Age and Gender Estimation Using the Osseous Microanatomy: Original Research.

Aim: This study was performed with the idea of assessing age and gender utilizing differences in osseous microanatomy in human jawbones. Materials and Methods: The study was conducted retrospectively among human jawbone samples. Various morphometric assessments such as trabecular width, marrow space, and their corelation were studied. In the samples, variations among osteon numbers, differences in the shapes of the osteocytes of jawbones, and amount of inflammation in the bony areas were recorded. Results: It was noted in this study that mean values of the diameter of the Haversian canal and vessel density had a noteworthy increase in female jawbone samples. The amount of osteocytes in both female and male bone samples was also statistically significant in terms of the correlation coefficient. Conclusion: We concluded that more sensitive identification of human remains, that is, age and gender analysis, can be performed by histomorphometric evaluation of bone remains.

Comparative Histomorphometric Analysis of Bone Regeneration According to Bone Graft Type.

PURPOSE: To use histomorphometric analysis to evaluate bone reconstruction in rabbit calvaria with autogenous bone, anorganic bovine bone, undecalcified human tooth bone (UdTB), and decalcified human tooth bone (dTB) grafts. MATERIALS AND METHODS: Extracted human teeth were crushed, and tooth bone with and without decalcification was prepared. Bony defects were made in 10 rabbit calvaria and allocated to one of the following four groups: group 1, in which UdTB was grafted; group 2, in which dTB was grafted; group 3, in which anorganic bovine bone was grafted; group 4, in which autogenous bone was grafted. The rabbits were sacrificed at 2 or 8 weeks postoperatively, and histomorphometric comparison was performed. RESULTS: Histologically, new bone formation was observed at the defect margin and around all graft materials. The dTB group revealed significantly greater new bone areas at 2 and 8 weeks compared to the UdTB group and the anorganic bovine bone group (P < .05). The dTB group revealed no significant difference in the new bone area at 2 weeks but revealed significantly less new bone area at 8 weeks compared to the autogenous bone group (P < .05). The dTB group also revealed significantly less graft material area compared to the anorganic bovine bone group at 8 weeks (P < .05). The autogenous bone group revealed significantly less graft material area and significantly greater bone marrow area compared to other groups at 8 weeks (P < .05). CONCLUSIONS: Grafting with dTB resulted in better bone regeneration than UdTB and anorganic bovine bone grafting at 8 weeks and addresses the potential disadvantages of autogenous bone grafting.

A Bone Histomorphometric Analysis of Hypophosphatasia-related Osteoporosis after Teriparatide Treatment.

A 79-year-old man was admitted with a compression fracture of the first lumbar vertebra. His alkaline phosphatase (ALP) level was 35 IU/L, and his dual energy X-ray absorptiometry T score was -3.7 standard deviations, indicating osteoporosis. A genetic analysis showed a mutation of the alkaline phosphatase biomineralization-associated gene encoding tissue-nonspecific alkaline phosphatase. Hypophosphatasia-related osteoporosis was diagnosed. Alendronate, teriparatide, and minodronate were administered in that order. The ALP level increased during teriparatide use. A bone biopsy performed after three years of teriparatide treatment showed that cancellous bone was adynamic. In cortical bone, tetracycline double-labeling indicates enhanced bone formation. Teriparatide may thus be a viable treatment option even in patients with hypophosphatasia.

Assessment of 28-day oral exposure to Pueraria candollei var. mirifica (Fabaceae) roots on pituitary-ovarian axis function and selected metabolic parameters in ovary-intact rats.

