错患者β角的临床评价

目的推介一种新的准确评价上下颌骨矢状向关系的头影测量方法:β角。方法β角由A点、B点、髁状突中点三个骨性标志点构成,测量值反应上下颌骨在矢状方向的不调;样本选取137名患者,按照3 项标准分三组,分别反应三种错类型,并计算均数和标准差。结果安氏Ⅰ类错β值为36.42°±3.33,安氏Ⅱ类错的β值为26.88°±6.81,安氏Ⅲ类错的β值为45.36°±3.68;各组β值在性别上没有显著性差异。结论β角能反应上下颌骨的矢状关系,β值在33°-39°之间为安氏Ⅰ类错畸形,安氏Ⅱ类错β角较锐,安氏Ⅲ类错患者的β角较钝。     

ANB角与Wits值评价颌骨矢状不调的研究

目的分析X线头影测量参数ANB角与Wits值在评价安氏Ⅱ类错颌骨矢状位置不调中的差异。方法为84例青少年安氏Ⅱ类与40例安氏Ⅰ类错患者正畸治疗前拍摄X线头颅侧位片,选择与ANB角和Wits值相关的十项头影测量项目,将安氏Ⅱ类错患者分为两组后与安氏Ⅰ类错组进行单因素方差分析。结果ANB角与Wits值在评价安氏Ⅱ类错颌骨矢状位置不调时具有显著性差异;差值较大组,平面较陡,矢状不调更显严重。结论患者颌骨矢状不调较严重且平面较陡者,ANB角与Wits值差异较大,ANB角更能反映其真实性。     

错(牙合)患者β角的临床评价

目的推介一种新的准确评价上下颌骨矢状向关系的头影测量方法:β角.方法β角由A点、B点、髁状突中点三个骨性标志点构成,测量值反应上下颌骨在矢状方向的不调;样本选取137名患者,按照3项标准分三组,分别反应三种错(牙合)类型,并计算均数和标准差.结果安氏Ⅰ类错(牙合)β值为36.42°±3.33,安氏Ⅱ类错(牙合)的β值为26.88°±6.81,安氏Ⅲ类错(牙合)的β值为45.36°±3.68;各组β值在性别上没有显著性差异.结论β角能反应上下颌骨的矢状关系,β值在33°-39°之间为安氏Ⅰ类错(牙合)畸形,安氏Ⅱ类错(牙合)β角较锐,安氏ⅢⅡ类错(牙合)患者的β角较钝.     

颌骨前后向不调指数与骨性安氏Ⅲ类骨性错矢状关系的分析

目的:探讨颌骨前后向不调指数(APDI)与上、下颌骨矢状向的位置关系,以利于骨性安氏Ⅲ类错的诊断及治疗。方法:测试对象共100例,其中正常成人组20例,正常青少年组20例,骨性安氏Ⅲ类错成人组28例,早期骨性安氏Ⅲ类错治疗组24例,早期骨性安氏Ⅲ类错治疗失败组8例。头颅侧位定位片测量指标为,腭平面角、面角、AB平面角及APDI值。采用SAS6.12软件包对数据进行t检验。结果:正常人群的APDI均值在85°以下,骨性安氏Ⅲ类错APDI均值在90°以上,青少年的各项测量值相对成人小,需行正颌外科的患者,APDI均值超过100°。APDI值各组间均有显著性差异,P<0.01。结论:APDI均值超出正常标准值越多,上、下颌骨骨性矢状向畸形就越严重。APDI值是评价骨性安氏Ⅲ类上、下颌骨矢状向关系较为有效的指标。     

不同矢状向错颅底形态特征的研究

目的:比较不同矢状向错的颅底形态,探索其规律性。方法:选取均角型错牙合患者56例,年龄10～15岁,包括安氏Ⅰ类组17例;安氏Ⅱ类组20例,安氏Ⅲ类组19例。对三种牙合型进行颅底指标的测量分析,对测量指标进行单因素方差分析和两两比较。结果:从安氏Ⅱ类到安氏Ⅰ类再到安氏Ⅲ类错牙合患者后颅底长度依次缩短并有统计学差异;颅中基底角依次减小并有统计学差异;颅前基底角和后颅底平面角依次增大并有统计学差异。安氏Ⅱ类错的前颅底长度SN减小,安氏Ⅰ类和安氏Ⅲ类的SN长度没有显著的统计学差异。不同矢状向错牙合的颅底角,蝶鞍角,颅基底角,后颅底平面角和SO-Ar距均无统计学差异。结论:矢状向错牙合颅底结构呈现了一定的规律性,说明颅底的生长部分参与了错的形成;后颅底和蝶筛点对矢状向错的形成意义重大。     

