Ghodke Swapnil, Utreja Ashok Kumar, Singh Satinder Pal, Jena Ashok Kumar
Unit of Orthodontics, Department of Dental Surgery, All India Institute of Medical Sciences, Sijua, Dumduma, Bhubaneswar, India.
Prog Orthod. 2014 Dec 23;15(1):68. doi: 10.1186/s40510-014-0068-3.
The use of functional appliances for the correction of retrognathic mandible is very common in orthodontics. Similar appliances known as oral appliances are also frequently used in adults for the treatment of mild to moderate obstructive sleep apnea (OSA). Many studies have reported improvement of pharyngeal airway passage (PAP) dimensions following functional appliance therapy in children and oral appliance therapy in adults. There is only one study in the literature that discussed the effect of oral appliance therapy on posterior pharyngeal wall thickness (PPWT) among subjects with OSA. The effect of functional appliance therapy on PPWT has never been investigated. Thus the present study was conducted to evaluate the effects of twin-block appliance on pharyngeal airway passage (PAP) dimensions and posterior pharyngeal wall thickness (PPWT) in class II malocclusion subjects with retrognathic mandibles.
Thirty-eight class II malocclusion subjects in the age range of 8 to 14 years with mandibular retrusion were divided into a treatment (n = 20) and control (n = 18) group. Mandibular retrusion in the treatment group subjects was corrected by twin-block appliance. The effect of twin-block appliance on PAP and PPWT dimensions were evaluated from lateral cephalograms recorded prior-to and after 6 months of appliance therapy in the treatment group subjects and the changes were compared with the changes in the control group subjects. Student's t-test was used for statistical analysis; P-value of 0.05 was considered a statistically significant level.
The depth of the oropharynx was increased significantly in the treatment group subjects (P < 0.001) as compared to the control group subjects (P < 0.05). The depth of the hypopharynx increased significantly in treatment group subjects (P < 0.01). The PPWT at the level of the nasopharynx, oropharynx, and hypopharynx were maintained in the treatment group subjects; whereas in control group subjects, the PPWT was further reduced although the changes were not statistically significant.
Correction of mandibular retrusion by twin-block appliance in class II malocclusion subjects increased the PAP dimensions and maintained the pre-treatment thickness of posterior pharyngeal wall.
在正畸治疗中，使用功能性矫治器矫正下颌后缩非常普遍。类似的矫治器，即口腔矫治器，也常用于成人治疗轻至中度阻塞性睡眠呼吸暂停（OSA）。许多研究报告了功能性矫治器治疗儿童和口腔矫治器治疗成人后咽气道（PAP）尺寸的改善情况。文献中仅有一项研究讨论了口腔矫治器治疗对OSA患者后咽壁厚度（PPWT）的影响。功能性矫治器治疗对PPWT的影响从未被研究过。因此，本研究旨在评估双阻板矫治器对下颌后缩的安氏II类错牙合患者咽气道（PAP）尺寸和后咽壁厚度（PPWT）的影响。
将38名年龄在8至14岁、有下颌后缩的安氏II类错牙合患者分为治疗组（n = 20）和对照组（n = 18）。治疗组患者的下颌后缩通过双阻板矫治器进行矫正。在治疗组患者矫治器治疗6个月前后记录的头颅侧位片上评估双阻板矫治器对PAP和PPWT尺寸的影响，并将这些变化与对照组患者的变化进行比较。采用学生t检验进行统计分析；P值<0.05被认为具有统计学显著性水平。
与对照组患者相比，治疗组患者口咽深度显著增加（P < 0.001）（对照组P < 0.05）。治疗组患者下咽深度显著增加（P < 0.01）。治疗组患者鼻咽、口咽和下咽水平的PPWT保持不变；而在对照组患者中，PPWT进一步减小，尽管变化无统计学意义。
双阻板矫治器矫正安氏II类错牙合患者的下颌后缩可增加PAP尺寸，并维持治疗前的后咽壁厚度。
