Histomorphometric Data Research Articles

Horizontal Augmentation of Chronic Mandibular Defects by the Guided Bone Regeneration Approach: A Randomized Study in Dogs.

Various biomaterial combinations have been studied focusing on their ability to stabilize blood clots and maintain space under soft tissue to support new bone formation. A popular combination is Deproteinized Bovine Bone Mineral (DBBM) placed with a native collagen membrane (NCM) tacked to native bone. In this study, we compared the outcome of this treatment option to those achieved with three different graft/membrane combinations with respect to total newly occupied area and the mineralized compound inside. After bi-lateral extraction of two mandibular premolars in five adult beagles L-shaped alveolar defects were created. A total of 20 defects healed for 6 weeks resulting in chronic type bone defects. At baseline, four options were randomly allocated to five defects each: a. DBBM + NCM with a four-pin fixation across the ridge; b. DBBM + RCLC (ribose cross-linked collagen membrane); c. DBBM + NPPM (native porcine pericardium membrane); and d. Ca-sulfate (CS) + RCLC membrane. Membranes in b/c/d were not fixed; complete tensionless wound closure was achieved by CAF. Termination after 3 months and sampling followed, and non-decalcified processing and toluidine blue staining were applied. Microscopic images obtained at standardized magnification were histomorphometrically assessed by ImageJ software (NIH). An ANOVA post hoc test was applied; histomorphometric data are presented in this paper as medians and interquartile ranges (IRs). All sites healed uneventfully, all sites were sampled and block separation followed before Technovit embedding. Two central sections per block for each group were included. Two of five specimen were lost due to processing error and were excluded from group b. New bone area was significantly greater for option b. compared to a. (p = 0.001), c. (p = 0.002), and d. (p = 0.046). Residual non-bone graft area was significantly less for option d. compared to a. (p = 0.026) or c. (p = 0.021). We conclude that collagen membranes with a prolonged resorption/barrier profile combined with bone substitutes featuring different degradation profiles sufficiently support new bone formation. Tacking strategy/membrane fixation appears redundant when using these biomaterials.

Histomorphometric Comparison of New Bone Formed After Maxillary Sinus Lift With Lateral and Crestal Approaches Using Periostal Mesenchymal Stem Cells and Beta-Tricalcium Phosphate: A Controlled Clinical Trial.

The present study investigated clinical and histomorphometric data after sinus lift procedures performed with and without mesenchymal stem cells (MSCs) added to a graft. Twenty-four patients underwent maxillary sinus lift for implant placement. Twelve patients each were assigned to control (Group 1) and test (Group 2) groups. An MSC suspension was added to the graft used in patients of Group 2. Five of 12 patients in both groups underwent crestal-approach sinus lift with immediate implant placement, while seven patients received a lateral-approach sinus lift. The MSC suspension was obtained using the Rigenera protocol. Samples from the grafted site were evaluated, processed, and stained using three staining techniques 90 days after surgery. Histomorphometric analysis was performed using an imaging software (ImageJ). Two types of tissues were defined: Type 1 'mature bone' and Type 2 'osteoid tissue'. The mean Type 1 tissue percentage was 27.24% in Group 1 and 44.45% in Group 2 (P < 0.05). The mean Type 2 tissue percentage was 10.86% and 7.04% in Groups 1 and 2, respectively. The mean Type 1 tissue percentages for the crestal approach were 24.52% for Group 1 and 50.78% for Group 2, while the mean Type 1 tissue percentages for the lateral approach were 29.18% for Group 1 and 39.92% for Group 2. Patients treated with grafts containing MSCs showed 63.18% increased bone formation compared to those treated with grafts not containing MSCs (P < 0.05). Although our data showed a positive trend in patients treated with MSCs, differences between subgroups were not significant (P > 0.05).