Pueraria candollei var. mirifica (Fabaceae) root (PMR) has recently been developed as a potential selective estrogen receptor modulator (SERM) in menopausal women. Nowadays, many premenopausal women also take dietary PMR supplements, however, the exact biological effects of PMR have not been evaluated. This study included the application of the OECD guideline 407 for the assessment of 28-day oral exposure to PMR on pituitary-ovarian (PO) axis function and metabolic parameters in the premenopausal rat model. Ovary-intact adult rats were orally administrated with 10, 100, 750, 1000, and 1500 mg/kg body weight (BW)/day of PMR powder. The positive estrogenic group was given 2 mg 17ß-estradiol (E2)/kg BW/day. Serum levels of reproductive hormones, lipid and thyroid parameters, estrous cycle determination, and histomorphometric and histopathological evaluations of the anterior pituitary, ovary, uterus, vagina, mammary gland, and liver were investigated. PMR displayed neutral effects on uterine, vaginal, and body weights, and circulating E2 and prolactin levels. PMR exerted E2-like effects by i) reducing ovarian and increasing hepatic weights, ii) decreasing serum gonadotropins, iii) lowering serum lipids without altering thyroid parameters, iv) increasing the prevalence of abnormal estrous cycles with prolonged estrus, v) increasing nuclear diameter of anterior pituitary cells, vi) decreasing ovarian size and follicular numbers and increasing follicular degeneration, vii) thickening of uterine myometrium and luminal epithelium, and vaginal epithelium, and viii) induction of mammary alveolar hyperplasia and ductal secretion. Unlike E2, the appearance of very small numbers of focal microvesicular steatosis in hepatocytes demonstrated mild toxicity at high PMR doses. This is the first report that high-dose PMR exerted actions exactly like E2 on gonadotrope-ovarian axis function and histology, lipid, and thyroid parameters without affecting uterine and vaginal growth in ovary-intact rats according to OECD guidelines.

Which Histometric Analysis Approach Is More Reliable for Assessing Histological Bone Tissue Samples?

This study aims to evaluate the grid of Merz and ImageJ methods for histometric quantification, verifying which is more reliable and defining which is most suitable based on the time required to perform. Thirty histological samples of maxillary sinuses grafted with xenografts were evaluated using an optical light microscope attached to an image capture camera and connected to a microcomputer. The images were digitalized and recorded as a TIFF image, and the new bone formation was evaluated using the grid of Merz and ImageJ. The Bland-Altman analysis was used to identify the agreement between the methods and determine suitable future research options. The timing of the quantification was also performed to identify a possible advantage. The mean value for the quantification analysis timing for the grid of Merz was 194.9 ± 72.0 s and for ImageJ was 871.7 ± 264.4, with statistical significance between the groups (p = 0.0001). The Bland-Altman analysis demonstrated a concordance between the methods, due to the bias being next to the maximum concordance (-1.25) in addition to the graphic showing the scattering points next to the mean of differences and inside of limits of agreement. Thus, it was demonstrated that the grid of Merz presents reliable outcomes and advantages over the ImageJ methodology regarding the time spent to contour the areas of interest.

Age-Related Changes in Calcitonin-Producing Thyroid C-Cells of Male Wistar Rats.

Thyroid C-cells secrete the hormone calcitonin (CT) which acts as an inhibitor of bone resorption. Our aim was to examine the age-related changes in the structure and function of CT-producing C-cells, using histomorphometric, ultrastructural, and biochemical analyses. We used young adult (3-months-old), middle-aged (16-months-old), and old (24-months-old) male rats. The peroxidase-antiperoxidase method was applied for localization of CT. Stereological analysis was performed using the newCAST stereological software package. Serum samples were analyzed for the determination of CT, testosterone (T), calcium (Ca2+), and phosphorus (P). We found a significant increase in the volume density (Vv) of C-cells in both older groups (p < 0.05). The percentage of smaller volume range C-cells increased (p < 0.0001), while the proportion of greater volume range C-cells decreased (p < 0.05) with ageing. Ultrastructural analysis revealed a larger number of secretory granules in older rats. Serum CT increased (p < 0.001), while serum T and P were reduced (p < 0.01) in older rats. Serum Ca2+ was lower (p < 0.0001) in middle-aged rats compared to young adults. We revealed a 20% incidence of C-cell hyperplasia in older rats and one case of medullary thyroid carcinoma in an old rat. Our findings indicate that the ageing process causes significant histomorphometric changes at the thyroid C-cell level.

Efficacy of hyaluronic acid, absorbable collagen sponge, and their combination in minimizing bisphosphonate-related osteonecrosis of the jaws (BRONJ) after dental extraction: a preliminary animal histomorphometric study.

