早期上颌扩弓纠正单侧后牙反(牙合)改善功能性下颌偏斜

目的:通过头颅定位后前位片(P-A)测量,探讨上颌扩弓纠正单侧后牙反(牙合),改善早期功能性下颌偏斜的临床效果.方法:混合牙列或早期恒牙列,上颌单侧后牙反(牙合)伴有/或不伴有前牙反(牙合),下颌功能性偏斜病例16例,采用上颌Quad-Helix扩弓方法,矫治前后头颅定位后前位片(P-A)测量分析,用统计软件处理数据.结果:单侧后牙反(牙合)矫正后,面部不对称有明显改善.结论:混合牙列或早期恒牙列,由于单侧后牙反(牙合)导致的功能性下颌偏斜,采用扩大上颌牙弓方法,可使下颌骨的不对称得到明显改善,是早期纠正下颌功能性偏斜的有效方法.     

上颌四眼簧扩弓纠正早期功能性下颌偏斜的髁突位置变化研究

目的:通过颞下颌关节断层片测量,探讨上颌四眼簧扩弓纠正单侧后牙反(牙合),改善早期功能性下颌偏斜后髁突位置的变化.方法:混合牙列或早期恒牙列,单侧后牙反(牙合)伴有或不伴有前牙反(牙合),下颌功能性偏斜患者16例,采用上颌Quad-Helix扩弓法,对矫治前后颞下颌关节断层片进行测量分析.结果:单侧后牙反(牙合)矫正后,偏斜侧T1期与T2期髁突位置变化无统计学意义(P＞0.05).对侧髁突向后移动,即治疗后,对侧关节腔前间隙增大,上间隙和后间隙比治疗前减小(p＜0.05).结论:混合牙列或早期恒牙列,上颌四眼簧扩弓器纠正单侧后牙反(牙合),使髁突与关节窝关系发生改变,两侧髁突运动逐渐对称.     

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目的 探讨多曲方丝弓技术(MEAW)矫治恒牙列单侧后牙反(殆),改善功能性下颌偏斜的疗效.方法 选取2007-2010年就诊于山西医科大学口腔医院正畸科门诊的安氏Ⅲ类错(殆)伴下颌偏斜患者10例,排齐整平牙列,采用MEAW技术调整后牙在三维方向上的位置,配合双侧不对称的短Ⅱ美和短Ⅲ类牵引,调整上下中线.拍摄矫治前后X线片并进行头影测量分析.结果 10例患者均取得良好矫治效果,矫治后磨牙为中性关系,覆(殆)覆盖正常.结论 轻度恒牙列单侧后牙反(殆)患者通过MEAW技术可有效纠正磨牙关系及下颌偏斜.     

正畸治疗安氏Ⅲ类错(牙合)伴下颌偏斜的临床研究

目的 探讨治疗安氏Ⅲ类错(牙合)伴有单侧的后牙反(牙合)、锁(牙合)和单侧前牙反(牙合)的牙源性下颌偏斜的有效方法.方法 选择安氏Ⅲ类错牙合伴单侧的后牙反(牙合)、锁(牙合)和单侧前牙反(牙合)等牙源性下颌偏斜患者21例,年龄8～25岁,平均15.5岁.单侧后牙反牙合、锁(牙合)引起的下颌偏斜通过上颌扩弓、上下牙交互牵...     

单侧后牙反(牙合)时下颌骨的功能性移位及颞下颌关节适应性改变的实验性研究

本实验是研究用活动扩弓导板治疗单侧后牙反(牙合)时,下颌骨功能性移位的改善及髁突变化情况。研究对象是6名7～11岁儿童,单侧后牙反(牙合)且下颌中线向反(牙合)侧偏移2mm以上,ICP位髁突位置正常。 研究方法 Ⅰ阶段,用覆盖(牙合)面的平面扩弓导板消除因双侧咬合不平衡引起的不对称神经肌反射(该     

