下颌后退术后舌骨、舌体位置和咽腔间隙变化的锥形束CT分析

目的研究正畸-正颌联合治疗骨性Ⅲ类错畸形对舌骨、舌体位置和咽腔间隙的影响,分析下颌后退与舌骨、舌体位置改变和咽腔间隙缩窄之间的相关性。方法选取经正畸-正颌联合治疗的患者20例为研究对象,于正颌手术前1周及术后6个月拍摄锥形束CT,三维重建颅颌面、气道及舌骨的立体模型,建立以蝶鞍中心（S）点为原点的三维坐标系。测量治疗前后咽腔各段最窄处的矢状径、冠状径、截面积,各段容积和咽腔总容积,同时测量颏前点、舌骨点、舌根点的三维位置,分析颏前点的变化与咽腔间隙及舌骨、舌体位置变化的相关性。结果治疗后,咽腔间隙呈现整体缩窄趋势。舌骨发生了后下移位,其中向后、向下平均移动距离分别为5.72、2.76 mm（P<0.05）;舌根点向后平均移动了4.04 mm（P<0.01）。19项相关性比较中,有统计学意义的项目有14项,其中下颌后退量与咽腔总容积改变的相关性最强（r=0.834,P<0.01）。结论正畸-正颌联合治疗骨性Ⅲ类错畸形可造成咽腔缩窄,舌骨后下移位,舌体向后移位;下颌后退量与咽腔间隙缩窄、舌骨和舌体位置的改变具有较强的相关性。     

下颌骨后退术后舌根和舌骨位置的改变

目的　通过下颌后退手术与舌根和舌骨位置变化相关性研究 ,了解二者关系 ,为临床治疗提供依据。方法　描记 18例接受经口内下颌骨升支垂直截骨术矫治下颌前突畸形患者的术前及术后 1个月的标准颅颌侧位头影测量图 ,测量项目 5项 ,测量数值配对t检验 ,并将下颌骨后退距离与各测量项目变化作相关分析。结果　术后 1个月下颌骨后退的平均值是 10 .2 0mm± 1.31mm ,下颌骨后退术后后气道间隙的宽度显著减小 ,舌骨垂直方向显著降低 ,在水平方向上无显著后移。下颌骨后退距离与舌骨垂直方向变化密切相关。结论　双侧下颌升支垂直截骨后退术后舌骨向下移位 ,舌根后移 ,咽腔气道缩小 ,如果患者同时具有超重、短颈、舌体大等其他危险因素 ,下颌骨后退手术可能导致睡眠呼吸暂停综合征的发生。下颌骨后退距离与舌骨垂直方向变化呈正相关。     

颌骨后退术后舌骨位置和后气道间隙变化的相关性研究

目的　通过X线头影测量分析下颌后退手术对舌骨位置和后气道间隙 (PAS)变化的影响 ,为临床治疗提供依据。方法　下颌前突畸形患者 18例 ,均接受经口内下颌骨升支垂直截骨术 ,术前和术后 1个月拍摄标准颅颌侧位片进行头影测量 ,测量项目 6项 ,测量数值配对t检验 ,并将下颌骨后退距离与各测量项目变化作相关分析。结果　术后下颌骨后退的平均值是 (10 .2 0± 1.31)mm。各测量项目显著差异的有 :舌骨垂直方向变化 ,舌根后缘至咽后壁的距离 ,后气道间隙面积。下颌骨后退距离与PAS面积的减小值和舌骨垂直方向变化密切相关 ,与PAS宽度减小值和舌骨水平方向变化没有密切相关。结论　双侧下颌升支垂直截骨后退术后近期 ,舌骨向下移位 ,舌根后移 ,咽腔气道缩小 ,如果患者同时具有超重、短颈、舌体大等其他危险因素 ,下颌骨后退手术可能导致睡眠呼吸暂停综合征的发生。下颌骨后退距离与后气道间隙面积的减小值和舌骨垂直方向变化呈正相关。     

