应用CBCT研究不同矫治器正畸拔牙矫治对前牙区牙根及牙槽骨的影响

目的 应用CBCT研究无托槽隐形矫治及传统固定矫治器正畸拔牙对前牙区牙根及牙槽骨的变化情况.方法 选择成人拔牙矫正的患者60例,随机分为无托槽隐形矫治器组及传统固定矫治器组(N=30).正畸治疗前后拍摄CBCT,测量两组正畸患者上下颌中切牙、侧切牙、尖牙的牙根长度及牙槽骨的厚度变化情况.结果 固定矫治器组较无托槽隐形矫...     

Twin-block与高位头帽肌激动器功能矫治后上切牙区牙槽骨改建的对比研究

目的:探讨生长发育高峰期患者功能矫治后上颌切牙位移及牙槽骨改建情况。方法:选择使用高位头帽肌激动器（HGAC）和Twin-block功能矫治器矫治成功的30例骨性Ⅱ类下颌骨后缩患者为研究对象,根据使用矫治器的不同将其分为HGAC组和Twin-block组,每组15例患者。治疗前及治疗后分别拍摄锥形束CT（CBCT）,观察上颌中切牙在牙槽骨内的相对位置变化及牙槽骨改建情况。采用SPSS 20.0 软件包对治疗前、后唇腭侧牙槽骨厚度、中切牙及牙槽骨角度变化进行分析。结果:在水平方向上,HGAC组和Twin-block组中切牙切缘均发生舌侧移动,而HGAC组根尖发生舌侧移动,Twin-block组根尖发生唇向移动;在垂直方向上,所有患者中切牙切缘均发生向下移动,根尖发生向上移动,但HGAC组切缘垂直方向向下移动较少,根尖垂直方向向上移动较多。HGAC组多数位点牙槽骨厚度增加,而Twin-block组唇侧牙槽骨厚度均减少,腭侧牙槽骨厚度增加。2组牙槽骨总厚度均增加,但Twin-block组牙槽骨总厚度增加更多,HGAC组牙槽骨角度减小更多。结论:2种功能矫治器均可使上切牙区牙槽骨发生积极的生长改建。HGAC在对上切牙实现控制性倾斜内收的同时,可使切牙有一定程度的压入,同时使上切牙区牙槽骨生长角度发生一定变化,而这种变化有利于改善Ⅱ类骨面型。Twin-block可使上切牙倾斜内收,提示在Twin-block功能矫治后行固定正畸内收前牙时,需更加注意前牙转矩的控制。     

正畸拔除下颌中切牙治疗的测量研究

目的　探讨拔除下颌中切牙矫治的适应征和矫治特点。方法　选择拔除下颌中切牙矫治病人 32例。应用Steiner方法和Riedel方法进行X线头影测量 ,分析矫治前后颌面改变和下颌切牙的位置改变 ;并进行矫治前后模型测量分析。结果　矫治后上颌切牙至NA的距离、下颌切牙与NB的角度、牙弓拥挤度和前牙弓宽度显著低于矫治前 (p <0 0 1) ,矫治后前牙覆低于矫治后 (p <0 0 5 ) ,矫治后下颌切牙平均后移 1 4mm ,向移位 1 85mm ,舌向倾斜 4 0 6度。结论　拔除下颌中切牙矫治的适应征为前牙反或对刃、Bolton指数异常和牙列拥挤病人。对伴有个别下颌前牙牙周萎缩的牙列拥挤病人可选择5 |51拔牙模式矫治。临床矫治应严格选择适应征 ,不应单纯为了缩短疗程拔除下颌中切牙。矫治中可配合使用邻面去釉方法 ,使用柔和的正畸力量 ,防止牙间乳头丧失和牙龈退缩。     