Analysis of implant stability changes in immediate loading using a laser displacement sensor in vivo and comparison of its sensitivity with that of resonance frequency analysis

The aim of this study was to analyze the stability changes in immediately loaded implants by using an in vivo quantitative measurement of micromotion under functional dynamic loading and to verify the sensitivity of Resonance Frequency Analysis (RFA) as compared to that of actual micromotion. The micromotions of immediately loaded implants placed in the tibia of 11 rabbits were monitored using a laser displacement sensor. Functional dynamic loading forces were applied 5days a week for 6weeks. The implant stability quotient (ISQ) was monitored using RFA. The micromotion of the almost-loaded implants increased to peak values the day after loading was started and subsequently reached a plateau gradually. The ISQ changes in the loaded implants closely correlated with the alterations of the actual micromotion (r=-0.98, p<.01). Although the ISQ value itself correlated with the measured micromotion at the time of initial fixation (r=0.73, p<.05), it did not correlate with the micromotion of the implant that acquired integration. No close correlation was observed between the ISQ and the histomorphometrical data. The immediately loaded implants showed the lowest stability immediately after the start of loading, which gradually increased thereafter. RFA is considered a useful method for examining stability changes and initial stability; however, it cannot determine the absolute magnitude of the stability after integration.

ПАТОМОРФОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА ЛАДОННОГО АПОНЕВРОЗА У ПАЦИЕНТОВ С КОНТРАКТУРОЙ ДЮПЮИТРЕНА И ВИРУСНЫМ ГЕПАТИТОМ

Objective. To establish pathomorphologic peculiarities of palmar aponeurosis in the patients with Dupuytren’s contracture and concomitant virus hepatitis B and C. Methods. The data analysis of histomorphometric studies of the operation samples of 122 patients with Dupuytren’s contracture («Control» group, n=100) and Dupuytren’s contracture with virus hepatitis B and C («Hepatitis» group, n=22) were analyzed. Results. In patients of the «Hepatitis» group, the content of adiposed tissue in the palmar aponeurosis was 40.9% less (p &lt;0.01) than in the «Control» group, and the content of dense connective tissue was 18.9% higher (p &lt;0, 05). In all patients, arteries with the diameter up to 150 µm prevailed in the palmar aponeurosis, but in the «Hepatitis» group their percentage was reduced by 20%, with higher proportions of vessels with the diameter of 150-450 µm and the absence or recalibration of the largest arteries. In the «Control» group, the arteries had diameters from 50 to 660 µm, in the «Hepatitis» group they did not exceed 370 µm. Vessels less than 300 µm in diameter in both groups had comparable values of the Kernogan’s index. Arteries with a diameter of more than 300 microns in the «Hepatitis» group had higher values of the Kernogan’s index, which indicated a low conductance capacity compared to the vessels in the «Control» group. Most of the nerve trunks of the palmar aponeurosis in the patients of «Hepatitis» group showed signs of necrobiotic changes, i.e. fibrotic or swollen perineurium, withinflammatory cell infiltration, sometimes lost lamellar structure, and nerve fibers with signs of Wallerian degeneration. Conclusion. Obtained histomorphometric data of the tissue composition of palmar fascial fibromatosis, less amount of adiposed tissue and higher amount of dense connective one and more pronounced disorder of hemodynamics and innervation of the palmar aponeurosis in the group with concomitant virus hepatitis indicate significant effect of the liver pathology on the progression of the disease. What this paper adds For the first time, the pathomorphological features of the palmar aponeurosis have been studied in 122 patients with Dupuytren’s contracture and concomitant viral hepatitis B and C.It has been found that in patients with Dupuytren’s contracture and hepatitis in the palmar aponeurosis, the amount of adiposed tissue is reduced and the amount of dense connective tissue is increased; hemodynamic and innervation disorders are more pronounced.

