上颌尖牙与侧切牙易位的系列矫治

目的探索上颌尖牙与侧切牙易位的矫治方法,以提高临床矫治效果。方法对上颌尖牙与侧切牙易位的11例患者,采用开拓间隙、易位侧切牙人工反让道、易位尖牙远移并控根、舌侧弓丝近中移动侧切牙、交互控根、舌侧固定保持器保持的系列矫治法进行矫治。结果11例患者经系列矫治后均达到了较理想的效果,牙弓排列整齐,易位尖牙与侧切牙牙根平行。结论采用系列矫治法矫治尖牙与侧切牙易位,可有效提高临床矫治效果,缩短矫治时间。     

上颌尖牙-侧切牙唇侧易位的分步牵引治疗

目的:探讨应用锥形束CT(cone beam computed tomography ,CBCT)定位、诊断,指导上颌尖牙-侧切牙唇侧易位的分步牵引治疗。方法:选取在南京医科大学附属口腔医院正畸科矫治的上颌尖牙-侧切牙唇侧易位的青少年患者22例,计26颗尖牙,获取其治疗前的CBCT数据,根据其易位特征分为5类,并依据分类制定矫治方案,模拟矫治步骤与施力的方向,指导临床治疗。结果:19颗Ⅰ、Ⅱ、Ⅲ和部分Ⅳ类易位尖牙牵引复位,3颗Ⅳ、Ⅴ类易位尖牙牵引替代拔除的切牙,2颗Ⅳ类尖牙维持易位,2颗Ⅴ类尖牙被拔除。结论:CBCT辅助上颌唇侧易位尖牙分类,指导治疗方案的制定,提高治疗成功率。     

上颌埋伏并与侧切牙易位的尖牙的正畸矫治

目的：探讨上颌埋伏并与侧切牙易位的尖牙的正畸矫治。方法：采用带钩的改良Nance弓联合直丝矫治技术治疗了2例替牙期上颌埋伏并和侧切牙易位尖牙病例,首先用改良Nance弓的末端钩在高位水平地牵引尖牙冠向颊侧及后方移动,同时用直丝弓技术使侧切牙排齐、根近中移动、牙体整体腭侧移动,使尖牙冠和侧切牙根在冠状向分开。然后采用“随形弓”,在维持两者在冠状向和垂直向的距离情况下,不断改变“随形弓”置于尖牙托槽上弓丝水平臂的第二序列弯曲,使两个交叉的易位牙体不断换位。结果：2例患者尖牙及侧切牙恢复正常的排列顺序,牙髓、牙周健康,治疗时间27个月。结论：矫治上颌埋伏并与侧切牙易位的尖牙关键是创造足够的空间,使两个易位牙的牙体换位时无干扰。改良Nance弓联合直丝矫治技术是一种有效的方法。     

埋伏上尖牙与侧切牙发生不完全易位的矫治方法研究

目的 探讨埋伏阻生上尖牙与侧切牙发生不完全易位后的导萌方法,将易位的尖牙牵引至正常位置,以达到美观效果,行使正常功能.方法 选择不完全易位的单侧埋伏阻生上尖牙患者12例（男6例,女6例）,年龄11.5～21.0岁,平均14.5岁,其中尖牙偏腭侧阻生7例,偏颊侧阻生5例.外科手术暴露埋伏牙,应用固定矫治技术,调整牵引方向将埋伏牙牵引至正常位置.结果 易位的尖牙均与侧切牙发生位置交换,尖牙移至正常位置,且具有良好的冠根方向和咬合关系,尖牙及侧切牙均无明显根吸收.平均疗程19个月.结论 将不完全易位的埋伏尖牙牵引入正常位置的难点在于易位埋伏的尖牙翻越相邻侧切牙牙根时,二者不相互阻挡.解决此难点的关键是精确判断尖牙牙冠与侧切牙牙根的位置关系,适时调整牵引方向.     

