Atypical migration of an impacted lower third molar

This report describes the atypical migration of an impacted lower third molar tooth in a 42-year-old woman. Serial radiographs showed that, over a period of 13 years, the tooth migrated from its original disto-angular position posterior to and beneath the roots of the adjacent second molar to a more horizontal position beneath the roots of the first permanent molar. The tooth was surgically removed under general anaesthesia, with biopsy and curettage of soft tissue found in the bone posterior to the tooth along the path of migration. This pattern of tooth movement is highly unusual in an adult patient.     

Moving an ankylosed central incisor using orthodontics, surgery and distraction osteogenesis

When a dentist replants an avulsed tooth, the repair process sometimes results in the cementum of the root and the alveolar bone fusing together, with the replanted tooth becoming ankylosed. When this occurs, the usual process of tooth movement with bone deposition and bone resorption at the periodontium cannot function. If dental ankylosis occurs in the maxillary incisor of a growing child, the ankylosed tooth also cannot move vertically with the subsequent vertical growth of the alveolar process. This results in the ankylosed tooth leaving the plane of occlusion and often becoming esthetically objectionable. This report describes a 12-year-old female with a central incisor that was replanted 5 years earlier, became ankylosed, and left the occlusal plane following subsequent normal vertical growth of the alveolar process. When growth was judged near completion, the tooth was moved back to the occlusal plane using a combination of orthodontics, surgical block osteotomy, and distraction osteogenesis to reposition the tooth at the proper vertical position in the arch. This approach had the advantage of bringing both the incisal edge and the gingival margin of the clinical crown to the proper height in the arch relative to their antimeres. Previous treatment procedures for ankylosed teeth have often involved the extraction of the affected tooth. When this is done, a vertical defect in the alveolar process results that often requires additional bone surgery to reconstruct the vertical height of the alveolar process. If the tooth is then replaced, the replacement tooth must reach from the final occlusal plane to the deficient ridge. This results in an excessively long clinical crown with a gingival height that does not match the adjacent teeth.     

Minimally invasive treatment of an extruded deciduous tooth ‐ Case report

When a traumatic dental injury affects the deciduous teeth, the main management is to regularly review the patient until the successor permanent tooth erupts to avoid further consequences to the affected tooth and, especially, sequelae in the tooth germs of the successor permanent tooth. This report describes a case of a tooth extrusion in a 4‐year‐old male treated with a minimally invasive approach. After 4 years of follow‐up, there was a mild disturbance (demarcated opacity in the vestibular surface) and a satisfactory result with normal eruption of the permanent successor tooth.     

乳牙根管治疗技术的进展

乳牙根管治疗是针对乳牙牙髓炎及乳牙根尖周炎的一种常规治疗方法,其过程包含完善的根管预备、根管消毒和根管充填,以去除感染,控制炎症,消除疼痛,防止对继承恒牙产生病理性影响,延长患牙的保存时间。本文通过回顾乳牙根管治疗的研究历史,总结了乳牙根管解剖学形态、根管预备、根管消毒、根管充填及抗生素应用等乳牙根管治疗相关方面研究的新进展。     

Inverted eruption of a supplemental lower premolar: report of an unusual case

Summary. Eruption of an inverted tooth is a rare condition. This case report describes the inverted eruption of a supplemental lower premolar in a 10-year-old Caucasian female. The tooth erupted in a downward direction and reached the lower cortical border of the mandible 2 years later. During an 8-year follow-up period, the tooth did not interfere with eruption of permanent teeth and the patient remained symptom-free. Considering clinical examination, medical and dental history as well as scientific evidence, the inverted eruption was most likely caused by a developmental abnormality with an inverted location of the tooth bud. This reported eruption of an inverted tooth is extremely rare and requires a radiographic follow-up to evaluate the relative position of this tooth in the jaw bone and its potential interference with neighbouring teeth or anatomic structures.     

Dkk-Wnt信号通路在牙齿发育中作用的研究进展

哺乳动物的牙齿发育是外胚层上皮与间充质间相互调控和信号交流的结果,其中Dkk-Wnt信号通路是近年来牙胚发育研究领域的热点。Dkk-Wnt信号通路已被证实在牙体形成细胞功能的发挥、牙齿模式化、形态发生、牙冠钙化过程中扮演重要作用。牙齿发生发育分子机制的深入研究,将为牙再生组织工程技术以及相关技术的临床转化提供理论基础。本文就近十年对Wnt信号通路在牙齿发育中所起作用的研究作一综述。     

Absence of apical resorption during orthodontic treatment on a tooth with a complicated crown fracture and root canal treatment: a case report

Root resorption often occurs after tooth trauma and may also occur during orthodontic tooth movement. This has been attributed to bacteria and inflammation or a combination of both aetiologies. The literature suggests that root canal treatment performed on a traumatized tooth that will concurrently or subsequently undergo orthodontic tooth movement may forestall the resorptive process. This case report provides evidence for this prevention and discusses the hypothesis for the absence of resorption on root-treated teeth.     