INTRODUCTION: There is no study on the effectiveness of hyaluronic acid (HA) placement either with or without absorbable collagen sponge (ACS) in reducing or preventing bisphosphonate-related osteonecrosis of the jaws (BRONJ). This preliminary animal study examined the efficacy of this clinically important treatment. METHODS: For simulating BRONJ, zoledronic acid was administered to 40 rats for 5 weeks. Two weeks later, a right first molar was extracted from each rat. The rats were randomized into four groups of socket treatments: control (empty extraction socket) or with sockets filled with ACS, HA, or HA+ACS (n=4×10). After 2 weeks, 5 rats in each group were sacrificed and subjected to histopathologic and histomorphometric evaluation. Eight weeks post-surgically, the rest of rats were euthanized and histologically examined. The Kruskal-Wallis test was used to compare the four treatments at each time point (α=0.05). RESULTS: Six rats were lost overall. In the second week, vascularization was higher in ACS group (P<0.05); osteoclast activity was not different between groups (P>0.05); empty lacunae were the most and fewest in control and HA+ACS groups, respectively (P<0.05); eosinophil infiltration was maximum in HA group (P<0.05); lymphocyte counts were maximum and minimum in the HA+ACS and ACS groups, respectively (P<0.05); the highest and lowest neutrophil counts were seen in ACS and control groups, respectively (P<0.05); and the extent of live bone did not differ between groups (P>0.05). In the eighth week, vascularization was not different in groups (P>0.05); the highest and lowest osteoclast activities were seen in the control and HA+ACS groups, respectively (P<0.05); empty lacunae were the most and fewest in control and HA+ACS, respectively (P<0.05); maximum and minimum numbers of eosinophils were in control and HA+ACS groups, respectively (P<0.05); HA and control groups exhibited the highest and lowest lymphocyte counts, respectively (P<0.05); the lowest and highest neutrophil counts were observed in HA+ACs and control groups, respectively (P<0.05); and the highest and lowest extents of the live bone were observed in HA+ACS and control groups, respectively (P<0.05). CONCLUSIONS: Within the limitations of this preliminary animal study, HA and especially HA+ACS seem a proper method for preventing or treating BRONJ.

Osteogenic Induction with Silicon Hydroxyapatite Using Modified Autologous Adipose Tissue-Derived Stromal Vascular Fraction: In Vitro and Qualitative Histomorphometric Analysis.

Large bone defects requiring invasive surgical procedures have long been a problem for orthopedic surgeons. Despite the use of autologous bone grafting, satisfactory results are often not achieved due to associated limitations. Biomaterials are viable alternatives and have lately been used in association with Stromal Vascular Fraction (SVF), stem cells, and signaling factors for bone tissue engineering (BTE). The objective of the current study was to assess the biocompatibility of Silicon Hydroxyapatite (Si-HA) and to improve osteogenic potential by using autologous adipose-derived SVF with Si-HA in a rabbit bone defect model. Si-HA granules synthesized using a wet precipitation method were used. They were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). A hemolysis assay was used to assess the hemolytic effects of Si-HA, while cell viability was assessed through Alamar Blue assay using MC3T3 mouse osteoblasts. The osteogenic potential of Si-HA both alone and with enzymatically/non-enzymatically-derived SVF (modified) was performed by implantation in a rabbit tibia model followed by histomorphometric analysis and SEM of dissected bone after six weeks. The results showed that Si-HA granules were microporous and phase pure and that the addition of Silicon did not influence Si-HA phase composition. Si-HA granules were found to be non-hemolytic on the hemolysis assay and non-toxic to MC3T3 mouse osteoblasts on the Alamar Blue assay. Six weeks following implantation Si-HA showed high biocompatibility, with increased bone formation in all groups compared to control. Histologically more mature bone was formed in the Si-HA implanted along with non-enzymatically-derived modified SVF. Bone formation was observed on and around Si-HA, reflecting osseointegration. In conclusion, Si-HA is osteoconductive and promotes osteogenesis, and its use with SVF enhances osteogenesis.

Sealing materials for post-extraction site: a systematic review and network meta-analysis.

