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。     

多曲方丝弓技术矫治骨性安氏Ⅲ类错的临床研究

目的：运用MEAW技术矫治骨性安氏Ⅲ类错,探索骨性安氏Ⅲ类错非手术矫治方法。方法：选择恒牙期骨性安氏Ⅲ类错10例,男4例,女6例,年龄13～22岁,平均16.5岁。用多曲方丝弓技术矫治,矫治结束时至前牙反解除,尖牙磨牙为中性关系。治疗前后拍摄头颅侧位定位片,进行X线头影测量分析。结果：矫治后上前牙唇倾度加大,上后牙近中移动,下前牙代偿性舌向移动,下后牙远中直立。平面变平,颌骨变化较小。结论：多曲方丝弓矫治技术可以通过牙的三维移动矫治骨性前牙反,拓宽了正畸矫治范围。     

咬合与肌电

本文介绍了正常牙尖交错位、下颌后退接触位、前伸咬合和侧方咬合时肌电活动的特点;咬合运动时肌电的变化,咬合力与肌电的关系,并就错和干扰对肌电的影响作了分析;此外,患者接受板和导板治疗后,其肌电和肌活动型有改变,在临床上有参考价值。     

螺旋缩弓器治疗单侧后牙正锁的长期效果观察

目的：评价正畸螺旋缩弓器和MBT直丝弓矫治技术治疗单侧正锁后上颌牙弓宽度、前牙覆和覆盖的长期变化。方法：对23名（男13,女10）经正畸治疗后的患者4个阶段（治疗前,T1;螺旋缩弓后,T2;MBT治疗后,T3和去除保持器后2年,T4）的模型进行测量分析。结果：缩弓后上颌牙弓宽度明显减小（P〈0.05）。MBT治疗后尖牙宽度复发明显（P〈0.05）。停戴保持器2年后,尖牙宽度、第一前磨牙宽度、第一磨牙宽度、前牙覆和覆盖分别净减小（1.2±0.96）mm,（3.9±1.19）mm,（4.6±0.23）mm,（1.8±0.42）mm,（0.8±0.13）mm。结论：单侧正锁经正畸螺旋缩弓器和MBT直丝弓矫治技术治疗后上颌牙弓宽度稳定。     

后牙锁伴前牙Ⅲ°深覆的正畸治疗

本文通过对8例后牙锁伴前牙深覆的患者，以平导结合固定矫治器代替传统的垫式矫治器进行治疗，意在寻求一种有效、快速的矫治后牙锁的方法。结果表明：解除锁平均时间为2．6月，前牙咬合打开为3．4月，完成矫治为14．6月。本文认为平导结合固定矫治器能使锁解除、前牙压低及后牙升高、建同步进行而缩短疗程。     

后牙锁13例临床矫治观察

目的观察后牙锁的临床矫治效果。方法对13例后牙锁患者的矫治方法与疗效进行回顾性分析。结果13例病例解除锁治疗时间平均为4.2个月,治疗后均可建立广泛的咬合接触关系。结论所采用的4种矫治后牙锁的方法可以很好的控制后牙的垂直向高度,有效解除锁。     

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目的研究安氏Ⅱ1错矫治前后咬合功能状况的变化,借以评价正畸治疗对咬合接触变化的影响,并结合国内外学者的相关研究数据,对比分析本研究对安氏Ⅱ1错咬合稳定重建的可靠程度及对临床的指导意义。方法选取2008-2012年来济南市口腔医院正畸科就诊的安氏Ⅱ1错患者30例,用T-scanⅡ数字化咬合分析系统记录患者矫治前后最大牙尖交错位的力总值(TOF)、力不对称指数(AOF)、力中心点位置(COF)、力中心点的最大位移(MMCOF)、闭合时间(TO),并进行统计分析。结果安氏Ⅱ1错患者矫治后TOF高于矫治前(P<0.01);矫治后COF距上颌中线的距离与矫治前相比减小(P<0.01);矫治后AOF、MMCOF、TO均低于矫治前(P<0.01)。结论正畸治疗能够改善安氏Ⅱ1错患者的力水平及平衡性;T-scanⅡ数字化咬合分析系统能够客观、真实、准确的显示咬合接触状态,其测量结果可作为临床评价的指标。     

