Ghassemi Mehrangiz, Ghassemi Alireza, Showkatbakhsh Rahman, Ahmad Syed Sayeed, Shadab Mohammad, Modabber Ali, Jamilian Abdolreza
Department of Orthodontics, School of Medicine, University of Aachen, Aachen, Germany.
Department of Oral, Maxillofacial and Plastic Facial Surgery, School of Medicine, University Hospital, Aachen, Germany.
Natl J Maxillofac Surg. 2014 Jul-Dec;5(2):157-60. doi: 10.4103/0975-5950.154819.
The aim of this study was to evaluate hard and soft tissue change after bimaxillary surgery in class III patients by focusing on sella, nasion, A point (SNA) and sella, nasion, B point (SNB) angle and aesthetic outcome.
The sample consisted of 96 skeletal Class III patients (42 women, 54 men) with a mean age of 25 years with standard deviation (SD) of 8.4. The youngest patient was 16-years-old and the oldest 51-years-old at the time of surgery. In total, seven skeletal parameters, eight soft tissue parameters, and two dental parameters were evaluated on the cephalograms.
At the beginning of the treatment 49 Patients had SNA between 80° and 84°, 34 had SNA of less than 80° and 13 had SNA of more than 84°. Post surgically, 25 patients had SNA of 78°-84°, 19 had SNA less than 78° and 52 patients had SNA of more than 84°. Out of 96 patients 22 had SNB of 78°-82° before surgery, 16 had less than 78° and 58 had SNA of more than 84°. Postoperatively, we measured SNB of 78°-80° in 42, less than 78° in 18 and of more than 82° in 36 patients. The inclination of the maxilla relative to the cranial base changed from 7.2° (SD = 4)-8° (SD = 5.1) and the mandible changed from 35.7° (SD = 6.6) to 36° (SD = 6.3) postoperatively which was not significant. The distance from upper lip to E-line increased by 2.6 mm (SD = 3.9) after surgery (P < 0.001), while, the lower lip distance to E-line decreased slightly by 0.9 mm (SD = 3.2) (P < 0.01). Nasolabial angle was decreased by 9.5° (SD = 9.4) after surgery (P < 0.001). The nose prominence also decreased from 18.2 mm (SD = 3.5) -16.5 mm (SD = 3.3).
Although in many cases we did not have a SNA angle or SNB angle in normal range but a good aesthetic outcome have been observed. Consequently our study showed that soft tissue change and aesthetic aspects should be considered in surgical planning and achieving SNA angle or SNB angle of norm range should not be the only goal. As we could show the advancement of maxilla will result in a better lip and nose profile and this should be considered in treatment planning.
本研究旨在通过关注蝶鞍、鼻根点、A点（SNA）以及蝶鞍、鼻根点、B点（SNB）角度和美学效果，评估Ⅲ类患者双颌手术后的软硬组织变化。
样本包括96例骨骼Ⅲ类患者（42名女性，54名男性），平均年龄25岁，标准差（SD）为8.4。手术时最年轻的患者为16岁，最年长的为51岁。总共在头颅侧位片上评估了7项骨骼参数、8项软组织参数和2项牙齿参数。
治疗开始时，49例患者的SNA在80°至84°之间，34例患者的SNA小于80°，13例患者的SNA大于84°。手术后，25例患者的SNA为78° - 84°，19例患者的SNA小于78°，52例患者的SNA大于84°。在96例患者中，22例患者术前的SNB为78° - 82°，16例患者小于78°，58例患者的SNA大于84°。术后，我们测量到42例患者的SNB为78° - 80°，18例患者小于78°，36例患者大于82°。上颌相对于颅底的倾斜度从7.2°（SD = 4）变为8°（SD = 5.1），下颌从35.7°（SD = 6.6）变为36°（SD = 6.3），术后变化不显著。术后上唇到E线的距离增加了2.6 mm（SD = 3.9）（P < 0.001），而下唇到E线的距离略有下降，下降了0.9 mm（SD = 3.2）（P < 0.01）。术后鼻唇角减小了9.5°（SD = 9.4）（P < 0.001）。鼻突度也从18.2 mm（SD = 3.5）降至16.5 mm（SD = 3.3）。
尽管在许多情况下我们没有使SNA角或SNB角处于正常范围内，但观察到了良好的美学效果。因此，我们的研究表明，在手术规划中应考虑软组织变化和美学方面，达到正常范围的SNA角或SNB角不应是唯一目标。正如我们所展示的，上颌前徙将导致更好的唇部和鼻部轮廓，这在治疗规划中应予以考虑。