错(牙合)畸形患者YEN角的测量研究

用YEN角头影测量方法描述上下颌骨间的矢状向关系。将152例治疗前头颅侧位片分为安氏Ⅰ类(69例)、安氏Ⅱ类(43例)、安氏Ⅲ类(40例)3组,使用3个骨性标志点:S点(蝶鞍中点)、M点(前颌骨的中心点)和G点(下颌骨骨性联合的中心点)。3种安氏错类型患者YEN角值(°)分别为125.37±3.24、120.07±4.78和134.75±5.39,差异有统计学意义(P<0.05);性别间无显著差异。YEN角在122°～129°间为Ⅰ类骨面型。     

广东籍安氏Ⅰ类错[牙合]患者颅颌面三维结构分析

目的探索广东籍安氏Ⅰ类错[牙合]患者颅颌面结构的三维空间特征。方法从门诊随机抽取60例广东籍安氏Ⅰ类错[牙合]畸形患者,拍摄头颅定位正、侧位片,利用三维X线头影测量系统进行测量并与广东籍正常[牙合]人比较,进行统计学分析。结果广东籍安氏Ⅰ类错患者,面宽距、上下颌骨宽距、上下磨牙间宽度均明显减小;眶外缘矢状距、颧牙槽嵴矢状距、上下牙弓长度、上下中切牙覆盖、上中切牙矢状距均明显减小,年轻恒牙组的上下颌骨长度也明显减小;垂直线距除年轻恒牙组男性的左右下颌升支明显增高外,其余均未见明显异常。结论广东籍安氏Ⅰ类错[牙合]患者的横向间距与矢状长度明显减小。     

改良压膜透明保持器在安氏Ⅱ类错中的疗效观察

目的探讨改良透明压膜保持器在下颌后缩为主的安氏Ⅱ类错保持治疗中的临床疗效。方法选择48例年轻恒牙以下颌后缩为主的安氏Ⅱ类错患者,固定矫治结束后,随机分为2组,每组24例,分别采用普通透明保持器和改良式透明保持器。2年后观察矢状向的稳定性。结果改良式透明压膜保持器保持治疗2年后,配戴前、后的头影测量值改变在统计学上无显著性差异(P>0.05),前牙覆覆盖关系保持稳定并有减小趋势。普通透明压膜保持器组配戴前、后的头影测量值改变在统计学上有显著性差异(P<0.05)。结论改良式透明压膜保持器在年轻恒牙以下颌后缩为主的安氏Ⅱ类错患者矫治后保持中具有稳定上下颌关系的确切疗效。     

安氏Ⅱ类1分类错口周肌肌电活动的研究

目的对比研究恒牙列早期安氏Ⅱ类1分类错畸形,矫治前口周肌(上口轮匝肌、下口轮匝肌、颏肌)在不同功能状态下的肌电活动变化。方法选择20例恒牙列早期安氏Ⅱ类1分类错畸形患者,采用表面肌电仪对矫治前口周肌在下颌息止位、唇闭合、咬合、吞咽等不同功能状态下的肌电活动变化进行检测。通过计算机辅助软件与个别正常对照组进行肌电幅值的定量分析比较,并与相关颅面、牙头影测量参数进行多元回归分析。结果下颌息止位与咬合时,安氏Ⅱ类1分类错与个别正常对照组相比,口周肌肌电活动在统计学上均没有显著性差异;唇闭合时,安氏Ⅱ类1分类错组上口轮匝肌和颏肌的肌电活动幅值明显高于个别正常对照组;吞咽时,安氏Ⅱ类1分类错组口周肌肌电活动幅值均高于个别正常对照组,在统计学上具有显著性差异。结论安氏Ⅱ类1分类错上下颌骨矢状关系的不调以及上下切牙的唇向倾斜和前突,与功能活动中口周肌肌电活动的异常增高密切相关,是影响唇功能异常的重要因素。     

