Bone remodeling to correct maxillary deficiency after growth cessation
A 22-year-old girl was initially referred by a Maxillofacial surgeon to an orthodontic office for presurgical orthodontic treatment planning for advancing of her maxilla. She had no medical problems and there were no signs of temporomandibular joint dysfunction. Her impacted upper right and left canines were extracted at 17 years of age.\nExtraoral examination showed a retruded upper lip with higher than normal nasolabial angle [].\nIntraoral examination showed anterior and posterior crossbites and reverse overjet. The molars showed class I relationship; however, they had class III relationship due to the loss of upper left and right canines. Loss of upper left and right canines resulted in mesial migration of upper molars; thus, the relationship of molars changes from class III to class I malocclusion [Figures –]. Cephalometric analysis confirmed skeletal class III and vertical growth pattern with maxillary deficiency [] [Figures and ].\nThe treatment objectives for this patient were to:\n1 – correct the deficient maxilla, ideally by moving it to a forward position;\n2 – correct the anterior crossbite;\n3 – correct the posterior crossbite;\n4 – obtain an ideal overjet and overbite;\n5 – provide functional intercuspation.\nOperative maxillary advancement was considered as an alternative option. Another alternative treatment approach was surgically assisted maxillary expansion, followed by advancing the maxilla with facemask. Primarily, the patient was referred for the preoperative orthodontics; however, she rejected the surgery and insisted on orthodontic treatment. Therefore, after the patient signed the required consent forms to be treated orthodontically, it was decided to advance the maxilla by means of Tongue appliance 9, 10 slow maxillary palatal expansion, and lower fixed appliance, followed by reverse chin cup[] and upper fixed appliance.\nTongue appliance 9,10 and jack screw mounted in the midline were used for 6 months in order to advance the maxilla and correct the posterior crossbite. The patient was instructed to open the screw of the palatal expansion 1/4 of a turn per week for 6 months. A tightly fitting and well-retained upper removable appliance was fabricated with Adams clasps on the upper first permanent molars and two C clasps were placed on the upper permanent central and lateral incisors. Long tongue cribs were placed in the palatal area between canine to canine. These cribs were long enough to cage the tongue and were adjusted to avoid traumatizing the floor of the mouth. After 6 months of wearing the tongue appliance, the occlusion was improved; afterward, the lower first premolars were extracted and the patient was banded and bonded with 0.22 standard edgewise appliance in the lower arch []. At the same time, reverse chin cup[] was added in order to reinforce the process of bone remodeling in the nasomaxillary complex. Tongue appliance combined with reverse chin cup was used for 6 more months. Afterwards, the reverse chin cup was removed and the treatment was continued with the tongue appliance combined with 0.22 standard edgewise appliance in the upper arch for 1 year [].