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邻牙、对颌牙及颞下颌关节损伤是牙拔除术中较为严重的并发症,一旦发生,易引发医患矛盾。本文针对邻牙、对颌牙以及颞下颌关节损伤的原因、临床表现、处理和预防进行阐述,为口腔外科医生的临床操作提供参考。     

A Novel Approach to Repositioning and Stabilization of a Luxated Tooth With Displacement Using a 3D Printed Guide

The management of traumatic dental injury aims at functional and esthetic rehabilitation. After luxation injury, a displaced tooth must be replaced into its normal position as soon as possible. Incorrect tooth repositioning can cause discomfort to the patient and compromise the outcome. This report documents a novel digital technology–based approach for the management of teeth following luxation injury with displacement. A 25-year-old female reported 2 days after traumatic dental injury to her maxillary right central incisor tooth #8. After clinical and radiographic examination, a diagnosis of lateral luxation of tooth #8 was made. The preoperative high-resolution cone-beam computed tomography (CBCT) image data set confirmed palatal luxation of tooth #8 with fractured and displaced labial cortical plate. The CBCT data were imported into a medical image processing software program, and a segmentation tool was used to segment the fractured cortical plate, luxated tooth, and alveolar process. The socket is reconstructed by realigning fractured cortical bone over the alveolar process and repositioning the tooth in the virtual planning software. A three-dimensional (3D) guiding template was designed over the repositioned tooth and adjacent teeth and printed. This 3D printed guide was used for the repositioning of luxated tooth #8 and stabilizing it during the splinting procedure. This technique of using CBCT and 3D guide for repositioning is an objective, precise, and predictable approach. The 3D printed model of the dental arch after virtual tooth alignment can be used by the dentist to determine the exact splint length and contour before splinting.     

Replantation of avulsed central incisor with advanced periodontal disease: a case report.

This paper describes the case of a 31-year-old woman with advanced periodontal disease who lost a tooth due to trauma. The avulsed tooth had minimal bony support of only 4-5 mm. The patient described was under good periodontal maintenance. The tooth was kept moist, and replantation occurred within an hour of avulsion. The tooth was returned to its position, splinted, and later endodontically treated. After 2 years the tooth appears and functions normally as it did before avulsion.     

Replantation of avulsed central incisor with advanced periodontal disease: a case report

Abstract— This paper describes the case of a 31 -year-old woman with advanced periodontal dlsease who lost a tooth due to trauma. The avulsed tooth had minimal bony support of only 4—-5 mm. The patient described was under good periodontal maintenance. The tooth was kept moist, and replantation occurred within an hour of avulsion. The tooth was returned to its position, splinted, and later endodontically treated. After 2 years the tooth appears and functions normally as it did before avulsion.     

Tooth wear, a proposal for an evaluation system

The present-day terminology and definitions of tooth wear are not unambiguous. For diagnosing tooth wear, however, it is essential that they are unambiguous. In this article a proposal is presented for a tooth wear evaluation system with simplified definitions. This system consists ofa number of modules and can be used for various aspects of the diagnostic procedure. It can be used for the quantification of tooth wear, both for periodic screening and for the monitoring of tooth wear in individual patients. The scoring of occlusal/incisal tooth wear as well as of non-occlusal/non-incisal tooth wear is possible. The evaluative system is also suitable for determining which type of tooth wear, such as attrition, abrasion and erosion, is most likely to have caused any observed loss of hard tooth tissue.     

A very large maxillary cuspid

This brief report describes an extracted maxillary permanent cuspid tooth that is longer than any previously reported human tooth. This tooth was removed from a patient of short stature.     

The resin retained natural tooth pontic: a transitional esthetic solution

This case report presents an alternative treatment option for the premature loss of a maxillary anterior tooth due to severe periodontitis. A natural tooth pontic acid-etch prosthesis was fabricated using the patient's clinical crown from the extracted tooth. This measure proved to be a very adequate, esthetic treatment solution before a permanent restorative plan could be developed for the patient's long term dental needs.     