正畸治疗安氏Ⅲ类错伴下颌偏斜的临床研究

目的探讨治疗安氏Ⅲ类错伴有单侧的后牙反、锁和单侧前牙反的牙源性下颌偏斜的有效方法。方法选择安氏Ⅲ类错伴单侧的后牙反、锁和单侧前牙反等牙源性下颌偏斜患者21例,年龄8~25岁,平均15.5岁。单侧后牙反、锁引起的下颌偏斜通过上颌扩弓、上下牙交互牵引纠正宽度不调,促使下颌自行复位;前牙反通过Ⅲ类牵引予以解除。结果 21例患者均取得良好的矫治效果,治疗后颜面对称性和咬合关系恢复正常,颏点偏斜平均减少（2.9±0.6）mm,因长期错导致的下颌骨偏斜亦得到了明显改善。结论牙源性下颌偏斜,经过合理正畸治疗,随着单侧后牙反、锁及单侧前牙反的解除可得到明显的改善。     

单侧后牙扩弓的有效方法

目的:探讨附颊屏的(牙合)垫矫治器进行单侧后牙扩弓,治疗单侧后牙反(牙合)的可行性.方法:选择混合牙列期或恒牙列早期的单侧后牙反(牙合)病例4例,男2例,女2例,年龄12～15岁,平均13.5岁,应用附颊屏的(牙合)垫矫治器配合改良横腭杆进行治疗,对矫治前后模型进行测量分析.结果:4例患者经过3～5个月的治疗,单侧后牙反(牙合)均纠正,效果满意.模型分析显示,反(牙合)侧治疗前后第一、第二前磨牙腭尖及第一磨牙近中腭尖到腭中缝的距离变化均较正常侧明显.结论:附颊屏的(牙合)垫矫治器配合改良横腭杆治疗单侧后牙反(牙合),既可保持正常侧良好的咬合关系,又可快速矫治后牙反(牙合).     

用扩弓和多曲方丝弓技术矫治反(牙合)伴下颌偏斜畸形

目的 探讨扩弓和多曲方丝弓技术在安氏Ⅲ类错(牙合)伴下颌偏斜矫治中的作用机理。方法 选择安氏Ⅲ类错(牙合)伴下颌偏斜患者8例,均采用上颌扩弓技术矫治单侧上颌后牙反(牙合),多曲方丝弓技术不同程度地直立后牙,调整后牙在三维方向的位置,并解除前牙的反(牙合),调整下颌中线。结果 8例Ⅲ类错耠伴下颌偏斜患者均取得良好的矫治效果,矫治后磨牙为中性关系,前牙覆(牙合)覆盖正常。结论 轻度及中度安氏Ⅲ类错(牙合)伴下颌偏斜畸形患者通过上颌的扩弓及多曲方丝弓矫治技术可有效地矫正磨牙关系及下颌偏斜。     

安氏Ⅲ类错(牙合)伴有下颌偏斜者颌面部不对称性研究

目的:通过头颅正位片的测量,揭示安氏Ⅲ类错(牙合)伴有下颌偏斜者颌(牙合)面在水平向及垂直向不对称的特点.方法:早期恒牙(牙合),安氏Ⅲ类错(牙合)伴有下颌偏斜患者40名,治疗前的正位片与40名正常(牙合)者进行比较,用SPSS统计软件处理数据.结果:下颌骨及下牙弓宽度增大;偏斜侧上颌基骨宽度及上下牙弓宽度大于对侧;偏斜侧下颌综合长度及下颌体长度小于对侧,差异均有显著性意义.结论:面部不对称主要表现在面下1/3及牙弓区;下颌不对称主要发生于下颌的水平部.     

