Three-dimensional, non-destructive visualization of vertical root fractures using flat panel volume detector computer tomography: an ex vivo in vitro case report

AIM: To detect and to visualize radiographically vertical root fractures in extracted teeth with a prototype of a novel, high resolution, three-dimensional flat panel volume detector computer tomograph (FD-VCT) system. SUMMARY: Five teeth with root fillings and clinical symptoms such as fistulas and isolated periodontal pockets of 8 mm or more were extracted after dental radiography indicating lateral or periapical lesions. Vertical root fractures or cracks were suspected because of the symptoms and clinical findings were evident after extraction in all cases but fracture lines were not visible on routine dental radiographs acquired before extraction. The extracted teeth were explored with a prototype of a FD-VCT. Using the FD-VCT, in all cases vertical root fractures or crack lines could be detected clearly in different views, depiction-modes and cross-sections at a spatial resolution of 140 microm. The evaluation of the fracture lines and teeth could be performed in three-dimensional views. The FD-VCT findings were confirmed by detailed inspection of the extracted teeth. KEY LEARNING POINTS: The FD-VCT is an innovative diagnostic tool for non-destructive, three-dimensional evaluation of extracted teeth in pre-clinical and experimental studies. The FD-VCT allows precise visualization and evaluation of vertical root fractures or cracks in extracted teeth. Clinical application of the system may be possible if technical modifications reduce the exposure dose: the high resolution detector systems of the FD-VCT should be combined with radiation systems that focus the radiation to the area of interest.     

颧上颌复合体骨折的诊断与治疗

颧上颌复合体是面部最突出的部位之一,由于其解剖部位的特殊性,颧上颌复合体骨折在面中部骨折中占有相当大的比例。骨折后不仅引起局部凹陷畸形,甚至导致开口受限、复视等功能障碍。作者结合文献复习和临床经验,对颧上颌复合体骨折的原因、临床表现、治疗方法、手术入路和术后并发症等进行了讨论。认为眉侧切口联合口内切口入路,可以避免冠状切口的种种弊端。此法可在直视下开放复位,较好地暴露颧骨、上颌骨连接处及眶下区骨折,切断颧骨咬肌附丽,松解颧骨骨折块,再进行内固定,效果良好。手术后瘢痕小,面神经功能无损伤,外形及功能恢复良好,值得推广。     

Healing of 400 intra-alveolar root fractures. 1. Effect of pre-injury and injury factors such as sex, age, stage of root development, fracture type, location of fracture and severity of dislocation

Abstract – This retrospective study consisted of 400 root‐fractured, splinted or non‐splinted incisors in young individuals aged 7–17 years (mean = 11.5 ± 2.7 SD) who were treated in the period 1959–1995 at the Department of Pediatric Dentistry, Eastman Dental Institute, Stockholm. Four hundred of these root fractures were diagnosed at the time of injury; and 344 teeth were splinted with either cap‐splints, orthodontic appliances, bonded metal wires, proximal bonding with composite resin or bonding with a Kevlar^® or glass fiber splint. In 56 teeth, no splinting was carried out for various reasons. In the present study, only pre‐injury and injury factors were analyzed. In a second study, treatment variables will be analyzed. The average observation period was 3.1 years ± 2.6 SD. The clinical and radiographic findings showed that 120 teeth out of 400 teeth (30%) had healed by hard tissue fusion of the fragments. Interposition of periodontal ligament (PDL) and bone between fragments was found in 22 teeth (5%), whereas interposition of PDL alone was found in 170 teeth (43%). Finally, non‐healing, with pulp necrosis and inflammatory changes between fragments, was seen in 88 teeth (22%). In a univariate and multivariate stratified analysis, a series of clinical factors were analyzed for their relation to the healing outcome with respect to pulp healing vs. pulp necrosis and type of healing (hard tissue vs. interposition of bone and/or PDL or pulp necrosis). Young age, immature root formation and positive pulp sensibility at the time of injury were found to be significantly and positively related to both pulpal healing and hard tissue repair of the fracture. The same applied to concussion or subluxation (i.e. no displacement) of the coronal fragment compared to extrusion or lateral luxation (i.e. displacement). Furthermore, no mobility vs. mobility of the coronal fragment. Healing was progressively worsened with increased millimeter diastasis between fragments. Sex was a significant factor, as girls showed more frequent hard tissue healing than boys. This relationship could possibly be explained by the fact that girls experienced trauma at an earlier age (i.e. with more immature root formation) and their traumas were of a less severe nature. Thus, the pre‐injury or injury factors which had the greatest influence upon healing (i.e. whether hard tissue fusion or pulp necrosis) were: age, stage of root development (i.e. the size of the pulpal lumen at the fracture site) and mobility of the coronal fragment, dislocation of the coronal fragment and diastasis between fragments (i.e. rupture or stretching of the pulp at the fracture site).     

