Prognosis of replanted primary incisors after injuries

Abstract – Between 1979 and 1997, 58 avulsed primary teeth were treated at the Pedodontic Clinic of Niigata University Dental Hospital. Among these, we replanted six avulsed incisors of four patients and treated two teeth of two patients replanted at other dental clinics. Referring to the clinical records, oral photographs and radiographs, we examined the injury age, cause of injury, condition of tooth storage, length of time until replantation, and also the prognosis after replantation. Three teeth of two cases remained until eruption of their permanent successors, and one tooth of one case remained under observation without extraction. Although the other four teeth of three cases resulted in extraction, no secondary infection was detected due to replantation. The following reasons were suspected for the poor prognosis of the four teeth. One avulsed tooth was not fixed immediately after replantation. One replanted tooth might not have been compatible with the alveolar socket. In the other two teeth, the periodontal vital tissues might have been removed before replantation. It is generally suggested that replantation of primary teeth is not a good option. However, from the present results, it was considered that replantation can be an effectual method when the condition of the avulsed primary tooth is suitable.     

A report of an impacted primary maxillary central incisor tooth

– Primary tooth impaction is a rare phenomenon when compared to permanent teeth impaction. The purpose of this report is to present a 5‐year‐old Chinese girl who exhibited impaction of tooth 51, its unusual consequence on the permanent successor tooth and its comprehensive management. Her parents revealed that at 6 months of age, the patient had fallen from her bed and struck her face on the floor; however, there were no teeth present in the oral cavity. The intraoral examinations identified a bony‐like projection on the buccal aspect of the alveolus in the 51 region. Radiographic examination revealed that tooth 51 exhibited an unfavourable orientation, with the crown directed towards the palate. Therefore, the impacted tooth 51 was surgically removed, and two years later tooth 11 erupted into the oral cavity with an indentation on its incisal aspect, which resembled the crown of the primary teeth, thus giving the appearance of a tooth within a tooth or ‘dens in dente’. Subsequently, enameloplasty and composite resin build‐up was performed on tooth 11 for aesthetic reasons. It is very unusual to have the clinical crowns of both primary and permanent teeth in such close proximity within the alveolar bone, and the present case is a good example to emphasize that trauma to the primary teeth is of considerable importance due to the close proximity of the primary teeth to permanent tooth germs.     

Treatment after inadequate immediate replantation of accidentally extracted immature mandibular premolar during primary molar extraction

During extraction of the primary mandibular right second molar in an 11‐year‐old girl, the unerupted second premolar was accidentally extracted. Clinical and radiographic examination showed that the immediately replanted immature premolar was not oriented and positioned correctly. Four hours later, treatment consisted of manual extrusion of the permanent tooth bud, rotation, and gentle repositioning into its original position. Adequate replantation was confirmed by a post‐operative radiograph. After 2 years and 4 months, clinical examination revealed normal, healthy appearance of the replanted tooth, no sensitivity to percussion, no tenderness to palpation, and a slight response to a cold pulp sensibility test. A radiograph showed completely developed root with closed apical foramen, slightly irregular root morphology and shorter root length, complete obliteration of the pulp, and no signs of periapical pathosis.     

牙齿磨损的病因学研究进展

牙齿磨损因其高发病率已成为继龋病、牙周病之后口腔领域又一高发疾病，受到了越来越多的关注。牙齿磨损是一种多病因疾病，其发生发展往往是多种因素共同作用的结果。近年来关于牙齿磨损病因学方面的研究较多，本文主要从腐蚀作用、牙齿自身状况、病理性磨损作用等方面作一综述。     

Beyond冷光美白与过氧化脲漂白四环素牙的疗效比较

目的评价Beyond冷光美白法漂白四环素牙的疗效及安全性。方法用Beyond冷光美白仪及配套的冷光美白剂,对试验组50例患者712颗四环素牙进行脱色。对照组50例患者717颗四环素牙用奥伦增白剂漂白作对照。用VITA比色板作脱色前、后比色,比较脱色效果,观察牙齿敏感情况。结果试验组脱色总显效率为86.5%,对照组为58.7%,两者差异有显著性(P<0.05)。试验组有6例(12.0%)患者出现牙齿轻度酸痛不适感,对照组有11例(22.0%)患者出现不同程度的牙齿酸痛感,两者差异有显著性(P<0.05)。结论Beyond冷光美白法脱色四环素牙有效、安全、快速。     

Effects of antiresorptive medications on tooth root formation and tooth eruption in paediatric patients

