Ⅲ类错(牙合)下颌偏斜正畸疗效的初步分析

目的 探讨Ⅲ类错(牙合)牙性、功能性和轻度骨性下颌偏斜的正畸矫治效果,为临床治疗提供参考.方法 选择Ⅲ类错(牙合)牙性、功能性和轻度骨性下颌偏斜患者共35例,男性14例,女性21例,年龄7～22岁(平均16.5岁).牙性偏斜主要通过扩大上颌牙弓,促使下颌自动复位;功能性下颌偏斜应用双颌式功能矫正器或不对称性前方牵引和Ⅲ类颌间牵引进行治疗;轻度骨性下颌偏斜行拔牙正畸掩饰性治疗.结果 通过正畸临床矫治,22例Ⅲ类错(牙合)牙性和功能性下颌偏斜患者的颜面外形和咬合均达到满意的疗效.13例Ⅲ类错(牙合)骨性下颌偏斜患者,拔牙掩饰性正畸矫治仅可改善颜面美观.结论 Ⅲ类错(牙合)牙性和功能性下颌偏斜是正畸治疗的适应证;而对于Ⅲ类错(牙合)轻度骨性下颌偏斜的患者,单纯正畸治疗仅可减轻牙(牙合)畸形的程度.     

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。     

骨性Ⅲ类下颌偏斜成人上颌牙列垂直特征的研究

目的 通过锥体束CT(cone-beam computed tomography,CBCT)研究骨性Ⅲ类下颌偏斜者双侧上颌牙列垂直向特征及其与下颌偏斜间的关系.方法 选取成年骨性Ⅲ类下颌偏斜患者21例(男10例,女11例),测量有关下颌骨偏斜和上颌牙列垂直向测量指标,双侧进行配对t检验或配对秩和检验,下颌偏斜指标与上颌...     

成人下颌偏斜伴颞下颌关节紊乱病的正畸治疗

［摘要］ 本文报道了1例成人轻度骨性Ⅲ类,下颌偏斜伴颞下颌关节紊乱病的正畸治疗病例。该病例通过去程序化治疗及固定矫治器的掩饰性治疗,纠正前牙反牙合,下颌偏斜有所改善,关节症状消失。     

安氏Ⅲ类错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伴有下颌偏斜者颌面在水平向及垂直向不对称的特点。方法 :早期恒牙 ,安氏Ⅲ类错伴有下颌偏斜患者 4 0名 ,治疗前的正位片与 4 0名正常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     

伴有或不伴有下颌偏斜的成人骨性Ⅲ类患者的颈椎姿势差异的研究

目的：比较伴有或不伴有下颌偏斜的成人骨性Ⅲ类患者颈椎姿势的差异。方法：选择伴有和不伴有下颌偏斜的成人骨性Ⅲ类患者各20例作为实验组1和实验组2,20例正常牙合者作为对照组,对其自然头位时拍摄的头颅侧位片进行颈椎姿势的测量及统计学分析。结果：实验组1和实验组2的SN-CP、SN-OPT及SN-CVT明显小于对照组,HOR-CVT、HOR-OPT明显大于对照组（P〈0.05）;CVT-OPT大于对照组,但差异不显著。实验组1、2之间的各测量结果差异均不显著。结论：伴有或不伴有下颌偏斜的成人骨性Ⅲ类患者的颈椎姿势均存在异常,颈椎成前倾位。应提高对无下颌偏斜的单纯成人骨性Ⅲ类患者颈椎姿势的关注。     

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。     

安氏Ⅲ类错He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He伴有下颌偏斜者颌He面在水平向及垂直向不对称的特点。方法：早期恒牙He，安氏Ⅲ类错He伴有下颌偏斜患者40名。治疗前的正位片与40名正常He者进行比较，用SPSS统计软件处理数据。结果：下颌骨及下牙及宽度增大；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。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。     

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.     

