下颔骨嗜酸性肉芽肿

曲面体层片（图1）示左下颌骨体部椭圆形病损，范围从第一前磨牙至第二磨牙，界限清晰，第一、二前磨牙及第一、二磨牙未见牙根吸收征象，但根间及牙间牙槽骨可见溶骨性破坏。     

14例正畸减数第一恒磨牙病例临床疗效分析及相关问题初探

目的 评价正畸减数第一磨牙的临床疗效,并就减数第一磨牙的相关矫治原则、间隙关闭情况及第三磨牙的建（牙合）等问题进行初步探讨.方法 选取我科近10年完成的14例减数第一磨牙矫治病例进行分析.通过对矫治前后模型的PAR指数和头颅侧位片,对矫治后磨牙间隙关闭、咬合关系及软组织侧貌进行评价;并通过曲面断层片,初步评价第二磨牙的牙根吸收和牙槽骨的改建以及第二磨牙和前磨牙的牙根平行状况.结果 14例患者平均疗程（29.5±4.3）个月,PAR疗效分析显示治疗后变差或无改变0例,改善5例,明显改善9例,提示拔牙间隙关闭满意,牙（牙合）关系良好;软组织侧貌协调,面型满意;曲面断层片显示第二前磨牙与第二磨牙牙根平行状况良好,第二磨牙牙根及牙槽骨无明显吸收.结论 减数第一磨牙病例只要严格把握适应证,合理的支抗设计和严谨的临床操作,可以获得满意的临床矫治效果.     

下颌第一磨牙缺失两基牙双端固定桥修复的生物力学分析

目的：研究下颌第一磨牙缺失两基牙双端固定桥修复的应力分布。方法：采用CT扫描获取健康成人上、下颌牙及其支持组织二维图像,通过计算机重建技术获得右下颌第一磨牙缺失后的双端固定桥桥体颊舌径分别为正常时的100%、90%、66.7%和50%与右下颌双端固定桥桥体及右下颌第二磨牙颊舌径均分别为正常时的90%、66.7%和50%的7个三维有限元模型,在相同垂直载荷和斜向载荷下分析了基牙牙槽骨高度及桥体大小对固定桥应力分布的影响。结果：当双端固定桥桥体颊舌径分别为正常大小的66.7%和50%时,固定桥两基牙中的第二前磨牙在垂直向加载时均出现明显应力集中;当下颌第二磨牙牙槽骨吸收程度等于及大于35%时,下颌第二前磨牙在其垂直向加载与斜向加载时均出现明显的应力集中,下颌第二磨牙在其垂直向加载时出现明显的应力集中。结论：固定桥受载的Von Mises最大应力集中于连接体表面。对于下颌567双端固定桥,当桥体变窄,颊舌径小于正常大小的66.7%时,有可能会对基牙中的第二前磨牙造成损害。当下颌第二磨牙牙槽骨吸收程度等于及大于35%时,可能对双基牙都造成损害,并可能促使并加速牙槽骨的进一步破坏吸收。     

2000年前出土人颌骨的牙周病研究

目的：调查距今2000年前人类牙周病状况,探寻人类牙周病的流行规律。方法：观察并统计秦始皇帝陵区山任陶窑遗址出土的104具人骨架全部2452个牙齿的牙周病患病情况。按个体的年龄分组,分别对牙周病患病率、罹患的牙位进行统计分析与比较。结果：该人群牙周病的平均患病率49．04％,其中30岁以上年龄组的牙周病患病率最高（76．19％）。在不同年龄组中,牙周病的患病率和患牙数占观察牙总数的比例随个体年龄的增长而增高。不同牙位牙周病发生率顺序为：M1〉M2〉P2〉P1〉M3〉C=I2〉I1。结论：牙周病在2000年前的人群中已广泛存在,其发病率较现代人高。     