A new non targeted bone remodeling model combined with an interpolation meshless method

Regardless of the bone remodeling type (i.e. targeted or non targeted), disturbances in this process can have serious repercussions in bone diseases’ progression. Therefore, research in this field has been continuous in recent decades, producing clinically relevant results. Regarding non targeted remodeling, distinct computational models were developed to describe the process. However, they only offer a time analysis, lacking mathematical models able to simulate the process in space. Thus, this work combines, for the first time, advanced numerical discretization techniques with non targeted remodeling models. The mathematical formulation used is based on Komarova’s model, correlating the remodeling activity of osteoclasts and osteoblasts with their autocrine and paracrine signaling pathways. For the numerical example, a two-dimensional bone patch was studied, allowing a spatio-temporal analysis of bone mass, cell density of osteoclasts and osteoblasts during an event of bone remodeling. A biological stimulus was applied to trigger remodeling and the obtained bone mass variation is consistent with the applied stimulus. Also, results are supported by the histomorphometric data available in the literature. The numerical methods used in this work are the Finite Element Method (FEM) and the Radial Point Interpolation Method (RPIM). The inclusion of the meshless method RPIM conveys a great advantage for future work since the model will be combined with medical images obtained with CT scans and MRI.

Histological, Fluorescence and Ultrastructural Assessment of Presumptive Effect of Carbimazole Treatment and its Co-administration with Bone Marrow-Derived Mesenchymal Stem Cells on Parotid Glands of Albino Rats

Background: Carbimazole is a popular drug for hyperthyroidism. However, it has many side effects on different tissues. Bone marrow-derived mes‌enchymal stem cells (BM-MSCs) are efficient in tissue regeneration. Aim: To appraise the consequence of carbimazole (antithyroid drug) intake on albino rat parotid gland structure and plausible outcome of bone marrow-derived mes‌enchymal stem cells (BM-MSCs) application at different durations.Material and methods: Forty adult male albino rats were used and categorized into: Group I: obtained distilled water. Group II: acquired therapeutic dose of carbimazole. Group III: received carbimazole and single dose of BM-MSCs at the start of experiment. Group IV: got carbimazole then by finishing of 3rd week they received solitary injection of BM-MSCs. Preparation of specimens for examination by light, fluorescent and transmission electron microscope was performed. Histomorphometric data of acini area% was statistically analyzed using ANOVA test.Results: Both histological and ultrastructural examinations illustrated that parotid gland has normal structure in Group I and approximately normal features in Group III. Group II demonstrated distorted acini and duct system. Group IV presented normal features in some acini and some areas of duct system but degenerative features in others. Results of fluorescence labeling explored some labeled-BM-MSCs in Group III but apparently copious labeled cells in Group IV. Statistical results showed highest mean acini area% in Group I, subsequently Group III, then Group IV, followed by Group II.Conclusions: Carbimazole has deteriorative outcomes on the parotid gland of albino rats. BM-MSCs ameliorate the damaging upshot of carbimazole in a direct proportion manner with time factor.

Effects of tamoxifen therapy on sciatic nerve crush injury: An experimental study in rats.