儿童功能性单侧后牙反患者的髁突对称性及矫治后髁突位置变化的研究

目的探讨儿童功能性单侧后牙反患者的髁突对称性及上颌扩弓治疗后髁突位置的变化。方法选择22例通过上颌扩弓成功矫治的功能性单侧后牙反儿童患者,男10例,女12例,年龄6.0-8.5岁,平均7.5岁作为实验组。另选择22例正常患者,男11例,女11例,年龄6.5-9.0岁,平均7.5岁作为对照组。反组矫治前后与对照组患者均拍摄曲面断层片和双侧闭口位矫正薛氏位片,测量髁突形态的不对称指数和髁突在关节窝中的相对位置。用SPSS 12.0软件进行统计分析。结果反组患者两侧髁突形态无明显不对称,与对照组相比,髁突高度(CH)、升支高度(RH)以及两者之和(CH+RH)的不对称指数均无统计学差异。反组矫治前(T1)两侧髁突在关节窝中的位置有明显差异,非反侧关节前间隙减小(P<0.05),上后间隙增大(P<0.05)。非反侧髁突在关节窝中的位置(R)相对反侧更加靠前(P<0.01)。矫治后(T2)双侧髁突位置变得相对对称。结论儿童功能性单侧后牙反患者的髁突形态相对对称,而髁突位置存在不对称性,说明下颌向反侧发生功能性偏斜,而这种偏斜并未导致髁突发生骨性不对称;正畸治疗可使两侧髁突位置更加协调。     

Morphological and positional asymmetries of young children with functional unilateral posterior crossbite.

This prospective clinical study evaluated the morphological and positional mandibular asymmetry of young patients with functional unilateral posterior crossbite. The sample included 9 girls and 6 boys (8.8 +/- 1.0 years of age), evaluated at the initiation of treatment and approximately 6 months after the retention phase (1.1 +/- 0.2 years after initiation of treatment). Each patient had a complete unilateral posterior crossbite involving 3 or more posterior teeth, a functional shift from centric relation-intercuspal position, and no signs or symptoms of temporomandibular disorder. A bonded palatal expansion appliance was used to rapidly expand the maxilla (1 month) and retain the treatment changes (6 months). Zonograms were used to assess articular joint spaces, and submental vertex radiographs were used to assess morphological and positional asymmetry. The results showed that the mandible was significantly longer on the noncrossbite side than it was on the crossbite side. The asymmetry was most evident for the ramus and involved both the condylar and the coronoid processes. The posterior and superior joint spaces were larger on the noncrossbite side than they were on the crossbite side. After treatment and retention, the mandible showed no significant morphological asymmetries. Mandibular growth was greater on the crossbite side than it was on the noncrossbite side, and the mandible had been repositioned; the crossbite side had rotated forward and medially toward the noncrossbite side. We concluded that unilateral posterior crossbites produce morphological and positional asymmetries of the mandible in young children, and that these asymmetries can be largely eliminated with early expansion therapy.     

Mandibular asymmetry and condylar position in children with unilateral posterior crossbite.

The purpose of this retrospective study was to determine if condylar position in children with functional unilateral crossbites was different from that found in children with Class I noncrossbite malocclusions and if there was a change in condylar position after correction of the crossbite by palatal expansion. Mandibular asymmetry in children with functional unilateral posterior crossbite was also compared to that of a Class I noncrossbite group. Thirty-one children aged 6 to 14 years (mean, 9.3 years; standard deviation, 2.2) with functional unilateral crossbites were compared to 31 children aged 9.5 to 14.1 years (mean, 11.9 years; standard deviation, 1.3) exhibiting Angle Class I noncrossbite malocclusions. Pretreatment submentovertex radiographs were used to study mandibular skeletal, dental, and positional asymmetries with reference to cranial floor and mandibular coordinate systems. In addition, the anterior, superior, and posterior joint spaces were measured to determine differences between the groups with the use of pretreatment and posttreatment horizontally corrected tomograms of the temporomandibular joints. Finally, the distances of the mesiobuccal cusp of the upper first molar relative to the buccal groove of the lower first molar were measured in both groups before treatment. Univariate analyses revealed that the mandibles of children in the functional unilateral posterior crossbite group exhibited asymmetry in both anteroposterior and transverse dimensions when compared with the Class I noncrossbite group (P <. 05). These asymmetries were the result of a functional deviation of the mandible that was present in all subjects in the crossbite group. This deviation was manifested occlusally by a Class II subdivision on the crossbite side as indicated from the study model analysis (P <.05). Examination of condylar position as evidenced by horizontally corrected tomograms demonstrated a large standard deviation, resulting in an inability to detect any significant differences within or between groups at both T1 and T2 (P >.05). This study raised the question of the appropriateness of measuring joint spaces for routine diagnostic purposes.     

