前牙开He畸形颅面形态的分类研究

目的 对前牙开Ｈｅ畸形进行分类研究，为临床诊断和治疗提供参考。方法 随机选取１１６例恒牙期前牙开Ｈｅ患者，借助计算机Ｘ线头影测量技术对其颅面软硬组织及气道结构进行测量，综合运用多种现代多元统计方法，对开Ｈｅ畸形的颅面形态进行分类。结果 对年龄、性别、颅面特征等１５６项指标经聚类和主成分分析精简为３０个变量，再通过因子分析提取出４个因大（下颌旋转因子、面高因子、牙骨矢状因子和上颌旋转因子）。采用农步聚类法对１１６例患者的４个因子得分进行聚类分析，将前牙开Ｈｅ畸形这一群体分为牙齿槽型开Ｈｅ、下颌顺时针旋转开Ｈｅ、长面型开Ｈｅ、上颌逆时针旋转型开Ｈｅ和骨性Ⅲ类开Ｈｅ５类并归纳出可供临床使用的简单分类方法。结论 对前牙开Ｈｅ畸形进行分类在诊断和矫治设计中起着重要作用。     

错(牙合)畸形的下颌功能运动轨迹及其分类

目的对错畸形者的下颌运动轨迹进行分类。方法对错畸形患者的口颌功能进行临床检查并以下颌运动轨迹描记仪进行轨迹分析。结果对２２３例错（男１０６名，女１１７名，平均年龄１４６岁）的观察表明，将近４０％的患者存在功能性错，特定的错类型常呈现出特征性的下颌运动轨迹。同时发现，下颌运动轨迹受上下颌骨、肌肉、关节及牙齿等综合因素的影响。结论本项研究总结归纳出功能性错的分类方法（包括功能性１、２、３、４类错）。     

前方牵引器治疗骨性前牙反(牙合)的研究

目的　评价早期前方牵引矫治骨性前牙反引起的牙颌面形态学变化及其对前牙反儿童牙颌面生长发育的影响。方法　挑选 40名年龄 8～ 11岁的骨性前牙反儿童 ,随机分为 2组 ,一组进行前方牵引矫治器治疗 ,另一组作对照观察。 2组儿童在治疗或观察期前后分别拍摄头颅侧位定位X线片 ,行X线片头影测量 ,以计算机进行统计分析。结果　治疗组儿童的A点平均前移 3 5mm(对照组为 - 1 75mm) ,代表下颌突度的SNB、SNPg角明显减小 ,代表上下颌间关系的测量项目ANB角、NA PA角明显增大。结论　在替牙中晚期应用前方牵引矫治器治疗 ,可刺激上颌骨前移、控制下颌骨的旋转及生长速度 ,使反患者的Ⅲ类面型得到明显改善     

前牙开正畸治疗和外科治疗的限度

目的　探讨前牙开畸形正畸治疗与外科治疗的界限。方法　选择正畸治疗开患者70人 ,平均年龄 18 0岁 ;外科治疗开患者 14人 ,平均年龄 2 5 1岁。对经计算机头影测量得出的15 4项颅面软硬组织测量项目值进行单因素和多因素判别分析。结果　下切牙下颌平面角 (L1MP)可作为单因素判别指标 ,当其值≤ 89 5°时 ,可判断为外科治疗的适应证 ,>89 5°时则判断为正畸治疗。根据多因素逐步判别分析建立的判别函数 :Z =- 0 80 188L1MP +0 9140 1Age +0 6 71111Antigonialnotch MP +0 5 99992SNPg ,当Z≥ 0时 ,判定为外科治疗组 ,Z <0时判为正畸治疗组。结论单因素判别指标和多因素判别函数均可用于确定正畸治疗与外科治疗的界限 ,判别函数优于单因素判别指标。     

安氏Ⅱ类1分类错患者亲子间相似性的个体研究

目的　研究安氏Ⅱ类 1分类错患者亲子间的相似性。方法　以家庭为单位 ,比较 5 8个家庭 172人的面部结构曲线多角型图及亲子间的重叠图。结果　①安氏Ⅱ类 1分类错患者亲代的颅面结构有明显的安氏Ⅱ类凸面型倾向 ;② 84%的家庭中子代与亲代一方或双方均值曲线相似 ,骨骼部相似的家庭较牙部相似者多。结论　①安氏Ⅱ类 1分类错有家庭聚集性 ;②安氏Ⅱ类 1分类错患者亲子间的相似有遗传作用的可能且骨骼部受遗传作用更强 ,环境对牙部的作用更大     

