Abstract The treatment of maxillary transverse deficiency in post-pubertal patients has been an area of disagreement among orthodontists. Much of the controversy is over the timing of when it is appropriate for these patients to be referred to an oral and maxillofacial surgeon for an adjunctive surgical procedure or whether traditional orthodontic mechanics should be attempted. The decision, therefore, by an orthodontist of when to refer a patient for surgery appears to be an individual one. The question then becomes which of the three basic surgical procedures would be most appropriate for the patient. Specifically, consideration must be given to surgically assisted rapid palatal expansion, segmental LeFort I osteotomy, or mandibular midline osteotomy with constriction.