正畸矫治埋伏阻生上颌前牙的临床研究

目的 探讨上颌前牙埋伏阻生的牙位分布、矫治方法和相关并发症的发生和预防.方法 对43例48颗埋伏阻生的上颌前牙,应用固定正畸技术,结合适宜的外科助萌术或开窗导萌术进行矫治.助萌组15颗,导萌组33颗.结果 48颗埋伏阻生的上颌前牙均顺利萌出至正常位置.助萌组无并发症出现;导萌组有5颗出现矫治后牙周附着不足,6颗出现牙根吸收.结论 正畸技术是矫治埋伏阻生上颌前牙的有效手段,治疗中应注意避免炎症的发生和减少手术创伤,以预防矫治并发症的发生.     

上颌尖牙埋伏阻生的外科-正畸联合治疗

目的:探讨尖牙埋伏阻生的外科-正畸联合治疗方法。方法:20例患者28颗上颌埋伏阻生尖牙,先用滑动直丝弓矫治器初步排齐牙列后,再局部间隙扩展,采用外科闭合式助萌技术,暴露埋伏尖牙牙冠,粘贴托槽,再进行正畸牵引导萌。结果:24颗埋伏尖牙均牵引入正常牙列,牙髓、牙周情况正常。有4颗尖牙因横位阻生和根冠成角采用外科拔除。结论:通过外科手术暴露和正畸牵引导萌联合治疗,能有效矫治埋伏阻生尖牙。     

上颌埋伏阻生前牙正畸治疗的临床研究

目的：观察上颌埋伏阻生前牙应用固定正畸方法进行矫治的临床疗效,探讨埋伏阻生前牙有效的治疗方法。方法：对49例58颗上颌前牙埋伏阻生病例,应用固定正畸进行矫治,结合牙槽外科开窗术,对埋伏牙进行牵引。其中20颗进行开拓间隙使之自然萌出,38颗进行开窗封闭式牵引导萌矫治。结果：55颗阻生牙矫治后牙髓活力正常、未见埋伏牙及邻牙牙根吸收、牙周组织正常。开窗封闭式牵引导萌有3颗牙治疗失败,总体成功率94.8%。结论：应用固定正畸技术开拓间隙或结合牙槽外科开窗术导萌埋伏阻生牙,可有效保存上颌埋伏阻生前牙。     

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目的：探讨阻生上颌尖牙合适的临床处理策略,为其合理治疗提供依据。方法回顾2000-2012年期间在大连市口腔医院正畸科接受治疗的35例阻生上颌尖牙病例的临床资料,总结分析尖牙阻生状况及相应的治疗措施和疗效。临床处理方法包括拔除、助萌和导萌。结果拔除2例;只做正畸治疗的助萌法16例,留出足够间隙后等待阻生尖牙自行萌出,观察时间5～24个月,均取得良好治疗效果,矫治后阻生尖牙牙龈形态及牙根状况良好;正畸附加外科手术牵引的导萌法17例,除1例21岁男性患者外,其余16例均牵引到位,但矫治后部分阻生尖牙牙龈形态不如助萌法矫治后。结论当阻生上颌尖牙牙体严重畸形、根弯曲短小及高位近远中向横位阻生时考虑拔除;阻生上颌尖牙近远中向错位不严重,扩弓或减数拔牙即可为阻生尖牙留出足够萌出间隙,判断其能自然萌出时首选助萌法;阻生上颌尖牙近远中向错位严重或阻生尖牙已伤及邻牙牙根、仅用正畸治疗无法去除阻生尖牙萌出障碍时采用导萌法,导萌术后的牵引需注意控制牵引方向及大小,要避免伤及邻牙牙根,尽量使阻生牙从附着龈萌出,有利于形成良好的牙龈形态。     