AIM: By means of a systematic review and network meta-analysis, this study aims to answer the following questions: (a) does the placement of a biomaterial over an extraction socket lead to better outcomes in terms of horizontal and vertical alveolar dimensional changes and percentage of new bone formation than healing without coverage? And (b) which biomaterial(s) provide(s) the better outcomes? MATERIALS AND METHODS: Parallel and split-mouth randomized controlled trials treating ≥ 10 patients were included in this analysis. Studies were identified with MEDLINE (PubMed), Embase, Cochrane Central Register of Controlled Trials, and Scopus. Primary outcomes were preservation of horizontal and vertical alveolar dimension and new bone formation inside the socket. Both pairwise and network meta-analysis (NMA) were undertaken to obtain estimates for primary outcomes. For NMA, prediction intervals were calculated to estimate clinical efficacy, and SUCRA was used to rank the materials based on their performance; multidimensional ranking was used to rank treatments based on dissimilarity. The manuscript represents the proceedings of a consensus conference of the Italian Society of Osseointegration (IAO). RESULTS: Twelve trials were included in the qualitative and quantitative analysis: 312 sites were evaluated. Autologous soft tissue grafts were associated with better horizontal changes compared to resorbable membranes. A statistically significant difference in favor of resorbable membranes, when compared to no membrane, was found, with no statistically significant heterogeneity. For the comparison between crosslinked and non-crosslinked membranes, a statistically significant difference was found in favor of the latter and confirmed by histomorphometric NMA analysis. Given the relatively high heterogeneity detected in terms of treatment approaches, materials, and outcome assessment, the findings of the NMA must be interpreted cautiously. CONCLUSIONS: Coverage of the healing site is associated with superior results compared to no coverage, but no specific sealing technique and/or biomaterial provides better results than others. RCTs with larger sample sizes are needed to better elucidate the trends emerged from the present analysis. CLINICAL RELEVANCE: Autologous soft tissue grafts and membranes covering graft materials in post-extraction sites were proved to allow lower hard tissue shrinkage compared to the absence of coverage material with sealing effect. Histomorphometric analyses showed that non-crosslinked membranes provide improved hard tissue regeneration when compared to crosslinked ones.

Histomorphometric analysis of the sinus lateral wall and Schneiderian membrane: A cadaveric study.

OBJECTIVES: Sinus augmentation is frequently used to maintain implant stability when there is severe alveolar bone loss. The aim of this study was to determine the thicknesses and histologic features of the sinus lateral wall and Schneiderian membrane in embalmed cadavers. DESIGN: This study included 35 hemimaxillae from 25 cadavers (19 males and 6 females with a mean age at death of 59 years). Specimens obtained from the first premolar to the second molar were embedded in paraffin, stained with hematoxylin-eosin, and observed under a light microscope. The thicknesses of the lateral wall and Schneiderian membrane were measured according to tooth site and measurement level, and their histologic features were evaluated. RESULTS: The mean thicknesses of the lateral wall were 2.22, 2.17, 2.64, and 2.64 mm at the first premolar, second premolar, first molar, and second molar, respectively, and 2.79, 2.24, and 2.12 mm at 0, 2, and 8 mm from the sinus floor. The mean thickness of the Schneiderian membrane did not differ significantly between at the sinus floor (0.41 mm) and 2 mm above the floor (0.38 mm). The lateral wall consisted of the outer cortical plate, trabecular bone in the center, and the inner cortical plate near the Schneiderian membrane, being the inner cortical plate the more porous. CONCLUSIONS: These histomorphometric results for the sinus lateral wall and Schneiderian membrane are expected to provide relevant information for use in sinus augmentation procedures.

The effect of low intensity pulsed ultrasound on mandibular condylar growth in young adult rats.

There is a need for more effective methods to enhance mandibular growth in young adults with mandibular deficiency. Previous studies suggest that low intensity pulsed ultrasound (LIPUS) can enhance mandibular growth in growing individuals. This study aimed to evaluate the potential growth changes of the mandible following 4-week LIPUS application in young adult rats. Nineteen ≈120-day-old female rats were allocated to experimental (n = 10) and control (n = 9) groups. The animals in the experimental group were treated with LIPUS to their temporomandibular joints (TMJs) bilaterally, 20 min each day for 28 consecutive days. Animals were then euthanized; gross morphological evaluation was performed on 2D photographs and 3D virtual models of hemi-mandibles, and microstructural assessment was done for the mandibular condyle (MC). Evaluation of mineralization and microarchitecture properties of subchondral cancellous bone was performed by micro-computed tomography (µCT) scanning. Qualitative and histomorphometric analysis was done on condylar cartilage and subchondral bone following Alcian Blue/PAS and Goldner's Trichrome staining. Vital flourochrome (calcein green) labeling was also utilized to determine the amount of endochondral bone growth. Gross morphological evaluations showed a slight statistically non-significant increase especially in the main condylar growth direction in the LIPUS group. Moreover, 3D evaluation depicted an enhanced periosteal bone apposition at the site of LIPUS application. Microstructural analysis revealed that LIPUS stimulates both chondrogenesis and osteogenesis and enhances endochondral bone formation in young adult rat MC. Furthermore, the effect of LIPUS on osteogenic cells of subchondral cancellous bone was notable. To conclude, LIPUS can enhance young adult rats' MC residual growth potential.

