Comparison of Jones JIG and distal jet molar distalizing appliances

ABSTRACT

The purpose of the present study was to evaluate and compare the effects of Jones jig and distal jet appliance during class-II molar correction with maxillary first molar distalization, its tipping, extrusion, rotation as well as anchorage loss at premolar-incisor unit. Sixty patients were selected from Orthodontics department de,Montmorency College of Dentistry, Lahore, Pakistan and pre and post distalization lateral cephalograms and study casts were used as evaluation tools. Distal jet group showed 3.88 mm space creation during 7.11 months, out of which 2.93 mm [75.52%] was molar distalization while 0.93 mm [24.48%] was premolar mesialization as anchorage loss. There was 3.41§ molar tipping with 0.20 mm extrusion and 7.33 § distal tipping with 0.90 mm second cuspid extrusion whereas incisors had 1.65 § labial tipping. Right and left upper molars showed 1.30° and 1.18° rotation respectively. In the Jones jig group, the maxillary first molars were distalized to 3.30 mm on each side and tipped 6.70° distally. The maxillary second premolars moved mesially 2.00 mm with tipping of 7.48°.Therefore a total space created between first molar and second premolar was 5.30 mm i.e. 62.26% from first molar distalization while 37.74% from second premolar mesialization. In addition maxillary first molar extruded 0.70 mm and second bicuspid extruded 1.58 mm. Both right and left first molars were also disto-palatally rotated by 2.00° and 2.55° respectively though upper incisors showed 2.25° proclination during distalization. Distal jet appliance was found to be a more effective and predictable method for themaxillary first molar distalization through bodily translation with minimum tipping, extrusion, and rotation as well as anchorage loss