Objective: To study the mechanics of Pendulum appliance, and its effects on craniofacial and dentoalvaolar structure.
Methods: 16 class II malocclusion patients (13 females and 3 males) were selected as the subjects, aged from 9.3 to 22.8 years(13.6 on average). All the patients were treated with Pendulum appliance. The duration for distolization of upper molars was from 1 to 6 months(3.7 months on average). Cephalomatric analysis was used.
Results: 1. The upper molar was distalized by 3.59 mm per side with mainly tilting movement. 2. Incisors moved mesially by 3.28 mm per side (tilting movement). 3. Anterior overjet was increased by 1.56 mm after treatment and more than 6 mm space was created per side. 4. The upper molars extruded slightly by 0.69 mm. 5. The width of upper arch was increased by 2.03, 1.66, 1.10 mm at molar, premolar and canine region respectively. 6. The Pendulum appliance had less effects on craniofacial structure because of short treatment time.
Conclusions: The Pendulum appliance can distalize the upper molars effectively without patients' active cooperation. However, it should be cautions in using the appliance because of its side effects on tilting of molars and mesial movement of incisors.