Mandibular Fracture in Conjunction with Bicortical Penetration,Using Wide‐Diameter Endosseous Dental Implants

Prosthodontic rehabilitation of a patient with an atrophic edentulous mandible presents a significant challenge in restoring esthetics and function. The purpose of this clinical report is to describe fracture of an atrophic edentulous mandible opposing maxillary natural dentition in association with endosseous dental implants. The patient received two wide‐diameter implants in the anterior mandible for an implant‐assisted mandibular overdenture, in which the implants penetrated the inferior border of the mandible for bicortical stabilization. Three months following implant placement surgery, the patient experienced pain, swelling, and intraoral purulent drainage around the right implant. Panoramic radiograph revealed a fracture of the mandible through the right implant site and signs of infection around the left implant. The implants were removed surgically, and open reduction and fixation of the fracture site were undertaken using a titanium bone fixation plate. This clinical report demonstrates that placement of wide‐diameter implants in conjunction with bicortical penetration in a severely atrophic edentulous mandible can risk fracture of the mandible.     

The management of a completely edentulous patient using simultaneous maxillary and mandibular CAD/CAM-guided immediately loaded definitive implant-supported prostheses: a clinical report

Functional rehabilitation of a completely edentulous patient with removable prostheses is a clinical challenge. A patient with an edentulous maxilla and mandible received 6 endosseous implants in the maxilla and 5 implants in the mandible using CAD/CAM surgical templates. Definitive maxillary and mandibular implant-supported fixed complete dentures were connected immediately after implant placement using a CAD/CAM-guided implant surgical placement protocol.     

无牙颌位至最大开口位下颌运动规律的初步探讨

目的：探讨从无牙颌位至最大开口位时下颌颏部及髁突顶部的运动轨迹的规律，分析在无牙颌患者牙尖交错位建He与此运动轨迹的关系。方法：分别对22例无牙颌患者行无牙颌位、牙尖交错位和最大开口位时的头颅侧位X线片拍摄，测定在二三个位置时颏前点、髁突顶点以及相应的面角的改变。结果：颏前部从无牙颌位至牙尖交错位及最大开口位发生向下向后的移位，髁突顶发生向下向前的移位，SNPg角逐渐减小。结论：颏部及髁突从无牙颌位到最大开口位下颌的位置出现旋转性的位移，颏前部及髁突顶部可出现不同的旋转曲线，在此轨迹上有助于帮助确定牙尖交错位建He点。     

Full-arch restoration of the jaw with fixed ceramo-metal prosthesis: late implant placement

BACKGROUND: The completely edentulous patient has few treatment options in conventional dentistry. When implants are considered, treatment plans range from a 2-implant overdenture to a completely implant-supported prosthesis. Fixed prosthesis is often the preferred selection of the edentulous patient. This study assesses the 5-year cumulative survival rate of implants placed to support full-arch fixed restoration. METHODS: During 1990 to 1995, 171 implants were placed in 22 completely edentulous jaws of 20 patients. All patients were discharged wearing immediate dentures. The implants were analyzed as to the number of implants per jaw, implant location, length, and diameter. RESULTS: The 5-year cumulative survival rate was 89.9%. The mean number of implants per jaw was 7.7 for the maxilla and 8 for the mandible. In the maxilla, the preferred implant locations were the canines, centrals, laterals, and first premolars; in the mandible, they were the canines, laterals, and first molars. The mean implant length was 14.2 mm for the mandible and 13.2 mm for the maxilla. The mean implant diameter was 3.6 mm for the maxilla and 3.8 for the mandible. CONCLUSIONS: The results of the present study indicate that fixed full-arch ceramo-metal restorations can be a predictable implant treatment modality for the edentulous patient.     

Use of a two-piece Gunning splint as a mandibular guide appliance for a patient treated for ameloblastoma

Prosthodontic restoration in edentulous patients who have undergone hemisection of the mandible is difficult because of the instability of the mandible after resection and the lack of teeth necessary for successful retention of a guidance appliance. Successful prosthodontic restoration was accomplished through the use of a two-piece Gunning splint both for intermaxillary fixation and as a guidance appliance in an edentulous patient who underwent a hemisection of the mandible subsequent to treatment for an ameloblastoma. Because mandibular guidance therapy is most successful in patients whose resection involves only bony structures with minimal loss of soft tissue and no radical neck dissection or radiation therapy, the patient treated for ameloblastoma is an ideal candidate for the use of a two-piece Gunning splint for intermaxillary fixation and mandibular guidance therapy.     