运用横腭杆支抗、侧切牙托槽倒置矫治上颌尖牙与侧切牙异位5例

目的寻求简单,方便、有效的上颌尖牙与侧切牙异位的矫治方法。方法对5例已萌出上颌尖牙与侧切牙唇侧异位患者,联合使用上颌横腭杆、倒置粘结侧切牙托槽成功矫治异位尖牙。结果 5例患者的异位尖牙均进入牙弓,获较满意结果,用时6～8个月。结论上颌已萌出的异位尖牙通过横腭杆支抗和直丝弓矫治技术被纳入正常牙弓位置,保持了患者良好的牙齿排列和容貌。     

上颌中切牙与尖牙同时阻生的临床特征分析

目的分析上颌中切牙与同侧尖牙同时阻生病例的临床特征。方法选择上颌中切牙与同侧尖牙同时阻生病例21例,分析上颌中切牙阻生类型与尖牙阻生情况,测量阻生侧及对侧侧切牙发育或萌出异常情况。结果与中切牙阻生同时发生的尖牙76.2%为唇侧阻生,其中完全易位与不完全易位占唇侧阻生尖牙的68.8%,尖牙唇侧阻生病例中侧切牙根远中倾斜和伴牙冠近中倾斜者占87.5%,尖牙唇侧或腭侧阻生病例中,出现锥形或过小等畸形侧切牙的比例分别为31.25%和40.00%。上颌中切牙与尖牙不同阻生类型患者,前牙反牙合比例都超过40%,且多为牙型反牙合。结论与中切牙阻生同时发生的尖牙阻生多为唇侧阻生,与中切牙阻生类型无关,与侧切牙根远中倾斜高度相关,尖牙完全易位与过小或锥形等畸形侧切牙有关。     

上颌尖牙-侧切牙唇侧易位的三维影像研究

目的应用锥形束CT(CBCT)研究上颌尖牙-侧切牙唇侧易位的三维特征。方法选取在南京医科大学附属口腔医院正畸科就诊并由CBCT三维影像诊断为上颌尖牙-侧切牙唇侧易位的患者40例,共计涉及46颗尖牙,在三维图像上分析易位尖牙与邻牙的关系、易位的特征,将易位尖牙分成5类。结果唇侧易位上颌尖牙均为冠唇向倾斜,近远中向以近中倾斜(80.4%)为主。在相邻中切牙、侧切牙中,10颗(21.7%)中切牙发生牙根吸收,且均累及根中1/3,8颗(17.4%)侧切牙发生重度牙根吸收。易位尖牙以Ⅲ、Ⅳ类多见,分别占总数的23.9%、39.1%。尖牙长轴越接近水平,尖牙牙尖距离正中矢状面越近,距离牙合平面越远,中切牙的牙根吸收率也越高。结论 CBCT三维定位有助于准确判断易位尖牙的位置以及与邻牙的关系,为制定治疗方案提供指导。     

双侧上颌尖牙与第二双尖牙易位1例报告

双侧上颌尖牙与第二双尖牙易位１例报告牙易位通常为相邻牙的位置发生交换。常见于上颌尖牙与第一双尖牙位置更换,也有侧切牙与尖牙发生易位者。而双侧上颌尖牙与第二双尖牙隔位易换,实属少见,报告如下。患者女性,３３岁。右上颌牙位不正,嵌食３年,要求拔牙而就诊。...     

上颌唇侧水平埋伏阻生尖牙正畸导萌的力学原理分析

目的：分析上颌唇侧埋伏阻生尖牙正畸导萌的力学原理，探讨上颌唇侧埋伏阻生尖牙的矫治力方向设计以及改良Nance弓的作用。方法：采用自行设计的改良Nance弓辅以直丝矫治器，对5例上颌唇侧水平埋伏阻生尖牙进行正畸一外科联合治疗，比较分析了直接牵引和改良Nance弓辅助牵引二种方式的矫治力方向，埋伏牙的移动方式及其力学原理。结果：5例上颌唇侧水平埋伏阻生尖牙顺利萌出至正常位置，尖牙及邻近侧切牙牙髓、牙周健康。力学原理分析显示采用改良Nance弓矫治方法，埋伏牙的移动方式更合理，所需矫治力更轻，支抗负荷更小。结论：矫治上颌唇侧水平埋伏阻生尖牙时，要合理设计矫治力方向，改良Nance弓是一种符合生理力学需要的辅助装置。     

双侧上颌尖牙与第二双尖牙易位1例

双侧上颌尖牙与第二双尖牙易位１例四川省攀枝花市第五医院口腔科宋玉荣牙易位通常为相邻牙的位置发生交换。常见于上颌尖牙与第一双尖牙位置更换，也有侧切牙与头牙发生易位者。而双侧上颌尖牙与第二双尖牙隔位易换，较为少见，报告如下。患者女性，３３岁。因食物嵌塞３...     