第二磨牙纳入正畸治疗对咬合接触指标的影响

目的：对比第二磨牙是否粘接托槽纳入矫治,对治疗结束后咬合状况的影响。方法选择15例未将第二磨牙纳入矫治的患者与16例将第二磨牙纳入矫治的青少年患者,均为单纯拥挤的安氏I类错患者,常规直丝弓固定矫治结束时,运用T-ScanⅢ咬合分析仪记录两组患者的咬合接触时间、前伸、左侧、右侧分离时间、咬合力不对称指数、COF近中距离、前牙力百分比等七项指标。结果第二磨牙未纳入矫治组的前伸分离时间、左侧分离时间、右侧分离时间均明显大于纳入组(P<0．05),前牙力百分比较大(P<0．05),咬合接触时间与力中心点( COF)近中位置、咬合力不对称指数无统计学意义。第二磨牙未纳入组的干扰发生率为86．7%,纳入组的干扰发生率为25%。前牙力百分比与咬合接触时间存在线性相关关系。结论第二磨牙未纳入矫治,在治疗结束时,更易出现不良咬合、力分布不均匀等不利的因素,存在造成口颌系统功能紊乱的隐患。     

轻中度骨性Ⅲ类错矫治后牙关系的PAR指数评价

目的比较轻中度骨性Ⅲ类错畸形拔牙矫治和非拔牙矫治的牙矫治效果。方法测量80例矫治完成的轻中度骨性Ⅲ类错患者治疗前后模型的PAR指数,并进行比较。结果两组治疗前,牙齿错位、咬合关系和覆盖的PAR指数有显著性,P<0.05;2组治疗后,牙齿错位与中线差异有显著性,P<0.05;治疗前后PAR减少的百分率中,牙齿错位、咬合关系项目差异有显著性,P<0.05。结论PAR分值能反映错严重程度,拔牙病例的错主要在牙齿错位、覆盖、中线不调方面较非拔牙病例重。拔牙矫治更有利于牙齿错位的调整。     

伴功能性因素前牙反牙合矫治前后下颌位置的头影测量分析

目的：分析伴功能因素前牙反患者矫治前牙尖交错位、下颌后退至切牙对刃位与矫治结束后牙尖交错位3种不同位置的相关关系。方法：对18例前牙反伴下颌能后退至切对切的患者，采用固定矫治技术进行矫治。拍摄矫治之前牙尖交错位（T1）、下颌后退至切牙对刃位（T2）及矫治结束牙尖交错位（T3）X 线头颅侧位片。采用方差分析对相关 X 线头影测量项目结果3组数据间进行相互比较，进行检验分析。结果：经平均25个月的治疗，前牙的反得以矫治，磨牙关系为 I 类， SNB、ANB、MP-FH、MP-SN、U1-SN、L1-MP、Y轴角、ANS-Me 这几项测量项目的3组数据之间的 F 检验结果有统计学意义。结论：伴功能性因素前牙反经固定矫治技术治疗后，在矢状向和垂直向上下颌骨位置处于治疗前牙尖交错位与后退至切牙对刃位之间，且更接近于后退位。     