Standard of care for the edentulous mandible: a systematic review

STATEMENT OF PROBLEM: Implant therapies have increased the range of prosthodontic options for the treatment of edentulism. Considering both dentist- and patient-mediated outcomes, a universal treatment intervention for the treatment of the edentulous mandible has not been demonstrated. PURPOSE: The purpose of this study was to test the null hypothesis that there is no single standard of care for the edentulous mandible as defined by a specific treatment modality. MATERIAL AND METHODS: A review of the literature was undertaken seeking evidence of a superior intervention for the treatment of the edentulous mandible. A search of the English language peer-reviewed literature was completed using Medline and Google Scholar for the period from 1995 to 2005, focusing on evidence-based research. This was supplemented with a hand search of selected dental journals and textbooks. Longitudinal retrospective studies, longitudinal prospective studies, longitudinal experimental clinical studies, nonrandomized controlled studies, and randomized controlled clinical trials were included for review using a general linear hierarchical classification of studies. Articles that did not focus exclusively on treatment interventions for mandibular edentulism or on the effects of such therapies on the patient were excluded from further evaluation. The search period included articles that were published before the criteria for evidence-based literature were established, but this was not necessarily used to exclude an article. The last search was conducted on September 25, 2005. RESULTS: The literature demonstrates that the functional demands of edentulous patients are highly variable and that patient treatment responses are individual, vary significantly, and are influenced by psychosocial forces. The literature further demonstrates that patient acceptance of specific treatment modalities is modified by social and cultural influences, financial means, and adaptive capacity. Additionally, patient acceptance of a particular treatment modality is influenced by the educational background, knowledge, and experience of the dental health care provider, as well as by a host of other socioeconomic, regional, cultural, age, and gender influences. CONCLUSIONS: Within the limits of this review, there is no evidence for a single, universally superior treatment modality for the edentulous mandible. Better designed, long-term studies are required to further explore differences in patient acceptance to each treatment intervention for the edentulous mandible.     

Surgical simulation of Class III edentulous patient using a 3D craniofacial model: report of a case

A case of edentulous prognathism in a 46-year-old Japanese male is presented. We described the outcome of the patient who underwent simultaneous sagittal splitting ramus osteotomy of the edentulous mandible, interpositional bone graft of severely atrophic edentulous jaws, and delayed placement of titanium implants for reconstruction. We highly recommend performing a surgical simulation using a craniofacial model of the patient's anatomy created using CT image data. The procedure provides almost ideal maxillary and mandibular contours.     

The oblique radiographic technique for bone height measurements on edentulous mandibles: a preclinical study and an introduction to the clinical use

OBJECTIVE: The aim of this study was to quantify the effect of mandibular angulation, position, and shape of the edentulous mandible on the distortion of its image on lateral oblique radiographs in a preclinical study. Suggestions for the clinical use of this technique are made. STUDY DESIGN: Five edentulous dry mandibles were used, varying in size from small to wide and equipped with metal bars in and on top of the mandible. The mandibles were radiographed at 9 different positions by tilting the mandible around the intercondylar axis and by using the oblique projection technique in a cephalostat. RESULTS: The length of the images of the metal bars varied significantly when we tilted the mandibles from 20 degrees to -20 degrees. As a result of the effects of magnification and distortion, the image size varied from between 0.96% and 1.06% of the real size. Neither the size of the mandible nor the position of the bars was related to the degree of magnification. CONCLUSION: The oblique projection technique has limited geometric errors in depicting the edentulous mandible. For evaluative bone height measurements in patients with extremely resorbed mandibles treated with dental implants, it is a promising technique if the patient (specifically the mandible) can be positioned reproducibly in the apparatus.     