双侧下颌升支矢状劈开截骨术对男性下颌前突患者舌骨位置及咽气道间隙影响研究

目的　研究双侧下颌升支矢状劈开截骨术（BSSRO）对男性下颌前突患者舌骨位置和咽气道间隙的影响,探讨BSSRO与阻塞性睡眠呼吸暂停低通气综合征（OSAHS）的关系。方法　选择2012—2017年于中国医科大学附属口腔医院行BSSRO的男性下颌前突畸形患者30例作为病例组,分别于术前、术后1 ~ 2周及术后6 ~ 12个月拍摄头颅侧位片;选择同期具有正常矢状骨面型的30例男性成年正畸治疗患者作为对照组,正畸治疗前拍摄头颅侧位片。AutoCAD软件测量上下颌骨位置、舌骨位置及咽气道间隙相关测量项目,比较分析病例组术前、术后的上下颌骨位置、舌骨位置和咽气道间隙的变化以及病例组与对照组之间的差异。结果　病例组术后下颌骨后移。病例组术前与对照组相比,舌骨测量值中舌骨体最前上点（H 点）到X 轴的垂直距离（H-X）、H 点到下颌平面的垂直距离（H-MP）显著减小（P < 0.05）,H 点到第三颈椎最前下点（C3点）的距离（H-C3）显著增加（P < 0.05）;咽气道测量值中腭垂尖至中咽壁点距离（U-MPW）、下颌骨后下缘与舌背交点到咽后壁距离（MT-MTP）、过会厌最上点（E点）咽腔间隙距离（EPA-EPP）显著增加（P < 0.05）。病例组术后1 ~ 2周及术后6 ~ 12个月与术前相比,H-X、H-MP显著增加,H-C3显著减小,U-MPW、MT-MTP、EPA-EPP显著减小（P < 0.05）;术后6 ~ 12个月与术后1 ~ 2周相比,H-X显著减小,H-C3显著增加,U-MPW、MT-MTP显著增加（P < 0.05）。病例组术后6 ~ 12个月与对照组相比,反映舌骨位置和咽气道间隙的各项指标差异均无统计学意义（均P > 0.05）。结论　男性下颌前突患者行BSSRO术后短期内舌骨位置向后下移位,咽气道间隙减小,随时间推移,逐渐回复到正常范围,提示男性下颌前突患者行BSSRO术后发生OSAHS的风险不大。     

双侧下颌升支矢状劈开截骨术对男性下颌前突患者舌骨位置及咽气道间隙影响研究

 目的　研究双侧下颌升支矢状劈开截骨术（BSSRO）对男性下颌前突患者舌骨位置和咽气道间隙的影响，探讨BSSRO与阻塞性睡眠呼吸暂停低通气综合征（OSAHS）的关系。方法　选择2012—2017年于中国医科大学附属口腔医院行BSSRO的男性下颌前突畸形患者30例作为病例组，分别于术前、术后1 ~ 2周及术后6 ~ 12个月拍摄头颅侧位片；选择同期具有正常矢状骨面型的30例男性成年正畸治疗患者作为对照组，正畸治疗前拍摄头颅侧位片。AutoCAD软件测量上下颌骨位置、舌骨位置及咽气道间隙相关测量项目，比较分析病例组术前、术后的上下颌骨位置、舌骨位置和咽气道间隙的变化以及病例组与对照组之间的差异。结果　病例组术后下颌骨后移。病例组术前与对照组相比，舌骨测量值中舌骨体最前上点（H 点）到X 轴的垂直距离（H-X）、H 点到下颌平面的垂直距离（H-MP）显著减小（P < 0.05），H 点到第三颈椎最前下点（C3点）的距离（H-C3）显著增加（P < 0.05）；咽气道测量值中腭垂尖至中咽壁点距离（U-MPW）、下颌骨后下缘与舌背交点到咽后壁距离（MT-MTP）、过会厌最上点（E点）咽腔间隙距离（EPA-EPP）显著增加（P < 0.05）。病例组术后1 ~ 2周及术后6 ~ 12个月与术前相比，H-X、H-MP显著增加，H-C3显著减小，U-MPW、MT-MTP、EPA-EPP显著减小（P < 0.05）；术后6 ~ 12个月与术后1 ~ 2周相比，H-X显著减小，H-C3显著增加，U-MPW、MT-MTP显著增加（P < 0.05）。病例组术后6 ~ 12个月与对照组相比，反映舌骨位置和咽气道间隙的各项指标差异均无统计学意义（均P > 0.05）。结论　男性下颌前突患者行BSSRO术后短期内舌骨位置向后下移位，咽气道间隙减小，随时间推移，逐渐回复到正常范围，提示男性下颌前突患者行BSSRO术后发生OSAHS的风险不大。     

