【作者】 杨茜；

【导师】 王春玲；

【作者基本信息】 山东大学 ， 口腔临床医学， 2013， 博士

【摘要】 [目的]偏颌患者多伴有特征性的髁突形态变化和下颌功能运动异常,本研究采用三维螺旋CT和八导联肌电图仪对替牙期和恒牙列期偏颌患者正畸治疗前后颞下颌关节和头颈部肌肉肌电有关数据进行定量研究,分析偏颌患者的颞下颌关节形态和功能特征及其矫治前后的变化情况,为偏颌患者的正畸治疗提供有价值的临床参考。[材料与方法]按照标准选择来山东大学口腔医院正畸科就诊的20例安氏Ⅲ类偏颌患者(替牙期10例,恒牙列期10例)年龄平均11.7岁,其中男8例,女12例,平均11.7岁。对生长发育期上颌牙弓狭窄的偏颌患者,采用上颌(?)垫式螺旋扩弓矫治器进行上颌扩弓,对恒牙列期偏颌患者,采用标准方丝弓技术或直丝弓技术进行固定矫治,排齐整平上下牙列,再进行精细调整。整个治疗过程平均18个月,矫治前后拍摄头颅侧位片,螺旋CT扫描及三维重建,运用Dentascan软件进行定量测量分析,测量数据12项,研究矫治前后颞下颌关节结构的改变。同时测试下颌姿势位、牙尖交错位、大张口时、左侧和右侧咀嚼等功能活动情况下,颞肌前束(TA)、咬肌(MM)、二腹肌前腹(DA)及胸锁乳突肌(SCM)的肌电活动,分别比较两组受试者4对肌肉正畸治疗前后的肌电幅值、肌活动不对称指数(包括同名肌肉和同侧肌肉)以及对偏颌的严重程度与治疗前肌肉不对称指数结果进行相关分析。所有测量结果使用SPSS统计学软件进行分析。[结果]①替牙期组(8-11岁)偏颌患者的髁突形态和关节结构：正畸治疗前两侧髁突形态,大小基本对称,偏斜侧的前斜面长度比对侧小,前倾角更小(P<0.05),说明在替牙期偏颌患者中,非偏斜侧关节前间隙减小,关节上间隙及后间隙明显增大,髁突位置相对靠前。在正畸治疗后,偏斜侧和对侧的差异无统计学意义,而对侧相关测量结果的变化有统计学意义,说明正畸治疗使对侧髁突由前、下位向后上方移至关节窝中位,偏斜侧位置基本不变,两侧髁突位置趋于对称。②恒牙列组(11-16岁)偏颌患者的髁突形态和关节结构：正畸治疗前两侧髁突形态,大小明显不对称,偏斜侧的髁突高度、髁突内外径比对侧小,下颌支高度比对侧小,后斜面长度和后倾角比对侧更大(P<0.05),这说明在下颌偏斜的恒牙列期患者中,下颌偏斜患者偏斜侧髁突高度降低,髁突在关节窝中的位置后移；对侧髁突高度增加,髁突在关节窝中的位置向前、下方移位。在正畸治疗后,偏斜侧和对侧的差异无统计学意义,说明正畸治疗使对侧髁突向后、上、外侧移至关节窝中位,使关节前后间隙趋于相等；而偏斜侧髁突位置没有明显的变化,这可能是因为在下颌偏斜的治疗中,下颌骨由偏斜侧向对侧移位的旋转中心更加接近偏斜侧髁突和下颌升支。③正畸治疗后肌电幅值：替牙期4对肌肉的肌电幅值均有提高,其中除下颌姿势位时健侧的MM,患侧DA,以及TA和SCM电幅值提高无统计学意义外,在其他功能位置治疗后各个肌肉的肌电幅值提高均有统计学意义。(P<0.05)恒牙期4对肌肉在正畸治疗后各项指标均有所提高,尤其MM和TA的肌电幅值在治疗后的变化有显著的统计学意义。(P<0.05)④治疗后肌不对称指数：替牙组均有所降低,在下颌姿势位时MM、DA肌不对称指数的降低有统计意义,其他4个功能位置4对肌肉不对称指数的降低均有统计学意义,左右侧咀嚼时治疗后的不对称指数的降低有显著的统计意义。(P<0.05)恒牙(?)4组肌肉中的肌不对称指数相对替牙组高,治疗后4对肌肉在各功能位肌不对称指数有不同程度降低且均有统计学意义。(P<0.05)⑤左右侧肌肉治疗后的不对称指数：替牙期组均降低且有统计学意义,尤其在牙尖交错位时,以及咀嚼运动时不对称指数的降低有显著的统计学意义。(P<0.05)恒牙期组左右侧肌肉治疗后的不对称指数均降低有统计学意义,其中右侧(患侧)肌肉不对称指数在大张口和咀嚼时降低有显著统计学意义。(P<0.05)⑥在牙间交错位时颏部偏离面部中线3-6mm范围内,偏颌的严重程度与治疗前肌不对称指数明显相关。[结论]①偏颌患者的颞下颌关节结构存在一定程度的不对称。②正畸治疗可以使替牙期偏颌患者两侧髁突位置趋于对称,使恒牙期患者关节结构趋于协调和稳定。③正畸治疗后良好的咬合关系能够改善偏颌患者头颈部肌肉功能运动的不对称性。④偏颌患者早期进行正畸治疗后,有利于改善面部对称性,同时也有利于颞下颌关节紊乱病症状的缓解。更多还原

【Abstract】 [Objective]Patients with facial asymmetry often have distinctive changes in condylar morphology and abnormal movements in mandibular function. This study employs three-dimensional spiral CT and eight guide contact electricity meter to record related quantitative data of temporomandibular joint (TMJ) and head and neck muscle electromyography before and after orthodontic treatments on patients with facial asymmetry in mixed dentition and permanent dentition stages, which analyse the morphology and functional characteristics on temporomandibular joint of patients with facial asymmetry and changes before and after orthodontic treatments. That will offer valuable clinical suggestions to orthodontic treatments on patients with facial asymmetry.[Methods]20children with Class III malocclusion and facial asymmetry were selected aged from8to16years, who all first visited in stomatological hospital of Shandong University.