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.     

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.     

Maxillary canine impactions related to impacted central incisors: two case reports

AIM: The purpose of this case report is to describe the combined surgical and orthodontic treatment of two cases with an impacted maxillary central incisor and canine in the same quadrant and to discuss the causal relationship between them. BACKGROUND: The most common causes of canine impactions are usually the result of one or more factors such as a long path of eruption, tooth size-arch length discrepancies, abnormal position of the tooth bud, prolonged retention or early loss of the deciduous canine, trauma, the presence of an alveolar cleft, ankylosis, cystic or neoplastic formation, dilaceration of the root, supernumerary teeth, and odontomas. Although impaction of the maxillary central incisor is almost as prevalent as impacted canines its etiology is different. The principal factors involved in causing the anomaly are supernumerary teeth, odontomas, and trauma. REPORTS: Case #1: A 10.5-year-old girl in the early mixed dentition stage presented with a chief complaint of the appearance of her anterior teeth. She had a Class I skeletal pattern and a history of trauma to the maxillary central incisors at age five with premature exfoliation. Radiographs revealed an impacted upper right central incisor in the region of the nasal floor, delayed eruption of the maxillary permanent central incisor, and the adjacent lateral incisor was inclined toward the edentulous space. Treatment was done in two stages consisting of surgical exposure and traction of the impacted central incisor and fixed orthodontic treatment. Case #2: An 11.5-year-old girl presented for orthodontic treatment with the chief complaint of an unerupted tooth and the appearance of her upper anterior teeth. She was in the late mixed dentition period with a Class III skeletal pattern along with an anterior cross-bite with some maxillary transverse deficiency. The maxillary right canine and central incisor were absent, but the maxillary right deciduous canine was still present. Treatment included arch expansion followed by surgical exposure and traction of the impacted teeth and fixed orthodontic treatment. SUMMARY: This case report provides some evidence of a significant environmental influence of an impacted maxillary central incisor on the path of eruption of the ipsilateral maxillary canine. When an impacted maxillary central incisor exists, the maxillary lateral incisor's root might be positioned distally into the path of eruption of the maxillary canine preventing its normal eruption. Ongoing assessment and early intervention might help to prevent such adverse situations from occurring.     

Radiographic assessment of maxillary incisor position after rapid maxillary expansion in children with clinical signs of eruption disorder

Background and objective

In this study we assessed the influence of rapid maxillary expansion (RME) on the intraosseous vertical position and inclination of the impacted incisors diagnosed at an early developmental stage on panoramic radiographs and subsequently treated by surgical removal of the obstacle.

Materials and methods

Following surgical removal of the obstacles to incisor eruption (T1), a group of 34 subjects (mean age 8 years 11 months ±11 months) underwent RME, while a group of 28 subjects (mean age 9 years 1 month ±1 year) was monitored after surgery without further treatment. At T2 (on average 10 months after T1), the prevalence rate of subjects with erupted incisors was recorded. The measurements were taken on the panoramic radiographs at T1 and T2 to assess the vertical position and angulation of delayed unerupted incisors.

Results

At T2, impacted incisors erupted in 82.4% of the patients in the RME group versus 39.3% of those in the monitored group (χ² =8.45, p<0.001). All the patients treated with RME showed an improvement in the vertical and angular position of the unerupted teeth. Logistic regression revealed RME therapy as the only significant predictive variable (p<0.001) for successful eruption of the delayed incisors at T2.

Conclusion

RME in early mixed dentition appears to be an effective procedure to increase the prevalence rate of impacted maxillary incisor eruption.     

基于锥形束CT的多生牙新分类方法临床意义研究

 目的　应用锥形束CT（cone-beam CT，CBCT）对多生牙进行新的临床分类，并分析新分类方法的临床意义。方法　收集2016-2019年首都医科大学附属北京友谊医院口腔科的CBCT影像资料5100例，其中多生牙患者209例，共计多生牙278颗。应用CBCT对多生牙进行新的临床分类，包括萌出型、骨埋伏高位型、骨埋伏低位型、骨埋伏复杂型和牙弓外型，并分析其临床意义。结果　（1）临床资料分析：多生牙发生率为4.1%，其中有1颗多生牙的患者占76.6%，有2颗多生牙的患者占19.1%，有3颗及以上多生牙的患者占4.3%。多生牙好发部位依次为：上颌切牙区、上颌磨牙区、下颌尖牙及前磨牙区、上颌尖牙及前磨牙区、下颌磨牙区。34.9%的多生牙对邻近恒牙产生了继发影响，以萌出错位及阻生为主，主要发生在上颌切牙区。（2）新分类方法的临床意义分析：上颌切牙区多生牙以骨埋伏低位型及萌出型为主，尖牙、前磨牙及磨牙区多生牙以萌出型为主。不同类型多生牙对邻近恒牙产生继发影响的发生率不同或不全相同（χ2 = 26.057，P < 0.001），提示对邻近恒牙易产生继发影响的多生牙类型依次为：萌出型、骨埋伏复杂型、骨埋伏高位型、牙弓外型、骨埋伏低位型。结论　基于CBCT的多生牙新分类方法简单实用，其中萌出型、骨埋伏复杂型及骨埋伏高位型多生牙更易产生错牙合畸形，建议尽早拔除多生牙、定期随访，必要时正畸治疗。     