Position of the mandible, range of movement and temporomandibular joint noises in edentulous patients (proceedings)]

The authors present studies on lateral displacements and ranges of horizontal and vertical movements of the mandible. Theyy used a new device--deviatiometer (fig. 1--4)--for measuring the position and the movements of the mandible. They stated no significant differences in the frequency of temporomandibular joint noises with regard to sex, age, lateral displacement of the mandible and ranges of movements. Consequently, temporomandibular joint noises should not be overvalued in the edentulous patient.     

Surgical and prosthodontic treatment using alveolar distraction osteogenesis and implant placement for a patient with mandibular prognathism: a clinical report

A 49-year-old patient presented with an Angle Class III malocclusion with a partially edentulous mandible, as diagnosed by orofacial examination and radiographic and cephalometric analyses. The patient refused orthognathic surgery; therefore, the treatment plan included the preparation of all teeth and fabrication of provisional restorations to reestablish optimal occlusion. To allow for the placement of 3 implants, the edentulous posterior mandibular ridge was improved via alveolar distraction. The patient was recalled 3, 6, 12, and 24 months after prosthodontic treatment. The oral situation was stable and patient satisfaction was reported as high.     

种植体支持球帽附着体固位下颌覆盖全口义齿的临床应用

目的:评价种植体支持球帽附着体固位的下颌覆盖全口义齿临床应用效果.方法:随机选择15例下颌无牙颌患者,每例植入2枚种植体,共植入30枚,随访观察1-12个月,从患者满意度、临床检查及种植体X线片观察修复效果.结果:种植体支持覆盖全口义齿修复下颌无牙颌,义齿固位和咀嚼功能满意率分别为100％和93.3％,义齿稳固,咀嚼功...     

Dental rehabilitation using an implant-supported overdenture after repair of a fracture in a severely resorbed edentulous mandible: a case report

Treatment of mandibular fracture in senior citizens with severely resorbed edentulous mandibles is extremely difficult. Such treatment must achieve successful osteosynthesis and restore functional mastication. A severely resorbed (Class V) mandible was successfully reconstructed with an autogenous bone graft on the inferior border of the mandible and a titanium mesh plate after a failed attempt to fix the fracture. After the placement of endosseous implants in the mandible, the patient was rehabilitated with an overdenture to restore masticatory function.     

Miniplate osteosynthesis of fractures of the edentulous mandible

This study was performed to analyze treatment of fractures of the edentulous mandible and to discuss this method in relation to the mandibular height at the fracture site. Fifteen fracture sites in 11 patients with an edentulous mandible were retrospectively examined. These fractures were located: nine fractures in the mandibular body, three in the paramedian region, and three in the mandibular angle. Fractures in a mandible measuring more than 10 mm in the vertical height were treated with one miniplate. Fractures in an extremely atrophic mandible with 10 mm or less were treated using one or two miniplates, also using a modified Champy plate with 1.3 mm in thickness. A mandibular fracture with a height of 5 mm was treated with a combination of a microplate on the buccal side and a miniplate on the inferior border of the mandible with additional direct circumferential wiring. Oblique or splitting fractures were treated with direct circumferential wiring or a Herbert screw, at one fracture site each, respectively. Complications, including infection, fibrous union, nonunion and trismus, were not seen. In one patient, hypesthesia of the lower lip was, however, persistent 1 month after surgery. Miniplate osteosynthesis is the less invasive treatment, and it is suitable for fractures of the atrophic edentulous mandible, except for comminuted or defect fractures. To obtain stable fixation in severely atrophic mandibles, we need to consider the use of two miniplates or a combination with microplates.     

有牙颌与无牙颌老年人下颌及髋部骨密度的比较研究

目的　观察有牙颌与无牙颌老年人下颌骨及髋部骨骨密度有无差别 ,探讨影响牙槽骨骨吸收及无牙颌发生的全身危险因素。方法　采用双能X线吸收法测量全部研究对象的右侧髋部骨密度及左侧下颌角骨密度。结果　无牙颌与有牙颌老年人相比 ,前者下颌角骨密度较低 (P <0 0 0 1) ;髋部 (股骨颈、大粗隆、Ward三角区 )骨密度也表现出不同程度的降低。结论　髋部或全身骨密度减低、下颌骨骨密度减低是导致牙齿缺失及无牙颌的因素之一。     

Mandibular fracture as a complication of inferior alveolar nerve transposition and placement of endosseous implants: a case report

Placement of endosseous implants and inferior alveolar nerve transposition is a treatment option for patients with an edentulous posterior mandible with inadequate bone height superior to the inferior alveolar canal. Complications associated with these procedures include infection, prolonged neurosensory disturbances, and/or pathologic fracture. This report presents the surgical management of a patient with a mandible fracture after inferior alveolar nerve transposition with concurrent placement of two endosseous implants.     

