前牙开畸形颅面形态的分类研究

目的　对前牙开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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畸形的颅面形态进行分类。结果　对年龄、性别、颅面特征等 15 6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个因子 (下颌旋转因子、面高因子、牙骨矢状因子和上颌旋转因子 )。采用逐步聚类法对 116例患者的 4个因子得分进行聚类分析 ,将前牙开畸形这一群体分为牙齿槽型开、下颌顺时针旋转型开、长面型开、上颌逆时针旋转型开和骨性Ⅲ类开 5类并归纳出可供临床使用的简单分类方法。结论　对前牙开畸形进行分类在诊断和矫治设计中起着重要作用。     

恒牙早期安氏Ⅱ类前牙开He的三维颅面结构特征

目的 系统描述年轻恒牙期前牙开Ｈｅ的三维颅面结构特征。方法 ２７例１１～１６风开Ｈｅ少年作为实验对象，通过三维头影测量系统，计算出各指标的实际测量值，与同年龄段正常Ｈｅ、安氏Ⅱ＾１分类非开Ｈｅ分类非开Ｈｅ少年采用同一技术所得的测量均值进行比较。结果与结论 ①长度方向：Ⅱ类开始Ｈｅ中Ⅱ类Ｈｅ关系的产生主要是因为下颌的后缩。同时下前牙的前突在Ⅱ类开Ｈｅ中表现明显。②宽度方向：Ⅱ类开Ｈｅ的宽度发育不足。     

功能性矫治器打开颌对大鼠颅面形态影响的X线片头测量分析

本实验选用３０只４周龄Ｗｉｓｔａｒ大鼠使用自制上颌前牙Ｈｅ平面板功能性活动矫治器打开大鼠下颌。用Ｘ线片头测量术，对实验前后大鼠的颅面形态进行测量分析。结果显示，实验组大鼠的下颌角前切迹加深，上下颌磨牙牙槽高度增加，下颌平面角增大，下颌向下后旋转；但对颅脑及上颌骨的形态及位置均无明显影响。     

儿童骨性前牙反He颅面形态的类型研究

由于Ⅲ类错Ｈｅ形成的表面具复杂和多样性，本文目的是探讨骨性前牙反Ｈｅ儿童面形态的类型研究对象为１０－１３岁一前牙反Ｈｅ患者，共６９便，其中男性３５例，女性３４例，平均１１．６岁。通过反映颅底结构、上颌和下颌骨长度、面部矢状和垂直向关系、牙及牙槽、软组织形态的１９项头测量指标的样本聚类分析，将本组病例儿童的颅面形态划分为四个亚类，其中上颌发育不足、下颌长度正常，但位置前移以及产下面高不足是儿童骨性前     

恒牙早期前牙开He的三维颅面结构特征

本研究以４１名１１－１６岁开Ｈｅ少年作为研究对角，通过三维头影测量系统，与同年龄段正常Ｈｅ采用同一技术所得的测量均值进行了比较，得出以下结论：（１）前牙开Ｈｅ是一种多因素所致的错Ｈｅ畸形，在长，宽，高三度方向上都有体现；（２）长度方向上看，下颌向后，下方旋转，移位，上颌前部上翘，（３）宽度方向上看，面宽度显著减小，上，下牙弓明显狭窄，可致呼吸道不畅，舌被动前伸，（４）高度方向上看，前全面高，前下面     

FR—1型功能矫治器矫治安氏Ⅱ类1分类错He的牙弓测量

目的 了解ＦＲ－１型矫治器矫治安氏Ⅱ类１分类错Ｈｅ的牙Ｈｅ变化，方法 对２３例生长发育快速期的安氏Ⅱ类，分类错Ｈｅ患者采用ＦＲ－１型矫治器矫治，并对治疗前后模型进行牙弓测量，结果 １．上颌牙弓宽度增加，长度减小；２．下颌牙弓宽度增加，长度增加，Ｓｐｅｅ’ｓ曲线变平，３．前牙覆Ｈｅ，覆盖减小，结论 ＦＲ－１型矫正器，能使上牙弓长，宽，高三维关系发生明显变化，有效地改善安氏Ⅱ类１分类错Ｈｅ。     

磁力He垫式矫治器的研制及临床应用

采用第三代稀土永磁体钕铁硼制成Ｈｅ垫式活动矫治器。利用磁极间的排斥力，形成上下颌后牙的压入作用，对前牙骨性开Ｈｅ患者进行畸形矫治的临床应用研究，以期寻找前牙开Ｈｅ畸形矫治的更佳途径。     