成人双颌前突患者正畸前后上颌切牙区唇腭侧牙槽骨的变化

目的:分析成人双颌前突患者治疗前后上颌切牙区唇腭侧牙槽骨的变化,为正畸治疗中在牙槽骨内的安全移动牙齿提供参考依据.方法:纳入23例成人双颌前突的患者,拔除4颗第一前磨牙,采用直丝弓矫治技术一步法整体内收上下前牙.患者治疗前后均拍摄锥体束CT片,测量上颌切牙区唇腭侧牙槽骨厚度(alveolar bone thickness,ABT)、釉牙骨质界-牙槽嵴顶的高度(alveolar bone height,ABH)和牙槽骨面积(alveolar bone area,ABA).结果:治疗后上颌切牙区唇侧的ABT在根中和根尖部水平显著升高,而腭侧的ABT在颈部、根中和根尖3个水平上均下降(P<0.05);中切牙在颈部和根中两个水平上总ABT显著减少(P<0.05),而侧切牙在颈部、根中和根尖处总ABT均减少(P<0.05);正畸治疗后,切牙区腭侧ABA减少,而唇侧ABA增加(P<0.05);上颌中切牙和侧切牙腭侧的ABH和上颌侧切牙唇侧的ABH显著增加(P<0.01).结论:正畸治疗会导致成人双颌前突患者的切牙区腭侧的牙槽骨发生显著吸收,减少整个切牙区的牙槽骨量,需关注其对牙周组织的长期影响.     

成人双颌前突患者正畸前后上颌切牙区唇腭侧牙槽骨的变化

目的:分析成人双颌前突患者治疗前后上颌切牙区唇腭侧牙槽骨的变化,为正畸治疗中在牙槽骨内的安全移动牙齿提供参考依据.方法:纳入23例成人双颌前突的患者,拔除4颗第一前磨牙,采用直丝弓矫治技术一步法整体内收上下前牙.患者治疗前后均拍摄锥体束CT片,测量上颌切牙区唇腭侧牙槽骨厚度(alveolar bone thickness,ABT)、釉牙骨质界-牙槽嵴顶的高度(alveolar bone height,ABH)和牙槽骨面积(alveolar bone area,ABA).结果:治疗后上颌切牙区唇侧的ABT在根中和根尖部水平显著升高,而腭侧的ABT在颈部、根中和根尖3个水平上均下降(P<0.05);中切牙在颈部和根中两个水平上总ABT显著减少(P<0.05),而侧切牙在颈部、根中和根尖处总ABT均减少(P<0.05);正畸治疗后,切牙区腭侧ABA减少,而唇侧ABA增加(P<0.05);上颌中切牙和侧切牙腭侧的ABH和上颌侧切牙唇侧的ABH显著增加(P<0.01).结论:正畸治疗会导致成人双颌前突患者的切牙区腭侧的牙槽骨发生显著吸收,减少整个切牙区的牙槽骨量,需关注其对牙周组织的长期影响.     

减数正畸治疗中中切牙牙根及牙槽骨形态变化的锥形束CT测量分析

目的： 研究减数正畸治疗对成人患者中切牙牙根吸收及牙槽骨形态的影响。方法： 选取11例行减数正畸治疗的成年患者,于治疗前、后进行全牙列锥形束CT（CBCT）检查,观察治疗前、后上、下中切牙牙根吸收、牙槽骨厚度变化与牙槽骨高度缺损,采用SPSS 23.0软件包对数据进行统计学分析。结果： 部分牙位出现牙长度减小及牙根长度减小,上颌切牙牙根长度变化量大于下颌切牙。中切牙舌腭侧颈部牙槽骨宽度表现为一定程度降低,其中上中切牙腭侧根颈部及下颌中切牙舌侧根中部牙槽骨宽度变化较为明显。下颌中切牙唇侧中部牙槽骨宽度增加,但舌腭侧牙槽骨在正畸治疗后骨开窗、骨开裂位点增多,且较上颌更明显。结论： 减数正畸治疗伴随中切牙牙根一定程度上的吸收和舌腭侧牙槽骨吸收,唇侧牙槽骨骨量增加。下颌舌侧牙槽骨吸收导致骨开窗、骨开裂位点增多。     

