Efficacy Evaluation Of Maxillary Skeletal Expansion For The Adult Patients With Transverse Maxillary Deficiency

Objective:The study was aimed to evaluate the effects of MSE to treat young adults with transverse maxillary deficiency.Methods:Twenty two patients aged from 18 to 31 years old(average 23.3±4.12 years old)with transverse maxillary deficiency were enrolled in this study,including 8 males and 14 females.The CBCT was taken before and immediately after the expansion.Three-dimensional measurements of craniofacial bones and teeth were performed with Invivo dental 5 software.Three-dimensional reconstruction and measurement of upper airway were performed using Mimics Medical 17.0 software.Statistical analyses were performed using paired t-test with SPSS 17.0 software.Results:1.A total of 22 samples were collected in this study.The midpalatal sutures of two samples were not opened successfulIy,and the success rate of MSE was 90.91%.2.The midpalatal suture was opened parallelly from the anterior to posterior.The opening of the midpalatal suture at the canine and the maxillary first molar were(3.18± 1.42)mm and(2.72±0.64)mm respectively.There was no statistical difference between the two above.From the top to the bottom(the side of the nasal cavity to the side of the mouth),the amount of expansion gradually increased.3.The maxillary first molar width increased by(4.56±2.14)mm,the base bone width of maxillary first molar was enlarged by(3.68±2.84)mm,the distance between the zygoma bones increased by(1.23 ± 0.55)mm,the distance between sphenoid wing outer plates increased by(1.18 ±0.96)mm,the distance between frontonasal sutures was enlarged by(0.72±0.41)mm.4.The inclination angles of the maxillary first molar,the maxillary second premolar and the maxillary second molar increased by(4.43 ± 3.47)°,(3.11 ±2.98)°and(2.14±2.33)°respectively without the mandible clockwise rotaing and the alveolar bone tipping buccally.5.The nasal cavity width was enlarged by(2.29± 1.36)mm and the nasopharynx and oropharynx volumes were not changed.6.The buccal bone plate of the maxillary first molar was not lost in the vertical direction.The thickness of the buccal plate at 5mm and 7mm of the CEJ apically were reduced by(0.56 ± 0.62)mm and(0.52±0.36)mm respectively.The palatal bone had not increased in the vertical direction.The thickness of the palatal bone plate at 5 mm 7mm and 9 mm of the CEJ apically increased by(0.92±0.76)mm,(1.10 ± 0.82)mm and(0.96±0.76)mm respectively.Conclusion:MSE can open the midpalatal suture with high success rate and obvious bone effects.However,the slight buccal tipping of the maxillary first molar,the maxillary second premolar and the maxillary second molar occured.The width of nasal cavity increased.The buccal bone plate thickness of the maxillary first molar was slightly lost and the thickness of the palatal bone plate was slightly increased.