This study aimed to determine the effects of tamoxifen on sciatic nerve crush injury in a rat model using histopathological, histomorphometric, and immunohistochemical approaches. In this study, 24 male Sprague-Dawley rats aged of 5 to 7 weeks and weighing between 300 g and 400 g were used. The rats were randomly divided into 3 groups: control (group C), sciatic nerve injury (group SNI), and sciatic nerve injury with tamoxifen (group SNT). The sciatic nerve crush injury model was performed using the De Koning's crush force method. In group C, only a skin incision was made and then the skin was sutured. In group SNI, the injury model was performed but no treatment was applied. In group SNT, the injury model was executed, and then 40 mg/kg/day tamoxifen was given for 4 weeks by intraperitoneal methods. At the end of 4 weeks, all animals were killed using high doses of an anesthetic. Approximately, 2-cm sciatic nerve samples were obtained for histopathological, histomorphometric, and immunohistochemical analyses using the old skin incision. In the histopathological examination, vascular congestion and density of vacuolization were significantly lower in group SNT than in group SNI (p<0.05). In the histomorphometric examination, the mean sciatic nerve diameter was 306±62 µm in group C, 510±42 µm in group SNI, and 204±23 µm in group SNT. A significant difference was observed in the sciatic nerve diameter measurements among the 3 groups (p<0.05). In pairwise comparisons, the mean sciatic nerve diameter was significantly lower in group SNT than in group SNI (p=0.00002). Sciatic nerve diameter measurements of both groups were found to be significantly higher than group C (p<0.05). The mean epineurium thickness was 17±0.8 µm in group C, 32±2.5 µm in group SNI, and 17±0.8 µm in group SNT. A significant difference was observed in the epineurium thickness measurements among the 3 groups (p<0.05). In pairwise comparisons, the epineurium thickness was significantly higher in group SNI than in groups SNT and C (p<0.05). In the immunohistochemical analysis, S100 immunoreactivity was found significantly higher in group SNI than in the other 2 groups (p<0.05). The histomorphometric, histopathological, and immunohistochemical data obtained from this study have shown that tamoxifen has a beneficial effect on sciatic nerve crush injury in the experimental rat model.

The bone microstructure from anterior cruciate ligament footprints is similar after ligament reconstruction and does not affect long-term outcomes

PurposeThe purpose of this study was to assess the quality of the bone tissue microstructure from the footprints of the anterior cruciate ligament (ACL) and its impact on late follow-up outcomes in patients who undergo anterior cruciate ligament reconstruction (ACLR).MethodsThe records of 26 patients diagnosed with a completely torn ACL who underwent ACLR were collected. During the surgery performed using the Felmet method, bone blocks from the native ACL footprints were collected. The primary measurements of the bone microstructure were made using a microtomographic scanner. In late follow-up examinations, a GNRB arthrometer was used.ResultsThere was no significant difference in the bone microstructure assessed using micro-CT histomorphometric data according to the blood test results, plain radiographs, age or anthropometric data. There was no difference in the bone volume/total volume ratio or trabecular thickness in the area of the native ACL footprints. Routine preoperative examinations were not relevant to the quality of the bone microstructure. The elapsed time from an ACL injury to surgery had no relevance to the results of arthrometry.ConclusionThe similarities in the microstructure of bone blocks from ACL footprints from the femur and tibia allow the variable use of these blocks to stabilize grafts in the Felmet method. The bone microstructure is not dependent on the time from injury to surgery. Histomorphometric values of the structure of the femoral and tibial ACL footprints have no impact on the long-term stability of the operated knee joint.Trial registrationThe approval of the Bioethics Committee of the Silesian Medical Chamber in Katowice, Poland (resolution 16/2014) was given for this research.Level of evidenceII.

Bone repair assessment of critical size defects in rats treated with mineralized bovine bone (Bio-Oss®) and photobiomodulation therapy: a histomorphometric and immunohistochemical study.

This study aimed to investigate the effects of administering photobiomodulation therapy (PBM) with bovine bone matrix on critical size defects in rats. Seventy-two adult male rats (albinus, Wistar), 90days old, were used. Defect of 5mm in diameter was made in their calvaria. The animals were divided into 4 groups: C-blood clot, B-Bio-Oss®, L-PBM, B+L-Bio-Oss®+PBM. Each group has been subdivided into 07, 30, and 60days of observation. For PBM, a low GaAlAs energy of 660nm was irradiated, total energy density of 45J/cm2 . PBM was conducted in a trans-surgical form once only. For immunohistochemistry, a semi-quantitative analysis was made of expression of osteoprotegerin (OPG), nuclear kappa B-factor ligand receptor activator (RANKL), and tartrate-resistant acid phosphatase (TRAP). All histomorphometric data were statistically analyzed by ANOVA and Tukey test, significance level of 5%. The groups that showed the highest proportion of neoformation were L (0.39% ± 0.13) and C (0.37% ± 0.97), but groups B and B+L had larger defect size (C-1.75mm2± 0.40, B-3.02mm2± 0.63, L-2.45mm2± 0.53, B+L-3.23mm2± 1.01). In immunohistochemistry, groups B and B+L had higher immunostaining scores for OPG and RANKL at 60days, and TRAP immunostaining increased in all groups at 30days, but group L was the only one to present specimens with score 0. Although, at 60days, groups L and C presented the highest proportion of bone neoformation, at 30days group B+L had more than twice as much bone neoformation as group B, the choice of treatment application should depend on the aim of the treatment.