FR3矫治乳牙期,替牙期前牙反He的头影测量对比研究

目的 为观察ＦＲ３矫治前牙反Ｈｅ的效果，尤其是矫治疗后颅面形态的改变。方法 采用ＦＲ３对１７例乳牙期和１０例替牙期前牙反Ｈｅ患者进行矫治，通过头影响测量分析其矫治前后的变化及矫治后与正常值的差异。结果 ＦＲ３能促进上颌生长发育，唇倾上切牙；使下颌后退，有效地改善异常的Ｈｅ间关系，乳牙期反Ｈｅ矫治后，除下切牙舌倾、颏角尖锐外、基本恢复Ⅰ类骨面型，矫治效果好。替牙期反Ｈｅ由于骨骼异常较严重，因而矫治后     

前牙开He畸形的四边形分析

本文对Ｄｉ ｐａｏｌｏＸ线头影测量上边形分析法＾［１］及改良后的边形分析法＾［２，３］作了介绍。并按后法对５６例前牙开Ｈｅ患者进行了分析。，结果：开Ｈｅ患者四边表各边关系失调，前下面高过大，矢状角明显增加。表明：开Ｈｅ患者前牙－齿槽高度发育不足，腭平面前部上倾；下颌升支、髁突垂直生长不足，下颌骨产生了正常不同的向后、下顺时针旋转生长趋势，使腭平面与下颌平面离散度加大、上下颌前部分离，形成开Ｈｅ。故     

乳前牙反He的追踪观察研究

目的：探讨乳前牙反Ｈｅ与恒前牙反Ｈｅ,磨牙关系及Ⅲ类骨面畸形的关系,方法：对１０２例口腔社区调查中诊断为乳前牙的Ｈｅ的儿童,６年后进行追踪调查。以同期调查中无乳前牙反Ｈｅ及恒前牙反Ｈｅ的１０２名儿童作为对照,进行牙颌发育情况的检查。     

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.     

Cervical column morphology in patients with skeletal open bite

OBJECTIVES: To examine and compare the cervical column morphology in adult patients with skeletal open bite with the cervical column morphology of an adult control group with neutral occlusion and normal craniofacial morphology. DESIGN: A retrospective case-control study. SETTING AND SAMPLE POPULATION: Thirty-eight open bite patients, 27 women, aged 17-39 years, and 11 males, aged 18-40 years were compared with 21 controls, 15 females, aged 23-40 years, and six males aged 25-44 years from profile radiographs. OUTCOME MEASURE: From each individual a visual assessment of the cervical column and angular measurements of the craniofacial dimensions were performed on profile radiographs. RESULTS: In the open bite group 42.1% had cervical column body fusion, and 13.2% had posterior arch deficiency. The fusion always occurred between C2 and C3. Cervical column deviations occurred significantly more often in the open bite group compared with the control group (p < 0.05). Associations were found between fusions of the cervical column and maxillary retrognathia (p < 0.05), large maxillary inclination (p < 0.05) and large cranial base angle (p < 0.05). Associations were also found between posterior arch deficiency and maxillary retrognathia (p < 0.05) and cranial base angle (p < 0.05). The craniofacial parameter most important for the fusions and posterior arch deficiency was the maxillary retrognathia (p < 0.01, R (2) = 0.20; p < 0.05, R (2) = 0.26, respectively). CONCLUSION: - New associations between skeletal open bite and cervical column deviations are described. It is suggested that this knowledge is incorporated in future diagnostic and orthodontic treatment planning.     

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.     

Morphologic analysis of dentofacial structure in patients with acromegaly

The purpose of this study was to investigate the morphologic changes of the oral and maxillofacial skeletal structure in patients with acromegaly and the correlation between growth hormone, age at onset, and duration. Fifty-four acromegalic patients (28 men and 26 women) were compared with 45 normal adults (23 men and 22 women) using casts and cephalometric analysis. The incisor relationship was classified into four types: edge-to-edge bite, crossbite, maxillary incisor protrusion, and normal bite. Many cases of edge-to-edge bite and crossbite were observed in acromegalic patients. The most characteristic craniofacial skeletal differences in patients with acromegaly were protruded glabella and increased anterior face height. Enlargement of the ascending ramus and prominence of the mandible, chin, and mouth were the most noticeable profile characteristics of acromegalic patients. Male patients tended to demonstrate downward mandibular advancement and crossbite, while females showed extension of the ascending ramus, downward displacement of mandible, bimaxillary alveolar protrusion, and edge-to-edge bite.     

Correction of anterior open bite in a case of achondroplasia.

Treatment planning for patients with skeletal deformities is often considered challenging. This article reports a female patient with achondroplasia who presented with severe maxillary retrognathism and vertical excess along with anterior open bite. The clinical and cephalometric findings of the patient are detailed here. The treatment plan consisted of modified anterior maxillary osteotomy for simultaneous vertical and sagittal augmentation along with orthodontic intervention. The course of surgical-orthodontic treatment and the results are presented. This treatment is to be followed by correction of vertical maxillary excess after completion of growth. This paper concludes that the dentoalveolar component of a skeletal deformity can be handled independent of the craniofacial management.     