Bilateral maxillary fused primary incisors accompanied by succedaneous supernumerary teeth: report of a case

Summary. A rare case of fusion between maxillary primary central incisors and supplemental teeth occurring bilaterally, accompanied by succedaneous supernumerary teeth, is presented. The patient was an 8·5-year-old Japanese boy. Intraoral examination revealed fusion of left and right maxillary primary central incisors to supplemental teeth, which had labial and lingual grooves. The maxillary primary lateral incisors were present. Radiographs showed that the fused teeth had separate roots, pulp chambers and root canals. There were two impacted supernumerary teeth and eruption of the permanent maxillary central incisors was delayed. Treatment was performed and the fused primary teeth and the impacted supernumerary teeth were extracted. After 6 months observation, surgical exposure of the two crowns of the permanent maxillary central incisors was performed. The teeth began to erupt and have since been kept under observation.     

Eruption of impacted permanent upper incisors after removal of of supernumerary teeth

In a retrospective study of 63 patients, an attempt is made to determine in how many cases retained permanent upper incisors erupt after the removal of supernumerary teeth, and what predisposing and etiological factors are of importance. It proved that the eruption of a supernumerary tooth positively contributed to the chance of a spontaneous eruption of the permanent incisors. No relationship could be demonstrated between the age of a patient from whom supernumeraries were extracted, the number of supernumeraries, the extent of root formation, marked apical displacement and the chance of spontaneous eruption of the permanent incisors. It also proved that only in 1 out of 2 children did spontaneous eruption occur after removal of the supernumeraries. It therefore seems advisable to provide all impacted upper incisors with a cervical ligature of bracket with twined wire sling during the first operation in order to create the possibility for orthodontic traction if spontaneous eruption of the incisor does not occur, and thus to prevent a second operation for the child.     

Multidisciplinary evaluation and clinical management of mesiodens

Supernumerary teeth are a disorder of odontogenesis relatively common in the oral cavity and characterized by an excess number of teeth. The term mesiodens is used to refer to an unerupted supernumerary tooth in the central region of the premaxilla between the two central incisors. The complications associated with mesiodens include: lack of eruption of permanent teeth, the deviation of the eruption path, rotations, retention, root re-absorption and pulp necrosis with loss of vitality, and diastema. Early detection of mesiodens is most important if such complications are to be avoided. This report describes the treatment of a maxillary central incisor impacted by a mesiodens. The case initially required only surgical treatment, to remove the supernumerary tooth. Successively, orthodontic therapy was done to bring into position the left permanent central incisor, which erupted physiologically, but rotated 90 degrees around along its long axis.     

基于锥形束CT的多生牙新分类方法临床意义研究

目的　应用锥形束CT（cone-beam CT,CBCT）对多生牙进行新的临床分类,并分析新分类方法的临床意义。方法　收集2016—2019年首都医科大学附属北京友谊医院口腔科的CBCT影像资料5100例,其中多生牙患者209例,共计多生牙278颗。应用CBCT对多生牙进行新的临床分类,包括萌出型、骨埋伏高位型、骨埋伏低位型、骨埋伏复杂型和牙弓外型,并分析其临床意义。结果　（1）临床资料分析：多生牙发生率为4.1%,其中有1颗多生牙的患者占76.6%,有2颗多生牙的患者占19.1%,有3颗及以上多生牙的患者占4.3%。多生牙好发部位依次为：上颌切牙区、上颌磨牙区、下颌尖牙及前磨牙区、上颌尖牙及前磨牙区、下颌磨牙区。34.9%的多生牙对邻近恒牙产生了继发影响,以萌出错位及阻生为主,主要发生在上颌切牙区。（2）新分类方法的临床意义分析：上颌切牙区多生牙以骨埋伏低位型及萌出型为主,尖牙、前磨牙及磨牙区多生牙以萌出型为主。不同类型多生牙对邻近恒牙产生继发影响的发生率不同或不全相同（χ2 = 26.057,P < 0.001）,提示对邻近恒牙易产生继发影响的多生牙类型依次为：萌出型、骨埋伏复杂型、骨埋伏高位型、牙弓外型、骨埋伏低位型。结论　基于CBCT的多生牙新分类方法简单实用,其中萌出型、骨埋伏复杂型及骨埋伏高位型多生牙更易产生错牙合畸形,建议尽早拔除多生牙、定期随访,必要时正畸治疗。     