Comparison of extraction sites versus artificial defects with xenogenic bone substitute in minipigs.

ObjectivesThe preclinical evaluation of bone substitutes is frequently performed in artificially created defects. However, such defects do not reflect the predominant clinical application of bone substitutes for socket preservation. Hence, the goal of this animal study was to compare the performance of a xenogenic bone substitute in extraction sites versus artificial defects.Material and MethodsFour study sites each were created in the mandibles of four minipigs in the region of the third premolars and first molars, respectively. On one side, fresh extraction sockets were established while contralaterally trephine defects were created in healed alveolar bone. All sites were augmented using a particulate xenogenic bone substitute, covered by resorbable membranes and allowed to heal for 12 weeks. The amounts of new bone, non‐bone tissue and remaining bone substitute granules were quantified through histological and micro‐CT analysis. Comparative statistics were based on t‐tests for two samples and ANOVA with the level of significance set at α = 0.05.ResultsHistomorphometric data from only two animals could be quantitatively analyzed due to difficulty with identifying the surgical sites. The percentage of newly formed bone ranged between 53.2% ± 5.6% for artificial defects and 54.9% ± 12.4% for extraction sites. With the exception of ANOVA indicating a greater amount of non‐bone tissue in extraction sites as compared to artificial sites (p = 0.047), no statistically significant differences were observed. Micro‐CT scans showed patterns similar to the ones observed in histomorphometry. As extraction sites could be identified only in two micro‐CT reconstructions, quantitative assessment was not undertaken.ConclusionsDespite the comparable performance of bone substitute material in artificial defects and extraction sites found here, the data gathered with this experiment was insufficient for showing equivalence of both approaches.

Rib histomorphometry: A reliability and validation study with a critical review of histological techniques for forensic age estimation.

Fragmented human remains present a challenge for forensic experts as they attempt to identify individuals using standard forensic methods. Several histological age estimation techniques have been developed during the last fifty years to aid in this process. However, very few validation studies have been conducted in order to test their accuracy and bias, and thus, validation assessment is required as we employ them while testifying in court. Histological variables are assessed from rib thin sections from two Mediterranean samples; Cretans (N=41) and Greek-Cypriots (N=47). Intra and inter-observer errors are assessed through TEM analysis and Intra-class Correlation Coefficient by testing observers with different levels of experience as they collected data on osteon counts and area measurements. The relation between the variables and age is determined using correlation coefficients. Histomorphometric data are applied to four widely used age estimation formulas assessing the performance of the methods for the entire sample. Inaccuracy and bias are calculated with age estimations and known age tested for significance and proportional bias assessed. Overall, histological parameters presented acceptable intra- and inter-observer errors. All variables exhibited statistically significant correlation with age (P<0.01). For three of the techniques, data showed a systematic underestimation of age with an increase in inaccuracy in older individuals. One of the age estimation formulas produced overestimation of young individuals yet, it more accurately estimated the age of older individuals. This validation study explores inter-population variation in bone remodeling dynamics and presents a critical evaluation on methodological issues that can affect the performance of existing histological techniques.

This issue of ACTA, printed and electronic

This issue of ACTA, printed and electronic

Reference Intervals for Bone Histomorphometric Measurements Based on Data from Healthy Premenopausal Women.