Tooth eruption is a pivotal milestone for children's growth and development. This process involves with the formation of the tooth root, the periodontal ligament (PDL) and the alveolar bone, as the tooth crown penetrates the bone and gingiva to enter the oral cavity. This review aims to outline current knowledge of the adverse dental effects of antiresorptive medications. Recently, paediatric indications for antiresorptive medications, such as bisphosphonates (BPs), have emerged, and these agents are increasingly used in children and adolescents to cure pathological bone resorption associated with bone diseases and cancers. Since tooth eruption is accompanied by osteoclastic bone resorption, it is expected that the administration of antiresorptive medications during this period affects tooth development. Indeed, several articles studying human patient cohorts and animal models report the dental defects associated with the use of these antiresorptive medications. This review shows the summary of the possible factors related to tooth eruption and introduces the future research direction to understand the mechanisms underlying the dental defects caused by antiresorptive medications.     

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目的评价Beyond冷光美白法漂白生理性黄牙的疗效及安全性。方法2006年5月至2008年5月于沈阳市口腔医院用Beyond冷光美白仪及配套的冷光美白剂对试验组30例患者428颗生理性黄牙进行脱色;用奥伦增白剂漂白的30例患者464颗生理性黄牙作对照;用VITA比色板作脱色前、后比色,比较脱色效果,观察牙齿敏感情况。结果试验组轻、中、重度生理性黄牙的显效率分别为94.44%、92.59%、74.04%,而对照组相应着色程度生理性黄牙的显效率分别为70.92%、66.16%、32.00%,两者差异有统计学意义(P<0.01)。试验组有7例(13.33%)患者出现牙齿轻度酸痛不适感,对照组有15例(50%)患者出现酸痛感,二者差异有统计学意义(P<0.05)。结论Beyond冷光美白法脱色生理性黄牙有效、安全、快速。     

一种新的牙齿记录法

目的:介绍一种新的牙齿记录法,以达到简便而准确地描述和记录牙齿的目的。方法:T或t作为记录牙齿的标识字符,T代表恒牙,t代表乳牙。用数字1～8和1～5从牙弓中线向远端对恒牙和乳牙编号。用"字母加数字"的方式对恒牙和乳牙、上颌牙和下颌牙、前牙和后牙以及牙位进行记录。结果:恒牙标记为T1～T8,乳牙标记为t1～t5。上、下颌恒牙分别标记为UT1～UT8和LT1～LT8。上、下颌乳牙分别标记为Ut1～Ut5和Lt1～Lt5。前牙、前磨牙和磨牙分别标记为T(1-3)、T(4、5)和T(6-8)。乳前牙和后牙分别标记为t(1-3)和t(4、5)。恒牙牙位用上下标牙位记录法或"UR、UL、LR、LL"加"T1～T8"标记。乳牙牙位用上下标牙位记录法或"UR、UL、LR、LL"加"t1～t5"标记。结论:新的牙齿记录法能简便而准确地标记牙齿、上下颌牙齿、前牙和后牙以及牙位。     

Age and order of eruption of primary teeth in Spanish children

Abstract – A longitudinal study on primary tooth eruption was performed in 114 Spanish children in two Primary Care Centers over 3 yr. Data from periodic observations and data collected by previously instructed parents was studied. Ages of tooth eruption were calculated for both sexes. Comparison between the two sides of the jaws showed a nonsignificant tendency towards earlier left side eruption. Comparison between maxillary and mandibular showed a significant earlier mandibular eruption for central incisors and second molars and a significant earlier maxillary eruption for lateral incisors. Comparison between sexes showed a tendency towards earlier eruption in boys for all teeth, significant only for mandibular central incisors, maxillary and mandibular lateral incisors and mandibular canines. Order of tooth eruption and its most frequent changes were also studied. When these findings were compared to studies performed in other populations it was concluded that ages and order of primary tooth eruption in Spanish children are similar to those found in other populations.     

半坡博物馆馆藏六千年前人颌骨牙齿的磨耗状况分析

目的:调查六千年前新石器时期古人牙齿的磨耗状况,以探寻牙齿磨耗的规律及其演化发展趋势。方法:观察记录并统计了西安半坡博物馆馆藏76例人头颅骨全部牙齿的磨耗情况,用SPSS 12.0软件对全部的904个牙齿进行了统计学分析。结果:不同磨耗度牙齿的构成比中,2°磨耗的比例最高(37.06%)。左右上下对称牙位牙齿的磨耗基本相同。第一磨牙的磨耗程度最重,第三磨牙的磨耗程度最轻。不同年龄段牙齿磨耗度有显著性差异,随年龄的增长,牙齿磨耗度逐渐加重。每一牙位牙齿平均磨耗度男女性别间无显著性差异(P>0.05)。结论:新石器时代古人牙齿的总体磨耗程度较现代人重。     