下颌偏斜患者下颌侧方运动时髁突的运动轨迹特征

目的 通过记录下颌偏斜患者的髁突运动轨迹，研究此类患者髁突运动的规律。方法 下颌偏斜患者31例（男性9例，女性22例），年龄12～26岁，平均18岁。使用CADIAX　Ⅲ型髁突运动轨迹轴图描计仪，记录并通过配对t检验和秩和检验分析患者下颌侧方运动时髁突的运动轨迹，并将其与患者下颌偏斜量进行多元线性回归分析。结果下颌偏斜患者下颌侧方运动时髁突的运动轨迹不对称，偏斜侧的运动位移大于非偏斜侧，差异有统计学意义（P＜0．01）；偏斜侧髁突的水平倾斜度小于非偏斜侧，差异有统计意义（P＜0．01）。随着偏斜量的增加，偏斜侧与非偏斜侧髁突的位移差距也相应增加，非偏斜侧髁突的位移相应减小，差异有统计学意义（P＜0．05）。结论下颌偏斜患者不仅颅面形态不对称，下颌侧方运动时髁突运动轨迹在长度、角度等方面也不对称，其与偏斜量有一定的相关性。     

老年人下颌磨牙牙根及根管的锥形束CT研究

目的：利用锥形束CT观察分析老年人下颌磨牙的牙根、根管数目和形态。方法：选择能够配合检查,并在扫描过程中头部保持静止状况的老年人,对其牙齿进行锥形束CT扫描,对扫描图像进行三维重建和选择不同方向的断层观察记录下颌磨牙的牙根和根管。结果：锤形束CT检查老年人166例,下颌磨牙共532颗。下颌磨牙近中根均为单根,远中双根仅发生于下颌第一磨牙,而C形根则仅发生于第二磨牙。近中根以两根管为主在下颌第一磨牙和第二磨牙分别占有95．26％和50．38％;远中根以一根管为主在第一磨牙和第二磨牙分别占有64．60％和56．97％,C形根管的发生率为22．48％。结论：下颌磨牙牙根和根管的变化主要发生在第一磨牙的远中根和第二磨牙的C形根及C形根管。     

Endodontic treatment of an unusual connation of permanent mandibular molars: a case report

A 27-year-old patient with an anomalous mandibular molar was referred for endodontic therapy. Clinical and radiographic examination revealed the connation of a second mandibular molar with a third molar. Challenging endodontic therapy was performed in the unusual connated molars. A 2-year recall showed good treatment result.     

罕见下颌双侧第二磨牙远中对称萌出混合型牙瘤

目的:分析罕见下颌双侧第二磨牙远中牙龈组织对称萌出的外周性混合性牙瘤临床特点,结合文献探讨该病发生机制。方法:结合我院确诊的罕见下颌双侧第二磨牙远中牙龈组织对称萌出的外周性混合性牙瘤患者的临床资料,对比相关文献进行分析研究。结果:该患者没有外伤史、特殊感染史及遗传病史,在下颌双侧第二磨牙远中牙龈组织对称萌出外周性混合性牙瘤,瘤体无牙齿形状,表面光滑不规则,呈叶状实性钙化团块,与下颌双侧第二磨牙远中牙合面吻合。结论:青少年牙瘤的发现更多来自X线检查,非创伤、感染、遗传病史的个体也可能发生外周性混合性牙瘤,其萌出力可能借助于磨牙的萌出,对称发生较罕见,可能与牙胚发育早期相关基因表达或调控异常有关。     

Preoperative assessment of the relationship between the mandibular third molar and the mandibular canal by axial computed tomography with coronal and sagittal reconstruction

OBJECTIVE: We sought to evaluate the relationship between the mandibular third molar and the mandibular canal by using axial computed tomography with coronal and sagittal reconstruction for third molar surgery. STUDY DESIGN: Forty-seven impacted third molars in 41 patients were found in close association with the mandibular canal during a panoramic radiographic assessment. The relationship between the mandibular third molar and the mandibular canal was evaluated by using computed tomography and compared in terms of operative exposure of the inferior alveolar nerve and postoperative labial dysesthesia. RESULTS: Twenty-four (51%) mandibular canals were buccal relative to the third molar, 12 were lingual, 9 were inferior, and 2 were between roots. At the time of the surgical procedure, the inferior alveolar nerve was visible in 7 patients. Postoperative lower lip dysesthesia occurred in 1 patient whose mandibular canal was in the lingual position. CONCLUSIONS: Axial computed tomography with coronal and sagittal reconstruction provides useful information to surgeons regarding the relationship between the mandibular third molar and the mandibular canal.     

Nerve injury during mandibular third molar surgery. The importance of preoperative diagnosis and surgical skill

A 26-year-old woman was referred by a dentist to an oral and maxillofacial surgeon after an unsuccessful attempt to remove a mandibular third molar. A panoramic radiograph showed the remaining root of the third molar and the patient suffered from insensitivity of the lower lip. The root of the third molar was removed surgically. The sensitivity of the lip recovered completely within three months. Injury of the inferior alveolar nerve and the lingual nerve is a serious complication after mandibular third molar removal. The inferior alveolar nerve is at risk for injury if the third molar root is intimately connected with the mandibular canal. Refraining from preoperative clinical and radiographic diagnostics is malpraxis. Surgical skill is a prerequisite to reduce the risk of nerve injury.     