This study has established the normal reference intervals for bone histomorphometric measurements derived from healthy premenopausal women, which is rarely available. We presented the static and dynamic bone histomorphometric data from trans-iliac bone biopsies in 62 healthy premenopausal women (19 blacks and 43 whites, ages 20-53years). There were no significant differences in age and BMI between black and white women. Since there was no significant difference in bone remodeling between the two ethnic groups, we pooled data of all 62 premenopausal women to establish normal reference intervals for bone histomorphometry. The results provide normal reference intervals for both static and dynamic histomorphometric variables in cancellous and cortical bone of the ilium. None of the bone remodeling-related variables correlated with age or BMI. This study provides reference intervals for bone histomorphometric measurements in both cancellous and cortical bone of the ilium, which would behelpful inthe evaluation of bone health in women.

Two-stage Lateral Maxillary Sinus Lift using Autogenous Bone and β-Tricalcium Phosphate: Clinical and Histomorphometric Evaluation

Background: To assess the clinical and histomorphometric data of the new bone tissue from a mixture of autologous bone and β-tricalcium phosphate. Materials and methods: A total of 72 two-stage sinus lift were performed in 54 patients during 2007 to 2010. The autologous bone was harvested from the mandibular ramus and mixed with the β-tricalcium phosphate Poresorb® TCP sized 1-2 mm. The materials were used in a proportion ranged between 1:1 and 1:3. After the healing period a total of 119 implants were placed and 10 samples of the regenerated bone were collected for the histomorphometric analysis. CBCT or panoramic X-rays were performed presurgically, before the implant placement, six months after implant placement and then yearly to evaluate the bone formation and marginal bone loss. The implant success rate was determined using the Albrektsson et al. Criteria. Results: The mean of the residual bone was 4.07 mm ± 1.87 mm. The bone gain in the sinus was 11.91 mm ± 2.80 mm. The implant success rate was 94.95%. The histomorphometric measurements on the biopsies showed a bone area mean of 39.7 ± 9.71%. The residual allograft area was 16.21 ± 8.78%. The connective tissue was 44.16 ± 5.85%. Conclusion: Within the limit of this study, the osteoconductive β-tricalcium phosphate associated with autologous bone is a viable grafting material for sinus lift procedures. The use of composite grafts can help to reduce the morbidity and aggressivity of the bone harvesting. Keywords: Sinus lift; Bone regeneration; Dental implants; β-tricalcium phosphate; Bone graft; Bone atrophy

SO074VASCULAR CALCIFICATION IN PREVALENT PERITONEAL DIALYSIS PATIENTS AND ITS RELATIONSHIP WITH CLINICAL AND BONE HISTOMORFOMETRIC PARAMETERS