四种常见离体牙保存液对牙齿颜色的影响

目的：评价离体牙在四种常见保存液中颜色的变化。方法：42名受试者的168颗第一前磨牙分组分别保存于生理盐水、75％的医用酒精、人工唾液和0．5％的麝香草酚中,使用一种电脑色度计测量离体牙拔除前及拔除后24h、1、2、3、4周时的颜色,并用Vita比色板和胶片相机记录每一时期的牙齿颜色。计算不同时期、不同保存液牙齿发生的改变。结果：拔牙前与浸泡后,各组牙色变化均具有显著性差异,并随浸泡时间延长颜色差异增大。酒精组影响最大。结论：牙齿一旦离开机体,其颜色势必发生改变,基于离体牙的齿科颜色研究应考虑到保存液对牙色的影响,人工唾液保存离体牙对牙齿颜色的影响相对于其他3种保存液较小。     

Endodontic management of mandibular lateral incisor fused with supernumerary tooth

Abstract In this article we report a case of a mandibular lateral incisor in which 3 separate root canals were located. Clinical and radiographic examinations suggested that fusion had occurred between the mandibular incisor and a supernumerary tooth. The endodontic management of the tooth is described, and repair of an apical periodontitis had occurred after 9 months.     

年轻恒牙嵌入性脱位的X线追踪观察分析

目的:通过对年轻恒牙嵌入性脱位的X线片进行回顾性研究,观察患牙复位、牙根发育和牙根吸收情况,并分析其影响因素。方法:收集2013年1月~2019年3月发生嵌入性脱位的年轻恒牙病例,分析其X线片,了解患牙复位、牙根发育及牙根吸收情况。结果:所有患牙基本复位,牙根继续发育占66.7%,发生替代性吸收占25%;嵌入程度较轻的患牙利于牙髓存活(P=0.008);自然再萌的患牙可减少替代性吸收(P=0.005);牙髓存活的患牙牙根可发育,且无替代性吸收(P<0.001)。结论:嵌入性脱位的年轻恒牙牙髓可存活,且牙根可继续发育。牙髓存活的患牙利于牙根发育、减少替代性吸收。重度嵌入的年轻恒牙可有萌出潜力。     

Comparative morphological analysis of the root developmental groove with the palato-gingival groove

The palato-gingival groove is an anomaly of shape that modifies dental tissues organization while the developmental root groove is described within normal root anatomy. The morphology of dental tissues in relation to the presence of the developmental root groove has not been properly described. This study analyzed microscopically the morphology of dental tissues related to the root developmental groove comparing it with that presented on teeth affected by palato-gingival groove. Many similarities were observed such as the increased cementum thickness, decreased dentin thickness, pulp compartment surface alteration, irregularity of the dentin-cementum junction and of the cementum surface. These results suggest a common determining factor to this structure organization pattern. It is possible that the palato-gingival groove could be the result of an alteration of genetic mechanisms, rather than a dental germ folding, determined by privation of space, as previously hypothesized.     

TGF-?TGF-?TGF-?蛋白在人牙胚表达的免疫组化研究

目的：探讨TGF-β1、TGF-β2、TGF-β3在人牙齿发育过程中的作用。方法：采用SP免疫组化方法,检测正常引产的胎龄为4～7个月的胎儿颌骨组织切片中TGF-β1、TGF-β2、TGF-β3在牙胚中的分布。结果：TGF-β1、TGF-β3主要在成釉细胞及成牙本质细胞表达,TGF-β2主要在内釉细胞及成釉细胞表达;TGF-β1、TGF-β2、TGF-β3在釉结均呈阳性表达。结论：TGF-β1、TGF-β2、TGF-β3是人牙齿发育过程中重要的调节因子,参与牙胚细胞分化、基质形成及牙齿形态形成。     

半导体激光漂白四环素牙的疗效观察

目的:评价半导体激光漂白四环素牙的临床效果和安全性。方法:采用自制漂白糊剂,对9例68个四环素活髓牙进行半导体激光漂白,分别于术前、术后、术后一周和术后一月进行牙髓敏感测试和测色,分析牙髓敏感性及牙色变化。结果:所有漂白的牙齿术后牙髓敏感程度均在正常范围内。术后牙齿增白明显,VITA比色板色级和色差值有显著性改变。结论:半导体激光漂白四环素牙是快速和安全的,短期漂白效果明显。