Tooth bioengineering leads the next generation of dentistry

International Journal of Paediatric Dentistry 2012; 22: 406-418 Background. As a result of numerous rapid and exciting developments in tissue engineering technology, scientists are able to regenerate a fully functional tooth in animal models, from a bioengineered tooth germ. Advances in technology, together with our understanding of the mechanisms of tooth development and studies dealing with dentally derived stem cells, have led to significant progress in the field of tooth regeneration. Aim and design. This review focuses on some of the recent advances in tooth bioengineering technology, the signalling pathways in tooth development, and in dental stem cell biology. These factors are highlighted in respect of our current knowledge of tooth regeneration. Results and conclusion. An understanding of these new approaches in tooth regeneration should help to prepare clinicians to use this new and somewhat revolutionary therapy while also enabling them to partake in future clinical trials. Tooth bioengineering promises to be at the forefront of the next generation of dental treatments.     

Contemporary aesthetic care for nonvital teeth: conservative treatment options

This article presents a series of considerations for the adhesive restoration of the nonvital tooth. Although ensuring the marginal integrity of all elements is critical to the final restoration, the most important parameter in the restoration of an endodontically treated tooth is the evaluation of the loss of substance in volume, architecture, and location. It is also important for the dentist to consider other clinical parameters (eg, the age of the patient, the length of time since trauma, even the occlusal scheme) prior to initiating care for these teeth. Learning Objectives: This article advocates the clinician's conservation of natural tooth structure when providing care to preserve the root anchorage due to repeated and invasive work that can result in microfractures or loss of tooth. Upon reading this article, the reader should: * Understand the need to preserve tooth structure by performing partial-coverage restorations. * Become more familiar with the indications for resin-bonded restoration for a devital tooth.     

Successful minimally invasive intervention in a primary central incisor after root fracture: A case report

Root fractures vary in severity, extent, and location, according to the physical and mechanical aspects of the accident. Root fractures are rare in primary teeth and they affect dentin, cementum, periodontal ligament and the pulp. This paper reports a case of a two-and-a-half-year-old baby who had a root fracture of the upper right primary central incisor (tooth 51) as a consequence of trauma that was managed with minimally invasive intervention. After clinical and radiographic examinations, the presence of tooth mobility, pain, bleeding and a horizontal apical root fracture was diagnosed on tooth 51. The treatment of choice was splinting for 120 days, which can deliver excellent results regardless of the patient's age. The tooth was preserved without needing endodontic intervention until its physiologic exfoliation and normal eruption of its permanent successor. As sequelae to the fractured tooth 51, there was some coronal color alteration and dystrophic calcification of the root canal. This tooth did not develop ankylosis or mobility during the follow-up period. After 57 months of follow-up, repositioning and splinting were appropriate ways to manage this horizontal root fracture in the apical third of this primary tooth. It allowed the tooth to be preserved in the arch with normal function.     

Evaluation of the knowledge of tooth avulsion of school professionals from Adamantina, São Paulo, Brazil

Abstract –  Tooth avulsion is common in children, and emergency management in these cases is critical. This management can be made, not only by a dentist but by people who are present where the accident occurs. Consequently, knowledge of tooth avulsion is fundamental for school professionals working with children. The purpose of the present study was to evaluate the knowledge of tooth avulsion of school professionals from Adamantina, São Paulo, Brazil. For that purpose a questionnaire, including questions regarding emergency procedures for tooth avulsion, was answered by 117 teachers. The results demonstrated that 75.2% of school professionals knew the importance of emergency management and 60.6% would look for a dentist for treatment of the cases; 18.8% would reimplant the tooth and 7.6% would keep it in milk. This study showed the lack of knowledge of teachers on tooth avulsion; educational campaigns are necessary to improve the emergency management of tooth avulsion.     

Reinforced composite resin foundations for endodontically treated teeth

An endodontically treated tooth having a healthy periodontium can contribute long service to the oral apparatus. A reinforced composite resin dowel and core provides the needed reinforcement to combat the effects of occlusal stresses. This allows an endodontically treated tooth to serve the patient as a normal tooth.     

Resorption of Permanent Teeth

The varying extent of permanent tooth resorption attributable to different types of orthodontic appliances is a continuing cause for concern. This paper reviews recent researches which contribute to an improved understanding of the origin and behaviour of osteoclasts; and considers the structure and behaviour of the periodontal ligament and its relationship to the cementum and bundle bone of the tooth socket. Permanent tooth resorption is identified as a normal phenomenon. A simple explanation is offered as to why under normal circumstances the bone of the tooth socket is more likely to be resorbed than the tooth itself. With this knowledge treatment procedures can be selected which will reduce tooth resorption risks to a minimum.