الفهرس 
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Abstract
A 3D finite element analysis study was carried out to evaluate stress distribution in the maxilla produced from molar protraction by using two different techniques, pull and push techniques. The analytical models were selected and scanned by CBCT scanner to get the ideal geometrical outline. Mimics software program was used to edit and crop the CBCT images. Three dimensional drawing of the model components was done by tracing every CBCT cut in Solidwork software program to produce a 3D model of the maxilla. A 3D model of teeth was obtained from drawing the teeth according to the actual length and width of every tooth. Assembling of different components with each other “bone and teeth, bone and screw and teeth and bandʼʼ were carried out to collect all parts of each model. The material properties for spongy bone, titanium alloy, stainless steel alloy, teeth and ligaments were identified. The two models were restrained at the posterior and superior border to avoid total body displacement. The models were meshed with a curved based solid mesh. Load was applied to the stainless steel arm and head of the mini-screw in the two models. The stresses at the maxillary sinus floor, nasal cavity floor, roots of upper second permanent molar, the screw (head and body), connecting arm, tuberosity and pre-alveolar area of upper second premolar were calculated. The results revealed that stresses produced from using push technique is higher in the head of mini-screw and the tuberosity than stresses produced from using pull technique.