减数拔除第一恒磨牙正畸治疗初探——附37例临床病例分析

目的 评估正畸减数拔除第一恒磨牙的临床疗效,探讨拔除第一磨牙矫治设计的一般原则和关闭磨牙间隙常见问题的处理方法.方法 对10年来临床完成的拔牙病例412例中37例减数第一磨牙矫治的病例进行分析.对治疗后第一磨牙间隙关闭情况、牙(牙合)关系和侧貌进行评价;并根据X线曲面断层片初步评估第二磨牙、前磨牙牙根平行状况,以及第二恒磨牙牙根吸收和齿槽嵴牙槽骨吸收情况.结果 37例患者平均疗程22.9±4.6月,磨牙拔牙间隙关闭满意,牙(牙合)关系良好,软组织面型协调.按单颌来看,第二磨牙弱支抗设计的有55.8%,中度支抗设计的有39.5%,即磨牙间隙关闭主要由第二磨牙前移完成.64颗减数拔除磨牙中,由于龋坏已经缺失、残根、残冠因素、大面积充填体因素分别占到36.9%、27.7%、21.5%.治疗后第二恒磨牙与前磨牙牙根平行状况良好.曲面断层片显示无明显第二磨牙根吸收,也未能显示治疗后第二磨牙牙槽嵴显著的水平吸收.结论 减数第一恒磨牙的病例经过仔细的支抗设计和谨慎的临床操作,可以获得满意的临床治疗效果.     

螺纹钉和PPF树脂核全冠修复后牙残根、残冠的体会

作者自2001年以来,采用成品螺纹钉加卡瑞斯玛PPF树脂核再以全冠修复后牙残根、残冠患者112例153牙,经1~3年的随访观察,疗效满意,报道如下。1材料和方法1.1一般资料本文共修复后牙残根、残冠患者112例153牙。男40例56牙;女72例97牙。年龄18~70岁。153个牙经X线片检查证实根管治疗较完善,牙槽骨吸收不超过根长的1/3,牙齿基本不松动,残根、残冠断端不超过龈下2 mm,修复后能定期复诊。153个患牙的牙位分布见表1。表1 153个患牙的牙位分布(n,%)颌位牙位第一前磨牙第二前磨牙第一磨牙第二磨牙合计上颌10(6.5)11(7.2)30(19.6)16(10.5)67(43.8)下…     

17例组牙功能(牙合)个体后牙磨道斜度变化趋势分析

目的：应用组牙功能(牙合)天然牙列模型的三维图像，观察不同个体“磨道斜度”的差异；不同牙位后牙“磨道斜度”的变化趋势；同一个体随磨耗进展“，磨道斜度”的变化。方法：选择拥有十年前后完整牙列模型的研究对象17名，平均年龄56.5岁。使用三维光栅扫描系统ATOSⅡSO扫描模型，获得三维图像。使用逆向工程软件Geomagic 12进行模型三维图像的测量和分析。测量研究对象双侧上颌第一前磨牙、第二前磨牙、第一磨牙、第二磨牙“磨道斜度”值，统计分析“磨道斜度”变化趋势。结果：不同牙位后牙的“磨道斜度”值差异有显著性（P<0.05），且无论十年前还是十年后，无论左侧还是右侧，均存在从第一前磨牙至第二磨牙“磨道斜度”逐渐减小的变化趋势。不同研究对象“磨道斜度”值差异同样有显著性（P<0.05）。十年前后，研究对象的“磨道斜度”值改变方向不一致，部分研究对象左右两侧变化不一致。结论“：磨道斜度”具有个体差异；同一个体从第一前磨牙至第二磨牙“磨道斜度”逐渐减小；同一个体随时间进展“磨道斜度”值变化方向可能与个体(牙合)运循环范围有关。     

一侧下颌磨牙舌侧多生两个前磨牙1例

一侧下颌磨牙舌侧多生两个前磨牙１例谭捷患者男，５８岁，１９９６－０９－２０因牙楔形缺损来诊，检查：右下颌第二前磨牙与第一磨牙间舌侧和第一磨牙与第二磨牙舌侧各多生一前磨牙，外形与正常前磨作者单位：１０００４１北京首钢总公司保健室牙相同。余牙排列正常，牙...     