Management of the malposition tooth that was caused by dentigerous cyst associated with impacted supernumerary tooth by using an obturator

This report presents a case of eruption guidance for an upper right central incisor with a dentigerous cyst associated with an impacted supernumerary tooth in a 5-year-9-month-old boy. A swelling was seen in the region of an upper right central incisor. Radiographic examinations showed that a well-defined cystic lesion, containing an impacted supernumerary tooth crown in it, was located between the root of the primary upper right central incisor and a permanent upper central incisor germ. Under general anesthesia, the dentigerous cyst was removed at extraction of the upper impacted supernumerary tooth. And then, a socket was kept open wound. A histopathological examination confirmed the diagnosis of a dentigerous cyst associated with a supernumerary tooth. By using an obturator, we guided eruption of an upper right central incisor with malposition that was caused by the dentigerous cyst, and observed the way of the tooth eruption for two years and seven months. The obturator was inserted in the socket directly for three months until it was closed. After that, the obturator was used as only a removable space maintainer. Eight months after the operation, the obturator was removed because the upper left central incisor began to erupt. Two years and seven months after the operation, both upper central and lateral incisors had erupted completely. In this case, the obturator was used for expectation of natural eruption of permanent incisors, space maintenance and aesthetic recovery. The permanent incisors had been able to be guided to almost correct position without traction.     

上颌埋伏阻生中切牙的影像学分类

目的:探讨上颌埋伏阻生中切牙的三维图像分类特征。方法:根据103例上颌中切牙埋伏阻生患者螺旋CT的Dicom原始数据,应用Mimics10.0软件重建出上颌埋伏阻生中切牙的三维图像,分析上颌埋伏阻生中切牙的阻生特点,并对其进行分类。结果:共有埋伏牙106颗。74颗牙为唇侧阻生,倒置阻生33颗,水平阻生28颗,倾斜阻生13颗;20颗为腭侧阻生,倾斜阻生11颗,水平阻生9颗;12颗为垂直阻生。上颌埋伏阻生中切牙根据牙冠的位置在垂直向、冠状向、矢状向可分为3类,即①唇侧埋伏阻生型,包括唇侧倾斜埋伏阻生型、唇侧前后水平埋伏阻生型、唇侧倒置埋伏阻生型;②腭侧埋伏阻生型,包括腭侧倾斜埋伏阻生型、腭侧后前水平埋伏阻生型;③垂直埋伏阻生型。结论:上颌埋伏阻生中切牙从三维方向上可分为3类,每一类又可分多个亚型,包括唇侧(倾斜、前后水平、倒置)埋伏阻生、腭侧(倾斜、后前水平)埋伏阻生和垂直埋伏阻生。     

328颗上颌恒切牙异常萌出原因的临床分析

目的分析导致上颌恒切牙异常萌出的原因,为提高诊疗水平提供理论依据。方法收集上颌恒切牙异常萌出的患者239例,共计328颗上领恒切牙,记录并分析导致上颌恒切牙异常萌出的原因,对数据进行统计学分析。结果328颗异常萌出的上颌恒切牙中,阻生或弯曲牙者64颗;上颌恒切牙已萌出,但位置异常者264颗,其中唇侧异常萌出45颗,腭侧异常萌出187颗,远中异常萌出32颗。对异常萌出的原因进行分析,上颌乳前牙根尖感染患者92例（38．5％）,上颌乳前牙外伤患者30例（12．6％）,上颌乳前牙滞留患者（非感染和外伤所致）26例（10．9％）,多生牙患者18例（7．5％）,上唇系带肥厚患者11例（4．6％）,口腔不良习惯、骨量不足等其它原因患者19例（7．9％）,另有43例（18．0％）患者合并局部或全身多种相关疾病。结论乳前牙根尖周炎是导致上颌恒切牙异常萌出的主要病因,儿童口腔医生应积极治疗乳牙疾病,去除或减轻导致上颌恒切牙异常萌出的因素,诱导儿童牙列和咬合功能的正常发育。     

Supernumerary teeth and mental retardation: the importance of early surgical intervention.

