ABSTRACT

Recently, studies on implant and/ or onplant supported molar distalization appliances to reduce patient cooperation have increased. The aims of the present study are, 1) to investigate the efficiency of intraosseos screws for anchorage in maxillary molar distalization 2) to investigate the sagital and vertical skeletal, dental and soft tissue changes following molar distalization using intraosseous screw-supported anchorage unit in the maxilla. Eleven subjects (9 girls and 2 boys; 11.3-15.6 years of age) with skeletal class I, dental class II malocclusion were participated in the present study. For molar distalization an anchorage unit was prepared by placing an intraosseous screw behind the incisive canal and a safe distance away from the midpalatal suture following the palatinal anatomy. After placement the screws were immediately loaded to distalize upper 1st molars or the 2nd molars when they were present. The average distalization time to achieve an overcorrected Class I molar relationship was 4.6 months. The skeletal and dental changes were measured on cephalograms and plaster models, obtained before and after the distalization. In cephalograms, upper 1st molars appeared to be tipped 10° and moved 3.6 mm distally on average. On plaster models, the mean distalization was 5 mm. The upper molars were rotated distopalatally. Mild protrusion (mean 0.7 mm) of the upper central incisors was also recorded. However, there was no change in overjet, overbite and mandibular plane angle measurements. In conclusion, immediately-loaded intraosseous screw-supported anchorage unit was found to be successful in achieving sufficient molar distalization without major anchorage loss.