Periodontitis with hypercementosis: report of a case and discussion of possible aetiologic factors

Background: Hypercementosis may be idiopathic or secondary to either local factors or systemic disorders. However, periodontitis as an aetiologic factor in the formation of hypercementosis has never been documented in the literature. Methods: We report a case of periodontitis with hypercementosis, affecting the right mandibular second premolar and first molar teeth. Results: Our patient’s maxillary was edentulous and the mandibular teeth #47, #43, #42, #41, #31, #32, #33, #36, #37 were missing. The right mandibular second premolar and first molar had first‐degree mobility and second‐degree mobility respectively. Periodontal pocket depth in the right mandibular second premolar and first molar were 5 mm and 8 mm at buccal pockets, 6 mm and 9 mm at distal pockets, respectively. The radiograph revealed that the roots of both teeth were grossly thickened and blunted. The right mandibular first molar was extracted and sent for histopathological examination. The definitive diagnoses were periodontitis and hypercementosis. Conclusions: The concomitant occurrence of periodontitis and hypercementosis in our patient suggests that periodontitis is a predisposing factor for hypercementosis development. This condition may be associated with various local stimuli and possible compensative phenomenon.     

The Prevalence of Three-rooted Mandibular Permanent First Molars in a German Population

The purpose of this retrospective study was to assess the prevalence of three-rooted mandibular first molars among a German dental school patient population. A total of 800 patients' full-mouth periapical radiographs were screened, and, out of these, 524 patients possessing at least one mandibular first molar were selected. The radiographs of these cases were evaluated under optimal conditions using double magnifying glasses. The incidence of three-rooted mandibular first molars and the correlation between left- and right-side occurrences and between males and females were recorded and analyzed using the chi-square test. A total of 1,024 mandibular first molars were evaluated. Left molars comprised 500 teeth and right molars 524 teeth. Seven patients were found to have a three-rooted mandibular first molar, three females and four males (p = 0.981). The overall incidence of patients with three-rooted mandibular first molars was 1.35%. All three-rooted molars occurred unilaterally. The prevalence of teeth showing an extra root from all teeth examined was 0.68%. The right first molar had an incidence of 0.57% and the left molar of 0.80%, respectively (p = 0.953). In conclusion, the occurrence of three-rooted mandibular first molars among this German population was rare.     

微创拔除压迫下牙槽神经的第三磨牙方法分析

目的: 应用牵引拔牙、截冠和超声骨刀微创拔牙技术拔除压迫下牙槽神经的第三磨牙,观察术后产生下唇麻木等并发症的发生情况。方法: 选择60例全景片和锥形束CT（CBCT）显示下颌第三磨牙牙根压迫下牙槽神经的患者,分别采用3种方法拔牙各20例,术后检查下唇麻木情况。结果: 应用牵引拔牙技术和截冠方法拔除压迫下牙槽神经的第三磨牙,术后无人发生下唇麻木,而应用超声骨刀微创拔牙的患者中有1例出现轻微的下唇麻木症状,经用药1个月后好转。结论: 牵引拔牙技术、截冠和超声骨刀3种方法均可有效避免智牙拔除后下唇麻木的并发症。     

Mandibular buccal bifurcation cyst: a case report and literature review

The mandibular buccal bifurcation cyst is a cystic lesion occurring on the buccal surface of the permanent mandibular first molar in 6- to 8-year-old children. The purpose of this article was to present a case report of an 8-year-old with a radiolucent area on the permanent mandibular left first molar, with clinical, radiological, and histological characteristics compatible with the pathological entity mentioned. The treatment adopted in this case was enucleation without extraction. The patient is still under observation without any sign of recurrence.     

Transplantation of mandibular third molar in seventh decade: long-term follow-up and evaluation

Transplantation of a nonfunctional mandibular third molar into the opposite mandibular second molar site, where it was necessary to remove the second molar of a 61-year-old patient, has been reported. There was long-term follow-up and evaluation, with radiographs and clinical examination during the ninth postoperative year. The patient had no complaints related to the transplant at the long-term follow-up visit. The periodontal tissues were in excellent condition. The tooth was firm, and the radiograph demonstrated growth of new attachment by showing lamina dura and periodontal ligament space. There was filling-in of bone in the lateral and periapical areas, and there was no evidence of resorption. A root canal filling had been acquired in the transplant between the second and ninth postoperative years.