(10children are in mixed dentition stage and10children are in permanent dentition stage) The average age is11.7years old.To patients with facial asymmetry in growth and development period, if they have constricted maxillary arch, we carried on maxillary expansion for them using maxillary screw expansion appliance with maxillary occlusal pad. To patients with facial asymmetry in permanent dentition stage, all patients were treated with edgewise or straight wire technique to align and level the dentition. Finally the occlusion was adjusted in detail with fixed appliance. All process took18months. The lateral cephalograms, three-dimensional spiral CT and three-dimensional reconstruction, then Dentascan software was used to quantitative measurement analysis. There are12measurement items, which will study changes of temporomandibular joint pre-and post-treatment. At the same time, when the mandible is in the condition of postural jaw position (PP), intercuspal position (ICP), open the mouth maximumly, chewing in left and right ride, myoelectric activities of anterior Temporalis (TA), masseter muscle (MM), anterior digastrics (DA) and sternoclleidomastoid muscle (SCM) are recorded. Then we compared four pairs of muscles from two groups of subjects with EMG amplitude, the asymmetry of muscle activity index (including same muscles and ipsilateral muscles) pre-and post-treatment and carried on correlation analysis between the severity of facial asymmetry and the asymmetry of muscle index pre-treatment. All the results were analyzed with SPSS software.[Results]①Before the orthodontic treatment, both sides of the condylar shape, size are basically symmetrical in patients with facial asymmetry in mixed dentition stage (8-11years old). The difference is that the length of anterior inclined plane and the front inclination angle in deviated side are smaller than the non-deviated side (P<0.05), which shows anterior joint space reduces while upper joint space and posterior joint space significantly increases in non-deviated side, the condylar position is relatively anterior. After the orthodontic treatment, there are no statistical differences in both sides, but there are changes in the non-deviated side, which reveals that orthodontic treatment drives the condyle in non-deviated side from anterior and inferior position to posterior and upper position until the center of articular pan. Meanwhile, the position of deviated side is essentially unchanged, both sides are tend to be symmetrical.②Before the orthodontic treatment, both sides of the condylar shape, size are significantly unsymmetric in patients with facial asymmetry in permanent dentition stage (11-16years old). The height of condyle, medial-lateral diameter of condyle and the height of mandibular ramus in deviated side are smaller than the non-deviated side, but the length of posterior inclined plane and the posterior inclination angle in deviated side are larger than the non-deviated side (P<0.05), which shows height of condyle reduces while the position of condyle in articular pan retroposed; the height of condyle increases and the position of condyle in articular pan shift to anterior and inferior in non-deviated side. After the orthodontic treatment, there are no statistical differences in both sides, which reveals that orthodontic treatment drives the condyle in non-deviated side to posterior, upper and outside position until the center of articular pan. That lets anterior joint space and posterior joint space tend to be equal; but there are changes in the non-deviated side, which was maybe caused by the center of rotation of mandible from deviated side to non-deviated side closes to deviated side of condyle and mandibular rami in the treatment of facial asymmetry.