Comparative Evaluation of PowerScope and Forsus

INTRODUCTION : Among different dental and skeletal combinations that can create a Class II malocclusion, mandibular retrusion is one of the most common characteristics.In such cases, to stimulate mandibular growth by forward positioning of the mandible, various removable and fixed functional appliances are commonly used to alter the position of mandible during the pubertal growth period.

Stimulation of mandibular growth, distal movement of upper dentition, mesial movement of lower dentition contributes to correction of Class II malocclusion with the use of fixed functional appliances. Of the various fixed functional appliances available to the orthodontist today for the correction of Class II malocclusion are Forsus fatigue resistant device which is the most popular fixed functional appliance6 and the PowerScope which is a recent addition to the armamentarium.

PowerScope is delivered as a one-size-fits-all appliance pre-assembled with attachment nuts for quick and easy chairside application. The appliance is a wire-to-wire installation with attachments placed mesial to the first molar in the maxillary arch and distal to the canine of the mandibular arch. Although there are a few case reports in the literature showing the treatment effects and clinical application of PowerScope, there is not a single study mentioning the effects of PowerScope appliance, which has a different status from other fixed functional appliances due to its special attachment. The purpose of this clinical study was to evaluate the skeletal and dental changes produced by the PowerScope and compare these effects with one of the most commonly used fixed functional appliance the Forsus Fatigue Resistant Device (FRD).

MATERIALS AND METHODS: The present study is a prospective, non-pharmacological, double blind, randomised clinical study conducted in the department of Orthodontics and Dentofacial orthopedics, PGIDS Rohtak.

The study sample consisted of 28 patients, were selected from subjects reporting to the department for fixed orthodontic treatment.

The primary researcher explained the nature of the study to the patients and their parents and their consent was taken. The final sample of 28 patients fulfilling the criteria were randomly divided in two groups: Group 1( PowerScope group) and Group 2 (Forsus group) All subjects in both the treatment groups were treated with MBT 0.022- inch slot preadjusted edgewise appliance (Ortho Organizers, San Marcos, Calif). Both arches were levelled and aligned upto 0.019" ×0.025" stainless steel wires and then the fixed functional appliance as per the group mentioned in the patients envelop was installed.

Lateral cephalometric radiographs were taken before starting fixed functional appliance therepy( T1) immediately (1-3 days) before placement of the fixed functional appliance (T2) and after removal of the fixed functional appliance(T3). All cephalometric radiographs were taken on the same cephalostat.

For evaluation of skeletal and dentoalveolar changes that contributed to the Class II correction, pitchfork analysis was used.

To check patient comfort, all the patients were given a questionnaire. The questionnaire was designed in English and then verbally translated into the patients and parents native language at the installation appointment though all the patients and their parents could read and understand it in English. After the installation all the patients were given the questionnaire and requested to bring it at the next scheduled appointment after filling the required details .

Inclusion criteria

• Patients in active growth period
• Skeletal Class II malocclusion
• Normal or mildly prognathic maxilla
• Retrognathic mandible.
• Increased overjet, not less than 5 mm.
• Horizontal to average growth pattern
• Positive pretreatment visual treatment objective (VTO).
• Minimum crowding in dental arches.
• Treatment completed without any permanent teeth extracted (excluding third molars).

Exclusion criteria

• Subjects with a history of orthodontic treatment
• Anterior open bite
• Severe proclination and crowding of anterior teeth
• Any systemic disease affecting bone and generalgrowth
• Vertical growth pattern
• Patient who fails to follow up or undergo complete treatment