Unilaterally impacted maxillary central incisor and canine with ipsilateral transposed canine-lateral incisor

Concurrent impaction and transposition of maxillary anterior teeth is uncommon and poses a challenge for dentists. Early diagnosis and management of eruption disturbances benefits esthetic and functional outcomes. This article describes the treatment of a teenager who had impactions of the left maxillary central incisor and canine as well as ipsilateral canine-lateral incisor transposition. Treatment alternatives and effective orthodontic techniques are delineated. To optimize the treatment results, the impacted maxillary canine was surgically exposed and orthodontically distalized with an innovative cantilever. Subsequently, the deeply impacted maxillary central incisor was uncovered and orthodontically mesialized into the arch. Finally, the displaced maxillary lateral incisor was brought into its normal position. The combined surgical-orthodontic approach resolved a difficult clinical issue and avoided additional restorations. An esthetic, functional outcome was achieved and satisfied the patient.     

Maxillary canine transpositions in two brothers and one sister: associated dental anomalies and genetic basis

Transposition is an uncommon dental anomaly involving positional interchange of two teeth. The maxillary canine is the tooth more frequently transposed in man. Maxillary canine-first premolar appears to be the most common type of tooth transposition, followed by maxillary canine-lateral incisor transposition. Maxillary canine transpositions are frequently associated with other dental abnormalities such as agenesis and pegshaped incisors. This report describes the presence of transposed canines in one sister and two brothers. The female showed bilateral maxillary canine-first premolar transposition with the left canine fully mesial to its neighboring first premolar, and the right canine blocked-out facially between the first and second premolar. One of the brothers showed full maxillary left canine-lateral incisor transposition. The other brother showed maxillary canine-first premolar transposition and agenesis of maxillary lateral incisors, with the left canine blocked-out facially between the first and second premolar. Findings from this case report and other previously published cases provide strong evidence that maxillary canine transpositions are a disturbance of tooth order and eruptive position resulting from genetic influences within a multifactorial inheritance model.     

Maxillary incisor impaction and its relationship to canine displacement.

This study aimed to examine the eruption status of unerupted maxillary permanent canines in patients who also had an impacted central incisor. Seventy-five unilateral cases of the incisor anomaly were retrospectively examined. Using the initial panoramic films, we assessed the positions of the ipsilateral and contralateral canines and the lateral incisors and the timing (eruption progress) of the canines. The final position of the canines was evaluated from patient records and progress photographs. The data showed a significant increase in prevalence and severity of displaced canines in the ipsilateral side (41.3%) compared with the contralateral side (4.7%). Palatally displaced canines occurred in 9.5%, buccally displaced canines in 30.2%, and canine-lateral incisor transposition in 1.6% of the patients. Half of the buccally displaced canines in the ipsilateral side were pseudotransposed with the adjacent lateral incisor. The eruption timing of ipsilateral undisplaced canines was either similar or delayed, relative to the contralateral tooth, but never accelerated. The ipsilateral lateral incisor was strongly angulated because of a more distally located apex (5 mm) rather than a mesially tipped crown. The ipsilateral canine was relatively more superiorly positioned (undererupted). Patients who had trauma had a significantly higher prevalence and severity of canine displacement and more distally displaced lateral incisor apices. Initial height of incisor impaction did not influence the results. These data provide evidence of a significant environmental influence of an impacted maxillary central incisor in delaying and altering the eruption path of the ipsilateral maxillary canine.     

Case of unilateral transposition of a maxillary lateral incisor and canine treated without extraction

In this article, we report the successful treatment of a patient, aged 11 years 5 months, who presented for treatment with a chief complaint of lack of eruption of his maxillary left canine. Panoramic radiography and computed tomography revealed complete transposition of the maxillary left lateral incisor and canine. The patient was treated with surgical exposure and traction of the impacted canine to an appropriate location, followed by nonextractive treatment with full resolution of the transposition of the lateral incisor and canine. The diagnosis, planning, appliance design and treatment sequences are described. Alternative treatments, including their advantages and disadvantages, are also discussed.     

Maxillary canine-lateral incisor transposition--orthodontic management

A case of maxillary canine-lateral incisor complete transposition is presented. Treatment options for transposed teeth, including alignment in their transposed positions, extraction of one or both transposed teeth, and orthodontic alignment to their normal positions in the arch, are discussed. The orthodontic technique and sequence used in this challenging case to align the fully transposed teeth to their normal position in the dental arch are described.