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.     

埋伏上颌中切牙影像学分类

目的应用口腔颌面专用锥形束CT检查分析埋伏上颌中切牙的影像特点并进行分类。方法收集上颌埋伏中切牙120例，共计125颗上颌埋伏中切牙。采用New Tom QR DVT-9000 Cone Beam CT扫描后进行多层断、曲断以及三雏重建观察埋伏牙的形态、位置、朝向以及与相邻牙、牙列的位置关系。结果上颌埋伏中切牙分为4种基本类型：①后翻型48例（共计51颗）；②后钩型29例（29颗）；③后前水平型25例（共计26颗）；④高位型（垂直或倾斜）18例（共计19颗）。后翻型和后钩型牙多弯曲畸形。结论口腔颌面专用锥形束CT检查可为临床医师的进一步治疗设计或手术前入路选择提供准确的信息。后翻型和后钩型牙多弯曲畸形，根细小，很难将其导入正常位置，应选择拔除后修复；后前水平型和高位型（垂直或倾斜）牙形态多数正常，应将其导入正常位置，恢复牙列完整及美观。     

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。     

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.

     

Orthodontic, genetic, and periodontal considerations in the treatment of impacted maxillary central incisors: A study of twins.

Treatment of twins each with one impacted maxillary central incisor and a mesiodens is described. Treatment included rapid expansion, extraction of the mesiodens, surgical exposure of the impacted central incisor, and its forced eruption. The impacted incisor was brought into functional position in one patient but was lost in the other because of insufficient root length and high mobility. Orthodontic, genetic, and periodontal considerations of these 2 cases are evaluated.     

上颌中切牙阻生的局部因素分析

目的 探讨上颌中切牙阻生的局部因素。方法 回顾分析70例(74颗)上颌阻生中切牙的临床资料,总结分析各种局部因素与中切牙阻生的关系。结果 74颗阻生中切牙的局部因素包括多生牙或牙瘤32颗(43.2%),乳切牙根尖病变12颗(16.2%),乳牙外伤6颗(8.2%),牙胚发育异常(位置、方向、形态)24颗(32.4%)。结论 中切牙阻生的病因较为复杂,及早诊断适时干预是治疗成功的重要因素。     

埋伏弯根上颌中切牙序列矫治的研究

目的探讨埋伏弯根上颌中切牙有效的正畸牵引治疗方法。方法选择11例患者共12颗埋伏弯根上颌中切牙为研究对象,常规拍摄定位X线片,配合口内检查、模型分析等,确定埋伏牙的位置及其与邻牙的相互关系,采用封闭式导萌、选择性根管治疗及根尖切除术、修复治疗等方法进行矫治。结果12颗埋伏牙通过治疗后顺利进入正常牙列,未见牙根吸收粘连,建立了良好的咬合关系。9例唇侧埋伏弯根上颌中切牙患者的临床牙冠唇倾角度较大,4例根尖位于唇侧黏膜下,进行了根管治疗加根尖切除术,其中1例行烤瓷冠改形修复;其余5例未做根管治疗,暂行观察。2例腭侧埋伏弯根上颌中切牙的疗效稳定。结论埋伏弯根上颌中切牙采用序列矫治可以取得良好的美观和功能效果。     

Labially impacted maxillary canines causing severe root resorption of maxillary central incisors

This is a case report of a patient with bilateral labial impaction of maxillary canines causing pressure resorption on the lateral aspects of the maxillary central incisors. The orthodontic treatment plan included extraction of the impacted canines, positioned between the central and the lateral incisors. Six years after the orthodontic treatment, the affected central incisors remained asymptomatic.     

The prevalence of root resorption of maxillary incisors caused by impacted maxillary canines

Objectives

The aim of this study was to evaluate the prevalence of root resorption of maxillary incisors caused by impacted maxillary canines using low-dose dental computed tomography and to gain additional knowledge of the underlying aetiology and the progression of root resorption.

Materials and methods

A total of 440 patients (mean age, 24.7 years) with 557 impacted maxillary canines were examined regarding their location and the occurrence of root resorption of maxillary incisors.

Results

The frequency of root resorption was 2 % of central and 7.7 % of lateral maxillary incisors. The location of the 557 impacted canines within the dental arch was palatal in 67.5 %, buccal in 15.4 % and central in 17.1 %. No significant differences could be shown with respect to the width and the shape of the dental follicle of the impacted maxillary canines and the presence of root resorption of incisors. The presence of root resorption of central (p?<?0.0001) and lateral (p?<?0.023) maxillary incisors was significantly correlated with an existing contact relationship of the impacted maxillary canines.

Conclusions

Our investigation confirms the theory of prior reports comprising a much larger patient population, hypothesising that the dental follicle of impacted maxillary canines does not cause resorption of adjacent maxillary incisors per se.