Early load mandibular hybrid prosthesis using the Ohio State University acrylic frame requiring no final impression

Background:  Although immediate/early loading protocols for dental implants have presented encouraging outcomes, immediate loading procedures may cause discomfort to the patient and may increase the possibility of damage to the surgical site during the impression procedures. The aim of this study was to describe an alternative technique to fabricate a mandibular hybrid prosthesis in three or four days without making any final impression and to evaluate the outcomes of this technique.
Methods:  Seven patients aged 41 to 71 years (mean age, 58 ± 11) were considered for this study. Each patient received five implants for the reconstruction of the edentulous mandible. These implants were placed in the anterior region of an edentulous mandible and restored with a final mandibular hybrid prosthesis in four days using the Ohio State University (OSU) acrylic frame requiring no final impression procedure. The patients were followed up to 19 months after implant placement.
Results:  No implants were lost, no technical complications were observed and only minor marginal bone loss was noted after an average 15 months.
Conclusions:  This clinical study shows that the OSU acrylic frame, which can easily be customized and accommodates variability in arch form, may be an alternative method to restore any edentulous mandible with an early load mandibular hybrid prosthesis.     

Effect of maxillary edentulousness on mandibular residual ridges

Bone mineral density (BMD) was measured in five different regions of the mandible of 77 postmenopausal women. These women were also classified according to the remaining, clinically determined alveolar height in the edentulous distal regions of the mandible. The duration of edentulousness in the maxilla and in the mandible was determined anamnestically. All subjects were edentulous in the maxilla, and 42 were also edentulous in the mandible. The other 35 women had teeth only in region d35-d45. This study shows that after extraction of the last teeth in the mandible, the BMD of the cortical bone is not lowered, but that the BMD of the trabecular portion is lowered more by mechanical stress caused by the remaining natural teeth than by maxillary dentures. This feature becomes apparent when duration of edentulousness in the maxilla is compared with the BMD values of different regions in the mandible.     

有牙颌与无牙颌老年人颌及髋部骨密度的比较研究

目的 观察有牙颌与无牙颌老年人下颌骨及髋部骨骨密度有无差别,探讨影响牙槽骨骨吸收及无牙无颌发生的全身危险因素。方法 采用双能Ｘ线吸收法测量全部研究对象的右侧髋部骨密度及左侧下颌角骨密度。结果 无牙颌与有牙颌老年人相比,前者下颌角骨密度较低（Ｐ〈０．００１）;髋部（有颈、大粗隆、ｗａｒｄ三角区）骨密度也表现出不同程度的降低。结论 髋部或全身骨密度减低、下颌骨骨密度减低是导致牙齿缺失及无牙颌的因素之一     

Rehabilitation of the edentulous mandible with a fixed implant-supported prosthesis.

Implant rehabilitation of an edentulous mandible presents significant improvements over conventional complete denture therapy with regard to patient satisfaction, and it can improve a patient's quality of life. Several implant prosthetic designs have been developed and successfully utilized in clinical practices. The goal of this article is to describe the prosthetic design and technical steps in the fabrication of a fixed implant-supported mandibular prosthesis. A technique is described in which the positioning of appropriately selected abutments is completed in a predictable manner. LEARNING OBJECTIVES: This article discusses the prosthetic designs and technical steps in fabricating a fixed implant-supported mandibular prosthesis. Upon reading this article, the reader should: Understand the prosthetic design for the treatment of an edentulous mandible. Recognize the significance of the technical steps in this rehabilitation process.     

The less than 7-mm edentulous mandible: the implant/overdenture reconstructive option

The edentulous patient with a severely atrophic mandible (less than 7 mm in height) can be successfully restored with two endosseous implants and a clip-bar overdenture, with minimal morbidity. Two of the three cases reported illustrate the long-term potential of this treatment modality.