西安地区恒牙早期Ⅲ类错颅面类型构成分析

目的：分析西安地区恒牙早期Ⅲ类错颅面类型的构成。方法：以本院正畸科2003～2008年恒牙早期Ⅲ类错患者为研究对象,采用计算机辅助X线头影测量技术,分析恒牙早期Ⅲ类患者在矢状向与垂直向的构成。结果：恒牙早期Ⅲ类错矢状向主要表现形式为双颌发育基本正常或上颌正常,下颌发育过度。垂直向主要表现为均角型。低角型、高角型差异不显著。交叉分析显示：上下颌均发育正常的均角型患者和上颌正常,下颌发育过度的均角型患者最多见;其次是上颌发育不足,下颌正常的均角型患者。结论：恒牙早期Ⅲ类错在矢状向与垂直向均表现出一定的趋势,分析与研究这类错的构成加深了对西安地区Ⅲ类错患者颅面类型的认识,并对临床上合理矫治提供一定的参考。     

Effects on the maxilla and cranial base caused by cervical headgear. A longitudinal study

Objectives: The aim of this study is to test the possible orthopedic effects of cervical headgear on the cranial base and maxilla. Study design: a sample consisting of 79 subjects with skeletal class II malocclusion was divided into two groups. The experimental group was made up of 41 patients all treated with cervical headgear. The control group included a total of 38 non-treated patients. Each one of these groups was then subdivided according to age into one of three groups: prepubescent, pubescent or post-pubescent. Cephalometric parameters were compared in both groups in order to measure the cranial base angle and the vertical and sagittal position of the maxilla. Additionally, cephalometric superimpositions taken at the beginning and end of the study were compared. Results: results revealed significant differences in the cranial base angle and in the SNA angle (p<0.05). However, no differences were observed in the variables that measure the maxillomandibular relationship. While no changes were noted in the palatal plane slope, a flattening of the cranial base was found caused by the cervical headgear, in addition to a retrusion of point A that does not mean there was a reduction in the maxillomandibular relationship. Conclusions: cervical headgear treatment induces cephalometric flattening of the cranial base and a decrease of the SNA angle.     

Effects on the maxilla and cranial base caused by cervical headgear: A longitudinal study

Objectives: The aim of this study is to test the possible orthopedic effects of cervical headgear on the cranial base and maxilla. Study design: a sample consisting of 79 subjects with skeletal class II malocclusion was divided into two groups. The experimental group was made up of 41 patients all treated with cervical headgear. The control group included a total of 38 non-treated patients. Each one of these groups was then subdivided according to age into one of three groups: prepubescent, pubescent or post-pubescent. Cephalometric parameters were compared in both groups in order to measure the cranial base angle and the vertical and sagittal position of the maxilla. Additionally, cephalometric superimpositions taken at the beginning and end of the study were compared. Results: results revealed significant differences in the cranial base angle and in the SNA angle (p<0.05). However, no differences were observed in the variables that measure the maxillomandibular relationship. While no changes were noted in the palatal plane slope, a flattening of the cranial base was found caused by the cervical headgear, in addition to a retrusion of point A that does not mean there was a reduction in the maxillomandibular relationship. Conclusions: cervical headgear treatment induces cephalometric flattening of the cranial base and a decrease of the SNA angle. Key words:Orthodontics, cervical headgear, class II treatment, cephalometry, superimposition.     

替牙期不同垂直骨面型儿童上气道形态和舌骨位置差异的研究

目的:比较替牙期不同垂直骨面型儿童上气道形态和舌骨位置的差异,为临床诊疗和颅面部生长发育的研究提供一定的参考依据。方法:采用计算机辅助X线头影测量技术,对120名替牙期不同垂直骨面型儿童的X线头颅定位侧位片进行测量研究,比较不同性别,不同垂直骨面型组间上气道矢状径和舌骨位置的差异。结果:上气道矢状径:女性大于男性,但除低角组PNS-Ad2、PNS-UPW、SPP-SPPW、U-MPW外无统计学差异;不同垂直骨面型组间存在统计学差异,高角组<均角组<低角组。舌骨位置:男性比女性偏前下;高、均、低角组间舌骨垂直向位置无显著差异,水平方向上高角、均角、低角组舌骨位置逐渐前移。结论:替牙期不同垂直骨面型儿童上气道形态,舌骨位置存在差异。     