Evaluation of single-dose applied teriparatide effect on bone healing with histomorphometric and micro-ct analysis.

The aim of the present study was to evaluate the effects of a single dose of locally administered teriparatide (TP) on healing critical-sized defects in rat mandibles through histomorphometric and microcomputed tomography (micro-CT) analyses. In this study, 48 Sprague-Dawley rats were used. The experimental animals were divided into 4 groups as follows: Group 1 had empty defects, Group 2 received autografts, Group 3 received allografts, and Group 4 received allografts combined with 40 µg of TP. Eight weeks after the surgical procedure, all rats were sacrificed, and all specimens were evaluated using micro-CT and histomorphometric analyses. The results of the histomorphometric analysis showed that Group 4 had the most new bone area (0.85 mm2 ± 0.13 mm2) (p = 0.002) and the highest number of osteoblasts (86.61 ± 4.86) (p = 0.001). In addition, the results of the micro-CT analysis showed that Group 4 had the highest bone volume/total volume (23.27% ± 0.15%) (p = 0.001). The histomorphometric and micro-CT values of Group 2 were higher than those of Group 1 but lower than those of Group 3 and Group 4. The results of the study show that a single dose of locally administered TP has a positive effect on the integration of allografts. However, further studies are necessary to identify the mechanism of action and the effective minimum and maximum doses of locally administered TP.

The Impact of Bone Mineral Density on Bone Metabolism and the Fracture Healing Process in Elderly Chinese Patients With Osteoporotic Vertebral Compression Fractures.

BACKGROUND: The aim of this study was to investigate the effect of bone mineral density (BMD) on bone histomorphological parameters and bone turnover markers (BTMs) following osteoporotic vertebral compression fracture (OVCF) and to determine the correlation between BMD and the percentage of middle height compression during the healing process. METHODS: A total of 206 patients with OVCFs were included in this study. Bone biopsy specimens were acquired during surgery. Blood samples were obtained to determine the serum concentrations of BTMs. The patients were divided into 2 groups according to BMD. RESULTS: The concentrations of N-terminal propeptide of type I collagen (PINP) in the T-score ≤ -2.5 group (50.92 ± 12.78 ng/ml) were significantly lower than those in the T-score > -2.5 group (68.75 ± 28.66 ng/ml, p = 0.025) 3-6 mo after fracture. Moreover, the volume of necrotic bone in the T-score ≤ -2.5 group (15.15 ± 5.44%) was higher than that (1.67 ± 0.79%, p < 0.001) in the T-score > -2.5 group during the same period. BMD was statistically correlated with cancellous bone content (RS = 0.761, p <0.001), PMHC (RS = 0.85, p < 0.001), fibrous tissue volume (RS = -0.376, p < 0.001), and necrotic bone content (RS = -0.487, p < 0.001). CONCLUSIONS: The healing process of OVCFs in the setting of low bone mass frequently occurs in the presence of decreased bone formation abilities, severe vertebral body height loss and a large amount of necrotic bone.

Split-Block Graft Versus Cortico-cancellous Block Graft for Horizontal Ridge Augmentation: Cone Beam Computed Tomography and Histomorphometric Study / Enxerto de bloco dividido versus enxerto de bloco córtico-esponjoso para aumento horizontal do rebordo: imagens de tomografia computadorizada de feixe cônico e estudo histomorfométrico

