Cell-based bone regeneration for alveolar ridge augmentation--cell source, endogenous cell recruitment and immunomodulatory function.

Alveolar ridge plays a pivotal role in supporting dental prosthesis particularly in edentulous and semi-dentulous patients. However the alveolar ridge undergoes atrophic change after tooth loss. The vertical and horizontal volume of the alveolar ridge restricts the design of dental prosthesis; thus, maintaining sufficient alveolar ridge volume is vital for successful oral rehabilitation. Recent progress in regenerative approaches has conferred marked benefits in prosthetic dentistry, enabling regeneration of the atrophic alveolar ridge. In order to achieve successful alveolar ridge augmentation, sufficient numbers of osteogenic cells are necessary; therefore, autologous osteoprogenitor cells are isolated, expanded in vitro, and transplanted to the specific anatomical site where the bone is required. Recent studies have gradually elucidated that transplanted osteoprogenitor cells are not only a source of bone forming osteoblasts, they appear to play multiple roles, such as recruitment of endogenous osteoprogenitor cells and immunomodulatory function, at the forefront of bone regeneration. This review focuses on the current consensus of cell-based bone augmentation therapies with emphasis on cell sources, transplanted cell survival, endogenous stem cell recruitment and immunomodulatory function of transplanted osteoprogenitor cells. Furthermore, if we were able to control the mobilization of endogenous osteoprogenitor cells, large-scale surgery may no longer be necessary. Such treatment strategy may open a new era of safer and more effective alveolar ridge augmentation treatment options.

Disjunção patalina apoiada em mini-implante: revisão de literatura / Palatal disjunction supported by mini-implants: literature review

A disjunção palatina foi descrita pela primeira vez em 1861, desde então é tem sido utilizada amplamente para correção da atresia maxilar. Sabe-se que com o aumento da idade o prognóstico para a disjunção piora. A expansão palatina é uma opção viável para pacientes adultos, desde que a deficiência transversal seja leve ou moderada. A disjunção palatina assistida cirurgicamente é uma alternativa de tratamento eficiente para pacientes em que a maturação das suturas craniofaciais está em estágio mais avançado. A disjunção palatina apoiada em mini-implantes é uma nova proposta de tratamento para a mordida cruzada posterior, que tem como objetivo alcançar a ampliação do arco dentário superior em adultos jovens, sem causar dano ao periodonto. O objetivo do estudo foi analisar os benefícios advindos desta nova técnica e reconhecer as principais indicações da disjunção maxilar apoiada por mini-implantes como método terapêutico. Foi realizada uma revisão de literatura através de um levantamento bibliográfico de artigos científicos nas principais bases de dados nacionais e internacionais. A disjunção palatina apoiada em mini-implante é um método promissor para a correção de deficiências transversais, mas ainda deve ser melhor estudada para que se estabeleça um protocolo de instalação, ativação e avaliação da manutenção dos resultados a longo prazo

The palatal disjunction was first described in 1861, since then it has been widely used for the correction of transverse maxillary deficiency. It is known that with the increasing of age the prognostics for the disjunction worsens Palatal expansion is a viable option for adult patients, as long as the transversal deficiency is light or moderate. The surgically assisted palatal disjunction is an efficient treatment alternative for patients in which the maturation of craniofacial sutures are in a more advanced stage. The palatal disjunction supported in mini-implants is a new proposition of treatment for the posterior cross bite, which has as objective to reach the enlargement of the superior dental arch in young adults, without causing damage to the periodontal. The technique shows good results also on the mixed and deciduous denture, including when associated with the facial mask used for Angle's bad occlusion of class III. The purpose of this paper was to study and analyze the benefits arising from this new technique and recognize the primary indications of palatal disjunction supported by mini implants as a therapeutic method. A literary revision was performed through a bibliographical research of scientific papers from national and international data base. The palatal disjunction supported by mini implants is a promising method for correcting transversal deficiencies, however it should be better studied in order to establish a protocol of installation, activation and maintenance's evaluation of the results in long term.

Advanced techniques in bone grafting procedures.

Technological advancement in bone grafting procedures using purified proteins or stem cells to induce osteogenesis is a significant contribution to patient care. Patients who would otherwise not have been suitable candidates for major autologous bone grafting procedures can continue to benefit from implant reconstruction, with a less debilitating bone reconstructive procedure.

Modern bone regeneration instead of bone transplantation: a combination of recombinant human bone morphogenetic protein-2 and platelet-rich plasma for the vertical augmentation of the maxillary bone-a single case report.

This publication describes the clinical case of a 75-year-old woman. She suffered from total alveolar ridge atrophy due to 20 years of wearing dentures. Bone transplantation, including harvesting of the iliac crest, was rejected by another clinic due to various existing diseases and risk of blood loss on donor side. Moreover, the minimal residual alveolar ridge did not allow bone fixation using screws nor did it allow osteodistraction. Before deciding which bone tissue engineering techniques should best be employed in this surgical treatment, cardiological and internistic consultations and treatments were carried out. In addition, anesthetic preparations were made. The surgical treatment was performed implementing special bridge flap techniques to preserve the periosteum. Tricalcium phosphate blocks soaked with recombinant human bone morphogenetic protein-2 and platelet-rich plasma were implanted on the narrow alveolar ridge. They were attached by tightening the soft tissue, including the periosteum. Four months later, after complication-free wound healing and bone regeneration, six dental implants were inserted into the new alveolar ridge. The histology of all bone samples showed vital lamellar bone. Three months after implantation, a new dental structure was fixed on the implants. The patient's quality of life improved significantly with this new situation.

A survey of clinical members of the Association of Dental Implantology in the United Kingdom. Part III. The use of augmentation techniques in dental implant surgery.

The aims of the survey were to: (1) determine the use of the staged and simultaneous augmentation techniques; (2) determine trends in the use of barrier membranes; (3) establish the perceived reliability of techniques used to monitor implants that have undergone simultaneous augmentation; and (4) assess the use of biopsy techniques to confirm the histologic outcome of bone augmentation. One hundred seventy-two respondents replied to this section of the survey and indicated that the "staged" and "simultaneous" augmentation techniques were used in roughly equal numbers during 1997, and a wide range of complications was reported with the latter. The majority used barrier membranes to correct defects of between 5 and 10 mm3, and resorbable membranes were preferred. With regard to clinical techniques used to monitor augmented implants, these were mainly considered to be "adequate" or "poor." Tissue biopsy was recognized as an important tool for determining the outcome of augmentation procedures but was rarely used. The use of resorbable membranes is likely to increase. The diagnostic tools currently used to monitor augmented implants are considered to have limited reliability, and they should be evaluated by prospective, comparative studies. More widespread use of biopsy techniques might help establish an evidence base for the histologic outcome of augmentation materials and techniques.

The sinus lift graft: basic technique and variations.

Following an early controversy concerning its efficacy, the sinus lift and graft technique is now considered to be a state-of-the-art surgery. In 1975, Tatum introduced the technique that increased maxillary bone height by placing graft material under the maxillary sinus and Schneiderian membrane; by the early 1990s, a modification of Tatum's original technique had become a standard procedure. This article describes and illustrates three variations of the basic sinus lift surgery and graft operation--the hinge osteotomy, the elevated osteotomy, and the complete osteotomy. Additional considerations affecting the surgical outcome are also discussed as is the management of possible complications. The learning objective of this article is to obtain up-to-date information regarding the basic technique and variations of the sinus lift procedure to the general practitioner as well as the specialist.