Beta角评价前牙反患者颌骨矢状关系的准确性分析

目的探讨Beta角判断替牙期与恒牙期前牙反[牙合]患者颅面矢状关系的可靠程度。方法应用X线头颅定位侧位片,比较替牙期与恒牙期前牙反[牙合]患者的Beta角、ANB角、Wits值和APDI指数的差异,并进行相关性和变异程度分析。结果替牙期与恒牙期前牙反[牙合]患者Beta角间差异有统计学意义（P〈0．05）;Beta角与ANB角、Wits值和APDI指数显著相关（P〈0．05）,但变异较ANB角和Wits值小,与APDI指数接近。结论Beta角可准确评价前牙反[牙合]患者的颌骨矢状关系。     

Cephalometric soft tissue profile analysis between two different ethnic groups: a comparative study

The aim of this investigation was to study and compare the cephalometric soft tissue profile analysis between Saudis and Caucasian Americans. The study was carried out using standardized cephalometric radiographs of 56 Saudi subjects (30 males and 26 females) with pleasant and balanced facial profiles, competent lips, normal overjet and overbite, and showing no craniofacial deformities. Subject ages ranged from 22 to 23 years. One skeletal and thirteen soft tissue variables were investigated. F-test, two samples t-test, Mann-Whitney, and Wilcoxon tests were used for data analysis. The results showed no statistical significant differences between the Saudi males and females except for the angle of total facial convexity, soft tissue facial plane angle, lower lip length, sagittal nasal tip to the most protrusive lip distance, and also sagittal chin to the most protrusive lip distance. The Saudi females had a greater angle of total facial convexity and soft tissue facial plane angle than the males. In addition, the females had a shorter lower lip. They also had a short distance between the nasal tip and chin to the most protrusive lip. These results reveal significant differences in most of the soft tissue variables when comparing Saudis with Caucasian Americans as well as in other ethnic groups. Most of these variables are essential for the diagnosis and treatment planning of cases requiring orthodontics and orthognathic surgery.     

A new approach of assessing sagittal discrepancies: the Beta angle.

An accurate anteroposterior measurement of jaw relationships is critically important in orthodontic diagnosis and treatment planning. The angular and linear measurements that have been proposed can be inaccurate because they depend on various factors. The purpose of this study was to establish a new cephalometric measurement, named the Beta angle, to assess the sagittal jaw relationship with accuracy and reproducibility. This angle uses 3 skeletal landmarks-point A, point B, and the apparent axis of the condyle-to measure an angle that indicates the severity and the type of skeletal dysplasia in the sagittal dimension. Seventy-six pretreatment cephalometric radiographs of white patients were selected on the basis of 4 criteria that indicate a normal Class I skeletal pattern; the mean and the SD for the Beta angle were calculated. This group was compared with Class II and Class III skeletal pattern groups. After using the 1-way analysis of variance and the Newman-Keuls test and running receiver-operating-characteristics curves, we obtained results that showed that a patient with a Beta angle between 27 degrees and 35 degrees can be considered to have a Class I skeletal pattern. A more acute Beta angle indicates a Class II skeletal pattern, and a more obtuse Beta angle indicates a Class III skeletal pattern.     

不同垂直骨面型成年患者上气道形态和舌骨位置差异的研究

目的:比较不同垂直骨面型成年患者上气道形态和舌骨位置的差异,为临床诊疗和颅面部生长发育的研究提供一定参考依据。方法:采用计算机辅助X线头影测量技术,对120名不同垂直骨面型成年患者的X线头颅定位侧位片进行测量,比较不同性别、不同垂直骨面型组间上气道矢状径和舌骨位置的差异。结果:上气道各段矢状径男性大于女性,但除V-LPW外无统计学差异;不同垂直骨面型组间存在显著差异,高角组<均角组<低角组。舌骨位置存在性别差异,AH-SN,AH-FH男性大于女性(P<0.01),AH-C3男性大于女性(P<0.001),舌骨位置男性比女性偏前下。不同垂直骨面型组间舌骨垂直向位置无显著差异(P>0.05),水平向从高角、均角到低角组AH-O逐渐减小,AH-C3逐渐增大,舌骨位置在水平向逐渐前移。结论:不同垂直骨面型成年患者上气道形态、舌骨位置存在差异,这可能与不同垂直骨面型下颌骨的旋转方式有关。     

The effect of zigzag elastics in the treatment of Class II division 1 malocclusion subjects with hypo- and hyperdivergent growth patterns. A pilot study.

