Maiolino Thomaz Fonseca Oliveira

Are insertion torque and early osseointegration proportional? A histologic evaluation

OBJECTIVES The objective of this histologic study was to determine the effect of three drilling protocols (oversized, intermediate, and undersized) on biologic responses to a single implant type at early healing periods (2 weeks in vivo) in a beagle dog model. MATERIALS AND METHODS Ten beagle dogs were acquired and subjected to surgeries in the tibia 2 weeks before euthanasia. During surgery, each dog received three Unitite implants, 4 mm in diameter by 10 mm in length, in bone sites drilled to 3.5, 3.75, and 4.0 mm in final diameter. The insertion torque was recorded during surgery, and bone-to-implant contact (BIC), and bone area fraction occupied (BAFO) measured from the histology. Each outcome measure was compared between treatment conditions with the Wilcoxon signed-rank test. Bonferroni-corrected statistical significance was set to 95%. RESULTS Insertion torque increased as an inverse function of drilling diameter, as indicated by significant differences in torque levels between each pair of conditions (P = 0.005). BIC and BAFO levels were highest and statistically similar in the recommended and undersized conditions and significantly reduced in the oversized condition (P < 0.01). CONCLUSIONS Reduced drilling dimensions resulted in increased insertion torque (primary stability). While BIC and BAFO were maximized when drilling the recommended diameter hole, only the oversized hole resulted in evidence of statistically reduced integration.

Treatment of an extensive unicystic ameloblastoma in a 7-year-old child: the best approach?

Ameloblastoma is a benign, slow-growing neoplasm of the jaw that arises from odontogenic epithelium. We present the case of a 7-year-old girl with a unicystic ameloblastoma of the mandible, and describe our approach to treatment.

The approach of ameloblastoma of the mandible: a case treated by hyperbaric oxygen therapy and bone graft reconstruction

BackgroundReconstruction of mandibular defects after tumor resection is a challenge to the head and neck surgeon because of associated functional and esthetic problems. The intention of mandibular reconstructive surgery is to achieve maximum possible functionality, which means the restoration of masticatory function and speech with a good esthetic result. Hyperbaric oxygen therapy (HBO) is already a well-accepted adjunct in the treatment of extensive bone defects. It has been shown to enhance osteogenesis and improve soft tissue wound healing in a variety of circumstances.Case reportThe following case report describes a 29-year-old woman who was diagnosed with mandibular ameloblastoma. The treatment of choice is resection with mandibular base maintenance. The patient underwent 10 sessions of hyperbaric oxygen therapy and subsequent nonvascularized iliac crest graft. Six months after, mandibular reconstruction is possible to observe the preservation of mandibular contouring and facial esthetics. A panoramic radiograph revealed good positioning of the bone graft and volume maintenance.DiscussionThe mandibular reconstruction is extremely important for the rehabilitation of the patient who underwent bone resection. The restoration of mandibular function and facial esthetics is essential to maintain the quality of life. The use of HBO in mandibular reconstruction is an important adjunct to successful treatment, however, more studies are needed to establish the best modalities of rehabilitation.

Immediate Prosthetic Loading of Implants Placed in Reconstructed Jaws After Hyperbaric Oxygen Therapy

T reatment of facial tumors by mandibulectomy can cause severe esthetic, functional, and psychosocial issues. Reconstruction of facial bone defects is challenging, generally involving multidisciplinary approaches to rehabilitate affected patients. Large reconstructions using free bone grafts are possible; however, some patients require special attention when it comes time to decide which type of reconstruction procedure will be performed, such as cancer patients and patients under bisphosphonate treatment. Additionally, these grafts may present increased difficulty to be incorporated compared with vascularized bone grafts. Thus, the use of hyperbaric oxygen therapy (HOT) has been stimulated due to the potential neo-osteogenesis and angiogenesis offered by this technique in accelerating healing of bone grafts. Oral rehabilitation following bone reconstruction is commonly indicated and conducted using different techniques. Implant-supported restorations are the primary restorative option, because dental implants can be successfully installed over grafted areas after the bone maturing period. However, the ideal loading moment of such implants is still a controversial topic. However, some studies suggest that adequate osseointegration is possible after immediate loading of implants in reconstructed areas. This report describes 3 cases of mandibulectomy followed by reconstruction using free iliac bone grafting associated to HOT and rehabilitation with immediate prosthetic loading of implants.

Concepts in Management of Advanced Craniomaxillofacial Injuries

The authors present a sequencing assessment of patients who were victims of traumatic deformities of the craniomaxillofacial complex. To that end, the authors highlight the eight steps worthy of particular attention, namely (1) clinical history and photograph‐ ic documentation; (2) clinical assessment; (3) assessment through image and diagnos‐ tic exams; (4) planning of the treatment; (5) bases for the three-dimensional reconstruction of the face; (6) reconstruction sequence of multiple facial fractures; (7) support measures; and (8) complications. The proposed assessment sequence allows the oral and maxillofacial surgeon or craniomaxillofacial surgeon to assess the degree of impairment of traumatic deformity, which contributes in a significant way to the decision-making process of the treatment.

Recurrent condylar luxation after third molar extraction: an uncommon condition treated by eminectomy

INTRODUCAO: A exodontia dos terceiros molares raramente promove complicacoes pos-operatorias como desordens temporomandibulares. OBJETIVO: Embora a literatura apresente uma serie de discussoes sobre a evidencia clinica relacionada a este assunto, neste artigo, apresentamos um caso incomum de uma paciente submetida a extracao dos terceiros molares que apresentou, no acompanhamento pos-operatorio, luxacao condilar recorrente bilateral. CONCLUSAO: Devido a este estado critico, a paciente foi tratada com sucesso pela eminectomia bilateral apos tentativas terapeuticas nao cirurgicas.

Reconstruction of Mandibular Defects

Surgical reconstruction of mandibular bone defects is a routine procedure for rehabilitation of patients with deformities caused by trauma, infection or tumor resection. The mandible plays a major role in masticatory and phonetic functions, supporting the teeth and defining the contour of the lower third of the face. Therefore, mandibular discontinuity produces se‐ vere cosmetic and functional deformities, including loss of support for suprahyoid muscles and subsequent airway reduction. Reconstruction of these severe defects is mandatory for restoring the patient’s quality of life. Surgical techniques have improved considerably in the last decade, but reconstruction of large bone defects of the mandible still pose a great chal‐ lenge in maxillofacial rehabilitation. Several things can be done to optimize the surgery; the use of prototyping modeling for instance provides a better assessment of the bone defect and pre-contouring of the fixation plates, reducing operating time. The choice of the most suitable titanium plate system is critical to the success of the procedure. Mandibular defects with loss of continuity require more robust (load bearing) systems supporting mandibular function. Many studies consider the use of plates and screws temporary treatment due to the large number of complications such as fracture of plates and screws, plate exposure and infection. Thus, the use of grafts both in the first operation or in a two-stage procedure en‐ sures a more predictable result.