AIM: This paper reported a rare case of hyperdontia in a child of 10 years who revealed a mixed dentition and a light mental retardation. MATERIALS AND METHODS: The therapeutic approach has been based on interdisciplinary cooperation between the pediatric dentist, orthodontist and oral surgeon. TC-Dentascan, with a panoramic and occlusal radiographs revealed the presence of two supernumerary teeth in the premaxillary region and clinical examination showed an abnormality of dentoalveolar complex. Both impacted supernumerary teeth were extracted under general anesthesia. Clinical examination revealed that they appeared two premolars in shape with fully formed crowns and partly formed roots. RESULTS: Three months after the extraction of supernumerary teeth there was a spontaneous eruption of permanent central incisors and left lateral incisor. CONCLUSION: The authors emphasized the importance of removal of supernumerary teeth to eliminate the cause of a delayed eruption of permanent teeth.     

Trattamento chirurgico-ortodontico degli incisivi in malposizione: protocollo terapeutico

Objectives

The aim of this report is to provide clinicians with useful information for immediate management of impacted maxillary incisors due to obstacles to eruption.

Materials and methods

A 8-year-old boy was seen in the Operative Unit of Orthodontics of Policlinico Tor Vergata in Rome. Radiographic images showed intraosseus impaction of the maxillary left central incisor due to a compound odontoma. The treatment plan consisted of three stages: (1) removal of the odontoma and extraction of the deciduous incisors; (2) rapid maxillary expansion in order to improve the intraosseus tooth position; (3) surgical exposure and orthodontic traction of the impacted central incisor to its right position.

Results

The impacted maxillary left central incisor was brought into proper alignment with the adjacent teeth and produced a nice smile. Two years after the treatment, the patient presented good occlusal stability, adequate width of attached gingiva, no periodontal bone loss, symmetric gingival margins for both maxillary central incisors.

Conclusions

The improvement of the intraosseus position of the unerupted incisor, obtained by removal of the odontoma and rapid maxillary expansion, has enabled a conservative surgery and the achievement of an excellent esthetics and periodontal result.     

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。     

Bilaterally impacted maxillary central incisors: surgical exposure and orthodontic treatment: a case report

Maxillary central incisor impactions occur infrequently. Their origins include various local causes, such as odontoma, supernumerary teeth, and space loss. Supernumerary and ectopically impacted teeth are asymptomatic and found during routine clinical or radiological examinations. The surgical exposure and orthodontic traction of bilaterally impacted central incisors after removal of impacted supernumerary teeth is presented in this report.     

上颌埋伏中切牙向新生牙槽骨内移动的三维有限元分析

目的　分析拔除多生牙后不同施力时机对埋伏牙矫治效果的影响,为临床矫治上颌唇侧阻生中切牙提供一定的理论依据。方法　建立上颌中切牙唇向阻生的三维有限元模型,于牙槽骨不同愈合时期向埋伏牙施以相同的复位力,分析埋伏牙、牙周膜、牙槽骨的初始应力及位移情况。结果　随着牙槽骨的愈合,牙齿、牙周膜的最大应力与位移、愈合期牙槽骨的最大位移逐渐减小,愈合期牙槽骨的最大应力逐渐增大。结论　阻碍埋伏牙正常萌出的多生牙去除后,可以即刻施力移动埋伏牙。但早期移动时牙齿的倾斜趋势比较明显,建议初期加载力值应适度减小,以利于埋伏牙的整体移动。     

上颌中切牙埋伏阻生的正畸治疗:28例报道

目的:通过对无萌出能力的埋伏阻生上颌中切牙进行外科开窗术 正畸牵引治疗,探讨埋伏上颌中切牙正畸牵引治疗的效果。方法:对28例30颗无萌出能力埋伏阻生的上颌中切牙进行外科开窗术 正畸牵引治疗。结果:28例埋伏牙中,1例已牵引萌出,因间隙不足,家长拒绝拔牙而未排齐;1例牵引3个月后萌出,因无时间复诊而放弃治疗,未排齐;其余均牵引入列,28例埋伏牙平均破龈时间为4.5个月,最长为10个月,最短为1个月;28颗埋伏牙牙髓活力测试全部正常,未见根吸收、黏连;4颗唇侧出现1￣4mm的牙龈退缩;2颗分别出现1.0mm和2.5mm的边缘骨丧失。结论:治疗的时机、合理的矫治方法、减少手术创伤、牵引力的大小以及支抗和炎症的有效控制是治疗成功的关键。     

倒位埋伏阻生上中切牙的临床矫治探索

目的 探索倒位埋伏阻生上颌中切牙的矫治方法,以提高临床矫治效果和保留更多的倒位阻生牙.方法对8例患者的9颗倒位埋伏阻生的上中切牙采用开拓间隙、手术开窗牵引、固定人工支点协助调向、排齐、反向控根等方法进行矫治.结果9颗倒位阻生的上中切牙中,有8颗经过15～30个月的矫治达到正常位置,牙齿稳定,功能正常.剩余1颗因牵引15...     

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。