The aim of this study was to investigate the effect of zigzag elastics in the treatment of Class II division 1 malocclusion subjects with hypo- or hyperdivergent growth patterns. Two groups were established, each consisting of 10 subjects classified as hypo- or hyperdivergent according to their pre-treatment SN-GoGn angle. The cephalometric radiographs taken before and after an elastic application period of approximately 4 months were used to generate 22 variables. In both groups, there were no statistically significant differences in the vertical position of the lower molars, the SN-GoGn angle or the inclination of the lower incisors, whereas the sagittal skeletal relationship was improved as a result of an increase in the SNB angle and the mandibular length (P < 0.01). Upper incisor extrusion was statistically significant in both groups (P < 0.05). The downward rotation of the occlusal plane and the increase in overbite were found to be significant in the hypodivergent group (P < 0.05). Significant differences were observed between the groups in the extrusion of the upper incisor, the inclination of the occlusal plane, and the amount of overbite (P < 0.05). The results show that the zigzag elastic system is preferable, especially in hyperdivergent Class II division 1 subjects, as the use of such elastics does not cause an unfavourable effect on vertical jaw base relationship.     

Overbite depth and anteroposterior dysplasia indicators: the relationship between occlusal and skeletal patterns using the receiver operating characteristic (ROC) analysis

This study was carried out to investigate the validity of the overbite depth indicator (ODI) and the anteroposterior dysplasia indicator (APDI), based on the cephalometric analysis of 122 Caucasians selected at random for assessment of vertical and sagittal relationships. Considering the occlusion, the sample was divided into three classifications in the sagittal component: 36 cases of neutrocclusion, 54 cases of distocclusion, and 34 cases of mesiocclusion. The sample was also categorized according to the overbite relationship: 54 cases of normal overbite, 34 cases of open bite, and 34 cases of deep overbite. In the sagittal component analysis, the APDI measurement resulted in significant differences between the neutrocclusion, distocclusion, and mesiocclusion groups. In the vertical component analysis, the ODI significantly distinguished between the normal and deep overbite groups, and the open bite and deep overbite groups, but not between the normal overbite and the open bite groups. A receiver operating characteristic (ROC) analysis showed that the APDI matched the anteroposterior molar relationship in 88 per cent, and the ODI matched the amount of incisor overbite in 81 per cent.     

Evaluation of cervical posture of children in skeletal class I, II, and III

Previous studies on the relationship between morphological structure of the face and cervical posture have predominantly focused on vertical dimensions of the face. The aim of this study was to investigate whether there are significant differences in cervical posture in subjects with a different sagittal morphology of the face, i.e., a different skeletal class. One hundred twenty (120) children (60 males and 60 females, average age 9.5 yrs., SD+/-0.5) were admitted for orthodontic treatment. Selection criteria was: European ethnic origin, date of birth, considerable skeletal growth potential remaining and an absence of temporomandibular joint dysfunction (TMD). Lateral skull radiographs were taken in mirror position. Subjects were divided into three groups based on their skeletal class. The cephalometric tracings included postural variables. The most interesting findings were: 1. children in skeletal class III showed a significantly lower cervical lordosis angle (p<0.001) than the children in skeletal class I and skeletal class II; 2. children in skeletal class II showed a significantly higher extension of the head upon the spinal column compared to children in skeletal class I and skeletal class III (p<0.001 and p<0.01, respectively). This is probably because the lower part of their spinal column was straighter than those of subjects in skeletal class I and II (p<0.01 and p<0.001, respectively). Significant differences among the three groups were also observed in the inclination of maxillary and mandibular bases to the spinal column. The posture of the neck seems to be strongly associated with the sagittal as well as the vertical structure of the face.