Results suggested a decrease in cell viability in the presence of HA.

Several biomaterials and techniques for bone grafting have been described in the literature for atresic bone tissue replacement caused by edentulism, surgical resectioning, and traumas. A new technique involves tissue engineering, a promising option to replace bone tissue and solve problems associated with morbidity of autogenous grafting. This literature review aims to describe tissue-engineering techniques using ex vivo cell culture as an alternative to repair bone maxillary atresias and discuss the concepts and potentials of bone regeneration through cell culture techniques as an option for restorative maxillofacial surgery.

This study investigates the applicability of adipose mesenchymal stem cells (mADSCs) and hyaluronic acid (HA) as a cellular compound for bone tissue engineering. A critical bone defect was created on each femur of 25 rats in vivo, receiving the following 5 graft treatments: I-Control-defect; II-HA; III-mADSCs; IV-mADSCsþHA; and V-previously osteoinduced mADSCsþHA. Evaluation using microcomputed tomography, histomorphometry, and RT-PCR analysis was performed 23 days after implantation. Microcomputed tomography analysis indicated higher means of bone contact surface (BCS) and bone surface density (BSD) for the mADSCsþHA group compared with Control and the HA groups (P < 0.05). Histomorphometric findings showed higher means of bone regeneration in the mADSCsþHA compared with HA and Control groups (P < 0.05). The RT-PCR ratios showed no difference in type 1 collagen (Col1A) gene expression or osteopontin (OP) gene expression, whereas for the osteonectin gene (ON) higher means were found in the HA and mADSCs osteoinþHA groups (P < 0.05). These results suggest that a combination of HA and mADSCs without prior osteoinduction might be applicable for bone tissue regeneration.

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Purpose: To determine the accuracy of different radiographic methods for bone height estimation at the mental foramen area.Methods: Twenty dry human hemimandibles were examed by using periapical and panoramic radiography, and computed tomography. An electronic digital caliper was used to measure the tracings obtained from the radiographies in three different times (groups A1, A2 and A3) and in the cross-sectioned hemimandibles (group B). Measurements consisted of: Measure 1 -from the upper limit of the alveolar ridge to the upper limit of the mental foramen; Measure 2 -from the upper limit of the mental foramen to the inferior limit of the cortical bone of the base of the jaw; Measure 3 -from the upper limit of the alveolar ridge to the inferior limit of the cortical bone of the base of the jaw. Data were analyzed with Student-t and Friedman tests.Results: The average difference values in Measure 1 were 0.33 mm, 0.35 mm and 0.85 mm for the periapical radiography, computed tomography and panoramic radiography, respectively (confidence intervals of 0.17 mm to 0.49 mm, 0.18 mm to 0.53 mm and 0.38 mm to 1.32 mm, respectively). Panoramic radiographies showed the greatest differences in Measures 2 and 3, with average values of 1.05 mm and 1.93 mm, respectively. Conclusion: Periapical radiography and computed tomography showed the best accuracy. A safety margin for surgical purposes has been suggested.Key words: Computed tomography; radiography; dental implants; diagnostic imaging; mental foramen ResumoObjetivo: Determinar a acurácia de diferentes métodos radiográficos para estimação de altura óssea na região do forame mentual.Metodologia: Vinte hemi-mandíbulas humanas, secas, foram examinadas por radiografia periapical e panorâmica e tomografia computadorizada. Um paquímetro digital foi usado para medir os traçados obtidos das radiografias em três diferentes tempos (grupos A1, A2 e A3) e nas hemi-mandíbulas seccionadas transversalmente (grupo B). As medições foram: Medida 1 -do limite superior da crista óssea ao limite superior do forame mentual; Medida 2 -do limite superior do forame mentual ao limite inferior do osso cortical da base da mandíbula; Medida 3 -do limite superior da crista óssea ao limite inferior do osso cortical da base da mandíbula. Os dados foram analisados por teste t de Student e teste de Friedman.Resultados: Os valores médios de diferença na Medida 1 foram 0,33 mm, 0,35 mm e 0,85 mm para a radiografia periapical, tomografia computadorizada e radiografia panorâmica, respectivamente (intervalos de confiança de 0,17 a 0,49 mm, 0,18 a 0,53 mm e 0,38 a 1,32 mm, respectivamente). As radiografias panorâmicas mostraram as maiores diferenças nas Medidas 2 e 3, com valores médios de 1,05 mm e 1,93 mm, respectivamente.Conclusão: A radiografia periapical e a tomografia computadorizada mostraram a melhor acurácia. Sugere-se uma margem de segurança em caso de cirurgias.