双侧下颌支矢状劈开截骨术后咽腔气道的变化

目的：通过头影测量分析骨性下颌前突患者双侧下颌支矢状劈开截骨术后咽腔气道的变化,为术后保持与防止复发提供依据。方法骨性下颌前突患者20例,均接受口内入路的下颌支矢状劈开截骨术。术前1周、术后1周、术后6个月拍摄标准颅颌侧位片进行头影测量,通过治疗前、后对照,比较下颌支矢状劈开截骨术后咽腔气道的改变。采用SPSS 17.0 软件包对数据进行统计学分析。结果术后1周与术前1周相比,软腭长度显著增加,咽腔气道显著减小;术后6个月咽腔气道有所恢复,与术后1周相比软腭长度显著减小,咽腔气道显著增加;术后6个月与术前1周相比,软腭长度及咽腔气道变化无显著差异。结论骨性下颌前突患者行双侧下颌支矢状劈开截骨术后短期内咽腔气道较术前显著减小,可能加大发生睡眠呼吸暂停综合征的几率。但经过一段时间的组织适应和改建后,咽腔气道有恢复至术前宽度的趋势。     

骨性下颌前突正畸—正颌联合治疗前后髁突位置变化的研究

目的:研究骨性下颌前突正畸-正颌联合治疗前后髁突位置的变化,探讨下颌双侧升支矢状劈开后退术对于治疗骨性下颌前突的可靠性和安全性。方法:15例骨性下颌前突的安氏Ⅲ类错牙合畸形病人,行下颌双侧升支矢状劈开后退术(bilateral sagittal split ramus osteotomy,BSSRO)与正畸矫治联合治疗,分别在术前两周和术后半年拍摄许勒式X线片,测量BSSRO术前、术后双侧髁突在关节窝内前、后、上间隙的距离,进行统计学分析比较术前术后髁突位置的变化情况。结果:15例病例经BSSRO配合正畸治疗后均达到正常的咬合关系,恢复了口腔功能,改善了面部容貌;正颌术前:左侧关节前、后、上间隙均数为1.91、2.30、2.51 mm;右侧前、后、上间隙均数为2.14、2.65、2.98 mm;正颌术后:左侧关节前、后、上间隙均数为1.99、2.38、2.62 mm;右侧前、后、上间隙均数为2.14、2.66、2.60 mm。术后半年双侧髁突在关节窝内的上、前、后间隙与术前两周相比,差异均无统计学意义。结论:下颌双侧升支矢状劈开后退术(BSSRO)配合正畸治疗,能够安全有效的矫治骨性下颌前突,并且未使其出现新的关节症状。     

