Reconstruction of the edentulous mandible with fresh frozen bone grafts and implants: a 4-year report of a prospective clinical study

Allogen bones from tissue bank are often used in dentistry although the data analyzing the long-term success in mandible are scarce. This study evaluated by computed tomography scans (CTS) the bone resorption around the implants installed on fresh frozen bone (FFB) previously grafted, after 4 years of occlusal rehabilitation. Six subjects were grafted with blocks in posterior mandible using FFB. After 6 months, 27 implants were placed and after further 4 months the prostheses were delivered. Following 4 years of the final rehabilitation procedures, another CTS was done in order to measure the resorption in periimplant bone crest at the proximal implant surfaces. It was observed a 100 % survival rate of the implants after 4 years of the fixture installation. The marginal bone resorption after 48 months was 2.82 ± 1.63 mm and no statistical significant difference was observed along the region where the implants were fixed when compared with the interimplantar space. In addition there was no significant correlation regarding the length of the implant used and the amount of marginal bone resorption. The conclusion is that grafted areas with FFB are suitable to implant installation in the posterior mandible.     

Accelerated rehabilitation of an edentulous patient with an implant retained dental prosthesis: a case report

This case report details the successful rehabilitation of an edentulous patient using a complete upper prosthesis and a lower implant retained overdenture. The provision of care was split between a specialist centre and a primary care setting. This approach reduced inconvenience to the patient. Modern surgical and prosthodontic techniques also reduced the total delivery time. After initial consultation a new set of complete dentures was prescribed with changes in design to the originals. The patient was also planned for placement of two mandibular implants to stabilise and retain the mandibular denture. The first line of treatment involved provision of a new set of dentures constructed by the patient's general dental practitioner. Dental implants were then placed in a specialist centre and the patient returned to the dental practice for attachment of the lower denture to the dental implants. The benefits and success of mandibular implant retained dentures are well documented. With delivery of the overdenture, the patient reported increased satisfaction with his prostheses which allowed him to eat a greater range of foods and enabled him to feel confident when speaking and socialising.     

Effect of electromagnetic field on bone regeneration around dental implants after immediate placement in the dog mandible: a pilot study

doi: 10.1111/j.1741‐2358.2011.00525.x Effect of electromagnetic field on bone regeneration around dental implants after immediate placement in the dog mandible: a pilot study Background: Accelerating bone healing around dental implants can reduce the long‐term period between the insertion of implants and functional rehabilitation. Objective: This in vivo study evaluated the effect of a constant electromagnetic field (CEF) on bone healing around dental implants in dogs. Materials and methods: Eight dental implants were placed immediately after extraction of the first pre‐molar and molar teeth on the mandible of two male dogs and divided into experimental (CEF) and control groups. A CEF at magnetic intensity of 0.8 mT with a pulse width of 25 μs and frequency of 1.5 MHz was applied on the implants for 20 min per day for 2 weeks. Result and conclusion: After qualitative histological analysis, a small quantity of newly formed bone was observed in the gap between the implant surface and alveolar bone in both groups.     

Resonance frequency analysis of overdenture retainer implants with immediate loading

doi: 10.1111/j.1741‐2358.2011.00488.x
Resonance frequency analysis of overdenture retainer implants with immediate loading Objective: To evaluate 16 patients of both sexes with lower overdenture and upper complete dentures, by analysing the resonance frequency of the initial and late stability of implants used to retain the overdenture under immediate loading. Background: Oral rehabilitation treatment with complete dentures using implants has been increasingly more common among the specialists in the oral rehabilitation area. This is an alternative for obtaining retention and stability in treatments involving conventional complete dentures, where two implants are enough to retain the overdenture satisfactorily. Materials and methods: The Osstell? Mentor device was used for the analysis in the initial period (primary stability), 3 and 15 months after the installation of the lower overdenture (secondary stability). The statistical analysis was performed with the repeated measures model (p < 0.01). Results: The implant stability quotients were observed to increase after 15 months of the rehabilitating treatment. Conclusion: The use of overdentures over two lower implants should become the treatment of choice for individuals who have a fully edentulous mandible.     

Segmental mandibulectomy and immediate free fibula osteoseptocutaneous flap reconstruction with endosteal implants: an ideal treatment method for mandibular ameloblastoma

Thirteen patients with large ameloblastomas of the mandible underwent segmental mandibulectomy and immediate reconstruction, with simultaneous placement of osseointegrated implants. All patients received palatal mucosal grafts around the dental implants 6 to 10 months after surgical treatment and received implant-supported prostheses another 1 to 2 months later. There were five female and eight male patients, with a mean age of 32 years (range, 17 to 50 years). The mean length of the mandibular defect was 8.8 cm (range, 5 to 13 cm). All free fibula flap procedures were successful, with no reexplorations or partial flap losses. There was no clinical or radiographic evidence of failure during the osseointegration process for any implant. With functional occlusal loading, the marginal bone loss around the implants was less than 1.5 mm in a mean follow-up period of 40 months (range, 18 to 70 months). There were no recurrences during that time. The technique described allows improved access to the bone at the time of reconstruction, immediate assessment of alveolar ridge relationships, and accurate fixation of the implant-fibula construct. The advantages of this procedure include a reduced risk of recurrence with segmental resection, reliable mandibular reconstruction, and reduction of the number of surgical procedures, allowing full oral rehabilitation in a shorter time. It is concluded that segmental mandibulectomy and immediate vascularized fibula osteoseptocutaneous flap reconstruction, with simultaneous placement of osseointegrated implants, represent an ideal treatment method for large ameloblastomas of the mandible.     

Partial trisomy 4q syndrome: Case report and review

Summary In the course of chromosome studies of atomic bomb survivors in Hiroshima using the trypsin-G-banding and Q-banding methods, a 40-year-old male was found to have an abnormal banding pattern in the long arm of a chromosome 7, although no such abnormality was detected by ordinary staining method. Since all other chromosomes apparently had normal banding patterns, the abnormality was determined to be a paracentric inversion of a chromosome 7, which is described as 46,XY,inv(7)(q22q31). This is the first demonstration of a possible paracentric inversion in man.     

Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible

This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology.     

Long-term restoration of masticatory function with fixed mandibular implants in cases of oral cancer

The results of the present study show that the fixed mandibular implant system enables patients who have operations to treat oral cancer to use a stabilized denture continuously over an extended period of time.