面型对正畸治疗中牙根吸收的影响

目的 :评价面型对正畸治疗中出现的牙根吸收的影响。方法 :选择 12 0例经方丝弓矫治器矫治的青少年 ,按下颌平面角将面型分为高角型、平角型、低角型三个组 ,每组治疗前后分别拍摄全颌曲面断层片 ,配对测量正畸治疗前后牙根等级 ,将牙根等级改变的频数经计算机进行统计分析。结果 :三组病例正畸治疗前后牙根等级分布改变有显著性差异 (P <0 .0 0 1)。组间差异各不相同。高角型病例牙根吸收最轻 ,低角型病例易出现重度牙根吸收。三组病例组间差异有显著性 (P <0 .0 1)。结论 :正畸治疗中不同面型对牙根吸收程度有影响 ,面型是影响牙根吸收的一个重要因素。     

平面导板对正畸治疗中牙根吸收影响的临床研究

目的：探讨平面导板配合直丝弓矫治对牙根吸收的影响。方法：随机选择66例经过直丝弓矫治的成年非拔牙患者，其中33例配合使用平面导板治疗。治疗前后拍全口曲面断层片，分别测量2组治疗前后下颌4个切牙的牙根吸收等级，并经过计算机进行X^2检验。结果：2组正畸治疗后均有明显的牙根吸收，治疗前后牙根吸收等级有显著性差异（P〈0．01）。治疗后2组间牙根吸收等级也有显著性差异（P〈0．01）。结论：直丝弓配合平面导板矫治组较单独使用直丝弓矫治的牙根吸收更严重。     

面型对正畸治疗中牙根吸收影响的临床研究

目的 评价面型对正畸治疗中出现的牙根吸收的影响。方法 选用120例经方丝弓矫治器固定矫治的青少年，按面型分为高角型、正常型、低角型三个组，每组病人治疗前后分别拍摄全口曲面断层片，配对测量正畸治疗前后牙根等级，将牙根各等级改变的频数量以计算机进行统计分析。结果 三组面型的病例正畸治疗前后牙根等级分布改变有显著的统计学意义(P＜0．001)。三组之间组间差异的表现各不相同。高角型病例牙根吸收最轻，而低角型病例易出现重度牙根吸收。三组病例组间差弄有显著的统计学意义(P＜0.01)。结论 在正畸治疗中不同面型对牙根吸收程度有显著的影响，是影响牙根吸收的一个重要因素。     

方丝弓矫治器配合使用平面导板对牙根吸收影响的临床研究

的 探讨方丝弓矫治器配合使用平面导板正畸治疗对牙根吸收的影响。方法 选择方丝弓矫治器配合平面导板正畸治疗的65例患者为研究对象,分别在戴平面导板前、停戴平面导板时、停戴平面导板6个月时拍摄全口曲面断层片,对下颌中切牙及侧切牙进行根吸收等级测量分析。结果 戴平面导板前、停戴平面导板时、停戴平面导板6个月时牙根吸收等级间的差异均有统计学意义（P<0.05）;男性和女性患者在平面导板戴入前后的牙根吸收等级间的差异无统计学意义（P>0.05）。结论 平面导板会造成下前牙牙根的吸收,但根吸收程度轻微。     

面型对正畸支抗牙牙根吸收影响的临床研究

目的 探讨不同面型在正畸治疗中对支抗牙牙根吸收的影响。方法 选择120例经方丝弓矫治器治疗的患者,按面型分为高角型、正常型、低角型3个组,每组患者治疗前后分别拍摄头颅侧位定位片,配对测量分别被确定作为支抗的后牙或前牙正畸治疗前后牙根长度,将牙根长度改变量以计算机进行统计分析,并评价牙根吸收情况。结果3组病例正畸治疗前后支抗牙牙根长度改变有统计学意义(P<0.001)。3组之间相对应牙齿的牙根吸收量不同,高角型病例牙根吸收轻,而低角型病例牙根吸收重。组间不同的吸收量差异有统计学意义(P<0.01)。结论 在正畸治疗中不同面型对支抗牙牙根吸收程度有不同影响,面型是影响支抗牙牙根吸收的一个重要因素。     

