This study evaluated the effect of low-level laser therapy (LLLT) on the chemical composition, crystallinity and crystalline structure of bone at the site of distraction osteogenesis. Five rabbits were subjected to distraction osteogenesis (latency = 3 days; rate and frequency = 0.7 mm/day for 7 days; consolidation = 10 days), and three were given LLLT with arsenide-gallium-aluminum (AsGaAl; 830 nm, 40 mW): 10 J/cm(2) dose per spot, applied directly to the distraction osteogenesis site during the consolidation stage at 48 h intervals. Samples were harvested at the end of the consolidation stage. X-ray fluorescence and X-ray diffraction were used to analyze chemical composition, crystallinity and crystalline structure of bone at the distraction osteogenesis site. The analysis of chemical composition and calcium (Ca) and phosphorus (P) ratios revealed greater mineralization in the LLLT group. Diffractograms showed that the crystalline structure of the samples was similar to that of hydroxyapatites. Crystallinity percentages were greater in rabbits that were given LLLT. Crystallinity (41.14% to 54.57%) and the chemical composition of the bone at the distraction osteogenesis site were similar to the that of the control group (42.37% to 49.29%). The results showed that LLLT had a positive effect on the biomodulation of newly formed bone.

Objectives: This study evaluated the action of low level laser therapy (LLLT) on the percentage of newly formed bone in rabbit mandibles that underwent distraction osteogenesis (DO). Study design: Ten rabbits underwent bone lengthening according to the following protocol: Latency -3 days; Activation -7 days 0.7 mm/d; and Consolidation -10 days. The control group was composed of 4 rabbits. The experimental group, composed of 6 rabbits, received infrared GaAlAs LLLT (λ=830 nm, P=40 mW) according to the following protocol: point dose of 10 J/cm2 applied directly on the bone site that underwent DO during bone consolidation at 48-hour intervals. Results: The percentage of newly formed bone was greater in the LLLT group (57.89%) than in the control group (46.75%) (p=0.006). Conclusion: The results suggest that LLLT had a positive effect on the percentage of newly formed bone. Betterquality bone sites may allow early removal of the osteogenic distractors, thus shortening total treatment time.

Abstract. The retinoblastoma (Rb) and p53 genes play a fundamental role in cell cycle mechanisms, and their deregulation is related to many steps of oral cancer carcinogenesis. This study was conducted to evaluate the expression of the p53 and Rb proteins in malignant and pre-malignant oral cavity lesions. This retrospective study was conducted at the Federal University of Bahia, Salvador, Brazil, and the Molecular Biology Laboratory of the Otorhinolaryngology Department at the University of Heidelberg, Heidelberg, Germany. Excisional biopsy samples of oral cavities were collected from patients with suspected oral lesions. The samples were processed by immunohistochemistry to be classified by a semi-quantitative score: samples with a ≤10% positivity were considered to have weak/negative expression (-); those with 11-50% positivity, moderate expression (+); and those with >50% positivity, high expression (++). Seventy-one patients were studied (75% male; median age, 52 years; range, 24-84). Of the samples studied, 59.4% were oral squamous cell carcinoma (OSCC) and 40.6% were pre-neoplastic lesions (leukoplakia and actinic cheilitis). OSCC presented higher expression of Rb protein compared to pre-malignant lesions: 75 vs. 25% (p<0.001). Pre-neoplastic lesions presented higher expression of p53 protein compared to OSCC lesions: 55.2 vs. 44.8% (p= 0.030). Despite the small number of samples, the expression of these cell cycle biomarkers (p53 and Rb protein) in excisional biopsies suggests that molecular lesion assessment can determine pre-malignant lesions, and that its use may improve the clinical and surgical treatment of early lesions. Thus, p53 protein expression may be related to the early steps of carcinogenesis in OSCC. Finally, a higher Rb expression was also observed in malignant lesions.

