orthodontic treatment such as rapid palatal expansion ( rpe ) and rapid maxillary expansion ( rme ) are widely used to correct the problem1 . after completion of skeletal maturation , palatal expansion without surgery causes more dentoalveolar movement than bony displacement . this can lead to many problems , including extrusion of the molars and periodontal complications2 . therefore , combined surgical and orthodontic treatment is more effective and safe for the correction of transverse discrepancies in adults3 . the segmental le fort i osteotomy and surgically - assisted rapid maxillary expansion ( sarme ) are the most commonly used surgical methods to treat transverse discrepancy . although many studies have reported short - term stability surgical outcomes , few data support long - term stability . however , most studies reported that sarme is more stable and has lower morbidity in complications than segmental osteotomy1 . in our case , a le fort i osteotomy with paramedian split was performed on an adult patient to expand the maxillary transverse dimension and skeletal class iii facial deformity . however , the patient experienced maxillary constriction shortly after the operation . this patient 's maxillary constriction was successfully recovered with an rme device after a le fort i osteotomy with paramedian split . a male patient in his mid - twenties visited our orthodontic department with the chief complaint of mandibular prognathism with a maxillary bilateral crossbite and tooth crowding through a high , narrow palate.(fig . the horizontal discrepancy of the posterior molars with the crossbite was noted in the maxillary dental arch.(fig . 2 ) parasagittal splitting with a le fort i osteotomy for maxillary transverse deficiency and bisagital split ramus osteotomy ( bssro ) with genioplasty were performed to treat mandibular prognathism and maxillary transverse deficiency.(fig . 3 ) the patient was transferred to the orthodontic department for postsurgical orthodontic treatment 6 weeks postoperatively . loss of horizontal width and crossbite on the right side molars were observed after removal of the surgical wafer . the wafer on the affected side which had a crossbite was removed after the cut between the right maxillary canine and the first premolar . 4 ) a week later , an rme device was inserted and fixative plates were removed on the right side . activation was performed twice a day with a daily expansion rate of 0.5 mm until the necessary expansion was achieved . the rme device was left in place for 4 months as a fixed retainer , which was replaced with a transpalatal retainer for further retention.(fig . 5 ) the palatal transverse width was successfully increased and the correction of posterior crossbite was achieved.(fig . 6 ) we did not observe complications or relapse during 3 years of follow - up , and the occlusion has remained stable.(fig . surgical procedures such as sarme and the le fort i osteotomy have been reported to be an effective treatment to correct transverse maxillary deficiency in adults . vandersea et al.1 reported that the sarme technique is indicated in cases with a deficit of 7 mm or more who also have isolated transverse deficiency not required correction in the vertical or sagittal plane . segmental le fort i osteotomy can be applied in patients who have a transverse deficiency of less than 7 mm that also require vertical or sagittal repositioning of the maxilla . we treated a skeletally mature patient with transverse maxillary deficiency with a para - sagittal split and a le fort i osteotomy . however , six weeks after surgery , we observed a relapse in the crossbite of the right molars . in our case study , first , mechanical resistance from circummaxillary sutures could be a factor . according to isaacson and ingram5 , maxillary articulations , which are adjacent to the midpalatal suture , are the main points of resistance to expansion of the maxilla . this finding is inconsistent with previous studies insisting that the midpalatal suture is the main cause of resistance to expansion of force . lines6 insisted that facial skeletal resistance to expansion came from zygomaticotemporal , zygomaticofrontal , and zygomaticomaxillary sutures . koudstaal et al.7 reviewed previous studies indicating that the zygomaticomaxillary junction was the major site of resistance . many studies reported a higher relapse rate after segmental le fort i osteotomy than after sarme . we chose the le fort i osteotomy technique because the patient required 3 mm of transverse expansion and vertical repositioning to correct asymmetry . proffit et al.8 performed segmental le fort i osteotomy and found a 0.1 mm relapse in intercanine teeth in 5% of patients and a 2 mm relapse in intermolar teeth in 50% of patients . phillips et al.9 reported a relapse rate of 49% in molars and 30% in premolars after le fort i and segmental osteotomy , followed by orthodontic treatment in 39 patients . however , according to a study using a reflex microscope on dental casts , the relapse rates between le fort i with orthodontic expansion and multisegment le fort i osteotomies were not significantly different10 . kretschmer et al.11 studied surgical expansion of the maxilla and found high relapse rates in the dentoalveolar portion suggesting that orthodontic relapse matters in these cases . although the resisting pillars in the zygomatico - maxillary area were released via surgical methods , tough palatal mucosa would limit surgical expansion . pogrel et al.12 reported that patients with 1 year of orthodontic treatment after the surgery showed an 11.8% relapse rate in the first molar . bays and greco13 retrospectively evaluated 19 patients more than 6 months after removal of orthodontic appliances , and reported mean relapse rates of 8.8% in the intercuspids and 7.7% in intermolar expansion . northway and meade14 also reported a 4% relapse rate with 0.2 mm of intercanine distance and a 3% relapse rate with 0.2 mm of intermolar distance . third , previous studies recommended over - expansion and longer retention periods to prevent relapse . in our case , the retention period following the expansion of dento - osseous segments plays a significant role in preventing relapse1 . an occlusal splint should be placed at the mid - palatal osseotomies as a retainer where bone begins to fill the space at least 6 weeks after surgery . the relapse rate with a 6-month stabilization period16 was lower than the relapse rate with a 3-month stabilization period3 . pogrel et al.12 recommended that retention should be maintained for at least 3 months until the palatal gap is filled by bone tissue , whereas phillips et al.9 reported that only a 6-week period would be required for retention . petrick et al.17 investigated the bone density of the midpalatal suture 7 months after sarme in adults and showed that the density achieved was only 1/2 to 3/4 of the pretreatment value . in our case , the surgical wafer was maintained for 6 weeks and transverse relapse occurred almost immediately after wafer removal . this relapse can be explained by the short retention period , and could have been prevented by a longer retention period . the retention period after transverse gain in adult patients should be at least 3 months18 , and lengthening of the retention period is recommended when it is critical to maintain arch width . phillips et al.9 suggested that overexpansion of 2 to 3 mm should be performed to prevent relapse . based on the literatures , correction of transverse maxillary deficiency seems to be one of the least stable surgical movements . however , this shortcoming can be overcome with forthcoming advances , and an rme application may be a good option for treating early relapse of maxillary transverse expansion . for long - term stability , the proper retention period also should be considered on a case - by - case basis .
maxillary transverse deficiency is one of the most common deformities among occlusal discrepancies . 
 typical surgical methods are segmental le fort i osteotomy and surgically - assisted rapid maxillary expansion ( sarme ) . 
 this patient underwent a parasagittal split with a le fort i osteotomy to correct transverse maxillary deficiency . during follow - up , early transverse relapse occurred and rapid maxillary expansion ( rme ) application with removal of the fixative plate on the constricted side was able to regain the dimension again . 
 rme application may be appropriate salvage therapy for such a case .