口外J钩配合矫治安氏Ⅱ类1分类错疗效观察

目的　探讨采用口外J钩治疗安氏Ⅱ类 1分类错牙合患者的疗效。方法　对 15例安氏Ⅱ类 1分类需拔牙矫治患者 ,用标准方丝弓矫治技术 ,配合J钩口外牵引 ,关闭拔牙间隙 ,调整咬合关系 ,并对患者治疗前后X线头颅侧位片进行头影测量与分析。结果　口外J钩配合方丝弓矫治技术矫治安氏Ⅱ类 1分类错牙合可获得较理想的治疗效果。结论　口外J钩可有效地防止上颌支抗丧失 ;同时可减少因Ⅱ类颌间牵引而致上前牙伸长 ,达到改善外貌的作用。     

口外J钩配合矫治安氏Ⅱ类1分类错(牙合)疗效观察

目的探讨采用口外J钩治疗安氏Ⅱ类1分类错He患者的疗效。方法对15例安氏Ⅱ类1分类需拔牙矫治患者，用标准方丝弓矫治技术，配合J钩口外牵引，关闭拔牙间隙，调整咬合关系，并对患者治疗前后X线头颅侧位片进行头影测量与分析。结果口外J钩配合方丝弓矫治技术矫治安氏Ⅱ类1分类错He可获得较理想的治疗效果。结论口外J钩可有效地防止上颌支抗丧失；同时可减少因Ⅱ类颌间牵引而致上前牙伸长，达到改善外貌的作用。     

异常牙根形态对正畸治疗前后前牙根吸收的影响

目的 调查异常牙根形态在正畸治疗前后对牙根吸收的影响。方法 随机选择经直丝弓矫治技术完成的病例153例,分析患者治疗前后的全口曲面断层片,将前牙按根形态分为正常组、短根组、钝根组、弯根尖组及滴管状根组5组,以Levander和Malmgren的牙根吸收分级法记录每个前牙牙根根吸收程度,将牙根根吸收程度及其改变的频数进行统计分析。结果 前牙中异常根形态的发生率为16.92%,以弯根尖与钝根最为常见;根形态异常组与正常组的根吸收均值间在正畸治疗前有显著性差异（P<0.05）,正畸治疗后亦有显著性差异（P<0.01）,其中短根组根吸收值最高,其次为滴管状根组;根形态异常组在正畸治疗前后的根吸收发生率均较正常组高,差异有显著性（P<0.01）。结论 异常牙根形态能显著增加牙根吸收的发生率和严重程度。     

口外J钩配合矫治安氏Ⅱ类1分类错(牙合)疗效观察

目的探讨采用口外J钩治疗安氏Ⅱ类1分类错(牙合)患者的疗效.方法对15例安氏Ⅱ类1分类需拔牙矫治患者,用标准方丝弓矫治技术,配合J钩口外牵引,关闭拔牙间隙,调整咬合关系,并对患者治疗前后X线头颅侧位片进行头影测量与分析.结果口外J钩配合方丝弓矫治技术矫治安氏Ⅱ类1分类错(牙合)可获得较理想的治疗效果.结论口外J钩可有效地防止上颌支抗丧失;同时可减少因Ⅱ类颌间牵引而致上前牙伸长,达到改善外貌的作用.     

正畸治疗中拔牙与牙根吸收关系的临床研究

目的评价拔牙对正畸治疗中的牙根吸收的影响。方法选取120例年龄在11～18岁经方丝弓矫治器固定矫治治疗的青少年,分为拔牙组和不拔牙组,两组病人治疗前后分别拍摄全口曲面断层片,牙根形态按等级分级,计算机进行统计分析各等级频数分布变化。结果两组病例在治疗后牙根吸收均以1、2级居多、拔牙组治疗后牙根3、4级吸收多于未拔牙组,两组之间的差异有显著性(P<0.001)。结论拔牙治疗会加重正畸治疗中的牙根吸收。     