正畸前牙牙根吸收的年龄因素及好发牙位的探讨

目的:探讨年龄因素对正畸治疗引起牙根吸收的影响及在前牙中的好发牙位,以供临床参考。方法:选择60例拔牙后经直丝弓矫治完成的病例,分为成人组与儿童组,每组各30例。以上、下颌前牙作为研究对象,每组各360颗牙。应用全颌曲面体层片,研究正畸治疗后牙根吸收情况,采用SPSS13.0软件包对结果进行统计学分析。结果:60例患者正畸治疗前、后牙根吸收指数改变均有统计学意义(P<0.01),正畸治疗后牙根吸收发生率明显升高;成人组与儿童组牙根吸收等级比较有显著差异(P<0.01)。上、下前牙各牙位牙根吸收好发顺序是上颌中切牙、上颌侧切牙、下颌中切牙、下颌侧切牙、上颌尖牙、下颌尖牙。结论:正畸治疗中,成人比儿童更易发生牙根吸收,上、下前牙各牙位牙根吸收发生率不同,中、重度牙根吸收易发生在成年人的上颌中、侧切牙。     

安氏Ⅰ类拔牙正畸治疗牙槽嵴高度变化的CBCT研究

目的 通过分析锥形束CT(cone beam CT, CBCT)比较成人和青少年安氏Ⅰ类正畸患者经减数正畸治疗前后的牙槽嵴高度,探究减数治疗对成人及青少年安氏Ⅰ类患者牙槽骨高度的影响及差异。方法 研究纳入成人和青少年安氏Ⅰ类拔牙正畸患者共40例(成人20例,青少年20例),均减数4颗第一前磨牙进行矫治,通过术前及术后CBCT分别对青少年及成人患者的20颗牙颊、舌侧牙槽嵴高度进行测量及分析。结果 在测量的3 200个根面中,成人在正畸治疗后前牙区牙槽骨高度降低明显;成人矫治前有210个根面骨开裂,拔牙矫治术后为477个,青少年矫治前骨开裂有14个,拔牙矫治术后为40个。结论 正畸拔牙矫治将导致成年患者牙弓前部牙槽骨高度降低,而青少年组拔牙矫治前后各区段牙槽骨高度未见明显变化。     

基于锥形束CT的不同垂直骨面型重度骨性Ⅲ类错牙合成人患者上下前牙冠根成角分析

目的    应用锥形束CT分析不同垂直骨面型重度骨性Ⅲ类错牙合成人患者上下前牙牙冠与牙根所成的角度（冠根成角）,为正畸治疗过程中上下前牙更安全而有效地移动提供参考依据。方法    选取2012年1月至2021年1月于大连市口腔医院正畸科就诊的重度骨性Ⅲ类错牙合成人患者152例,根据下颌平面角分为高角组（53例）、均角组（52例）、低角组（47例）,应用Invivo dental 5.0软件将所有患者的锥形束CT影像进行三维重建,测量并比较各组上下前牙的冠根角（CRA）和面轴角（SSA）。结果    各组上下中切牙冠根成角总的比较,差异均有统计学意义（均P < 0.05）。组间两两比较结果显示,上中切牙CRA和下中切牙SSA由大至小均依次为低角组、均角组和高角组,而下中切牙CRA和上中切牙SSA由大至小均依次为高角组、均角组和低角组,差异均有统计学意义（均P < 0.05）;其中,低角组上中切牙CRA > 180°且SSA为负值。结论    重度骨性Ⅲ类错牙合患者上下中切牙冠根成角在不同垂直骨面型之间有显著差异,其中高角和均角患者上中切牙冠相对牙根向舌侧倾斜,且高角患者更加明显;低角患者上中切牙与之相反,表现为牙冠相对牙根向唇向倾斜。3种骨面型患者的下中切牙牙冠相对牙根均向舌侧倾斜,且下颌平面角越小,其牙冠舌向倾斜越明显。     