Objetivo: Correlacionar medidas de fissuras alveolares obtidas por radiografias convencionais e tomografias computadorizadas do feixe cônico (TCFC). Método: Estudo transversal no qual participaram 11 pacientes com idades entre 6 e 32 anos, com fissuras pré-forame e transforame alveolar, não submetidos ao enxerto ósseo. Foram realizadas radiografias periapicais, oclusais e TCFC. Nas radiografias periapicais, foram mensuradas: a) largura da fissura em relação ao dente adjacente nos terços apical, b) médio, e c) cervical. Nas radiografias oclusais: d) largura da fissura nas superfícies vestibular, e) mediana, e f) na superfície palatina. Nas TCFC: g) a largura da fissura em relação ao dente adjacente nos terços apical, h) médio, e i) cervical, em corte longitudinal panorâmico para a correlação com a radiografia periapical e; j) a largura da fissura nas superfícies vestibular, l) na mediana, e m) palatina, em cortes axiais, para a correlação com a radiografia oclusal. As mensurações foram realizadas nas radiografias com régua milimetrada e nas TCFC pelo i-CAT Vision. Para a análise estatística foi empregado o teste de correlação de Spearman pelo software SPSS Statistics 17 for Windows. Resultados: A) Entre a radiografia periapical e a TCFC, obteve-se o coeficiente de correlação ρ de 0,618 no terço apical (significância de 0,05), 0,556 no terço médio (significância de 0,05) e 0,963 no terço cervical (significância de 0,01); B) Entre a radiografia oclusal e a TCFC, obteve-se correlação de 0,712 na superfície vestibular (significância de 0,01), na mediana 0,568 e na palatina 0,679 (ambos significância de 0,05). Conclusão: Os resultados indicam diferentes coeficientes de correlação positiva entre as medidas obtidas nas radiografias convencionais e na TCFC, sendo maior entre a radiografia periapical e a TCFC no terço cervical e, entre a radiografia oclusal e a TCFC na superfície vestibular. Fissura labial; Fissura palatina; Tomografia computadorizada do feixe cônico.Objective: To assess the correlation between alveolar cleft measurements obtained from conventional radiography and conebeam computed tomography (CBCT). Method: Eleven patients treated at 'Associação Maranhense da Alegria', a non-profit organization that offers treatment to patients with cleft lip and palate, were included in this cross-sectional, descriptive study. All patients presented pre-incisive and trans-incisive foramen clefts and had not been treated with bone grafting. Periapical and occlusal radiographs and CBCT scans were obtained from all patients. The following measurements were determined: on periapical radiographs, cleft width in relation to the adjacent teeth in the a) apical, b) middle, and c) cervical thirds; on occlusal radiographs, cleft width based on the d) buccal, e) middle, and f) palatal aspects of the cleft; on CBCT scans, cleft width in relation to the adjacent teeth in the g) apical, h) middle, and i) cervical thirds, in a panoramic longitudinal section, for the assessment of correlation with periapical radiographic findings, and ...

Introduction:Osteogenesis distraction (OD) is a mainstream technique in maxillofacial surgical reconstruction with varied applications. OD technique employs a distractor with the aim to get new bone in the site of interest. Osseous maturation time is necessary before the device can be removed and few patients’ complaint of related discomfort, especially when these devices are external, and induces superficial infections, paresthesia, hypertrophic scars and social relationship difficulties. The use of Low Level Laser Therapy (LLLT) has been proved beneficial to soft tissue and osseous repairs.Materials and Method:12 rabbits were randomly divided in to two groups. In all animals, distractor was placed and one group was exposed to LLLT while the other group served as control. After consolidation, animals were sacrificed, the new bone formed were subjected to investigations including histomorphometric, physical analysis and tomographical analysis. Statistical analyses were performed using SPSS software.Result:Newly formed bone was significantly different between the groups. The physical properties of the neobone were comparatively better when the animals were exposed to LLLT with varying statistical significance.Conclusion:The results obtained with smaller sample size in this study need to be interpreted with care. The results of this preliminary pilot study encourage the use of LLLT during healing period. However the histological, tomographical and physical findings need to be ascertained using a larger sample size to study the bio-stimulatory effects with laser therapy from basics to clinical relevance on wound and bone healing.