Tilted implants and prototyping: A security option for improving the anchorage in atrophic maxilla

Rehabilitating atrophic maxilla poses many challenges. Reconstructive techniques that require sinus grafting are viable and acceptable; however, these techniques also are considered to be expensive, invasive, and time-consuming. Tilted implants anchored in distal areas using available bone have been reported as a less invasive and highly predictable treatment option. This article presents a case involving implant anchorage via tilted implants as an alternative technique to bone grafting procedures. Copyright © 2013 by the Academy of General Dentistry.

Tilted and Short Implants Supporting Fixed Prosthesis in an Atrophic Maxilla: A 3D-FEA Biomechanical Evaluation

Purpose: This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla. Materials and Methods: The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-computer tomography imaging of implants. The different configurations considered were M4S, four vertical anterior implants; M4T, two mesial vertical implants and two distal tilted (45°) implants in the anterior region of the maxilla; and M6S, four vertical anterior implants and two vertical posterior implants. Numerical simulation was carried out under bilateral 150N loads applied in the cantilever region in axial (L1) and oblique (45°) (L2) direction. Bone was analyzed using the maximum and minimum principal stress (σmax and σmin), and von Mises stress (σvM) assessments. Implants were analyzed using the σvM. Results: The higher σmax was observed at: M4T, followed by M6S/L1, M6S/L2, M4S/L2, and M4S/L1 and the higher σvM: M4T/L1, M4T/L2 and M4S/L2, M6S/L2, M4S/L1, and M6S/L1. Conclusions: The presence of distal tilted (all-on-four) and distal short implants (all-on-six) resulted in higher stresses in both situations in the maxillary bone in comparison to the presence of vertical implants (all-on-four). © 2013 Wiley Periodicals, Inc.

Horizontal ridge augmentation of the atrophic anterior maxilla using rhBMP-2/ACS or autogenous bone grafts: A proof-of-concept randomized clinical trial

Aim To compare the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge carrier (ACS) with autogenous bone graft for augmentation of the edentulous atrophic anterior maxilla. Methods Twenty-four subjects were enrolled in a randomized, controlled, parallel-group, open-label clinical trial. Subjects either received rhBMP-2/ACS (1.5 mg/ml) or particulated autogenous bone harvested from the mandibular retromolar region. A titanium-mesh was used to provide space and wound stability. A guide was used to standardize clinical recordings using an analogue caliper. Alveolar ridge width was also assessed using cone-beam computed tomography. Results rhBMP-2/ACS yielded significantly greater radiographic horizontal bone gain compared with autogenous bone graft at immediate subcrestal levels (1.5 ± 0.7 versus 0.5 ± 0.9 mm; p = 0.01); non-significant differences were observed at mid- (2.9 ± 0.8 versus 2.9 ± 0.9 mm; p = 0.98) and apical (1.7 ± 0.9 versus 1.8 ± 1.1 mm; p = 0.85) crestal levels. No significant differences in clinical horizontal bone gain were observed at 6 months between rhBMP-2/ACS and autogenous bone graft (3.2 ± 0.9 mm versus 3.7 ± 1.4 mm; p = 0.31). Sixty-two implants were placed after 6 month of healing with no significant differences between groups for number of implants, implant size, primary stability and survival. Conclusions rhBMP-2/ACS appears a realistic alternative for augmentation of the edentulous atrophic anterior maxilla. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mechanical behavior of dental implants in different positions in the rehabilitation of the anterior maxilla

Statement of problem. In dental rehabilitations that involve implants, the number of implants is sometimes smaller than the number of lost teeth. This fact can affect the biomechanical behavior and success of the implants.Purpose. The purpose of this study was to investigate the mechanical behavior of different implant positions in the rehabilitation of the anterior maxilla.Material and methods. Three-dimensional models of the maxilla were created based on computed tomography images for 3 different anterior prosthetic rehabilitations. In group IL, the implants were placed in the lateral incisor positions with pontics in the central incisor positions; in group IC, the implants were in the central incisor positions with cantilevers in the lateral incisor positions; and, in group ILIC, one implant was in a lateral incisor position and one was in a central incisor position, with a pontic and a cantilever in the remaining positions. A 150 N load was distributed and applied at the center of the palatal surface of each tooth at a 45-degree angle to the long axis of the tooth. The resulting stress-strain distribution was analyzed for each group.Results. The lowest displacement of the prosthetic structure was observed in group IC, although the same group exhibited the largest displacement of the bone tissue. In the bone tissue, the von Mises stress was mainly observed in the cortical bone in all groups. The maximum value of the von Mises stress shown in the cortical tissue was 35 MPa in the implant that neighbors the cantilever in group ILIC. The maximum von Mises stress in the trabecular bone was 3.5 MPa.Conclusion. The prosthetic configuration of group IC limited the displacement of the prosthetic structure but led to greater displacement of the bone structure. The use of a cantilever increased the stress concentration in the implant and in the bone structure adjacent to the cantilever under the conditions studied here.

Synchronous Ossifying Fibromas of Maxilla and Mandible

Ossifying fibroma is a benign neoplasm composed of fibrocellular tissue and mineralized material of varying appearance, which is most commonly seen in the posterior region of the mandible as a solitary lesion. We report an unusual case of synchronous ossifying fibroma of maxilla and mandible. To the best of our knowledge, only 13 similar cases have been previously reported.