③After the orthodontic treatment, in mixed dentition stage, EMG amplitude in four pairs of muscles all increased. In the condition of postural jaw position (PP), EMG amplitude in MM of deviated side, DA of non-deviated side, TA and SCM had no statistical significance, EMG amplitude in every muscle in other functional sites had statistical significance.(P<0.05)After the orthodontic treatment, in permanent dentition stage, EMG amplitude in four pairs of muscles all increased, especially that in TA and MM had significant statistical significance.(P<0.05)④After the orthodontic treatment, in mixed dentition stage, the asymmetry of muscle indexes all decreased. In the condition of postural jaw position (PP), MM/DA asymmetry of muscle indexes had statistical significance. the asymmetry of muscle indexes in four pairs of muscles all decreased in other four functional sites and had statistical significance. When chew in left and right sides, the asymmetry of muscle indexes had significant statistical significance.(P<0.05)After the orthodontic treatment, in permanent dentition stage, the asymmetry of muscle indexes are higher than those in mixed dentition stage. The asymmetry of muscle indexes in four pairs of muscles all decreased in varying degrees in every functional site and had statistical significance.(P<0.05)⑤After the orthodontic treatment, in mixed dentition stage, the asymmetry of muscle indexes in left and right sides all decreased and had statistical significance, especially in the condition of ICP. The asymmetry of muscle indexes had significant statistical significance in chewing activity.(P<0.05)After the orthodontic treatment, in permanent dentition stage, the asymmetry of muscle indexes in left and right sides all decreased and had statistical significance. The asymmetry of muscle indexes in right side (affected side, non-deviated side) decreased and had significant statistical significance when the mandible is in the condition of opening the mouth maximumly and chewing activity.(P<0.05)⑥In the condition of ICP, chin deviates facial midline in3-6mm, the severity of facial asymmetry significantly related to the asymmetry of muscle index pre-treatment.[Conclusion]①There are osseous asymmetric in patients with facial asymmetry to some extent.②In patients with facial asymmetry in mixed dentition stage, orthodontic treatment drives e both sides of the condyl to be symmetrical.③After orthodontic treatment, in patients with facial asymmetry in mixed and permanent dentition stages, EMG amplitude in four pairs of muscles from two groups of subjects increased, the asymmetry of muscle activity index (including same muscles and ipsilateral muscles) decreased. After orthodontic treatment, better occluding relation could improve the asymmetry of muscle functional activity in head and neck areas.④Early orthodontic treatment, to patients with facial asymmetry, improves facial symmetry and aesthetics and is beneficial to relief of temporomandibular disorders.更多还原