Objective: The aim of this study was to compare the horizontal dimensional changes of split-bone block and cortico-cancellous block graft in horizontal ridge augmentation using Cone Beam Computed Tomography (CBCT). The quality of the regenerated bone in both groups was compared histologically and histomorphometrically. Material and methods: Twenty patients were randomly divided in two equal groups (n= 10): Split-bone block group which was harvested from the external oblique ridge or cortico-cancellous block graft group which was harvested from the mandibular symphysis. Pre-augmentation crestal ridge width was measured using bone caliper. CBCT scans were taken on the 2nd week and 4th month post-operatively to measure crestal and total horizontal ridge dimensions. A biopsy was collected from the regenerated ridge immediately before implant insertion on the 4thmonth post-operatively. Results: Pre-augmentation crestal bone widths of both groups were comparable (P= 0.870). On the 2nd week and 4th month post-operatively, split-bone block showed a significantly wider crestal (P= 0.028 and P= 0.001 respectively) and total horizontal ridge dimension (P= 0.025 and P= 0.002 respectively), and on the 4th month post-operatively, it showed significantly lesser resorption at crest (P= 0.040) and in total horizontal ridge dimension (P= 0.017) than cortico-cancellous block. Histologically, the regenerated bone quality was similar in both groups. Histomorphometric analysis showed a non-significant difference in percentage of mature (P= 0.365) and immature collagen (P= 0.531) between both groups. Conclusion: Split-bone block maintained a significantly wider ridge and experienced less resorption after 4 months than the cortico-cancellous block graft, with no difference in regenerated bone quality between both groups. (AU)

Objetivo: O objetivo deste estudo foi comparar as mudanças dimensionais horizontais do enxerto de bloco ósseo dividido e do enxerto de bloco córtico-esponjoso no aumento de rebordo horizontal por meio da Tomografia computadorizada de feixe cônico (TCFC). A qualidade do osso regenerado em ambos os grupos foi comparada histológica e histomorfometricamente. Material e Métodos:Vinte pacientes foram divididos aleatoriamente em dois grupos iguais (n=10): Grupo de blocos de osso dividido retirado da crista oblíqua externa ou Grupo de enxerto em bloco córtico-esponjoso retirado da sínfise mandibular. A largura da crista pré-aumentada foi medida usando calibrador ósseo. Os exames de TCFC foram realizados na segunda semana e quarto mês de pós operatório para medir as dimensões da crista e dimensões horizontais totais do rebordo. Uma biopsia foi coletada da crista regenerada imediatamente antes da inserção do implante no quarto mês pós-operatório. Resultados: As larguras do osso crestal pré-aumentado de ambos os grupos eram compatíveis (p = 0,870). Na segunda semana e quarto mês pós-operatórios, o bloco ósseo dividido mostrou uma crista significativamente mais larga (p = 0,28 e p = 0,001 respectivamente) e a dimensão da crista horizontal total (p = 0,025 e p = 0,002 respectivamente), e no quarto mês pós-operatório, apresentou reabsorção significativamente menor na crista (p = 0,040) e na dimensão da crista horizontal total (p = 0,017) em comparação ao bloco córtico-esponjoso. Histologicamente, a qualidade do osso regenerado foi semelhante em ambos os grupos. A análise histomorfométrica mostrou uma diferença não significativa na porcentagem de colágeno maduro (p = 0.365) e colágeno imaturo (p = 0,531) entre ambos os grupos. Conclusão: O bloco ósseo dividido manteve uma crista significativamente mais larga e apresentou menos reabsorção após 4 meses, em comparação ao enxerto em bloco córtico-esponjoso, sem diferença na qualidade do osso regenerado entre ambos os grupos. (AU)

The Influence of Residual Alveolar Bone Height on Graft Composition after Maxillary Sinus Augmentation Using Two Different Xenografts: A Histomorphometric Comparative Study.