Long-term stability of unilateral posterior crossbite correction

OBJECTIVE: To evaluate the stability of orthodontically corrected unilateral posterior crossbite in patients treated either by rapid maxillary expansion or with slow expansion devices in the early (mean age 7.2 years, n = 50) or late mixed dentition (mean age 9.9 years, n = 50). MATERIALS AND METHODS: The observation periods were approximately 8 years for the early treatment groups and 6.5 years for the late treatment groups. The measurements were made on plaster casts at the following time points: before treatment (T1), after crossbite correction (T2), at the end of active orthodontic treatment (T3), and about 2 years after the end of active treatment (T4). Midline deviation and the skeletal classification of the malocclusion were also evaluated. RESULTS: Almost 80% of the treated patients showed long-term stability of the corrected unilateral posterior crossbite. More than 70% of the patients were treated for the mandibular midline deviation. At the end of active treatment, 50% of the patients showed a skeletal Class III craniofacial morphology. CONCLUSIONS: The results emphasize that determination of the correct treatment approach for the individual patient is the basic principle underlying the therapeutic success in unilateral crossbite cases. In patients where a broad lower arch is a cofactor in the etiology of the lateral crossbite, the treatment approach should be focused on both arches and not be limited to the constricted upper arch.     

儿童单侧后牙反患者下颌及颞颌关节的对称性研究

目的研究儿童单侧后牙反牙合患者下颌及颞颌关节的对称性。方法以26例替牙期单侧后牙反牙合患儿为试验组,28名正常牙合替牙期儿童为对照组,分别摄定位颏顶位片及双侧颞颌关节中位断层片进行比较。结果替牙期单侧后牙反牙合患儿在下颌骨坐标系中DMP点更靠颊侧。在颅底坐标系中,反牙合侧DMP点更靠远中,DMP、MM、DM点更靠颊侧。双侧髁突位置不对称、非反牙合侧关节前间隙减小,上后间隙均增大。结论相对于下颌坐标系,反牙合侧第一磨牙位置与对侧相比更靠远中及颊侧。在骨性结构上,未见下颌的不对称。试验组双侧髁突位置及关节间隙有差异,说明下颌发生功能性侧方移动。     

偏颌畸形患者的牙弓特征

目的　分析偏颌畸形患者的牙弓特征,为临床矫治提供参考。方法　采用三维坐标测量仪在20例偏颌 畸形患者(试验组)和20例正常人(对照组)的牙模型上测量上下颌尖牙、前磨牙和磨牙牙尖的三维坐标值,分 析牙弓矢向和横向的对称性、上下牙弓的协调性和牙齿倾斜度,采用SAS 6·03进行统计学检验。结果　试验组上 颌尖牙和第一前磨牙距腭中缝的距离偏向侧大于偏离侧(P<0·05),下颌从尖牙到第二磨牙偏向侧距中线的距离 小于偏离侧(P<0·05);上颌尖牙和第一前磨牙的牙弓宽度比率较对照组小(P<0·05),而上颌第二前磨牙和第一 磨牙的牙弓宽度比率与正常无统计学差异(P>0·05);上颌后牙偏向侧颊向倾斜度大于偏离侧,下颌后牙偏向侧 舌向倾斜度大于偏离侧(P<0·05);上颌偏向侧和偏离侧牙齿的矢向位置无统计学差异(P>0·05)。结论　偏颌畸 形患者上牙弓前部窄于下牙弓,上颌牙齿矢向位置无差别,而上下颌两侧后牙颊舌向倾斜度存在明显差异。     

A bonded functional ramp to aid in asymmetric expansion of unilateral posterior crossbites.