上颌阻生尖牙牵引治疗后邻近切牙牙根吸收情况的研究

目的 分析上颌阻生尖牙正畸牵引治疗后邻近切牙的牙根吸收情况及可能的相关因素。方法 选取上颌尖牙阻生且符合标准的43例患者,年龄10～23岁,共60颗上颌埋伏阻生尖牙。上颌阻生尖牙正畸牵引治疗前后分别拍摄锥形束CT,分析阻生尖牙邻近切牙的牙根吸收程度,并对可能存在的相关因素进行分析。结果 上颌阻生尖牙正畸牵引治疗后,上颌中切牙发生轻、中、重度牙根吸收的概率分别为71.7%、15.0%、13.3%,上颌侧切牙发生轻、中、重度牙根吸收的概率分别为48.3%、36.7%、15.0%,上颌中切牙与侧切牙牙根吸收严重程度存在差异(P<0.05)。位于腭侧及颌骨内、低位且靠近面中线的阻生尖牙,在正畸牵引治疗后,侧切牙牙根吸收程度较重(P<0.05)。低位阻生尖牙牵引治疗后,中切牙牙根吸收较重(P<0.05)。牵引时间较长时,中切牙牙根吸收程度较重(P<0.05)。治疗前已发生牙根吸收的切牙,在阻生尖牙牵引治疗后发生的牙根吸收程度较重(P<0.05)。结论 上颌侧切牙在阻生尖牙正畸牵引治疗后,发生的牙根吸收程度较重。上颌阻生尖牙正畸牵引治疗后,邻近切牙牙根吸收情况与阻生尖...     

Evaluation of apical root resorption following extraction therapy in subjects with Class I and Class II malocclusions

The purpose of this study was to determine the amount of root resorption during orthodontic treatment, and to examine the relationship between tooth movement and apical root resorption. Twenty-seven Class I and 27 Class II patients treated with edgewise mechanics following first premolar extractions were selected. The following measurements were made on the pre- and post-treatment cephalograms: upper central incisor to palatal plane distance, the inclination of upper central incisor to the FH and AP planes, the perpendicular distances from the incisor tip to the AP and PTV planes, and incisor apex to PTV. The amount of apical root resorption of the maxillary central incisors was determined for each patient by subtracting the post-treatment tooth length from the pre-treatment tooth length measured directly on cephalograms. Intra-group differences were evaluated by the Student's t-test and inter-group differences by the Mann-Whitney U-test. For correlations the Pearson correlation coefficient was used. The results show that there was a mean of approximately 1 mm (P < 0.01) of apical root shortening in Class I patients, but in Class II division I subjects the mean root resorption was more than 2 mm (P < 0.001). The inter-group differences were statistically significant. No significant correlations were found between the amount of apical root resorption and tooth inclination, or the duration of active treatment.     

三种矫治器治疗安氏Ⅱ类2分类对切牙牙根吸收的影响

目的 比较不同矫治器治疗安氏Ⅱ类2分类错牙合畸形患者切牙牙根的吸收状况。方法 选择使用不同矫治器的安氏Ⅱ类2分类成年患者30例,其中传统MBT托槽、自锁托槽以及无托槽隐形矫治器的患者各10例,共计240颗切牙。收集患者治疗前后的锥形束CT(CBCT)影像学资料,并导入Dolphin Imaging软件,Mimics软件以及3-Matics软件测量分析治疗前后切牙牙根吸收情况。结果 传统MBT托槽组和自锁托槽组的上下颌中切牙以及侧切牙的牙齿长度(L)与无托槽隐形矫治器组上下颌中切牙及上颌侧切牙的牙齿长度治疗后较治疗前显著减小,差异具有统计学意义。使用无托槽隐形矫治器的患者下颌侧切牙治疗前后的牙齿长度无显著变化。而三组之间的对比,上下颌中切牙牙齿长度变化无显著统计学差异。无托槽隐形矫治器组上下颌侧切牙的牙齿长度减少量相对更低,差异具有统计学意义(P＜0.05)。此外,无托槽隐形矫治器组平均牙齿长度变化为(-0.37±0.11)mm,显著小于传统MBT托槽组(-1.32±0.47)mm及自锁托槽组(-1.05±0.38)mm。在牙根吸收区域的比较上,各组均表现为腭侧吸收多于唇侧吸收,近中吸收多于远中吸收。结论 无托槽隐形矫治器治疗安氏Ⅱ类2分类错牙合畸形可有效降低切牙牙根吸收严重程度。     