恒牙期前牙开正畸治疗时机和疗效的研究

目的　通过对恒牙初期和恒牙晚期正畸治疗成功的病例进行分析 ,探讨恒牙期前牙开患者正畸治疗的时机及引起颅面形态的变化。方法　选择 13名恒牙初期和 12名恒牙期前牙开患者 ,利用计算机X线头影测量分析治疗前后的软硬组织变化 ,并进行统计学处理。结果　正畸的治疗变化以牙齿倾斜度的变化为主 ,前牙有一定的伸长 ,垂直高度有所增加 ,软组织面型有一定程度的改善。恒牙初期与恒牙期正畸治疗相比 ,除了上下前牙倾斜度的变化以外 ,还存在一定的下颌逆时针旋转趋势 ,而恒牙期者下颌平面角有顺时针旋转倾向。结论　提倡在恒牙初期即开始正畸治疗。     

广东籍患者安氏Ⅱ1类与Ⅰ类错畸形的三维立体结构分析

目的分析广东籍患者安氏Ⅱ1类错与安氏Ⅰ类错畸形三维立体空间的颅颌面结构特点。方法从门诊随机抽出广东籍安氏Ⅰ类错、安氏Ⅱ1类错畸形患者各60例,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,并将两组患者进行比较,进行统计学分析。结果广东籍患者安氏Ⅱ1类错与安氏Ⅰ类错畸形相比较,上颌长度明显增加,上颌较前突,覆盖增大;下颌在长、宽、高三方面均明显减小;覆加深。结论与广东籍安氏Ⅰ类错畸形患者相比,安氏Ⅱ1类错畸形患者上颌长度增加,下颌的长、宽、高均明显减小,上下颌明显不协调。     

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。     

骨性Ⅱ类高角型开拔除上颌第一前磨牙及下颌第二磨牙矫治的临床研究

目的用回顾分析方法,评价拔除上颌第一前磨牙及下颌第二磨牙矫治骨性Ⅱ类高角型开的临床疗效。方法选取12例骨性Ⅱ类开病例,男4例,女8例,平均年龄15.6岁,拔除上颌第一前磨牙及下颌第二磨牙后,使用直丝弓矫治技术对其进行矫正治疗。治疗前后拍摄X线头颅侧位片,并对其进行头影测量分析。结果矫正治疗结束后,12例患者均取得了满意的治疗效果,侧貌明显改善,覆覆盖正常,平面发生逆时针旋转,下颌平面角变小。结论拔除上颌第一前磨牙及下颌第二磨牙矫治骨性Ⅱ类开临床疗效可靠,效果较稳定。     

前牵引矫治乳牙期严重骨性Ⅲ类错畸形的侧貌变化

目的探讨上腭快速扩大联合前牵引矫治乳牙期严重骨性Ⅲ类错畸形和矫治前后颌骨软组织侧貌头影测量值的变化。方法选择乳牙期严重骨性Ⅲ类错畸形患儿8名,患儿呈凹面型,前牙或合并后牙反,上颌相对下颌后缩,乳磨牙末端呈近中阶梯,不存在功能性下颌移位。上下牙列无牙周疾病,牙体疾病须治疗,之前未做过正畸治疗。应用上腭快速扩大联合前牵引矫治,正畸前后头影测量,采用配对t检验,统计学分析结果。结果乳牙期严重骨性Ⅲ类错畸形患儿经上腭快速扩大联合前牵引矫治6个月左右,患儿的上颌N-A增长,上颌前移,N-B缩短,下颌后旋,颌骨面角减小、软组织面角相应减小;骨组织和软组织前下面高增加,乳上切牙唇倾,乳下切牙舌倾;上唇突度增大、倾斜度减小,下唇突度减小、倾斜度减小。结论上腭快速扩大联合前牵引矫治乳牙期严重骨性Ⅲ类错畸形,凹面型显著改善且呈直面型。颌骨和软组织侧貌发生相应的改变。     

Classification of Anterior Open Bite Using Individualized Cephalometry

OBJECTIVE: The objective of this study was to describe the cephalometric characteristics of the open bite, and to classify the open bite according to individualized norms. MATERIAL AND METHOD: The lateral cephalograms of 134 patients with an anterior open bite (min -0.5 mm) were analyzed. Patients were classified according to the inclination of the jaws, applying the principles of individualized cephalometry. The harmony box described by Hasund was used to define individualized norms for the inclination of the upper and lower jaws in each patient. The open bite was classified into four sub-types: (1) dental, (2) skeletal with enlarged ML-NSL angle, (3) skeletal with reduced ML-NSL angle, and (4) skeletal with deviations in upper and lower jaws. A skeletal open bite was found in 89 patients (66.4%). A dental open bite was found in 45 patients (33.6%). RESULTS: A number of significant differences were found between these four groups using single-factor variance analysis and the Bonferroni a posteriori test, (p < or = 0.05, p < or = 0.01, p < or = 0.001). The most prominent variables were index value of anterior facial hight, total facial height ratio, gonial angle, and Y-axis. No significant differences were found for overbite, however. CONCLUSION: It was possible to use individualized norms to classify the open bite into four sub-types. The demarcation between the four groups was supported statistically. The extent of the anterior open bite does not allow any conclusions as to the craniofacial pattern.     