环切导萌术与封闭性导萌术的对比性研究

目的 临床研究上颌埋伏阻生产牙的外科导萌及正畸联合治疗方法。方法 分别采用环切导萌术和封闭性导萌术联合正畸治疗两种方法矫治埋伏阻生前牙８７颗。结果 行环切导萌术完成矫治后患牙临床冠较长,牙龈形态欠佳,疤痕可见。行封闭性助萌术正畸完成后其暴露牙齿的远中面宽度较小,唇侧骨高度增加。结论 行封闭性助萌术矫治的埋伏牙在美学效果等方面较行环切导萌术的好。     

磁力导萌埋伏切牙

磁力导萌埋伏切牙浙江省瑞安市南岸牙病医疗所（３２５２０７）黄世贵上颌前牙埋伏阻生，临床常见，因其破坏牙列的完整性，影响功能和美观，以往多采用移植或外科暴露，橡皮牵引的方法予以矫治。笔者利用磁性同极排斥、异极相吸的特性，导萌埋伏牙获得满意效果，现报告如...     

伴囊肿的上颌埋伏阻生中切牙早期引流助萌治疗

目的:探讨采用引流助萌的方法对伴囊肿的上颌埋伏阻生中切牙的早期治疗。方法:选取单侧上颌中切牙埋伏阻生、处于替牙早期伴囊肿的患者8例。外科囊肿切除同时对埋伏阻生上颌中切牙引流助萌治疗。治疗前后拍摄CBCT,Dolphin11.0软件测量矫治前后阻生牙及对侧正常同名牙的冠根长度。结果:8例患者的埋伏阻生上颌中切牙平均矫治时间6.7个月。矫治后阻生牙和对侧正常同名牙的冠根长度均有生长。阻生牙冠根长度较对侧正常同名牙明显短(P<0.05)。结论:本研究所采用引流助萌方法为埋伏阻生牙的矫治提供了一个安全、有效的新途径。     

一例间隙不足导萌病例的治疗取舍

<正>尖牙埋伏阻生在口腔正畸临床中较为常见,表现为尖牙萌出位置不足或完全不能萌出,易导致邻牙牙根吸收、牙源性感染、口角塌陷等^[1],对面部美观及口牙合功能影响较大,上颌尖牙是阻生牙中除智齿外发病率最高的阻生牙位,发病率约为1%～4%^[2]。其矫治难度较大,常需多学科协同治疗。现报道1例以非对称拔牙及导萌为主要治疗策略的牙列拥挤伴尖牙阻生的患者,旨在为此类病例的诊断与治疗提供参考。     

正畸牵引联合牙槽外科矫治上颌尖牙埋伏阻生的临床观察

目的 观察正畸牵引联合牙槽外科手术矫治上颌尖牙埋伏阻生的临床疗效。方法 对30例上颌尖牙埋伏阻生病例,利用正畸牵引联合牙槽外科手术进行矫治。结果 6例埋伏尖牙,经开拓间隙或减数助萌治疗,3～5个月后自然萌出;24例行牙槽外科开窗术配合正畸牵引,8～12个月后萌出。牙髓活力正常,牙龈形态美观,牙周情况良好。结论 正畸牵引联合牙槽外科手术,可快速有效地矫治上颌埋伏阻生尖牙。     

固定正畸结合开窗导萌矫正下颌第一磨牙阻生

目的: 探讨采用正畸直丝弓矫治技术矫正下颌第一磨牙阻生的治疗方法, 评估其疗效。方法: 选择8例下颌第一磨牙阻生患者, 采用MBT直丝弓矫治技术治疗。阻生牙开拓足够间隙后, 结合外科开窗导萌牵引第一磨牙萌出。采用SPSS12.0软件包对治疗前、后磨牙升高的距离进行配对t检验。结果: 8例埋伏阻生的第一磨牙全部萌出到正常平面, 平均升高(3.94±0.49) mm, 覆、覆盖正常, 咬合关系良好。X 线片显示阻生磨牙周围牙槽骨生长良好。结论: 正畸治疗结合外科开窗导萌可有效治疗下颌第一磨牙埋伏阻生。     

Tooth eruption: evidence for the central role of the dental follicle

Abstract The roles of the gubernaculum dentis, root formation, tooth crown and dental follicle in pre-functional eruption of a mandibular premolar have been studied in nine beagle dogs by radiographic and histologic evaluations of the effects of surgical ablation or removal of these structures on tooth eruption. The dental follicle was the only one of these structures required for the coordinated enlargement of the eruption pathway and formation of bone in the base of the bony crypt, the radiographic and histologic hallmarks of tooth eruption. These data, together with the topographic relationships of the dental follicle to areas of localized bone resorption and formation, are interpreted to mean that the dental follicle may influence, if not coordinate, these processes in tooth eruption.     

