, promene na kranijalnoj bazi i mekotkivnom profilu lica, kao i promene u položaju sekutića iTMZ-a. Rezultati. Statistički značajne razlike dobijene su prilikom korišćenja M bloka u analizama razvijenosti i položaja gornje vilice i donje vilice, međuviličnih uglova, dužine prednje i zadnje kranijalne baze, pravca rasta lica, dužine prednje i zadnje visine lica, položaja gornje usne u odnosu na estetsku liniju i položaja gornjih i donjih sekutića i TMZ-a. Zaključak. M blok dovodi do preusmeravanja položaja gornje i donje vilice i korekcije II klase u I.