青少年正畸治疗中影响牙根吸收的因素探讨

目的：探讨影响青少年错[牙合]畸形患者正畸矫治后牙根吸收的相关因素。方法：选择已完成正畸固定矫治的青少年患者78例．在其矫治前后的曲面断层片上,对4个上切牙进行根尖形态的分析,以获得正畸矫治后牙根吸收的定性数据。在对受试者按年龄、性别、牙位、牙龄、拔牙与否及疗程分组后,利用SPSS12．0软件对所得数据进行非参数检验分析。结果：所有正畸患者都存在一定程度的牙根吸收,根尖形态分析显示：①牙龄ⅣA期患者比ⅢC期的患者存在更严重的牙根吸收（P〈0．01）,但按年龄比较不存在显著差异;②拔牙组比不拔牙组有更加严重的牙根吸收（P〈0．01）;③疗程越长,牙根吸收也越明显（P〈0．05）;④牙根吸收的严重程度与性别及上切牙牙位之间无相关性。结论：在第二恒磨牙完全建验前（ⅣA期前）进行正畸治疗、不拔牙矫治、缩短矫治疗程,均可以减少正畸治疗中的牙根吸收。     

Is mild dental invagination a risk factor for apical root resorption in orthodontic patients?

The purpose of this retrospective study was to assess if dental invagination is a risk factor for root resorption during orthodontic treatment. The sample consisted of 91 patients (32 males, 59 females) with a mean age of 13.1 years (range 9.3-32.1 years) with complete orthodontic records, including periapical radiographs of the maxillary incisors before and after treatment. Forty-nine patients had at least one maxillary incisor invaginated, whilst the remaining 42 patients were free of dental invaginations. Variables recorded for each patient included gender, age, Angle classification, extraction or non-extraction therapy, ANB angle, overjet, overbite, trauma, habits, agenesis, tooth exfoliation, treatment duration, Class II elastics, body-build, general factors, impacted canines, and root form deviation. Crown and root length of the maxillary incisors were measured on pre- and post-treatment long cone periapical radiographs corrected for image distortion. The percentage of root shortening and root length loss in millimetres was then calculated. Most of the invaginated teeth were minor type 1. Statistical analysis revealed no significant difference in the severity of apical root resorption between invaginated and non-invaginated incisors in patients without dental invaginations, nor was the extent of dental invagination related to the severity of apical root resorption. However, invaginated teeth had malformed roots more often than non-invaginated teeth. Dental invagination, and particularly type 1, cannot be considered a risk factor for apical root resorption during orthodontic tooth movement.     

Factors related to root resorption in edgewise practice

In a series of 200 consecutively debanded patients receiving comprehensive orthodontic treatment with the edgewise appliance, six (3%) showed severe resorption (greater than one-quarter of the root length) of both maxillary central incisors. For other teeth, resorption of this extent occurred in less than 1% of the patients. Using a case-control design, the characteristics of 21 patients with severe resorption were compared to randomly selected controls from the case series. There were significantly more Class III patients among the severe resorption cases than would have been expected. Risk indicators for resorption that were related to treatment procedures included approximation of the maxillary incisor roots against the lingual cortical plate (odds ratio 20), maxillary surgery (odds ratio 8), and root torque (odds ratio 4.5).     

Incisor root resorption due to ectopic maxillary canines: a long-term radiographic follow-up

