Kori Chaitra, Shetty Prajwal, Shetty Mukul, Ravi M S
Orthodontics and Dentofacial Orthopaedics, Private Clinic, Hubli, Karnataka, India.
Department of Orthodontics and Dentofacial Orthopaedics, AB Shetty Memorial Institute of Dental Sciences, NITTE (Deemed to be University), Derlakatte, Karnataka, India.
J Clin Exp Dent. 2022 May 1;14(5):e404-e412. doi: 10.4317/jced.59542. eCollection 2022 May.
To compare the effects of bimaxillary surgery ( Maxillary advancement and mandibular setback) and mandibular setback surgery (Bilateral Sagittal Split Osteotomy) on the pharyngeal airway space (PAS) and the hyoid bone position in a skeletal class III patients.
Thirty four subjects (21 males, 13 females, mean age 26.5 ± 8 years) with skeletal class III pattern (ANB angle of -2° to -6°) were divided into two groups of equal sizes. Group A consisted of 17 individuals who underwent Bilateral Sagittal Split Osteotomy (BSSO)and Group B consisted of 17 individuals who underwent bimaxillary surgery. In both the group, lateral cephalograms were taken, traced and analyzed for the specified parameters at 3 intervals, pre treatment (C1), post surgical (C2), and post orthodontic treatment (C3). Changes in PAS was evaluated at 3 levels i.e, nasopharynx (Upper PAS), oropharynx (Middle PAS) and hypopharynx (Lower PAS). Changes in hyoid bone position were evaluated in anteroposterior and vertical direction at all the 3 intervals.
There was a significant constriction of airway at oropharyngeal and hypo-pharyngeal level at C2 and C3 in both the groups. However, the reduction at the oropharyngeal airway was greater in group A. In group B, there was significant increase in the airway at the level of nasopharynx, Hyoid bone was positioned more posteriorly post-surgery in group A which did not return to its original position post treatment. In group B hyoid bone was positioned postero-inferiorly post surgically which came back to its original position by the end of orthodontic treatment.
Patients undergoing bimaxillary surgery showed a significant increase in the airway at the level of nasopharynx. Hyoid bone returned to its original position by the end of orthodontic treatment in the bimaxillary surgery group. This study suggested that while treating a skeletal class III malocclusion it is advised to perform maxillary advancements along with mandibular setback surgery. Bimaxillary surgery, Hyoid bone, Bilateral Sagittal Split Osteotomy, Pharyngeal airway space.
比较双颌手术（上颌前徙和下颌后退）与下颌后退手术（双侧矢状劈开截骨术）对骨性III类患者咽气道间隙（PAS）和舌骨位置的影响。
34例骨性III类患者（21例男性，13例女性，平均年龄26.5±8岁，ANB角为-2°至-6°）被分为两组，每组人数相等。A组由17例行双侧矢状劈开截骨术（BSSO）的个体组成，B组由17例行双颌手术的个体组成。两组均在治疗前（C1）、术后（C2）和正畸治疗后（C3）3个时间点拍摄头颅侧位片，进行描图并分析特定参数。在鼻咽（上PAS）、口咽（中PAS）和下咽（下PAS）3个水平评估PAS的变化。在所有3个时间点评估舌骨位置在前后方向和垂直方向的变化。
两组在C2和C3时口咽和下咽水平气道均有明显狭窄。然而，A组口咽气道的缩小更为明显。B组鼻咽水平气道有明显增加。A组术后舌骨位置更靠后，治疗后未恢复到原来位置。B组术后舌骨位置向后下移位，正畸治疗结束时恢复到原来位置。
接受双颌手术的患者鼻咽水平气道有明显增加。双颌手术组正畸治疗结束时舌骨恢复到原来位置。本研究表明，在治疗骨性III类错合畸形时，建议在上颌前徙的同时进行下颌后退手术。双颌手术、舌骨、双侧矢状劈开截骨术、咽气道间隙。