恒牙早期前牙反患者颅颌面硬组织形态特征的二维有限元法研究

目的：探讨恒牙早期前牙反患者的颅颌面硬组织形态特征。方法：采用专门建立的颅颌面形态有限元分析系统，对８０例恒牙早期前牙反患者的颅颌面硬组织形态特征进行二维分析。结果：反组患者各单元的大小变化均小于形状变化。男女反组后颅底均有异常，后颅底均有一定程度的逆时针旋转；男女反组上面部及上颌骨发育不足；男女反组下颌骨中，以颏前上部大小变化和形状变化最大，各单元均有不同程度的逆时针旋转。结论：骨单元形状的异常变化和不利的旋转方式是前牙反颅颌面形态的重要特征，也可能是反形成的重要原因。     

The use of skeletal anchorage in open bite treatment: a cephalometric evaluation

The aims of the present study were to assess the effectiveness of skeletal anchorage for intrusion of maxillary posterior teeth, to correct open bite malocclusion, and to evaluate the usage of titanium miniplates for orthodontic anchorage. Anterior open bite is one of the most difficult malocclusions to treat orthodontically. Currently, surgical impaction of the maxillary posterior segment is considered to be the most effective treatment option in adult patients. Various studies have reported the use of implants as anchorage units at different sites of midfacial bones for orthodontic tooth movement. The zygomatic buttress area could be a valuable anchorage site to achieve intrusion of maxillary posterior teeth. Ten patients, 17 to 23 years old and characterized with an anterior open bite and excessive maxillary posterior growth, were included in this preliminary study. Titanium miniplates were fixed bilaterally to the zygomatic buttress area, and a force was applied bilaterally with nine mm Ni-Ti coil springs between the vertical extension of the miniplate and the first molar buccal tube. The results showed that, with the help of skeletal anchorage, maxillary posterior teeth were intruded effectively. As compared with an osteotomy, this minimally invasive surgical procedure eased treatment and reduced treatment time and did not require headgear wear or anterior box elastics for anterior open bite correction. In conclusion, the zygomatic area was found to be a useful anchorage site for intrusion of the molars in a short period of time.     

Passive correction of an anterior open bite related to non-nutritive sucking habits: report of a case

The term anterior open bite refers to a vertical space between the upper and lower front teeth in maximum intercuspation. This malocclusal trait can accompany many malocclusions of the Angle's classification. Two types of anterior open bite have been described: skeletal and dental open bite. The latter may have Non Nutritive Sucking Habits (NNSH) as causal factor and is deemed to aggravate without treatment. This article presents an interceptive approach based on the use of a fixed passive appliance interfering with sucking habit. It consists of a crib soldered to bands adjusted to the maxillary first permanent or temporary second molars. The device was globally well accepted by the patient and has been effective in breaking the sucking habit and subsequently in closing the bite after only 5 month. When psychological approach is not effective, a fixed deterrent device may be recommended for weaning children off nonnutritive sucking habits.     

Skeletal and dento-alveolar stability after surgical-orthodontic treatment of anterior open bite: a retrospective study.

The aim of this investigation was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction of skeletal anterior open bite treated by maxillary intrusion (group A) versus extrusion (group B). The cephalometric records of 49 adult anterior open bite patients (group A: n = 38, group B: n = 11), treated by the same maxillofacial surgeon, were examined at different timepoints, i.e. at the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), early post-operatively (+/- 20 weeks, T4) and one year post-operatively (T5). A bimaxillary operation was performed in 31 of the patients in group A and in six in group B. Rigid internal fixation was standard. If maxillary expansion was necessary, surgically assisted rapid palatal expansion (SRPE) was performed at least 9 months before the Le Fort I osteotomy. Forty-five patients received combined surgical and orthodontic treatment. The surgical open bite reduction (A, mean 3.9 mm; B, mean 7.7 mm) and the increase of overbite (A, mean 2.4 mm; B, mean 2.7 mm), remained stable one year post-operatively. SNA (T2-T3), showed a high tendency for relapse. The clockwise rotation of the palatal plane (1.7 degrees; T2-T3), relapsed completely within the first post-operative year. Anterior facial height reduction (A, mean -5.5 mm; B, mean -0.8 mm) occurred at the time of surgery. It can be concluded that open bite patients, treated by posterior Le Fort I impaction as well as with anterior extrusion, with or without an additional bilateral sagittal split osteotomy (BSSO), one year post-surgery, exhibit relatively good clinical dental and skeletal stability.