正畸拔牙矫治病例中出现牙龈折痕的临床研究

目的: 探讨正畸拔牙矫治病例出现牙龈折痕原因,为临床预防牙龈折痕的发生提供依据。方法: 在拔除前磨牙进行固定矫治的错牙合畸形患者中,筛查出发生的牙龈折痕病例87例,选择其中一侧出现牙龈折痕,另一侧未出现的病例65例,将出现牙龈折痕的一侧作为实验侧,未出现牙龈折痕的一侧作为对照侧,通过CBCT测量分析,比较两侧牙槽骨宽度、高度及骨密度的变化与出现牙龈折痕的相关性。结果: 牙龈折痕多发生在下颌,牙周探针牙龈折痕深度下颌均大于上颌。牙龈折痕侧牙槽骨宽度减小、高度降低以及密度减小均明显大于对照组,两组数据统计结果有显著性差(P<0.05)。结论: 正畸拔牙矫治病例中牙龈折痕的出现与牙槽骨宽度、高度及骨密度的变化具有相关性,拔牙间隙关闭过程中牙槽骨吸收,对软组织支持的丧失,可能是出现牙龈折痕的解剖学因素。     

牙槽嵴裂骨移植修复术后影响骨吸收因素的初步研究

目的对牙槽嵴裂骨移植修复的患者进行随访评价，对植入骨的成活率及影响骨吸收的因素做初步研究。方法随访108例牙槽嵴裂骨移植患者，运用多因素回归统计方法进行分析。结果植入骨成活率为88％，临床成功率为60％；影响骨吸收的主要因素是：感染、手术年龄、裂隙类型、功能刺激、手术操作等，其中感染因素仅占22％。结论提高牙槽嵴裂植骨修复效果的因素：①手术应在患者8～11岁进行；②术前应行正畸治疗；③手术操作技术应进一步完善；④建立必要的功能刺激；⑤积极控制伤口感染。     

牙槽骨再生正畸技术治疗成人错畸形伴原发性牙槽骨缺损的远期疗效评价

目的: 定量评价牙槽骨再生正畸技术治疗成人错畸形伴原发性牙槽骨缺损的远期疗效。方法: 从上海交通大学医学院附属第九人民医院口腔颅颌面科2014年1月起就诊的连续病例中,选择下前牙区存在原发性牙槽骨缺损且治疗结束后随访时间> 2 年的成人错畸形患者,将其中接受牙槽骨再生正畸治疗的30例患者作为研究对象。通过锥形束CT（cone-beam CT,CBCT）评价不同观察时间点术区的牙槽骨形态,采用SAS 9.1软件包对数据进行统计学处理。结果: 牙槽骨再生正畸治疗成人错畸形伴原发性牙槽骨缺损后,术区未见牙根吸收。根尖水平骨厚度增量效果最佳且远期疗效最为稳定,根长3/4水平次之,根长1/2水平未见骨厚度增量效果。术区唇舌侧出现少量牙槽骨高度降低。结论: 牙槽骨再生正畸技术是治疗成人错畸形伴原发性牙槽骨缺损的有效方式,但仍存在术区少量牙槽骨垂直丢失等局限。     

即刻种植义齿的临床研究

目的 评估即刻种植义齿的临床技术特点及近期临床效果。方法 32例患者共59个牙位在拔牙的同时植入了种植体，55个牙位同时植骨。平均6个月后行Ⅱ期手术，暴露种植体，修复牙冠。修复后追踪时间平均39个月。结果 1颗种植体在愈合期内脱落，其余病例在修复后至最后1次复查，临床效果良好。结论 即刻种植的临床方法可行，3年成功率与传统种植方法相同，其具有避免骨吸收，手术创伤小，种植体位置与轴向好，修复美学效果好等优点。     

Restoring teeth following crown lengthening procedures

Crown lengthening procedures are often necessary to successfully restore teeth that have been mutilated at or below the level of the bone crest. Forced eruption is preferred to surgical removal of supporting alveolar bone, since forced eruption preserves the biologic width, maintains esthetics, and at the same time exposes sound tooth structure for the placement of restorative margins. To properly construct a crown, the minimal distance from the alveolar crest to the coronal extent of sound tooth structure should be 4 mm. Before initiation of forced eruption, the restorability of the root after completion of the orthodontic phase must be considered. A technique is suggested to calculate the root-to-crown ratio that will be created after root extrusion with respect to the coronal level of sound tooth structure before treatment.     