青少年错(牙合)患者正畸治疗后动态(牙合)接触特征变化初探

目的 探讨经正畸治疗后获得正常牙列形态的青少年错(牙合)患者矫治结束后12个月内动态(牙合)接触的变化规律,以期为正畸矫治结束前的精细调整提供参考.方法 选择20例正畸矫治后戴用标准霍利保持器的青少年患者,并将20例患者分为(牙合)干扰组与无(牙合)干扰组,其中(牙合)干扰组患者11例,无(牙合)干扰组9例,使用T-ScanⅡ咬合分析系统分别于矫治结束即刻(T1)和矫治结束12个月(T2)时检查患者的动态(牙合)接触,对比分析两个时间点总体与分组情况下患者动态(牙合)接触特征.结果 20例患者的总体情况:T1至T2的前伸、左侧方和右侧方(牙合)分离时间明显减少,从(1.07±0.87)、(0.91±0.47)、(0.76±0.43)s分别降至(0.43±0.25)、(0.67±0.41)、(0.50±0.27)s,两时间点差异均有统计学意义(P＜0.05).其中4例存在(牙合)干扰的患者(牙合)干扰消失.1例出现(牙合)干扰侧咀嚼肌不适症状.无(牙合)干扰组T1至T2的前伸、左侧方和右侧方(牙合)分离时间明显减少,从(1.25±1.11)、(0.84±0.15)、(0.52±0.49)s降至(0.35±0.15)、(0.36±0.15)、(0.33±0.11)s,两时间点差异均有统计学意义(P＜0.05),(牙合)干扰组T1与T2的前伸、左侧方和右侧方(牙合)分离时间的差异无统计学意义(P＞0.05).结论 戴用标准霍利保持器12个月后患者的动态(牙合)接触总体改善,但(牙合)干扰的存在影响了咬合的自行改善进程,矫治器拆除前对动态抬(牙合)接触的评估与精细调整仍是必要的.     

青少年错(牙合)畸形正畸后牙尖交错位(牙合)接触特征初探

目的 通过了解青少年错(牙合)畸形正畸后牙尖交错位的(牙合)接触特征,从功能角度对正畸效果进行评价.方法 选择14例经正畸治疗获得正常牙列形态的青少年错(牙合)畸形患者作为病例组,17名性别、年龄与病例组匹配的正常(牙合)健康人作为健康对照组,使用T-ScanⅡ咬合分析系统记录两组牙尖交错位的(牙合)接触特征并进行比较.结果 在1/10、1/4、1/2、3/4最大(牙合)力页面及最大(牙合)力页面上病例组前牙(牙合)接触点数目的 中位数(四分位数间距)分别为1.5(1.0)、3.0(1.3)、4.5(3.3)、5.5(3.0)及5.5(3.3)个,显著大于健康对照组[分别为0.0(0.3)、0.0(0.6)、0.3(0.5)、0.3(1.0)及0.0(1.8)个,P＜0.05];各页面上病例组后牙(牙合)接触面积与健康对照组的差异无统计学意义(P＞0.05);与健康对照组相比,病例组(牙合)力中心点明显偏近中.病例组牙尖交错位建(牙合)时间的中位数(四分位数间距)为0.192(0.141)s,略大于健康对照组[0.163(0.200)s],但两组差异无统计学意义(P＞0.05).结论 与正常猞健康人相比,青少年错(牙合)畸形患者正畸后其前牙承受(牙合)力明显偏大.     

Functional occlusion: I. A review

The features that constitute an "ideal" functional occlusion have not been conclusively established. Orthodontic treatment has the capacity to change static and functional occlusal relationships fundamentally. In this article, we present the evidence on which features of the occlusion are reported to be detrimental to the teeth and masticatory system Deficiencies in this research area are highlighted, together with the need for prospective longitudinal trials to clarify the requirements of an ideal functional occlusion Based on the existing evidence this paper suggests which occlusal features may be significant in producing an "ideal" functional occlusion As no long-term studies exist to measure the impact of non-ideal occlusal relationships on the dentition, it is debatable whether orthodontic treatment should be prolonged in order to ensure that "ideal" occlusal contacts are achieved As the occlusion tends to "settle" in the period following appliance removal, we propose that it may be more appropriate to examine the functional occlusal relationships after retention has ceased rather than prolong active orthodontic treatment to achieve "ideal" functional occlusal goals.     