正颌手术前后舌骨位置和咽下气道变化及相关性研究

目的　通过X线头影测量分析了解颌骨后退与前徙对舌骨位置及咽下气道变化的影响情况,为临床治疗提供参数。方法　下颌前突患者23例与小颌畸形患者9例,分别行双侧矢状劈开后退或前徙下颌,手术前后拍摄X线头颅定位侧位片,进行头影测量,测量项目13项,测量数值配对t检验,并将下颌后退距离与各测量项目变化值作相关分析。结果　各测量项目显著差异的有:(1)下颌前突组,下咽腔矢状面积(PSA),舌骨垂直向变化,舌根后缘至咽后壁距离(TBPW),舌背高点至FH平面距离(DTFH),会厌谷至咽后壁距离(VPW),悬雍垂尖点至后咽壁距离(UPW),下颌颏部水平、垂直向变化(PogPTV,MeFH)。舌骨垂直向变化与下颌颏部垂直向变化显著相关。(2)小颌畸形组,舌骨垂直向变化显著。结论　下颌前突组,(1)舌骨向下移位,舌背上抬,舌根向后移动。(2)咽腔气道空间缩小可表现为永久性,但后气道间隙接近正常人,不会发生通气阻塞,更未出现OSAS。舌骨与下颌前部垂直向变化呈负相关。(3)小颌畸形组,舌骨垂直向显著变化,舌骨因颏舌骨肌牵拉而上移。舌骨水平向无显著移位。除会厌谷前移外,舌体无显著移位,说明颌骨前徙对舌体形态没有大的影响。颌骨前徙对后气道无明显影响。从临床病例来看,小颌畸形愈重,前徙颌骨手术对周围组织结构的影响愈大。     

双侧下颌升支矢状劈开后退术后骨稳定性评价

目的 探讨影响双侧下颌升支矢状劈开后退术并行坚固内固定后骨稳定性的因素。方法 对进行双侧矢状劈开后退术后的15例患者于术后1周及术后1年摄头影测量侧位片,对其相关角度及线距进行测量,并作统计学处理。结果 下颌矢状劈开后退术1年后的平均复发量为2.5mm,后退量>6mm组与后退量<6mm组两者变化量之间无显著性差异。结论 下颌双侧矢状劈开后退术并行坚固内固定是矫正下颌前突最有效的方法之一。     

双侧下颌骨升支矢状劈开截骨术治疗下颌前突畸形

目的探讨口内进路双侧下颌骨升支矢状劈开截骨后退小钛板内固定治疗重度下颌前突畸形的临床疗效。方法9例上颌骨发育正常、下颌骨真性前突、严重反He关系的患者，行术前牙齿正畸治疗后，采用口内进路双侧下颌骨升支矢状劈开截骨后退小钛板内固定，术后正畸治疗，恢复尖窝咬He关系。结果所有病例均取得满意的疗效，获得协调的上下颌骨关系，术后随访1年，未见下颌前突复发。结论重度下颌前突畸形采用口内进路双侧下颌骨升支矢状劈开截骨术及正畸治疗是有效的，值得临床推广应用。     

骨性Ⅲ类错患者双颌手术后鼻咽及口咽部气道及其周围软硬组织的变化

目的:通过锥形束CT(cone beam computer tomography,CBCT)观察骨性Ⅲ类错患者双颌手术后鼻咽及口咽部气道及其周围软硬组织的变化。方法:纳入双颌手术治疗的骨性Ⅲ类错患者19例,女性12名,男性7名,平均年龄23.8岁。分别于术前1周及术后3个月拍摄CBCT扫描照片,通过Mimics 10.01建立术前及术后鼻咽、口咽气道三维影像并进行测量。结果:术后患者口咽部容积与气道总容积(包括鼻咽与口咽)均显著减小(P<0.05),口咽部气道容积平均减小8.37%,气道总容积平均减小6.91%。术后软腭处气道横截面积平均减小19.83%(P<0.05)。舌骨位置、软腭形态均有明显变化(P<0.05)。术后气道分别与舌骨位置(H-X,H-Y)、软腭形态变化(PNS-UT,U-T,UT/ANS)有显著相关性(P<0.05),软腭形态变化与舌骨位置变化也具有显著相关性(P<0.05)。结论:骨性Ⅲ类错患者双颌术后气道容积减小。     

Effect of occlusal plane control procedure on hyoid bone position and pharyngeal airway of hyperdivergent skeletal Class II patients