Clinical relevance

Root resorption of maxillary incisors is correlated with effects of contact of the impacted maxillary canines, and these findings should be considered in treatment planning. Our findings are consistent with other reports and may develop new treatment approaches for the treatment of this sequela.     

105例上颌中切牙埋伏阻生的类型及处理

个别上中切牙埋伏在临床上并不少见［１］。因其在功能及美观两方面的作用，故在治疗过程中，须尽可能地保留该牙。作者在１９８１～１９９４年间共收治１０５例埋伏上中切牙，对其临床表现进行了归类、分析，现报道如下。临床资料１一般资料患者１０５例。男４０例，女６...     

基于牙周生物型的上颌中切牙分类

目的采用树图分析法对南京大学青年人的上颌中切牙临床牙冠形态进行分类,为前牙美学修复提供参考。方法获得南京大学114例青年自愿者上颌中切牙临床牙冠的图像数据,使用Digimizer软件测量每个样本的牙冠长度(CL)、龈缘角度(GA)、邻接区高度(CS),使用SPSS、PAST软件将所有样本的CS/CL和GA值进行树图分析及Pearson相关性检验;根据Williams上颌中切牙分类法对样本进行分类,并对所有样本的TA/TB和GA值进行树图分析及Pearson相关性检验。结果CS/CL和GA值的树图分析结果显示为3类(A、B、C组),得到的分组指标数据分别为CS/CL≤42.6583%,42.685357.8067%。3组的GA值、CS/CL值均有统计学差异;TA/TB和GA值的树图分析结果显示分类节点为零,Pearson检验无相关性。结论本研究CS/CL和GA值的树图分析结果显示分组指标数据与美国塔夫斯大学采用树图分析法获得上颌中切牙的分类指标数据非常相近,可以对上颌中切牙进行分类。TA/TB和GA值无相关性,不能进行树图分类。     

Alternative anesthetic technique for maxillary periodontal surgery

Background: Maxillary periodontal surgery typically requires multiple injections and may inadvertently affect facial structures such as the upper lip, lateral aspect of the nose, and lower eyelid. To minimize these sequelae and reduce the number of total injections, a relatively new injection technique has been proposed for maxillary procedures. The anterior middle superior alveolar (AMSA) injection is reported to effectively anesthetize maxillary teeth and associated gingival tissues extending from the buccal root of the first molar mesially to the central incisor with a single injection while avoiding undesirable side effects. The purpose of this article is to provide background information on the AMSA injection and demonstrate its use in a variety of maxillary periodontal surgeries. Methods: Anesthesia was provided for five separate maxillary periodontal surgeries with unilateral or bilateral AMSA injections. Injections were administered via conventional syringe with a 27-gauge needle. Confirmation of anesthesia was subjectively tested with buccal mucosal sticks and palatal transgingival probing. Results: The AMSA injection provided promising results for a variety of maxillary periodontal surgical procedures. Benefits of the AMSA injection included outstanding palatal hemostatic control, avoidance of undesirable collateral anesthesia, and a reduced number of cumulative injections. Drawbacks of the AMSA injection included occasionally inadequate buccal hemostatic control and short-lived anesthesia of the maxillary central incisors. Conclusion: The AMSA injection is a novel anesthetic technique that may prove useful for certain maxillary periodontal surgeries.     

Effects of impacted maxillary canines on root resorption of lateral incisors

Objectives

The aim of this study was to analyze the amount of root resorption of maxillary lateral incisors by relating the position, location, and angulation of the impacted canine using cone-beam computed tomography (CBCT).

Materials and methods

The study sample consisted of panoramic and CBCT radiographs of 46 patients with a unilateral impacted canine (16 males and 30 females; mean age: 19.53 ± 6.66 and 19.44 ± 5.77 years, respectively). Sector location and canine angulation were measured in panoramics. All tomographs were obtained using CBCT (NewTom 5G, QR, Verona, Italy) and three-dimensional (3D) reconstructions of the maxillary laterals assessed by Mimics 14.01 image analysis software.

Results

Upper lateral incisor volume was smaller on the impacted side (401.95 ± 83.69 mm³) than on the nonimpacted side (433.54 ± 92.6 mm³, P < 0.05). There were no significant differences of lateral root resorption volume when comparing the impacted canines being on the labial or palatal sides (P > 0.05), but impacted canine angulation was significantly steeper on the labial side (70.85°) than on the palatal side (46.09°, P < 0.05). The volume of root resorption of laterals when comparing the various positions of the canine in different sectors or canine angulation in 30^o intervals was not statistically significantly different (P > 0.05).

Conclusions

The impacted canines caused root resorption of lateral incisors. The angulation of the canine was steeper on the labial side than on the palatal side but root resorption of adjacent laterals was not different. There were no statistically significant differences in the amount of root resorption of the laterals when the canine was evaluated according to localization and angulation.