Evaluation of a new design of the maxillary molar distalizer using palatally anchorage

Different intraoral methods are introduced to faciliate the movement of molars distally, which in most cases their major disadvantage is the undesirable movement of the anchorage unit.This study was undertaken to evaluate the effect of a new design of the maxillary molar distalizer using palatally anchorage to assess the anchorage loss. The survey was carried out on 10 patients with the mean age of 14.5 years old. A new fixed intraoral appliance was developed in order to achieve maxillary molar distalization. The appliance was consisted of two parts: The anchorage unit having of a wide Nance button with two Adams clasps on the first premolars and the active unit was composed of a NiTi open Coil spring on the 0.018" stainless steel wire. The patients were followed for total period of 6 weeks in 2 weeks interval time. Lateral cephalograms, study models and copies of the maxillary casts were provided and analyzed prior and after molar distalization by superimposition of the cephalograms and copies respectively. T-test was used to evaluate the changes after distal movement of the molar. The results showed that maxillary first molars were distalized with an average of 1.75mm without any extrusion. Distal tipping of the first molars was found to be 4.35°. Maxillary first premolars and incisors moved forward by 0.7mm and 0.67mm respectively. The first premolars with an average of 0.58mm extrusion were tipped by 6.17°. Distal outrotation of the first molars were showed to be 3.4° while mesial out-rotation of the first premolars were not significant. Intermolar width was increased by 2.26mm and interpremolar width was decreased by 1.58mm. This study showed that the designed appliance could be considered as one of the non-compliant appliances for maxillary molar distalization. No extraoral appearance, patient cooperation and acceptability and applying a light-continuous force could be considered as the other advantages of the appliance.