Functional Occlusion: I. A Review

Abstract

The features that constitute an ‘ideal’ functional occlusion have not been conclusively established.Orthodontic treatment has the capacity to change static and functional occlusal relationships fundamentally.In this article, we present the evidence on which features of the occlusion are reported to be detrimental to the teeth and masticatory system Deficiencies in this research area are highlighted, together with the need for prospective longitudinal trials to clarify the requirements of an ideal functional occlusion Based on the existing evidence this paper suggests which occlusal features may be significant in producing an ‘ideal’ functional occlusion As no long-term studies exist to measure the impact of non-ideal occlusal relationships on the dentition, it is debatable whether orthodontic treatment should be prolonged in order to ensure that ‘ideal’ occlusal contacts are achieved As the occlusion tends to ‘settle’ in the period following appliance removal, we propose that it may be more appropriate to examine the functional occlusal relationships after retention has ceased rather than prolong active orthodontic treatment to achieve ‘ideal’ functional occlusal goals.     

Changes in occlusal function after extraction of premolars: 2-year follow-up

Objective:To determine the effects of extraction and the number of teeth extracted on changes in occlusal function by measuring occlusal contact area and force before and after orthodontic treatment with a fixed appliance.Materials and Methods:Female patients treated with a fixed appliance were divided into nonextraction (n = 36), two maxillary premolar extraction (n = 31), and four premolar extraction (n = 18) groups. Bite pressure-sensitive films were used to analyze the occlusal contact area and force. Measurements were performed before treatment (Pre-Tx), immediately afterward (After-Tx), and 2 years later (2Y After-Tx). The data were analyzed using a linear mixed model and the post hoc Bonferroni test.Results:The occlusal contact area and force after treatment decreased significantly compared with Pre-Tx values but were increased 2 years later in all groups. There were no significant differences in occlusal contact area or force during the entire observation period among the three groups (P > .05). The occlusal contact area and force in the nonextraction and two maxillary premolar extraction groups recovered to Pre-Tx levels 2 years later (P > .05). The occlusal contact area in the four premolar extraction group was significantly lower than the Pre-Tx level after 2 years of retention (P < .05).Conclusions:The occlusal contact area and force showed a tendency to decrease immediately after treatment and then gradually increase to pretreatment levels during the observation period. However, the occlusal contact area did not recover fully after 2 years in the four premolar extraction group.     

安氏Ⅱ类1分类错（牙合）患者正畸前后咬合功能的研究

目的 研究安氏Ⅱ类1分类错（牙合）患者矫治前中后的咬合功能变化,分析评价固定矫治技术对牙颌功能的影响.方法 选择26名安氏Ⅱ类1分类错（牙合）患者,运用T-scan Ⅱ型咬合测量分析系统,记录其在矫治前、中、后牙尖交错位的（牙合）力（TOF）、（牙合）力不对称指数（AOF）、（牙合）接触点数（NOC）、（牙合）接触面积不对称指数（AOA）、（牙合）力中心点位置（COF）、（牙合）力中心点最大位移（MMCOF）及（牙合）干扰指数（OII）七项指标.结果 与矫治前相比,矫治中TOF及NOC下降,而矫治后升高（P＜0.05）,矫治后AOF、AOA、COF、MMCOF及OII均明显下降（P＜0.01）.结论 安氏Ⅱ类1分类错（牙合）患者正畸治疗后,咬合功能增强,明显消除了（牙合）不对称等不利因素,咬合功能更加平衡协调.     

Changes in tooth contacts following orthodontic treatment

Occlusal contacts in maximum intercuspation were examined in 38 patients at the end of the active phase of orthodontic treatment and again 3 months into the retention phase to assess the initial posttreatment occlusal changes. The sample consisted of 23 patients with conventional retainers and 15 patients with gnathological rubber tooth positioners. Polyether rubber impression bites were used to record occlusal contacts. The locations of the contacts were then transferred to study models. In the combined sample (N = 38), the total number of contacts increased 14% over the 3-month period. This was due entirely to an increase in the number of contacts on posterior teeth (premolars and molars). Those cases with fewer teeth in contact at the end of treatment developed more teeth in contact over the 3-month period. Although the group retained with positioners demonstrated a greater gain in the total number of teeth in contact over time when compared with the group with conventional retainers, the additional gain was minimal.     