AIM: To evaluate the hypothesis of a correlation between the preoperative residual alveolar bone height (RBH) and graft maturation after maxillary sinus floor augmentation procedures using two different bone substitutes. METHODS: A total of 20 patients who underwent unilateral maxillary sinus floor augmentation with either mineralized deproteinized bovine bone (DBBM) or a xenograft enriched with polymer and gelatin (NBS) were included in this prospective study. Six months after sinus surgery, bone biopsies were harvested with a 3.2 mm diameter trephine bur, prior to dental implant placement. Histomorphometric analysis was performed, and the results were correlated with the individual RBH. Implants were loaded after 5 months of insertion, and 1-year implant success and marginal bone level change were assessed. RESULTS: RBH was 2.17 ± 1.11 mm (range 0.5-3.5 mm) and 2.14 ± 0.72 mm (range 0.5-3.0 mm) in the NBS and DBBM group, respectively. The biopsy analyses for the DBBM group showed woven bone increases by 5.08% per 1-mm increment of RBH; medullary spaces decreased by 9.02%, osteoid decreased by 4.4%, residual biomaterial decreased by 0.34%, and lamellar bone increased by 5.68% per 1-mm increase of RBH. In the NBS group, samples showed woven bone increases by 8.08% per 1-mm increase of RBH; medullary spaces decreased by 0.38%; osteoid increased by 1.34%, residual biomaterial decreased by 0.58%, and lamellar bone decreased by 5.50% per 1-mm increase of RBH. There was no statistically significant difference in the correlation between RBH and lamellar bone, woven bone, and osteoid, independently of the material used. Implant success was 100% in both groups, and marginal bone loss was 1.02 ± 0.42 mm in DBBM and 0.95 ± 0.31 mm in the NBS group after the 1-year follow-up. CONCLUSION: In spite of the absence of significance, the observed trend for woven bone to increase and medullary spaces to decrease when RBH increases deserves attention. Residual bone dimension might be a determinant in the bone graft maturation after maxillary sinus augmentation.

Association between Bone Density Values, Primary Stability and Histomorphometric Analysis of Dental Implant Osteotomy Sites on the Upper Jaw.

INTRODUCTION: Sufficient bone volume, as well as the bone quality characteristics are necessary prerequisites to ensure optimal mechanical stability of the implants and subsequent osseointegration. AIM: The aim of the present study was to assess the correlation between bone density values obtained by cone-beam computed tomography (CBCT), the primary stability of dental implants and the histomorphometric analysis of bone quality. MATERIALS AND METHODS: Following tooth extraction, socket preservation with frieze-dried bone allograft or protein-rich fibrin (PRF) was performed on 30 patients with 30 maxillary teeth in the region from second premolar to second premolar. Four months after the procedure, CBCT was used to assess the bone density (Hounsfield units) in the area of extraction. Thirty bone samples were harvested from implant sites using a trephine drill. They were analyzed with Image J software. Immediately after placing the implant, the implant stability quotient was measured using the Osstell Idx device. RESULTS: The results revealed significant correlations between bone density and primary stability along the vestibulo-oral (r=0.392, p=0.032) and mesiodistal axes (r=0.407, p=0.026). Bone density also correlated strongly with the percentage of newly formed bone (r=0.776, p<0.001). CONCLUSION: Bone quality, in terms of bone density measured in CBCT and new bone formation are correlated to the primary stability of the dental implants and vice versa.

Influence of the position of the antrostomy in sinus floor elevation on the healing of mini-implants: a randomized clinical trial.

AIM: To evaluate histologically the healing of mini-implants installed after sinus floor elevation using a lateral approach and placing the antrostomy at different level from the sinus floor. MATERIAL AND METHODS: Sinus floor elevation using a lateral approach was performed in 24 healthy volunteers. The antrostomy was randomly placed either close to the base of the sinus floor (group base) or at about 3-4 mm cranially to it (group standard). After 6 months of healing, mini-implants were installed within the grafted region, through the alveolar crest. Three months later, biopsies were collected. RESULTS: Sixteen biopsies from 16 patients were available for histological analyses. The new bone reached fractions of 40.9 ± 11.9% and 48.5 ± 20.1% at the base and standard groups, respectively (p = 0.208). Xenograft particles were found in contact with the implant surface at percentages of 12.1 ± 11.0% in the base group, and 15.9 ± 23.7% in the standard group (p = 0.674). CONCLUSIONS: Based on the present study, the choice of one or the other position of antrostomy did not influence significantly the outcome and, therefore, should be left to the preference of the surgeon.

Histomorphometric Analysis of Anti-Aging Properties on Rat Skin.

We present a histomorphometric analysis to enable quantitative measurement of anti-aging activity of topical substances in rat skin. In this method, the measured parameters were closely related to changes that occur on the skin caused by exposure to UV light. We used this protocol to determine the anti-aging activities of an ethanolic extract of Curcuma heyneana rhizome and retinoic acid by a measurement of the changes in epidermal thickness, the number of sunburned cells, the number of fibroblasts, and the space between collagen fibers.