Objective:To evaluate the effect of occlusal plane control on the hyoid bone position and pharyngeal airway of hyperdivergent skeletal Class II patients during orthodontic treatment.Materials and Methods:Cephalograms of 47 hyperdivergent skeletal Class II subjects with occlusal plane control (OPC), and another 50 subjects without occlusal plane control (NOPC) were selected to compare the effects of the occlusal plane control procedure. Lateral cephalograms before treatment (T1), immediately after treatment (T2), and an average of 12 months after treatment (T3) were obtained, and 17 measurements were analyzed in each group and compared between groups.Results:With respect to the T2−T1 changes, the sagittal discrepancies in both groups were alleviated. In the OPC group, both the occlusal and mandibular plane angles decreased, accompanied by anterior and superior movement and counterclockwise rotation of the hyoid bone. The overall changes from T3 to T1 in each group exhibited trends similar to that induced by treatment. As for pharyngeal airway space alterations, no significant difference in OPC group was presented throughout treatment or retention periods.Conclusions:The customized occlusal plane control procedure was effective for hyperdivergent skeletal Class II patients: The occlusal plane rotated counterclockwise, followed by a counterclockwise rotation of the mandibular plane. The hyoid bone moved anteriorly and superiorly, accompanied by its counterclockwise rotation. However, this procedure did not induce significant alteration of the pharyngeal airway space.     

Long-term changes of hyoid bone position and pharyngeal airway size following mandibular setback by sagittal split ramus osteotomy.

INTRODUCTION: The purpose of this study was to determine long-term changes in hyoid bone position and pharyngeal airway size after mandibular setback osteotomies. MATERIAL AND METHODS: Serial cephalograms of 12 patients who underwent mandibular setback surgery were evaluated preoperatively, at 1 week, 6 months, and 14 months postoperatively, and finally after an average of 12 years. RESULTS: A mean setback of 5.6 mm was associated with a posterior and inferior movement of the hyoid bone. At long-term follow-up, the hyoid bone adapted horizontally to a position about 1.6 mm more posterior than its preoperative location. Immediately after surgery, the length of suprahyoid muscles correlated significantly with skeletal movements: suprahyoid muscles shortened by 4 mm but started lengthening after 1 year. Thereafter, it tended to correlate with the change of hyoid bone position rather than with skeletal relapse. Following the initial decrease after surgery, the size of the lower pharyngeal airway remained almost unchanged. The upper and middle pharyngeal airway sizes continued to decrease over the postoperative period of 12 years, and ultimately were smaller than their preoperative sizes by about 1.5 and 3 mm, respectively.     

Three-dimensional computed tomographic evaluation of morphologic airway changes after mandibular setback osteotomy for prognathism

OBJECTIVE: To observe changes in the pharyngeal airway and the hyoid bone position after mandibular setback osteotomy in 30 patients with mandibular prognathism by means of 3-dimensional computed tomography (3DCT). STUDY DESIGN: Preoperative and postoperative computed tomography (CT) examinations were performed on 17 patients treated by sagittal split ramus osteotomy with rigid osteosynthesis and on 13 patients treated by intraoral vertical ramus osteotomy without osteosynthesis. The amount of mandibular setback was measured by the preoperative to postoperative difference of the mandibular position in axial CT images. The sizes of the preoperative and postoperative pharyngeal airway were evaluated from semitransparent and crosscut 3DCT images. Postoperative displacement of the hyoid bone was evaluated by a technique to superimpose a postoperative hard tissue 3DCT image on the preoperative image. The helical scan technique was used in the CT examination. The volume rendering technique was used to create 3DCT images. RESULTS: The mean mandibular setback was 7.8 +/- 2.1 mm with a range of 5 to 11 mm. Three months after surgery, the lateral and frontal widths of the pharyngeal airway had decreased significantly in comparison with the preoperative width. The mean reduction rates of the lateral and frontal width were 23.6% and 11.4%, respectively. The diminished airway did not recover by either 6 months or 1 year after surgery in most cases. Downward and posterior displacement of the hyoid bone was seen postoperatively. There were positive correlations between the amount of mandibular setback and reduction of the lateral width of the pharyngeal airway (r = 0.54) and the amount of hyoid bone displacement (r = 0.42). There were no significant differences between the two surgical techniques. CONCLUSION: Three-dimensional computed tomography was a practical imaging technique to evaluate the morphologic airway changes. The pharyngeal airway may have irreversible narrowing after mandibular setback surgery.     

Changes in tongue and hyoid positions, and posterior airway space following mandibular setback surgery.