OBJECTIVE: To document the long-term fate of maxillary incisors with resorbed roots after correction of the associated ectopic canines. MATERIALS AND METHODS: The subjects were recruited from 107 children and adolescents age 9-15 years (mean 12.5 years) at initial registration, with 156 ectopically positioned maxillary canines. The children were referred to the specialist orthodontic clinic for consultation because of the risk of incisor root resorption. Of 51 patients contacted, 16 failed to attend. Eight of the remaining 35 were excluded because their lateral incisors had been extracted, leaving 27 subjects for follow-up registration. At initial consultation, all subjects had undergone radiographic examination, including computed tomography (CT) scans. At the follow-up consultation, the radiographic examination was limited to intraoral films. RESULTS: No resorbed incisor was lost during the 2- to 10-year follow-up period. The resorptive lesions had undergone repair in 13 teeth, remained unchanged in 12 teeth and progressed in 7 teeth. In the 13 teeth exhibiting signs of repair, no resorption was detectable in 11 teeth and minor resorption was detected in 2 lateral incisors. At the initial registration, severe or moderate resorption had been diagnosed in 12 lateral and 5 central incisors, compared with 11 lateral and 6 central incisors at follow-up. In 10 subjects initially diagnosed with resorption of 13 incisors, the lesions were no longer discernible on intraoral radiographs at follow-up. CONCLUSIONS: Even in cases of severe resorption, the incisor roots show good long-term healing. Incisors with root resorption can be used in an orthodontic appliance system.     

上颌切牙扇形移位的牙周-正畸联合治疗效果研究

目的    探讨伴上颌切牙病理性扇形移位错牙合畸形的牙周-正畸联合治疗效果。方法    选择2016年1月至2021年12月于南京大学医学院附属口腔医院正畸科就诊的经牙周-正畸联合治疗的伴有上颌切牙扇形移位的Ⅳ期/C级牙周炎患者18例，其中扇形移位的切牙31颗。回顾性分析患者正畸治疗前及正畸治疗后的出血指数（bleeding index，BI）、探诊深度（probing depth，PD）、探诊出血（bleeding on probing，BOP）位点百分比；采用锥形束CT评价扇形移位切牙的剩余牙槽骨高度（residual alveolar bone height，RBH）、切牙倾斜度及牙根吸收比的变化情况。结果    与正畸治疗前相比，正畸治疗后PD显著降低（P < 0.05）；正畸治疗后，扇形移位的切牙腭侧及近中RBH显著增加（均P < 0.05），切牙倾斜度显著减少（P < 0.001）；正畸治疗后唇侧、腭侧及远中上颌中切牙RBH的变化程度大于上颌侧切牙（均P < 0.05），上颌切牙总体牙根吸收比为0.08 ± 0.01。结论    在完善的牙周治疗基础上，正畸治疗有助于扇形移位切牙的牙周组织健康。     

Severe root resorption of the upper central incisors as a consequence of playing the flute

This study presents a case of severe root resorption of the maxillary central incisors in an 18‐year‐old woman who was referred for orthodontic treatment of irregular dental arches. A detailed history revealed that she used to play the block flute on an everyday basis during childhood. Against all warnings, she continued to firmly press her teeth into the mouthpiece of the instrument. Impressions of the upper central incisors were clearly visible on the instrument. Although it is well known that excessive occlusal forces can result in root resorption, to the authors’ knowledge, this case involves one of the first reported occurrences of extensive root resorption that was most likely caused by playing a wind instrument during childhood.     

External apical root resorption in Class II malocclusion: a retrospective review of 1- versus 2-phase treatment.

External apical root resorption (EARR) is an imperfectly understood problem of orthodontic treatment. The records of 138 children with Class II malocclusion (overjet > 7 mm) participating in a randomized clinical trial of early orthodontic treatment were reviewed. The patients were treated in either 1 phase with fixed appliances only (n = 49) or 2 phases with headgear (n = 49) or bionator (n = 40) followed by fixed appliances. The 3 groups were similar in age, sex, and malocclusion severity at enrollment. The records examined included anamnestic data, clinical examination records, panoramic radiographs before and after fixed appliance therapy, and posttreatment periapical radiographs. All radiographs were reviewed and scored independently by 2 examiners for maxillary incisor root development, morphology, and EARR. Of the 532 incisors scored, 11% of central and 14% of lateral incisors demonstrated moderate to severe (>2 mm) EARR. The proportion of incisors with moderate to severe EARR was slightly greater in the 1-phase treatment group. There was no difference in the incidence of EARR between teeth that had had trauma and those that had not, and there was only a slight increase in frequency of root resorption in teeth with unusual root morphology. Significant associations exist among EARR, the magnitude of overjet reduction, and the time spent wearing fixed appliances. However, not all incisors in a child respond in the same way, so other variables must play a role in determining the root response to orthodontic forces.