Abstract
Maxillary transverse deficiency is a common clinical problem in orthodontics, and treating it becomes more challenging when a unilateral posterior crossbite exists. Different treatment modalities have been used, including slow maxillary expansion (SME), rapid maxillary expansion (RME), surgically assisted rapid palatal expansion (SARPE), and corticotomy-assisted expansion. The type of treatment depends mainly on the patient's skeletal maturity. In this case report, we describe the treatment of a 20-year-old female patient with unilateral posterior crossbite using corticotomy-assisted expansion with fixed orthodontic appliances. The crossbite was corrected, and normal overbite and overjet were achieved with Class I canine and molar relationships. The duration of correction of the crossbite was relatively shorter, and periodontal health was maintained without any complications. The technique of selective alveolar bone corticotomy is considered a less invasive procedure when compared to SARPE and MARPE, and it may provide an efficient treatment option in cases of adult unilateral maxillary transverse deficiency.