Abstract Background and Aims Vascular calcification (VC) is associated to morbidity and mortality in chronic kidney patients. However, it remains to clarify the relationship between VC and renal osteodystrophy (ROD) evaluated by bone biopsy in peritoneal dialysis (PD) patients. Method In order to characterize the relationship between VC and ROD in prevalent PD population, we performed tetracycline-labelled bone biopsies with histomorphometric analysis according KDIGO guidelines. Hands and pelvis x-ray were performed to evaluate VC and to calculate Adragão Score. Exclusion criteria: previous kidney transplant, hemodialysis, treatment with agents interfering in bone metabolism (for example bisphosphonates). All patients were treated with biocompatible PD solutions, with calcium concentration of 1.25 mmol/L. Results Thirty-one patients participated in the study. Mean age was 52.32±11.09 years, 16 male, 6 with diabetes mellitus (DM), 22 on manual PD, median time on PD was 12 (3-61) months. Mean calcium, phosphate and PTH were 9.2±0.5 mg/dL, 4.9±1.0 mg/dL and 486.0±230.5 pg/mL, respectively. Most frequent diagnosed ROD pattern was adynamic bone disease (44.4%) followed by hiperparathyroid bone disease (33.3%) and normal bone (14.8%). VC was detected in 29% of patients and mean Adragão score was 1.13. However, 100% of diabetics had VC on x-ray compared to 12% of non-diabetics. Clinical, analytical and histomorphometric essential data is represented in table 1: Also no significant differences were observed between the patients with or without VC in ROD patterns on bone biopsy, glucose load in PD solutions, prescribed phosphate binders namely calcium-based binders, active vitamin D or calcimimetics. In diabetic patients, bone volume tended to be lower (17.26% vs 22.54%; p=0.072) comparing to non-diabetics. Bone formation rate was similar in diabetics and non-diabetics (25.39 vs 27.71µm3/µm2/y) as mineralization lag time (18.7 vs 20.1 days). Conclusion ROD evaluated by bone biopsy and the proportion of PD patients with VC on x-ray were similar to previous reports. However, in the present study a striking difference in VC was detected in diabetics – all diabetic patients had VC demonstrated radiographically. This finding was not explained by differences in calcium, phosphate, PTH levels or other studied factors. So DM could be a strong risk factor to VC in this population. Also, patients with VC were older, with higher sedimentation rate and lower total KT/V. It is possible that diabetic patients represent a different subgroup, particularly prone to lower bone volume and specially VC. They might benefit from higher dialysis dose and aggressive approaches to prevent or retard VC. This remains to be proved in properly designed prospective studies. In conclusion, age, sedimentation rate, total KT/V and presence of diabetes were associated to VC in prevalent PD patients. Diabetics may be a subgroup of PD patients with very high risk of VC.

Delivery of Interleukin-4-Encoding Lentivirus Using Multiple-Channel Bridges Enhances Nerve Regeneration.

Facial nerve injury is a source of major morbidity. This study investigated the neuroregenerative effects of inducing an anti-inflammatory environment when reconstructing a facial nerve defect with a multichannel bridge containing interleukin-4 (IL-4)-encoding lentivirus. Animal study. Eighteen adult Sprague-Dawley rats were divided into three groups, all of which sustained a facial nerve gap defect. Group I had reconstruction performed via an IL-4 multichannel bridge, group II had a multichannel bridge with saline placed, and group III had no reconstruction. Quantitative histomorphometric data were assessed 10 weeks after injury. On post hoc analysis, the IL-4 bridge group demonstrated superior regeneration compared to bridge alone on fiber density (mean = 2,380 ± 297 vs. 1,680 ± 441 fibers/mm2 , P = .05) and latency time (mean = 2.9 ms ± 0.6 ms vs. 3.6 ms ± 0.3 ms, P < .001). There was significantly greater regeneration in the IL-4 bridge group versus unreconstructed defect for total fiber and density measurements (P ≤ .05). Comparison of facial motor-evoked distal latencies between the IL-4 bridge group versus bridge alone revealed significant electrophysiological improvement at week 8 (P = .02). Inflammation has been implicated in a variety of otolaryngologic disorders. This study demonstrates that placement of a multichannel bridge with lentivirus encoding IL-4 improves regenerative outcomes following facial nerve gap injury in rodents. This effect is likely mediated by promotion of an anti-inflammatory environment, and these findings may inform future therapeutic approaches to facial nerve injury. NA Laryngoscope, 2020.

Effect of Systemic Oxytocin Administration on New Bone Formation and Distraction Rate in Rabbit Mandible

The main disadvantage of distraction osteogenesis is the prolonged treatment protocol. Recently, oxytocin (OT) has been found to have anabolic effects on bone metabolism. In this experimental study, the effects of OT on the mandibular distraction gap in rabbits at 2 different distraction rates were evaluated. This experimental study was conducted on 28 male New Zealand white rabbits. The animals were divided into 3 experimental groups and 1 control group. Group A (control group, n=7) consisted of animals with distraction at a rate of 1mm/day, and group B (n=7) consisted of animals with a distraction rate of 2mm/day; groups A and B received postoperative saline solution injection. Group C (n=7) consisted of animals with distraction at a rate of 1mm/day, and group D (n=7) consisted of animals with a distraction rate of 2mm/day; postoperative OT injection was performed in groups C and D. Both histomorphologic and micro-computed tomography evaluations showed increased bone healing in the OT-treated groups. On the basis of the evaluation of both the histomorphometric and micro-computed tomographic data, systemic OT administration was found to increase new bone formation and bone healing with distraction osteogenesis.