正畸治疗中磨牙的拔除和保留(十二)——拔除磨牙与拔除前磨牙矫治牙根吸收的对比研究

目的：通过对磨牙拔除病例与前磨牙拔除病例的牙根吸收情况的对比,探讨关闭磨牙间隙是否加重牙根吸收。方法：将矫治前后下颌第二磨牙的冠根比作为判断牙根吸收程度的指标。其中拔除下颌第一磨牙病例的牙根数为72个,拔除下颌第一前磨牙病例的牙根数为74个。将测量值进行配对t检验。结果：第一磨牙拔除病例与第一前磨牙拔除病例相比,虽然矫治后下颌第二磨牙牙根吸收的程度较大,但两组间比较并无显著性差异。结论：采用拔除第一磨牙后的第二磨牙近中平移技术,并不加重矫治后磨牙牙根的吸收。     

隐形矫治器远移下颌第一磨牙的三维有限元研究

目的 构建隐形矫治器远移下颌第一磨牙的有限元模型,探究是否使用微种植体支抗及不同第一磨牙起始位置进行远移时的牙列移动特点。方法 使用锥形束CT (CBCT)数据构建下颌骨、牙齿、牙周膜及隐形矫治器模型,依据是否辅助微种植体弹性牵引分为无支抗组及微种植体组（第一磨牙与第二磨牙根间）,在两组中以第一磨牙起始位置分为工况1：第一磨牙距第二前磨牙0 mm;工况2：第一磨牙距第二前磨牙1 mm,工况3：第一磨牙距第二前磨牙2 mm;工况4：第一磨牙距第二前磨牙3 mm。分析各工况牙列总体位移及各方向位移的数据特点。结果 无支抗组：除第一磨牙向远中移动外,其余牙均表现为反向移动。微种植体组：除工况1中第二磨牙表现为少量近中移动,其余工况全牙列均表现为远中移动、前牙舌向移动,其中工况4第一磨牙远中位移值最大。随着第一磨牙起始位置向远中改变,第一磨牙向远中、前磨牙向近中及前牙向唇侧移动量增加,而第二磨牙向近中移动量减小。结论 微种植体能够有效保护前牙支抗,增加磨牙远移的表达率,避免第二磨牙出现往返移动,且第一磨牙移动起始位置与其远移量及其余牙齿移动量有关。     

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。     

Reposition of intruded permanent incisor by a combination of surgical and orthodontic approach: a case report

This report presents a case of a completely intrusive luxation of an immature permanent central incisor in a 7 years 9 months-old girl. Because there are severe intrusive trauma and cortical alveolar bone fracture, it was impossible to reposition with orthodontic or surgical method alone. The intruded tooth was repositioned to healthy alveolar bone level by using surgical extrusion and stabilization with sutures and periodontal pack. After healing of adjacent bone, the intruded maxillary central incisor erupted orthodontically by removable orthodontic appliance. It was moved from a high position to level of adjacent tooth in about 7 months. A radiograph was taken 6 months after ceasing forced eruption, which demonstrated minor root resorption, but the alveolar bone height had increased.     

上颌切牙内收前后牙根及牙槽骨的变化

目的 通过锥形束CT（CBCT）测量并分析上颌前突患者上颌切牙内收治疗前后牙根及牙槽骨的变化。方法 选取2014年1月—2015年12月完成的正畸病例37例,其中男性17例,女性20例,平均14.5岁。所有患者拔除上颌双侧第一前磨牙且使用种植钉强支抗内收上颌切牙,通过头影测量获取上颌切牙内收角度、内收量及伸长量,使用NewTom NNT软件对CBCT数据进行多平面重建,调整冠状、轴向与矢状轴,选取通过切缘和根尖的牙齿长轴最长的矢状截面测量上颌切牙内收治疗前后牙根及牙槽骨的变化。结果 上颌前牙内收治疗前后,中切牙内收角度为12.92°±6.43°,内收量为（5.54±2.21） mm,伸长量为（0.60±0.95） mm,牙根吸收长度为（0.81±0.46） mm,牙根吸收率为6.80%±3.60%,切牙内收治疗前后牙根长度变化具有统计学差异（P<0.05）,治疗后唇侧牙槽骨高度降低量为（0.20±0.22）mm,治疗前后差异有统计学意义（P<0.05）。牙根吸收率与上颌中切牙切端的水平向位移及根尖至唇侧皮质骨的距离具有相关性;唇侧牙槽骨高度变化量与上颌切牙内收角度的相关系数为0.354,具有统计学意义（P<0.05）。结论 上颌前突患者代偿性治疗后,上颌切牙产生了明显的牙根吸收,唇侧牙槽骨高度降低。牙齿移动量越大,或超出了牙槽骨的解剖限制和改建限度,容易导致牙根吸收。唇侧牙槽骨高度变化量与切牙内收角度呈负相关。     

