Clinical Effectiveness of a Subperiosteal Anchorage Device

Abstract

The purpose of this pilot study was to evaluate the clinical efficacy of a subperiosteal anchorage device, the palatal OnPlant™, during orthodontic retraction of protruding anterior teeth in cases requiring maxillary premolar extraction. Seven subjects (5 female, 2 male), ages 13 to 55, were selected for the study. The OnPlant was surgically placed in the mid-palatal region through a well-defined subperiosteal tunnel. Following the manufacturer recommended osseointegration period of four months, the OnPlant was uncovered and attached to the first molars by means of a transpalatal bar. Standard orthodontic treatment then commenced to retract the anterior teeth after the first premolars were extracted. A new volumetric tomography scanner, the NewTom 9000, was used to evaluate the clinical efficacy of the OnPlant. The study design called for records to be taken at two intervals: 1) Following placement of the OnPlant-transpalatal bar, immediately prior to retraction of the anterior dentition and 2) Following completion of retraction as well as any necessary torquing of the maxillary incisors. Limited time allowed only partial treatment for three of the subjects, whose final NewTom records were taken within the retraction phase of treatment. Six of the OnPlants performed without failure, providing absolute anchorage of the molars during treatment. One OnPlant failed near the end of incisor retraction. The NewTom proved to be a consistent and reliable tool for evaluating the OnPlant\u27s clinical performance. Future research into the OnPlant and other such skeletal anchorage devices may continue to expose the orthodontic community to the benefits of such devices in cases requiring maximum anchorage