Analysis of bone resorption after secondary alveolar cleft bone grafts before and after canine eruption in connection with orthodontic gap closure or prosthodontic treatment.

PURPOSE: We sought to analyze the success rate of secondary alveolar cleft bone grafts before and after canine eruption in connection with orthodontic gap closure or gap opening. PATIENTS AND METHODS: Sixty-eight secondary alveolar cleft bone grafts with iliac crest spongiosa were carried out in 57 patients (mean age, 9 years; age range, 8 to 11 years) with 11 bilateral and 46 unilateral clefts of the lip, alveolus, or palate. Gap closures were carried out after 53 bone grafts (78%), and gap openings with subsequent dental implants were carried out with 15 bone grafts (22%). The parameters acquired radiologically (orthopantomograms) at the time of the surgery and the follow-up examination (mean age, 3 years; age range, 7 months to 9 years) were 1) bone resorption in relation to the interdental height of the alveolar process in the vicinity of the cleft and 2) root growth of the teeth in the vicinity of the cleft. The statistically significant differences (P <.05) were monitored with a software program. Resorption grades I and II (>50% of the interalveolar bone height) were considered to be a success. RESULTS: Resorption was grade I in 69%, grade II in 19%, grade III in 10%, and grade IV in 1% of cases. Thus, the overall success rate was 88%. At the time of the osteoplasty, the root growth of the tooth in the immediate vicinity of the cleft was fully completed in 27 teeth (39%), three-quarters completed in 23 teeth (26.5%), and semicompleted in 18 teeth (33.8%). Twelve teeth (18%) in the vicinity of the cleft (lateral incisors/canine) remained unerupted and displaced after the surgery. It was necessary to expose unerupted teeth surgically to reposition them orthodontically. The resorption losses were significantly lower with gap closures than with gap openings (P <.001). However, bone grafts performed before canine eruption were largely carried out with the objective of orthodontic gap closure, in contrast to the bone grafts that were carried out after canine eruption (P <.02). CONCLUSION: Gap closures provide more favorable results than do gap openings in regard to resorption. Controlled dental eruptions or orthodontic gap closures reduce the graft resorption. The exact timing of surgery proved to be only a secondary consideration.     

正畸牵引术在下颌第三磨牙低位近中阻生拔除中的应用

目的 :研究正畸牵引拔除下颌近中阻生第三磨牙对改善邻牙牙槽骨缺损的作用。方法 :选取2016-07—2018-01期间,我院收治的单侧或双侧有第二磨牙远中牙槽骨缺损的下颌第三磨牙近中阻生患者60例,按照随机数字表法将所有患者分为对照组(30例)和正畸牵引组(30例)。对照组患者常规拔除下颌第三磨牙,正畸牵引组患者经正畸牵引1~6个月后拔除下颌第三磨牙。检测患者正畸牵引治疗前(T0)、拔牙前(T1)、拔牙后3个月(T2)、拔牙后6个月(T3)这几个时间点,下颌第二磨牙近中及远中牙槽嵴顶至釉牙骨质界高度、下颌第二磨牙近中及远中牙槽骨密度、张口受限情况。结果:正畸牵引组患者在T1、T2、T3节点时,下颌第二磨牙近中牙槽嵴顶至釉牙骨质界高度分别为5.16、3.98、2.12 mm,均低于对照组的7.16、4.57、3.16 mm,差异有统计学意义(t/P=12.250/0.001、8.963/0.001、56.680/0.001)。正畸牵引组患者在T1、T2、T3节点时,下颌第二磨牙远中牙槽嵴顶至釉牙骨质界高度分别为5.24、3.15、2.34 mm,低于对照组的8.12、5.49、3.16 mm,差异有统计学意义(t/P=17.670/0.001、43.280/0.001、15.110/0.001)。正畸牵引组患者在T1、T2、T3节点时,张口受限评分分别为2.10、1.25、0.68分,均低于对照组的2.56、2.00、1.69分,差异有统计学意义(t/P=9.690/0.001、30.530/0.001、41.120/0.001)。结论:正畸牵引拔除下颌近中阻生第三磨牙可有效改善邻牙牙槽骨缺损现象,增大牙槽骨密度。     

