Low-level laser therapy enhances the number of osteocytes in calvaria bone defects of ovariectomized rats

Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.

Cell therapy stimulates bone neoformation in calvaria defects in rats subjected to local irradiation

Background:The purpose of the study was to analyze the effect of cell therapy on the repair process in calvaria defects in rats subjected to irradiation.Methods:Bone marrow mesenchymal cells were characterized for osteoblastic phenotype.Calvariae of male Wistar rats were irradiated(20 Gy)and,after 4 weeks,osteoblastic cells were placed in surgically created defects in irradiated(IRC)and control animals(CC),paired with untreated irradiated(IR)and control(C)animals.After 30 days,histological and microtomographic evaluation was performed to establish significant(P<0.05)differences among the groups.Results:Higher alkaline phosphatase detection and activity,along with an increase in mineralized nodules,in the IRC,C and CC groups compared to the IR group,confirmed an osteoblastic phenotype.Histology showed impaired bone neoformation following irradiation,affecting bone marrow composition.Cell therapy in the IRC group improved bone neoformation compared to the IR group.Microtomography revealed increased bone volume,bone surface and trabecular number in IRC group compared to the IR group.Conclusion:Cell therapy may improve bone neoformation in defects created after irradiation.

Lower limb balance,ankle dorsiflexion,orofacial tissue pressure,and occlusal force of rugby players

This cross-sectional study examined the lower limb balance,ankle dorsiflexion,orofacial tissue pressure,and occlusal strength of rugby players.Twenty-six participants were divided into groups:rugby players(n=13)and healthy sedentary adults(n=13).Participants underwent an analysis of lower limb balance using a composite score(Y-Balance Test).Ankle dorsiflexion was measured using the Lunge Test.The Iowa Oral Performance Instrument was employed to measure orofacial tissue pressure.Bite force was measured with a dynamometer,and T-Scan assessed occlusal contact distribution.Data were analyzed using the t-test(p<0.05)and ANCOVA with age and weight as covariates,where it is possible to verify that these factors did not influence the results obtained.Significant differences were observed in the balance of the right(p=0.07)and left(p=0.02)lower limbs,where rugby players had lower composite scores.There were significant differences in the right(p=0.005)and left(p=0.004)lunges,with rugby players showing lower values,as well as lower tongue pressure(p=0.01)and higher lip pressure(p=0.03),with significant differences to sedentary participants.There was no significant difference in molar bite force and distribution occlusal contacts between groups.Rugby seems to reduce lower limb displacement,cause ankle hypomobility,lead to changes in orofacial tissues,particularly the tongue and lips.This study is significant for identifying significant differences between rugby players and sedentary individuals,providing new insights into the impact of rugby on health and performance,which can benefit sports training and injury prevention.