INTRODUCTION: The postural response of the tongue after mandibular setback is clinically important for maintaining normal respiration. Although the hyoid bone moves progressively to adapt physiologically to the altered orofacial configuration following such surgery, it is not clear whether repositioning of the hyoid has an effect on the pharyngeal airway. In the present study, postoperative changes in hyoid position and pharyngeal airway space were assessed retrospectively in patients who had undergone mandibular setback surgery. MATERIAL AND METHODS: Digitized lateral cephalograms from 30 mandibular setback surgery cases taken preoperatively, and 1 month and more than 1 year postoperatively, were used to examine pharyngeal airway morphology and the position of hyoid bone. RESULTS: A significant downward movement of the hyoid bone was found 1 month after surgery, while the pharyngeal airway dimensions at the tongue were maintained. More than 1 year after surgery, the hyoid position returned to its original position, resulting in a significant decrease in retrolingual airway dimension. CONCLUSION: The results indicate that mandibular setback causes airway narrowing late after surgery, while the early postoperative airway dimension is maintained. Long-term observations should be performed because of the changes of oropharyngeal configuration following mandibular setback.     

Three-dimensional changes of the hyoid bone and airway volumes related to its relationship with horizontal anatomic planes after bimaxillary surgery in skeletal Class III patients

Objective:To evaluate longitudinal changes of the hyoid bone position and pharyngeal airway space after bimaxillary surgery in mandibular prognathism patients.Materials and Methods:Cone-beam computed tomography scans were taken for 25 mandibular prognathism patients before surgery (T0), 2 months after surgery (T1), and 6 months after surgery (T2). The positional displacement of the hyoid bone was assessed using the coordinates at T0, T1, and T2. Additionally, the volume of each subject''s pharyngeal airway was measured.Results:The mean amount of posterior maxilla impaction was 3.76 ± 1.33 mm as the palatal plane rotated 2.04° ± 2.28° in a clockwise direction as a result of bimaxillary surgery. The hyoid bone moved backward (P < .05, P < .001) and downward (P > .05, P < .05) at 2 months and 6 months after surgery, while the total volume of the pharyngeal airway significantly decreased at the same time points (P < .001, P < .001). There was significant relationship between the changes of the hyoid bone position and airway volume at 2 months after surgery (P < .05). The change of the palatal plane angle was positively correlated to the decrease in the total airway volume (P < .001).Conclusions:The null hypothesis was rejected. The hyoid bone moved inferoposteriorly, and the pharyngeal airway volume decreased for up to 6 months after bimaxillary surgery. The decrease in the pharyngeal airway volume was correlated to the changes in the palatal plane inclination and the positional change of the hyoid bone.     

Three-dimensional alterations in pharyngeal airspace,soft palate,and hyoid bone of class II and class III patients submitted to bimaxillary orthognathic surgery: A retrospective study

IntroductionThe aim of this retrospective study was to evaluate changes in pharyngeal airway space (PAS), soft palate, and hyoid bone position after bimaxillary orthognathic surgery in skeletal Class II and Class III patients.MethodsPatients were divided into Group 1: Class III patients who underwent maxillary osteotomies and mandibular setback surgery (N = 43); and Group 2: Class II patients who underwent maxillomandibular advancement surgery (N = 36). Cone beam computed tomography (CBCT) images were acquired one month before and six to eight months after orthognathic surgery. PAS area, volume and minimum axial area (MAA), soft-palate morphology, and hyoid bone position measurements obtained before and after orthognathic surgery were compared using the Gamma family test (p ≤ 0.10).ResultsIn Class II group the maxillomandibular advancement surgery significantly increased the PAS area, volume, and MAA and significantly affected hyoid bone position and soft-palate morphology. In Class III group, maxillary osteotomies and mandibular setback also showed increase in PAS area, however without statistically significant values for most of the evaluated measurements.ConclusionThe results of the present study indicate that PAS and related structures are expected to be improved in Class II patients submitted to bimaxillary surgery, and they are not negatively affected by bimaxillary surgery in Class III patients.