Long-term periodontal status of teeth moved into extraction sites

The present study was undertaken to assess the long-term periodontal status adjacent to teeth that had been moved orthodontically into extraction sites. Twelve persons with a mean age of 29.2 +/- 5.7 (SD) years, who had completed orthodontic therapy at least 10 years previously, were examined. The orthodontic treatment had included bilateral premolar extraction in only the maxilla. Interproximal tooth surfaces in the maxilla adjacent to the extraction sites (study group) were compared to corresponding tooth surfaces in the mandible (control group) with respect to plaque, visual inflammation, bleeding after probing, pocket depth, gingival recession, loss of connective tissue attachment, radiographic bone height, and root resorption. Statistical comparisons were made via analyses of variance and t tests. There were no differences between the groups for any clinical parameter except the presence of less visual inflammation in study subjects. Radiographically, there were no differences in crestal alveolar bone levels measured from the cementoenamel junction. Bone height evaluation by the Bjorn method showed less alveolar support in the study group. However, this was due to the influence of root resorption rather than an effect on crestal height. It was concluded that orthodontic movement of teeth into extraction sites had been without detrimental effect upon the adjacent periodontal status.     

青少年与成人正畸治疗前后上前牙冠根比变化的初步研究

目的探讨直丝弓矫治器矫治前后牙齿冠根比的变化规律,及年龄因素在其中所起的作用。方法选取青少年患者23例和成人患者23例共46例,分为青少年组和成年组,根据正畸治疗前后全口曲面断层片,以托槽为参照系,测量计算出治疗前后中切牙、侧切牙及尖牙的根尖吸收量、牙槽嵴吸收量及冠根比变化量,进行配对t检验,分析年龄因素与矫治前后冠根比变化的相关性。结果青少年组治疗前后中切牙平均冠根比分别为0.62±0.04,0.70±0.06;侧切牙平均冠根比分别为0.63±0.04,0.70±0.06;尖牙平均冠根比分别为0.54±0.05,0.60±0.06。成年组治疗前后中切牙平均冠根比分别为0.67±0.04,0.78±0.06;侧切牙平均冠根比分别为0.66±0.05,0.77±0.05;尖牙平均冠根比分别为0.57±0.05,0.70±0.06。各组治疗前后冠根比有显著性差异,成年组上前牙冠根比变化量较青少年组显著(P<0.01)。结论直丝弓矫治后,上前牙冠根比均明显增大,其中成年组较青少年组显著,但都仍在临床可接受的正常范围内。     

Decoronation of an ankylosed tooth for preservation of alveolar bone prior to implant placement*

Abstract – A 12‐year‐old patient sustained avulsions of both permanent maxillary central incisors. Subsequently, both teeth developed replacement resorption. The left incisor was extracted alio loco. The right incisor was treated by decoronation (removal of crown and pulp, but preservation of the root substance). Comparison of both sites demonstrated complete preservation of the height and width of the alveolar bone at the decoronation site, whereas the tooth extraction site showed considerable bone loss. In addition, some vertical bone apposition was found on top of the decoronated root. Decoronation is a simple and safe surgical procedure for preservation of alveolar bone prior to implant placement. It must be considered as a treatment option for teeth affected by replacement resorption if tooth transplantation is not feasible.