Anterior open bite in the deciduous dentition: longitudinal follow-up and craniofacial growth considerations.

The aim of this longitudinal cephalometric study was to evaluate craniofacial growth changes in subjects with an anterior open bite in the deciduous dentition. From longitudinal records of untreated subjects, an open bite group (n = 14) was selected at the age of 5 years based on the presence of a negative overbite and compared with a control group (n = 14) with a regular overbite at this age. Cephalometric measurements were analyzed at ages 5, 9, and 12 years. Although only 1 subject in the deciduous dentition open bite group had an open bite at 12 years of age, the overbite remained lower during the longitudinal follow-up. Early cephalometric characteristics of the open bite group included a reduced overbite depth indicator and a lower ANB angle. At ages 9 and 12 years, the open bite sample was also characterized by shorter ramus height. An underlying skeletal pattern seems to be present in the deciduous dentition open bite sample that persists during the longitudinal follow-up. The overbite depth indicator might help to identify patients with anterior open bite tendencies.     

恒牙期前牙开(牙合)正畸和外科治疗颅面形态变化的比较研究

通过对正畸治疗和外科治疗成功的病例进行比较分析 ,探讨恒牙期前牙开牙合者正畸治疗和外科治疗引起的颅面形态的变化所在。方法　选择正畸治疗和外科治疗患者各 12人 ,外科治疗组中 5人为外科正畸联合治疗 ,7人为单纯外科治疗。应用计算机X线头影测量对治疗前后颅面软硬组织的形态变化进行比较和统计学分析。结果　正畸治疗的主要作用部位是牙齿和齿槽骨 ,牙齿关系的变化有显著的统计学意义 ;外科治疗组除牙齿关系 (覆牙合、覆盖、下切牙伸长度、上切牙倾斜度 )发生显著变化外 ,骨骼的变化也比较显著 ;正畸治疗组和外科治疗组相比 ,前者牙牙合关系的改善更明显 ,而后者主要以上下颌骨的矢状不调改善为主。正畸外科联合治疗比单纯外科治疗者矢状方向的改变明显且牙齿倾斜度改善。结论　正畸治疗可通过拔牙矫治调整前后牙齿移动的比例 ,达到纠正开牙合 ,改善软组织侧貌的目的 ;正畸治疗以牙齿倾斜度的变化为主 ,而外科治疗还可产生骨骼的变化 ,面型更趋和谐 ;术前术后正畸治疗应列为外科治疗的常规。     

Moulding of the generate to control open bite during mandibular distraction osteogenesis

Distraction osteogenesis of the craniofacial skeleton has become a widely accepted, safe, and effective means of craniofacial reconstructive surgery. Despite excellent results in general, there are still some uncertainties related to the procedure, such as development of an anterior open bite (AOB) during mandibular distraction. The aim of this study was to examine whether 'moulding of the generate', i.e. use of intermaxillary elastics during the active distraction phase is possible to close the mandibular plane angle and open bite. Three subjects, 13- and 15-year-old males and a 7-year-old female, underwent mandibular linear and angular bilateral distraction osteogenesis with moulding of the generate. Lateral cephalograms were obtained before the introduction of elastics and following distraction, once the activation was stopped and the patients were ready for the consolidation phase. Conventional cephalometric measurements were used to assess possible changes in the mandibular plane angle and incisor position. Three different anchorage systems (dental, orthopaedic, and skeletal) were used for placement of the intermaxillary elastics. Cephalometric examination showed that the mandibular plane angle was decreased during active distraction osteogenesis with the introduction of elastics and angulation of the distraction device. Depending on the type of elastic anchorage system, smaller or greater amounts of extrusion of the incisors were noted. Moulding of the generate during active distraction can be performed to reduce the mandibular plane angle and open bite. To prevent unwanted dentoalveolar changes from occurring during elastic traction, skeletal rather than dental fixation of the elastics is recommended. Intrusive mechanics may be incorporated into the orthodontic appliances to balance extrusive force by the moulding elastics.     

