Changes in soft tissue profile using functional appliances in the treatment of skeletal Class II malocclusion

Abstract

Introduction The effects of orthodontic treatment are considered to be successful if the facial harmony is achieved, while the structures of soft tissue profile are in harmony with skeletal structures of neurocranium and viscerocranium. In patients with skeletal distal bite caused by mandibular retrognathism, facial esthetics is disturbed often, in terms of pronounced convexity of the profile and change in the position and relationship of the lips. Objective The aim of this study was to determine the extent of soft tissue profile changes in patients with skeletal Class II malocclusion treated with three different orthodontic appliances: Frankel functional regulator type I (FR-I), Balters' Bionator type I and Hotz appliance. Methods The study included 60 patients diagnosed with skeletal Class II malocclusion caused by mandibular retrognathism, in the period of early mixed dentition. Each subgroup of 20 patients was treated with a variety of orthodontic appliances. On the lateral cephalogram, before and after treatment, the following parameters were analyzed: T angle, H angle, the height of the upper lip, the position of the upper and lower lip in relation to the esthetic line. Within the statistical analysis the mean, maximum, minimum, standard deviation, coefficient of variation, two-factor analysis of variance with repeated measures and the factor analysis of variance were calculated using ANOVA, Bonferroni test and Student's t-test. Results A significant decrease of angles T and H was noticed in the application of FR-I, from 21.60° to 17.15°, and from 16.45° to 13.40° (p lt 0.001). FR-I decreased the height of the upper lip from 26.15 mm to 25.85 mm, while Hotz appliance and Balters' Bionator type I increased the height of the upper lip, thereby deteriorating esthetics of the patient. Conclusion All used orthodontic appliances lead to changes in soft tissue profile in terms of improving facial esthetics, with the most distinctive changes in the application of Frankel's functional regulator type I, which is the most successful appliance for achieving the overall facial harmony of the patient.

Uvod Da bi se učinak ortodontskog lečenja mogao smatrati uspešnim, neophodno je postići facijalnu harmoniju, pri čemu su strukture mekotkivnog profila u harmoniji sa skeletnim strukturama neurokranijuma i viscerokranijuma. Kod osoba sa skeletno-distalnim zagrižajem izazvanim mandibularnim retrognatizmom često je narušena facijalna estetika u vidu izraženog konveksiteta profila i promene u položaju i međusobnom odnosu usana. Cilj rada Cilj ovog istraživanja bio je da se utvrdi obim promena na strukturama mekotkivnog profila kod osoba sa skeletno-distalnim zagrižajem lečenim pomoću tri različita ortodontska aparata: Frenkelovog (Frankel) regulatora Funkcije tip I (FR-I), bionatora po Baltersu (Balters) tip I i Hocovog (Hotz) aparata. Metode rada Istraživanjem je obuhvaćeno 60 pacijenata sa dijagnozom skeletno-distalnog zagrižaja izazvanog mandibularnim retrognatizmom u periodu rane mešovite denticije. Svaka podgrupa od po 20 ispitanika lečena je različitim ortodontskim aparatima. Na profilnom telerendgenskom snimku pre i posle lečenja analizirani su sledeći parametri: ugao T, ugao H, visina gornje usne i položaj gornje i donje usne u odnosu na estetsku liniju. U okviru statističke analize izračunati su srednja, najveća i najmanja vrednost, standardna devijacija i koeficijent varijacije, urađene dvofaktorska analiza varijanse s ponovljenim merenjima i jednofaktorska analiza varijanse uz primenu testa ANOVA, Bonferonijevog (Bonferroni) testa i Studentovog t-testa. Rezultati Došlo je do značajnog smanjenja vrednosti uglova T i H pri primeni FR-I sa 21,60° na 17,15°, odnosno sa 16,45° na 13,40°, sa statističkom značajnošću na nivou p lt 0,001. Primenom FR-I smanjena je visina gornje usne sa 26,15 mm na 25,85 mm, dok se primenom Hocovog aparata i bionatora po Baltersu tip I povećala, čime se pogoršao estetski izgled pacijenta. Zaključak Svi korišćeni ortodontski aparati dovode do promena na mekotkivnom profilu u vidu poboljšanja facijalne estetike, pri čemu su promene najizrazitije pri korišćenju Frenkelovog regulatora Funkcije tip I, koji najuspešnije deluje na postizanje ukupne harmonije lica pacijenta.