Seven-year follow-up of the nonsurgical expansion of maxillary and mandibular arches in a young adult: A case report

BACKGROUND Palatal expansion treatment has been used to expand the constricted maxillary arch and has become a routine procedure in orthodontic practice over the past decades.However,the long-term stability of expansion in the permanent dentition without a surgical approach is uncertain.CASE SUMMARY We present the case of a 15-year-old boy with Class II malocclusion and constricted arches.The patient was treated with rapid palatal expansion(RPE)followed by a fixed orthodontic appliance.A 7-year follow-up evaluation was performed by analyzing cephalometric radiographs,plaster models,and photographs.The patient’s constricted maxillary and mandibular arches were relived after the expansion treatment.A Class I occlusion and normal arch form were established and maintained in the long-term.CONCLUSION RPE treatment is successful in solving constricted dental arch in the permanent dentition without a surgical approach.Permanent retention and even occlusal contact help prevent long-term relapse.

Evaluating the effect of midpalatal corticotomy-assisted rapid maxillary expansion on the upper airway in young adults using computational fluid dynamics

Midpalatal corticotomy-assisted rapid maxillary expansion(MCRME)is a minimally invasive treatment of maxillary transverse deficiency(MTD)in young adults.However,the effect of MCRME on respiratory function still needs to be determined.In this study,we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics(CFD).Twenty patients with MTD(8 males,12 females;mean age 20.55 years)had cone-beam computed tomography(CBCT)images taken before and after MCRME.The CBCT data were used to construct a threedimensional(3 D)upper airway model.The upper airway flow characteristics were simulated using CFD,and measurements were made based on the CBCT images and CFD.The results showed that the widths of the palatal bone and nasal cavity,and the intermolar width were increased significantly after MCRME.The volume of the nasal cavity and nasopharynx increased significantly,while there were no obvious changes in the volumes of the oropharynx and hypopharynx.CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment.Our results suggest that in these young adults with MTD,increasing the maxillary width,upper airway volume,and quantity of airflow by MCRME substantially improved upper airway ventilation.