Spontaneous osteonecrosis of the jaws in the maxilla of mice on antiresorptive treatment: A novel ONJ mouse model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Central Giant Cell Granuloma in Pediatric Maxilla: Surgical Management

Central giant cell granuloma (CGCG) is an intraosseous lesion consisting of fibrous cellular tissue that contains multiple foci of hemorrhage, multinucleated giant cells, and occasional trabeculae of woven bone. An 8-year-old boy presented himself complaining of a painless swelling in the left maxilla that had started 1 year. Computed tomography (CT) scan confirmed a poorly defined multilocular radiolucent lesion in the left maxilla crossing the midline. The patient underwent enucleation through an intraoral approach of the lesion. The biopsy revealed multinucleated giant cells in a fibrous stroma. A CT was taken approximately 1 year postoperatively. There was no clinical or radiographic evidence of recurrence. Therefore, surgical treatment of CGCG can be performed, trying to preserve the surrounding anatomic structures, which can be maintained in case the lesion does not show an aggressive clinical behavior, avoiding large surgical defects which are undesirable in children.

The Fresh Frozen Bone Allograft (FFBA) to reconstruc the atrophic maxilla: evaluation of the clinical and histological viability at six and nine months in the maxillary sinus

This work aimed to analyze clinically and histologically the allogen bone graft behavior at 6 and 9 months. A leukoderm, female, 55 years old patient sought dental care for oral rehabilitation with dental implants and implant supported fixed prosthesis in the maxilla. Bilateral sinus lifting procedure were performed in a same patient, the analysis were made after 6 and 9 months, respectively. At 6 months, there was lack of a better bone remodeling in the region, associated to the presence of fibrous connective tissue within the collected tissue, showing us that this is not the best stage of tissue maturation to place dental implants. The 9 months period showed an improvement, with a more organized bone tissue surrounding particles of homogenous bone, what possibly had increased implant stability at the time of surgery. There is no doubt about the increase of clinical applications of FFBA, but there are no studies available regarding the standardization of time to load implants inserted in allografts. So papers with long-term monitoring are necessary to eliminate questions that still remain to be answered.

Histologic and histometric evaluation of calvarial autogenous bone graft in reconstruction of atrophyc maxilla for dental implants

The calvarial bone is highlighted as a good donor area for large reconstructions of atrophic jaw for subsequent rehabilitation with implant-supported prosthesis. The aim of this study was to observe and measure through histological and histometric evaluation, the cellular events that occur at the interface of union from onlay parietal bone graft on the maxilla of 10 patients, after a period of 6 months of incorporation. The biopsies were performed at the time of installation of osseointegrated implants. The bone contact area represented 78.75% and connective contact 21.25%. The region of connective union between the bone graft to the maxillae presented new bone formation (41.26%), marrow bone (36.06%), osteoid tissue (15.86%) and connective tissue (6.80%). All samples had good graft incorporation to the receptor bed with osteogenic activity and absence of inflammatory cells.

Chronic osteomyelitis of the maxilla and mandible: microbiological and clinical aspects

Osteomyelitis of the mandible and maxilla are common in developing countries and their treatment may be long-standing and difficult. Thus, the aim of this study was to discuss the main biological aspects of the chronic osteomyelitis of the jaws of especial interest for dental team. These infections are associated with a complex microbiota composed mainly by anaerobic bacteria, sometimes associated with microorganisms originated from the skin and digestive tract. These data suggest that chronic osteomyelitis of the mandible and maxilla should be treated as anaerobic infections in most cases. In addition, local surgical treatments are relevant in the therapy outcome, associated to the use of antimicrobial agents, and the failure to accomplish them is a major cause of treatment failure.

The use of a bite fork to help mobilize the maxilla after downfracture during the Le Fort I osteotomy: a technical note

Introduction The Le Fort I osteotomy is indicated to reposition the maxilla in the surgical correction of dentofacial deformities. Although it is a known surgical step, like any surgical procedure, it can have complications and difficulties; among these, the initial mobility of the jaw is very common after completing all corticotomies. Methods The authors present a technique in which the bite fork is used as an auxiliary tool in maxilla downfracture, especially in cases of maxillary impaction where vertical space is created on the walls of the corticotomy. Findings As the bite fork acts as a scraper with a long leverage arm, an advantage would be the better distribution of forces along the corticotomy, minimizing the risk of bad fracture and facilitating maxillary downfracture movement.

Conservative Management of a Large Keratocystic Odontogenic Tumor in the Maxilla

Keratocystic odontogenic tumor is characterized by high recurrence rates. Conservative or aggressive management has been suggested as a method of treatment. Decompression is a conservative treatment that has been used in the treatment of large odontogenic cysts. The authors report a case of a 14-year-old patient with a keratocystic odontogenic tumor located in the right maxilla, which was treated by decompression followed by enucleation with curettage. The lesion did not recur on follow-up for 3 years after the enucleation surgery.

Central Granular Cell Odontogenic Tumor of the Maxilla

The central granular cell odontogenic tumor (CGCOT) is a rare benign odontogenic neoplasm composed of varying amounts of large eosinophilic granular cells and apparently inactive odontogenic epithelium. It tends to occur as a small asymptomatic swelling in the posterior region of the mandible with nonaggressive appearance. We report an unusual case of CGCOT in the maxillary region with clinical features of malignancy. The patient underwent surgical treatment, and the 2-year follow-up revealed no signs of recurrence. Central granular cell odontogenic tumor is a very rare condition with few cases reported, especially in the maxillary region. This case highlights the possibility of aggressive behavior by these lesions.