OBJECTIVES

To evaluate dento-skeletal effects of the Pendulum Hygienic Distalizer (P.H.D), utilized on expansion of the maxillary arch and distalizing of maxillary first molars.

MATERIAL AND METHODS

Ten patients were selected from the outpatient clinic of Department of Orthodontics, Faculty of Dentistry, Mansoura University having: (1) Skeletal Class I with moderate maxillary crowding; (2) Angle Class II molars relation; (3) Constricted maxillary arch (posterior crossbite); (4) Ages ranged from 11 to 14 years with an average age of 12 years and 2 months. The changes that, brought by the appliance were evaluated from the lateral cephalometric, postero-anterior radiographs and study cast model taken before and after appliance application by means of a paired t-test.

RESULTS

Significant amounts of maxillary expansion, molar distalization, molar distal tipping and anchorage loss were observed. The amount of maxillary expansion was 4.35 ± 072 mm. The mean maxillary first molar distal movement was 2.27 ± 0.52 mm with a distal tipping of 1.71 ± 0.74 degrees in 3.19 ± 0.53 months. The rate ofdistal movement was 0.70 mm per month. Reciprocal mesial movement of the first premolars was 1.73 ± 0.92 mm with a mesial tipping of 2.60 ± 1.02 degrees. Maxillary incisors moved 1.80 ± 0.85 mm and tipped 2.02 ± 1.43 degrees mesially.

CONCLUSIONS

It was concluded that the Pendulum Hygienic Distalizer works well with the treatment philosophy of Class II malocclusion with posterior cross-bite by expansion the maxillary arch and distalizing of maxillary molars.