The treatment of transverse maxillary deficiency in skeletally mature individuals should include surgically assisted rapid palatal expansion. This study evaluated the distribution of stresses that affect the expander’s anchor teeth using finite element analysis when the osteotomy was varied. For this, five models were virtually built and the surgically assisted rapid palatal expansion was simulated. The results showed tension on the lingual face of teeth and alveolar bone and compression on the buccal side of the alveolar bone. The subtotal Le Fort I osteotomy combined with intermaxillary suture osteotomy seemed to reduce the dissipation of tensions. Therefore, subtotal Le Fort I osteotomy without step in the zygomaticomaxillary buttress combined with intermaxillary suture osteotomy and pterygomaxillary disjunction may be the osteotomy of choice to reduce tensions on anchor teeth, which tended to move mesiobuccally (premolar) and distobuccally (molar).