A study of the anterior portion of the palate as it relates to orthodontic therapy.

1. The anterior portion of the palate does not appear to move lingually as orthodontic forces move incisor teeth lingually. Although the alveolar bone directly supporting the teeth can be moved distally (and elongated), it does not appear possible to move the apex of the root more distally than the pretreatment position of the palatal plate. Thus, there appears to be an anatomic limitation to the distal movement of maxillary incisor teeth. 2. When incisor teeth are moved distally within the boundaries of the present alveolar process, the supporting bone does not remodel to the roots' new position; when a root which was initially positioned nearer the labial alveolar plate is moved distally against the palatal plate, there was observed no adaptation in the bone to have the root once again located near the labial alveolar plate, the root remained stable against the palatal plate. 3. When great distal movement of incisor teeth results in an alteration in position of the supporting alveolar bone, remodeling of the bone maintains a relatively constant labiolingual width of this alveolar bone. The new position of the tooth and supporting bone appears to be stable. 4. The scanty metallic implant evidence would seem to support histologic observations that alveolar processes are remodeled by apposition of bone on the cortical plate toward which the tooth is moving and resorption of the cortical plate away from which the tooth is moving. 5. There does not appear to be a statistically significant correlation between posterior facial measurements (SNMP) and the labiolingual width of the anterior palate.     

Successful self-replantation of avulsed tooth with 42-year follow-up

Abstract This report presents a case of a 55-year-old woman who was hit in the mouth 42 years ago. The maxillary right central incisor was avulsed. The patient's mother replanted the tooth within 10–20 minutes and “splinted” it with aluminium foil from a cigarette package and a piece of cardboard. Clinical and radiographic examination after 42 years revealed a slightly discolored asymptomatic right central incisor. The root canal space was obliterated and no signs of root resorption or periapical radiolucency were observed.     

Factors influencing secondary alveolar bone grafting in cleft lip and palate patients: prospective analysis using CT image analyzer.

OBJECTIVE: To examine the effect of migration of the germ of the lateral incisor into the bone for eruption factors on bone bridge resorption. METHODS: Twenty-five subjects who underwent secondary alveolar bone graft were enrolled. The volume of the alveolar bone grafts immediately after the operation (V1), bone bridge formation 6 months postoperatively (V2), and tooth (teeth) migration into the bone bridge (Vt) were measured using a computed tomography (CT) image analyzer. Based upon these measurements, the following points were examined: (1) the correlation between the tooth-occupied ratio (Rt = Vt/V2 x 100) and the ratio of bone bridge resorption (Rv = (V1 - V2)/ V1 x 100); and (2) comparison of the tooth-occupied ratio (Rt) and the ratio of bone bridge resorption (Rv) between the groups with and without the germ of the lateral incisor. RESULTS: A significant negative correlation was found between Rv and Rt (p < .001). Comparison of Rv and Rt between the groups with and without a germ of the lateral incisor revealed that both indices were significantly higher in the former group than the latter one (p < .05). CONCLUSION: In cleft lip and palate patients with a germ of the lateral incisor, it is beneficial to carry out secondary bone grafting to the alveolar cleft at the age of 5 to 7 years, preceding eruption of the canine, in order to form a good bone bridge that will facilitate eruption of the lateral incisor and subsequent normal dentition and occlusion.     