Long-term dentofacial stability after bimaxillary surgery in skeletal Class III open bite patients

The purpose of this study was to evaluate long-term dentofacial stability after bimaxillary surgery in skeletal Class III open bite patients. Twenty-three Japanese adults (5 males, 18 females) were randomly selected as the experimental group from the files of Tohoku University Dental Hospital according to the following criteria: (1) skeletal Class III malocclusion with anterior open bite, (2) simultaneous Le Fort I and sagittal split ramus osteotomies, and (3) complete set of cephalograms taken at predetermined intervals until 5 years after debonding. Based on the manner of maxillary surgical repositioning, they were divided into the following 2 groups: (1) impaction group of 13 subjects (2 males, 11 females) who had maxillary superior repositioning without rotation of the palatal plane, and (2) rotation group of 10 subjects (3 males, 7 females) who had maxillary repositioning with clockwise rotation of the palatal plane. These patients were compared to a control group of 11 adults (1 male, 10 females) with skeletal Class III malocclusion without open bite who underwent bimaxillary surgery by the same techniques. Our data showed that overbite stability in the rotation group was better than that in the impaction group. This suggests that clockwise rotation of the palatal plane, which moves the anterior maxillary structures down, is an effective way to produce a reasonably stable correction of the anterior open bite. In contrast, superior repositioning of the maxilla that significantly rotates the mandible in the closing direction should be applied with caution.     

Skeletal and dental effects during observation and treatment with a magnetic device

The aim of this study was to evaluate the effects of a magnetic appliance, MAD IV, on the treatment of anterior open bites in growing patients. The study material included the lateral cephalograms and hand-wrist radiographs of 16 patients who had an anterior open bite malocclusion. The radiographs were taken at the beginning (T1) and at the end of observation period (T2) and at the end of MAD IV application (T3). At the beginning of the study, the mean age of the subjects was 11 years two months. To define the direction of facial growth, the patients were first observed for nine months without any orthodontic or orthopedic approach. At the end of the observation period, patients who had shown a vertical growth direction, resulting in an increase in open bite, were given an MAD IV appliance and were instructed to wear the appliance 18 hours a day for 7.5 months. Thirty-two different parameters were evaluated from the lateral cephalograms. Paired t-tests were used for statistical evaluation of differences that occurred during the periods and between the periods. During the observation period, the patients continued their mandibular posterior rotation resulting in an increase in lower facial height (P < .001) and an open bite (P < .01). During the treatment period, the patients showed an anterior mandibular rotation with statistically important decreases in lower facial height and open bite (P < .001). In the treatment of anterior open bite with the MAD IV appliance, skeletal changes played a role along with dental and dentoalveolar effects.     

Muscle function and craniofacial morphology: a clinical study in patients with myotonic dystrophy

The occlusal traits and the craniofacial morphology were studied in patients with an altered muscle function caused by myotonic dystrophy. Twenty-four adult patients were examined and compared with a matched group of healthy individuals. The condition of the masticatory muscles was evaluated by measuring the maximal bite force. The dental arches and the occlusal traits were analysed on dental casts. Lateral cephalograms were taken in the patients with myotonic dystrophy to study the craniofacial morphology. It was found that the patients suffering from myotonic dystrophy had weak masticatory muscles, which might be caused by the disease. A high prevalence of malocclusions (postnormal occlusion, anterior open bite and lateral cross bite) was found among these patients. Their craniofacial morphology showed a vertical aberration, characterized by a large angle between the mandibular and palatal planes and a steep mandible. These findings seem to be most pronounced in patients with an early onset of the disease and support the hypothesis that reduced muscle function may cause changes in the craniofacial morphology.     

微螺钉种植体支抗压低磨牙矫治前牙开（牙合）

近些年来各种骨性支抗系统被开发并应用于临床,来完成牙齿各种类型的运动.微型种植体用于垂直支抗控制方面比传统方法有着更多的优势.本文病例通过应用自攻型微钛钉种植体支抗压低上下颌后部牙齿槽,治疗严重的骨性前牙开（牙合）畸形,证明自攻型微钛钉种植体提供垂直支抗控制的能力.本文也提示通过简单有效的骨性支抗手段,可以提供一种治疗较复杂骨性开（牙合）畸形的全新方法.     

微螺钉种植体支抗压低磨牙矫治前牙开(牙合)

近些年来各种骨性支抗系统被开发并应用于临床,来完成牙齿各种类型的运动.微型种植体用于垂直支抗控制方面比传统方法有着更多的优势.本文病例通过应用自攻型微钛钉种植体支抗压低上下颌后部牙齿槽,治疗严重的骨性前牙开(牙合)畸形,证明自攻型微钛钉种植体提供垂直支抗控制的能力.本文也提示通过简单有效的骨性支抗手段,可以提供一种治疗较复杂骨性开(牙合)畸形的全新方法.