Bite force in children with unilateral crossbite before and after orthodontic treatment. A prospective longitudinal study

In this prospective, longitudinal study, bite force was examined in children with a unilateral posterior crossbite before (stage 1), immediately after orthodontic treatment (stage 2), and after retention (stage 3). The sample comprised 19 (7 girls, 12 boys) children aged 7-11 years. The children were treated according to conventional practice, with an expansion plate (seven subjects) or a quadhelix appliance (12 subjects). Unilateral bite force was measured at the first molars by means of a standardized method. Statistical analysis was undertaken using Shapiro-Wilks W- and t-tests, and analysis of variance. There was no significant difference in bite force regarding age, gender, appliance, or side, i.e. right or left molar region. However, during stage 2 the bite force was significantly lower ipsilaterally to the crossbite than contralaterally (P<0.05). In general, the bite force was systematically lower than reference values, but the mean bite force (P<0.05) and the bite force on the ipsilateral side (P<0.01) increased significantly from stage 2 to stage 3. The bite force level was reduced immediately after treatment, but increased again after retention and approached the bite force level in children with neutral occlusion. The fluctuation in bite force level during orthodontic treatment may be due to transient changes in occlusal support, periodontal mechanoreceptors, and jaw elevator muscle reflexes.     

An electromyographic evaluation of bilateral symmetry of masticatory, neck and trunk muscles activity in patients wearing a positioner

Summary  This study was designed to investigate the attitude of a positioner (Finition^©) or an Hawley's retention appliance to create a symmetric function of the masticatory, neck and trunk muscles during the orthodontic retention phase. Sixteen patients (18·5 ± 2·2 years) were included in the sample. All the patients received an orthodontic therapy for the treatment of an Angle's class I malocclusion and skeletal class I, for a period of 2 years. After removal of orthodontic brackets, eight patients wore a teeth positioner (group I) as retention appliance and eight subjects wore an Hawley's appliance as upper retention (group II). Surface electromyographic (sEMG) activity was recorded from the bilateral anterior temporal, posterior temporal, masseter, sternocleidomastoid (SCM), upper and lower trapezius and cervical muscles at mandibular rest position and during maximal voluntary clenching (MVC) at T0, i.e. soon after the removal of orthodontic brackets and at T1, i.e. after 3 months of retention treatment. No significant difference was observed between the two groups at T0. At T1, at mandibular rest position, the group I showed a significantly lower sEMG activity of anterior temporal and SCM muscles compared with the group II. During MVC, at T1, the group I showed a significantly lower sEMG activity of the SCM and posterior cervicals, compared with the group II. The positioner seems to show a relevant effect on the sEMG activity of masticatory, neck and trunk muscles.     

Changes in occlusal force and occlusal contact area after active orthodontic treatment: a pilot study using pressure-sensitive sheets

The aim of this study was to investigate functional changes in occlusion during retention. Data on occlusal force (OcFr) and occlusal contact area (OcAr) was obtained using the pressure-sensitive sheet, from a treated group (20 female patients) who had had four premolar extractions and treatment with standard edgewise appliances, and a control sample who matched the treated group of retainer for sex, age and Angle classification at 1 year after removal. A repeated measures analysis of variance showed that the mean values of total OcFr and OcAr in the treatment group gradually increased during retention and were 669.3 N and 15.1 mm2, respectively, at 1 year after removal of retainer. The increases of OcFr and OcAr were larger in the molar region, especially at the second molar. At 1 year after removal of retainer, OcFr and OcAr in the second molar were significantly larger in the treatment group than in the control sample, and a similar distribution pattern of OcFr and OcAr to those in normal occlusion was seen. These results suggested that balanced OcFr and OcAr might be obtained during and after retention, due to the settling of molars that had been discluded by active orthodontic treatment.