Bone inductive proteins to enhance postorthodontic stability: A pilot study

Objectives:To evaluate the use of bone morphogenetic proteins to enhance postorthodontic stability in sheep and to develop a biological method of postorthodontic retention.Materials and Methods:First incisors were extracted in four mature and healthy sheep, and the second incisors were tipped reciprocally toward the midline and then retained. Dried bone matrix was injected into the distal periodontal space of the left second incisor. The right second incisor was left as a control. Both incisors were retained in the tipped position for 4 weeks. Then, the orthodontic appliance was removed and the teeth were left without retention. Six weeks later, the animals were killed and serial sections were prepared for histologic observation.Results:Unlike the control, the experimental second incisor maintained its tipped position with minimal relapse. On the distal periodontal space of the experimental tooth, areas of focal fusion between newly formed bone and newly formed areas of hypercementosis were observed. In the distal periodontal space of the control tooth, osteoclastic activity was observed along most of the socket wall, and the periodontal space appeared narrow and compressed. This brought the tooth close to the boundary of the alveolar bone, confirming the relapse observed on that side.Conclusion:This study proposes a new method of retention in which a biologically safe osteoinductive material is used to retain the teeth via induction of points of approximation between the cementum and alveolar bone.     

大鼠下颌切牙拔出后剩余牙槽嵴吸收模型的建立

目的:建立大鼠切牙拔除后剩余牙槽嵴吸收的实验动物模型并探讨其发生机制。方法:选用健康雄性Wistar大鼠30只,局麻下齐龈缘磨除右下颌切牙牙冠,每3天磨除1次,共3次,最后磨除后3d拔除右下颌切牙,术后0、1、2、4、8、12周分别处死大鼠。用软X线摄片测量大鼠下颌剩余牙槽嵴的长度和保存率,组织学方法评价大鼠下颌切牙拔牙窝的愈合情况。对18只健康雄性Wistar大鼠通过HE染色观察磨除牙冠后的不同时期牙周组织形态学改变。结果:牙槽嵴长度:4、8、12周拔牙侧与非拔牙侧相比明显降低(P<0.05);拔牙4周后牙槽嵴保存率明显降低。组织形态学:拔牙后2周,拔牙窝内可见新生骨,残存的血凝块减少;拔牙后4周骨改建活跃;拔牙后8周,拔牙窝内充满新生骨;拔牙后12周,新生骨和周围牙槽骨界限不清。牙冠磨除后,牙周组织出现水肿,主纤维束断裂,丧失功能排列,血窦增加,随时间改变逐渐加重。结论:可以采用拔除大鼠切牙的方法建立剩余牙槽嵴吸收的动物模型。     

Moving an ankylosed central incisor using orthodontics, surgery and distraction osteogenesis

When a dentist replants an avulsed tooth, the repair process sometimes results in the cementum of the root and the alveolar bone fusing together, with the replanted tooth becoming ankylosed. When this occurs, the usual process of tooth movement with bone deposition and bone resorption at the periodontium cannot function. If dental ankylosis occurs in the maxillary incisor of a growing child, the ankylosed tooth also cannot move vertically with the subsequent vertical growth of the alveolar process. This results in the ankylosed tooth leaving the plane of occlusion and often becoming esthetically objectionable. This report describes a 12-year-old female with a central incisor that was replanted 5 years earlier, became ankylosed, and left the occlusal plane following subsequent normal vertical growth of the alveolar process. When growth was judged near completion, the tooth was moved back to the occlusal plane using a combination of orthodontics, surgical block osteotomy, and distraction osteogenesis to reposition the tooth at the proper vertical position in the arch. This approach had the advantage of bringing both the incisal edge and the gingival margin of the clinical crown to the proper height in the arch relative to their antimeres. Previous treatment procedures for ankylosed teeth have often involved the extraction of the affected tooth. When this is done, a vertical defect in the alveolar process results that often requires additional bone surgery to reconstruct the vertical height of the alveolar process. If the tooth is then replaced, the replacement tooth must reach from the final occlusal plane to the deficient ridge. This results in an excessively long clinical crown with a gingival height that does not match the adjacent teeth.