Three-dimensional ultrastructural imaging and quantitative analysis of the periodontal ligament.

The periodontal ligament (PDL) is a unique connective tissue mainly comprising collagen fiber bundles and cells between the roots of teeth and inner walls of the alveolar-bone socket. PDL fiber bundles are arrayed between teeth and bone, with both ends embedded in the cementum or alveolar bone as Sharpey's fiber. These bundles, synthesized by PDL fibroblasts (PDLFs), form several distinct groups within the PDL which has important functions besides tooth anchoring including tooth nutrition, proprioception, sensory detection, homoeostasis, and repair of damaged tissue. However, little is known about how the regular-PDL fiber bundle arrays are formed, maintained, and remodeled over large distances from cementum to alveolar bone. Recently, novel instruments and 3D-imaging methods have been developed that have been applied to the investigation of hard tissues including the PDL. Work from our laboratory has revealed the three-dimensional (3D) ultrastructure of PDLFs and PDL collagen bundles by focused ion beam/scanning electron microscope tomography. We have shown that PDLFs have a flat shape with long processes or a wing-like shape, while PDL bundles are a multiple-branched structure wrapped in thin sheets of PDLF cytoplasm. Furthermore, PDLFs form an extensive cellular network between the cementum and alveolar bone. The PDL cellular network is presumed to synchronize PDL fiber bundles and regulate arrays of PDL fiber bundles via gap junctions. In this review, we summarize and discuss our current 3D-histomorphometric studies of the PDL at the mesoscale level.

Do osteoconductive bone substitutes result in similar bone regeneration for maxillary sinus augmentation when compared to osteogenic and osteoinductive bone grafts? A systematic review and frequentist network meta-analysis.

The purpose of this network meta-analysis was to identify the most effective biomaterials producing higher new bone formation (NBF) and lower residual graft (RG) and connective tissue (CT) following maxillary sinus augmentation (MSA), and to generate a ranking based on their performance. The MEDLINE, Embase, and CENTRAL databases were searched to identify randomized controlled trials (RCTs) published until March 2018, evaluating histomorphometric outcomes after MSA. Predictor variables were autogenous bone (AB), allografts (AG), xenografts (XG), alloplastic bone (AP), AB+XG, AB+AP, AG+XG, XG+AP, and grafts combined with autologous platelet concentrates/recombinant growth factors, mesenchymal stem cells (MSCs), or recombinant bone morphogenetic proteins (BMPs). Outcome variables were NBF%, RG%, and CT%. Healing time was considered. The weighted mean difference (WMD) with 95% confidence interval (CI) was calculated via frequentist network meta-analysis using Stata software. Fifty-two RCTs (1483 biopsies) were included. At a healing time <6 months, AB was superior to AP (WMD-10.66%, 95% CI-16.38% to -4.94%) and XG (WMD-7.93%, 95% CI-15.11% to -0.75%) for NBF. Regarding CT, AB was superior to XG+AP, AP, MSCs, and XG. At a healing time ≥6 months, NBF was higher for AB than AP (WMD-7.06%, 95% CI-12.59% to -1.52%). RG was lower in AB than AP (WMD 12.03%, 95% CI 3.04% to 21.03%), XG (WMD 14.62%, 95% CI 4.25% to 24.98%), and growth factors (WMD 12.32%, 95% CI 0.04% to 24.60%). The three highest ranked biomaterials for increasing NBF were AG+XG (95%, very low quality evidence), growth factors (69.9%, low quality evidence), and AB alone (69.8%, moderate quality evidence). The three highest ranked biomaterials for decreasing RG were BMPs (88.8%, very low quality evidence), AB alone (81.5%, moderate quality evidence), and AB+AP (58.9%, very low quality evidence). Finally, XG+AP (84.7%, low quality evidence), AP alone (77.7%, moderate quality evidence), and MSCs (76.1%, low quality evidence), were the three highest ranked biomaterials for decreasing the amount of CT. Network meta-analysis provided moderate quality evidence that AB alone is probably the best option to obtain greater NBF after MSA in the first 6 months after surgery. Additionally, the results of this network meta-analysis support the hypothesis that osteoconductive bone substitute materials should be combined with osteogenic or osteoinductive grafts for superior histomorphometric outcomes in MSA.