舌翼垫夹板单颌固定治疗牙列段下颌骨折

为寻找理想的单颌外固定方法,作者自制舌翼(牙合)垫夹板作单颌固定治疗牙列段下颌骨折。临床应用30例,其中单线骨折11例,双线骨折3例,粉碎骨折16例,取得全部治愈,一年复查疗效满意。讨论了其作用机理,适应证和优缺点。认为本法是一种可行的较好方法。     

A systematic approach to preventing intracanal breakage of endodontic files

Abstract This study was conducted to determine the effectiveness of a method to prevent intracanal breakage of endodontic files. An application schedule with a predetermined number of periods of use for K-files of all sizes was implemented at the author's clinic for a 3-year period. All the files used under this schedule were discarded after the predetermined periods of use, whether they displayed any deformity or not. During the 3-year period, 1933 files (53.7 per month) were discarded after preparation of 3269 root canals. There were 5 file fractures (0.1 per month) compared with 1.4 fractures per month before the adaption of this system. The monthly average of files discarded during the 3-year research period was 53.7. Before the adoption of the trial system, the monthly average of discarded files was 76.5. It is concluded that the experimental system effectively reduced the incidence of intracanal instrument fractures and the total number of files consumed.     

Root Fractures in permanent teeth: a clinical review

A retrospective study of 22 root fractures in 21 patients was performed. Ten patients were less than 11 years of age, and boys were involved more often than girls. Ten patients had more than one injured tooth, but there was no case of alveolar fracture. Twenty-one of the teeth were upper central incisors. Only 11 teeth were seen within the first week, so that not all teeth were splinted and not all displaced teeth were repositioned. Long-term clinical and radiographic review showed that loss of vitality of the coronal pulp could not be reliably detected for at least 1 year. No tooth became abscessed or developed a sinus tract, and resorption of bone at the fracture line was observed in only one out of five non-vital teeth. Lack of displacement and placing of a splint increased the chances of the pulp remaining vital and healing of the fracture occurring with hard tissue. Sclerosis of the coronal pulp occurred mainly when healing was by connective tissue. The apical pulp always remained vital, and there was sclerosis of the apical pulp in almost every case.     

下颌下径路经口气管内插管在颌面部骨折治疗中的应用

目的：探讨下颌下径路经口气管内插管在复杂颌面部骨折治疗中的应用。方法：对16例颌面部复杂骨折患者实施下颌下径路经口气管内插管麻醉，术中使用自行研制的引管装置辅助引管。结果：16例患者均一次引管成功，在无麻醉干扰的状态下顺利完成手术。术后未发现严重并发症。结论：下颌下径路经口气管内插管操作简便、安全、创伤小，避免了麻醉导管对口腔手术野的干扰，是对传统麻醉插管方式的改进和补充，是复杂面部骨折手术麻醉的较好选择。     

螺旋CT及三维重建技术在髁突骨折中的临床应用

目的:研究螺旋CT及三维重建技术在髁突骨折中的诊断价值和对治疗的指导作用。方法:对58例75侧髁突骨折通过三维螺旋CT技术进行扫描检查。结果:螺旋CT及三维重建技术可以确诊髁突骨折并明确骨折的部位、旋转、方向、移位情况等,对治疗方法和手术方案的选择有重要的参考意义。结论:螺旋CT及三维重建技术能全面而直观的显示髁突骨折的情况,对髁突骨折的诊断、治疗方案的确定和疗效的评价有重要作用。     

小型钛板内固定治疗下颌骨骨折

目的：评估小型钛板内固定治疗下颌骨骨折的临床疗效。方法：对68例下颌骨骨折的患者行切开复位术，使用小型钛板内固定，保留骨折线上的牙齿。结果：68例患者创口均I期愈合，骨折愈合良好，64例恢复到术前咬合关系，仅4例出现咬合关系不良。结论：小型钛板内固定具有良好的稳定性，缩短了领间固定的时间，可早期恢复张口运动，对骨折线上牙齿可以保留，是一种较好的下颌骨骨折内固定方法。     

Traumatic dental injuries in a cohort of 16-year-olds in northern Sweden

Abstract The prevalence and yearly incidence of traumatic tooth injury between 1 and 16 years of age were studied in a cohort of 16 year-olds, born in 1975, and residing in the County of Västerbotten, northern Sweden. The study comprised 3007 dental records from the public denial health service. The general distribution was 50.3% girls and 49.7% boys. The records showed that 35% of the children on one or more occasions had sustained injury to their primary or permanent dentition. The frequency was nearly twice as high for boys (64%) as for girls (36%). Twenty-five percent of the 16-year-olds had met with tooth injury more than once and this group consisted predominantly of boys. The incidence of injury episodes to primary and permanent teeth was 28 per 1000 per year. The boys had sustained trauma to their teeth most frequently when they were 4 years of age and between the ages of 8 and 11. This was also true for girls at 4 and at 9 years of age, although less evidently so. In the primary dentition, the majority of dental injuries had affected the supporting tissue of the maxillary incisors. In the permanent dentition, 75% of the traumatised teeth were upper incisors. Fractures of varying severity constituted 60% of all registered diagnoses in this dentition, followed by subluxation (19%) and concussion (11%).