Palatal implant anchorage reinforcement of posterior teeth: A prospective study

Abstract

A new orthodontic implant anchor system (Orthosystem) has been developed. This 1-piece device made from titanium consists of a screw-type endosseous section (lengths of 4 and 6 mm), a cylindrical transmucosal neck, and an abutment. Clamp caps with slots provide for attachment of square orthodontic wires (transpalatal bars) to the implant. The aim of the present prospective study was to evaluate the anchorage capacity of palatally inserted Orthosystem implants for anchorage reinforcement of posterior teeth. The sample consisted of 9 dental Class II patients (age 15 to 35 years) whose treatment plan included extraction of the maxillary first premolars. Each of the patients received 1 implant inserted into the center of the anterior palate. After a mean unloaded implant healing period of 3 months, transpalatal bars were inserted to connect the posterior teeth to the implant. Retraction of the canines and incisors was accomplished without the use of compliance-dependent headgear or Class II elastics. The degree of anchorage loss as well as the amount of canine and incisor retraction were evaluated by measurements of the casts and lateral cephalograms. The mean anchorage loss was 0.7 mm on the right side and 1.1 mm on the left (P <.05). The right and left canines were retracted 6.6 and 6.4 mm, respectively, and the mean overjet reduction was 6.2 mm. Because clinical assessment and postremoval histologic assessment both revealed stability of the short implant, the small anchorage loss was most likely from the deformation of the transpalatal bars by the orthodontic forces. Nevertheless, the treatment goal was achieved in all patients without the use of compliance-dependent auxiliaries. The clinical experience during and after implant insertion, active orthodontic treatment, retrieval of the implant, and subsequent wound healing are described.