Changes during treatment of class III malocclusion by Y appliance and appliance with screw according to Bertoni

Abstract

Introduction/Objective. Class III malocclusion is caused by changes in skeletal and/or dentoalveolar structures with a typical mesial relationship of posterior teeth. The ?Y? appliance and the appliance with screw according to Bertoni can be used in treating Class III malocclusion caused by maxillary retrognathism in the period of mixed dentition. The aim of the study was to determine and compare changes on skeletal and dentoalveolar structures in patients with Class III malocclusion treated with the Y appliance and the appliance with screw according to Bertoni. Methods. Forty patients with Class III malocclusion were included in this study. The sample was divided into two groups, with 20 patients in each group. The including criteria were maxillary retrognathism, the period of mixed dentition, and pubertal growth. The excluding criteria were mandibular prognathism, patients with genetical predisposition for skeletal Class III malocclusion, patients with cleft lip and palate or craniofacial syndrome, and the period of permanent dentition. The appliances which caused most changes on the maxilla were used in this study because all patients had a deficiency of maxillary growth. Anamnesis, clinical and functional testing, study casts analysis, analysis of orthopantomograms, lateral cephalograms, extraoral and intraoral photos were done for each patient. Therapeutic effects were analyzed on study casts and lateral cephalograms after this phase of orthodontic treatment. Results. The main dentoalveolar effect was protrusion of the upper incisors. Skeletal effects were not significant. Conclusion. The Y appliance and the appliance with screw according to Bertoni caused greater changes on dentoalveolar structures compared to skeletal changes.