Unilateral posterior crossbite is a common finding in patients seeking orthodontic treatment. When treating this condition with a rapid maxillary expander, clinicians occasionally observe no resolution of the crossbite and document an unnecessary overexpansion of the contralateral dentition. This article describes a method for treating unilateral posterior crossbite and, specifically, the lack of crossbite correction after expansion with a rapid maxillary expander. A composite ramp is bonded to the mesial buccal cusp of the maxillary first molar in crossbite. The necessary materials and instruments are typically found in an orthodontic office. This adjunctive procedure requires no more than 5 extra minutes during an examination, and no additional appointments are necessary.     

A Study of Children with Unilateral Posterior Crossbite, Treated and Untreated, in the Deciduous Dentition Occlusal and Skeletal Characteristics of Significance in Predicting the Long-term Outcome

BACKGROUND AND AIM: The generally recommended treatment in children with unilateral posterior crossbite is expansion of the maxillary dental arch. The reported treatment success rate varies between 50% and 96%. The aim of the present study was to analyse whether some occlusal and skeletal characteristics could be found in the deciduous dentition of children with treatment success (including self-correction) in contrast to those showing non-correction (including relapse) in the young permanent dentition. PATIENTS AND METHOD: Two groups of children with unilateral posterior crossbite were followed from the age of 5 years up to 13 years of age. The children in one of the groups (n = 32) were treated in the deciduous dentition, while the children in the other group (n = 32) were to be treated in the late mixed or early permanent dentition. Another 25 children (5 years old) with excellent occlusion were included as controls. Results of clinical examination and biometric and cephalometric analyses, performed at the first examination (at 5 years of age), are presented for the three groups ("treated" "untreated" and controls). RESULTS AND CONCLUSIONS: Compared to the controls, asymmetry was registered in both dental arches. The crossbite side, measured to the midline, was narrower than the non-crossbite side in the upper jaw but broader in the lower jaw. Differences between upper/lower widths (at intercanine and intermolar level) seem to be of importance for correction or non-correction, both for "untreated" and "treated" children. A narrow crossbite side in the upper arch together with a broad crossbite side in the lower arch was found in non-corrected children in both groups, even among those treated with maxillary expansion, where the SNB angle was larger and the ANB angle smaller than in controls as well as in those with correction (including self-correction). Possibilities and limitations of treatment planning are discussed.     

Functional unilateral posterior crossbite. Orthodontic and functional aspects

summary The purpose of the study was to evaluate the effect of early orthodontic treatment of functional unilateral posterior crossbite (FUPC) and to evaluate temporomandibular function in the short and long term. Orthodontic treatment consisted of slow expansion of the maxillary dental arch by means of a removable expansion plate, with flat coverage of the occlusal surfaces of the left and right posterior teeth. Evaluation of the occlusion showed a strong correlation between the crossbite side and the direction of the RCP-ICP slide and with the side of first occlusal contact in RCP. In 26 of 27 children that were treated (one withdrew), the average time required for correction of the crossbite was 7 months, followed by a retention period, on average, for 6 months after completion of treatment. Early orthodontic treatment resulted in an elimination of occlusal disturbances, and the crossbite remained stable on follow-up during an average of 8 years after the retention period, except in two children with a class III tendency. In nine other children an orthodontic anomaly had developed requiring further treatment (two children showed crowding and seven children showed a class II malocclusion). This study showed that FUPC can be treated adequately by early orthodontic intervention; however, its correction does not guarantee the absence of functional disturbances at a later age. Therefore, FUPC should be treated early in order to achieve normal growth and development rather than to prevent temporomandibular disorders.