The apically repositioned flap in tooth exposure

Methods of exposing impacted teeth in order to bring them into the line of the arch include gingivectomy, the apically repositioned flap and closed eruption techniques. These procedures aim to facilitate the eruption of the impacted tooth with a minimum of disruption or damage to the tooth itself or adjacent structures. The aim of this paper is to discuss the various surgical methods of exposing impacted teeth and to help to identify where the use of the apically repositioned flap is indicated. Clinical examples are presented and a surgical method for carrying out this procedure recommended.     

Orthodontic treatment for an unerupted and severely rotated maxillary central incisor. A case report.

BACKGROUND: Many reports have indicated the treatment for permanent teeth with disturbed eruption due to the presence of supernumerary teeth. However, successful treatment for an unerupted maxillary incisor with severe rotation and another maxillary incisor with disturbed eruption by a supernumerary tooth is quite rare. CASE REPORT: We treated a 7-year-old Japanese male with an unerupted and severely rotated maxillary right incisor, along with a maxillary left incisor due to interference with eruption by an inverted supernumerary tooth. Orthodontic treatment using surgical exposure, traction and guidance of the rotated right incisor, and maxillary expansion following extraction of the supernumerary tooth were performed. FOLLOW-UP: At 27 months following extraction of the supernumerary tooth, and comprehensive orthodontic treatment led the malposititioned central incisors to a functional position and stable occlusion.     

原发性牙齿萌出障碍(PFE)的研究现状

原发性牙齿萌出障碍(PFE)是一种比较罕见的牙齿萌出异常性疾病,它是由于萌出机制本身异常而导致的牙齿萌出障碍,而非其他局部或全身因素所致。发病机制尚不十分明确,可能与基因突变有关,甲状旁腺激素受体1(PTH1R)突变是已经被证实的病因之一。临床表现以牙齿萌出不全和后牙开牙合为主要特征,正畸牵引无效。因其具有明显的家族聚集性,基因遗传分析是必要的辅助检查手段,对PFE的筛查、诊断和治疗具有重要意义。目前PFE尚无较好的治疗方法,可摘局部义齿、种植义齿和外科手术治疗等是可以参考的治疗手段。该文将从PFE的发病机制、临床特征、诊断和治疗等方面的研究现状作一综述。     

Regional control by the dental follicle of alterations in alveolar bone metabolism during tooth eruption

Tooth eruption is a localized, bilaterally symmetrical series of events which involves resorption and formation of alveolar bone on opposite sides of the tooth and requires the presence of the dental follicle. We examined the effect on eruption of selective surgical removal of parts of the follicle. Removal of either the basal or coronal halves of the follicle prevented eruption. Bone resorption and formation of an eruption pathway did not occur after removal of the coronal part of the follicle and bone formation did not occur after removal of the basal part of the follicle. Exposure and incisions of the follicle had no effect on eruption. We interpret these data to mean that the polarized resorption and formation of alveolar bone that occur around a tooth during eruption are regulated by the adjacent parts of the dental follicle.     

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.     

Spontaneous eruption of impacted maxillary incisors after surgical extraction of supernumerary teeth: a systematic review and meta-analysis

Objectives

To evaluate the spontaneous eruption potential of impacted human permanent teeth localized in the anterior part of the maxilla, after the surgical extraction of obstacles in their eruption pathway, by means of a systematic review and meta-analysis.

Materials and methods

A systematic literature search was carried out to locate studies reporting on the percentage of anterior permanent teeth erupting after surgical removal of the obstacle, without other interventions. Eruption potential of impacted teeth was calculated using a random-effects meta-analysis. Information about the sex proportion, follow-up duration, age and years during which the study was carried out was used for subgroup analyses.

Results

A total of twelve studies were included, with a total sample size of 960 cases and a follow-up period of up to 36 months. The results show that more than 65.5% of impacted teeth erupt spontaneously following surgical extraction of the obstacle, with an odds ratio of 4 (95% CI 1.9, 8.2) (p < 0.001) favouring spontaneous eruption.

Conclusions

When faced with an impacted maxillary anterior tooth, surgical extraction of the obstacle can lead to spontaneous eruption of the impacted tooth in the majority of cases, with better success with a longer follow-up for up to 3 years.

Clinical relevance

Based on the present meta-analysis, clinical recommendation would be to surgically remove the obstacle impeding the eruption of a maxillary anterior permanent tooth and wait for the eruption of the tooth for a period of 12–36 months, depending on the age of the patient.

     

Retrospective analysis of factors influencing the eruption of delayed permanent incisors after supernumerary tooth removal.

AIM: This was to assess the predictability of eruption of delayed permanent incisors after supernumerary removal and creation of adequate space, in relation to: root maturity, degree of vertical impaction, and degree of angulation of impaction. METHODS: The dental records of children with supernumerary teeth delaying the eruption of permanent incisors were analysed. The type of a supernumerary tooth, its location and position were recorded, along with the stage of root maturation, angulation and vertical distance of impaction of the permanent incisor. At the initial surgery, the unerupted supernumerary tooth and any retained primary incisors were removed. The unerupted permanent incisor was not exposed. If necessary, the maxillary primary canines were removed to create sufficient space for eruption of the delayed permanent tooth. A secondary surgical procedure was planned after 18 months if there was no significant progress of the permanent tooth towards eruption. STATISTICS: All data were entered onto a Microsoft Excel spread sheet and analysed using Fisher's Exact Tests throughout due to the small numbers. RESULTS: Sixty-six supernumerary teeth were removed, 22 from boys and 44 from girls with ages ranging from 6 to 10 years 6 months at the time of surgery. Primary canines were extracted in 59.1% of cases. Spontaneous eruption occurred in 89.4% of delayed permanent teeth. The mean time to eruption was 9.2 months (median = 7 months). There was no statistically significant association between tooth eruption and root maturity or the degree of vertical impaction. There was an association between eruption and the degree of the angle of impaction of the permanent incisor (p<0.05). CONCLUSION: The majority of delayed permanent teeth erupt spontaneously if sufficient space is available or created at the time of removal of the unerupted supernumerary. The angulation of impaction of the permanent incisor is associated with a delay in eruption.     

Traction--a surgical/orthodontic procedure.

Maxillary crowding may cause failure of eruption of the canine. The teeth so displaced are directed buccally or palatally. In both cases, surgical intervention is indicated after space has been made in the arch. Palatally displaced canines are treated by surgical excision of palatal mucosa to promote eruption. Wide excision is indicated to prevent the healing process from covering the exposed tooth crown. Because of the anatomy of the buccal mucosa, however, surgical excision of the crowns of buccally displaced canine frequently results in periodontal problems. An alternative technique is therefore presented; this involves the surgical exposure of the crowns of buccally displaced teeth to allow the attachment of a wire traction hook. The crown is then recovered. The traction hook provides a point of attachment, so that orthodontic forces may be applied to the unerupted tooth to guide its eruption. The preservation of the mucosal flap ensures a normal epithelial attachment develops on the buccal surface of the tooth, and the normal gingival anatomy of the buccal mucosa is maintained. The procedure may also be used in cases where upper incisors have been prevented from erupting because of the presence of supernumerary teeth. Even after surgical removal of the supernumerary teeth, the permanent incisors often fail to erupt. In such cases, the placement of traction hooks will enable the orthodontist to bring the unerupted teeth into their correct positions in the arch.