A Narrative Review of the Histological and Histomorphometrical Evaluation of the Peri-Implant Bone in Loaded and Unloaded Dental Implants. A 30-Year Experience (1988-2018).

Background: The aim of the present review was to assess the histological and histomorphometrical data from the paper published by our Laboratory on peri-implant bone in dental implants in different loading conditions. Methods: The papers published in different implant loading conditions, in dental implants retrieved from humans, and in the Hard Tissues Research Center of the University of Chieti-Pescara, Italy, were screened on MEDLINE/PubMed, Embase, Scopus, and other electronic databases until 31 December 2018. Only articles that reported the histological and histomorphometrical values of the Bone-Implant Contact (BIC) were selected. Results: The system selection provided a total of 155 papers. The manuscripts included for the narrative review were 57. These papers provided histological and histomorphometrical data. Conclusions: The bone remodeling around dental implants was found to be a dynamic process; loading changed the microstructure of the peri-implant bone; and implants were found to provide a successful function, over several decades, with different range of degrees of BIC in vivo (varying from a little more than 30% to a little more than 90%). Loaded implants presented a 10%–12% higher BIC values when compared to submerged, unloaded implants, and rougher surfaces had, on average, about a 10% higher BIC than machined surfaces.

Osteopromotion Capacity of Bovine Cortical Membranes in Critical Defects of Rat Calvaria: Histological and Immunohistochemical Analysis.

Membranes that aid the guided bone regeneration (GBR) process have been the subject of studies of compatible biomaterials that contribute to this repair process. The present study compared different membranes used in critical-size defects of rat calvaria by assessing GBR as well as histological, histomorphometric, and immunohistochemical reactions. Forty-eight male albino Wistar rats were randomly allocated into four groups (n = 12 each), namely, C: membrane-free control group (only blood clot, negative control group); BG: porcine collagen membrane group (Bio-Gide®, positive control group); GD: bovine cortical membrane group (first experimental group); and GDF: thicker bovine cortical membrane group (second experimental group). Rats were euthanized at 30 and 60 days postoperatively. Quantitative data from the histometric analysis were submitted to two-way ANOVA and Tukey's posttest when p < 0.05. Histomorphometric results of the thicker bovine cortical membrane at 30 and 60 days were promising, showing improved new bone formation values (p < 0.05), and the CD group presented similar results in both analysis periods, being surpassed only by the GDF group (p < 0.05). The immunohistochemical results were associated with the histomorphometric data. A less-thick membrane also assisted in GBR. All membranes promoted GBR, especially the positive control and experimental groups.

Withaferin-A Protects the Nigral Dopamine Neuron and Recovers Motor Activity in Aged Rats

Withaferin-A (WA) was evaluated for its neuroprotective efficacy on the dopamine (DA) neurons of the substantia nigra (SN) and striatum (ST) in aged rats. Wistar albino rats were divided into group I, young (3 months old); group II, aged (24 months old); group III, aged rats supplemented with WA (50 mg/kg bodyweight once per day for 30 days), and group IV, young rats supplemented with WA (50 mg/kg bodyweight). At the end of the experiment period, the animals were subjected to various motor behavior analyses, and were sacrificed by transcardial perfusion. The brains were dissected out and subjected to various analyses, including histological, histomorphometrical, and immunolocalization of the tyrosine hydroxylase (TH) enzyme. The data of rotarod analysis (p < 0.001) showed a significant motor impairment in aged rats (number of falls 10.2 ± 0.86) and reduction in retention time (31.23 ± 2.56 s) compared to young controls (2.41 ± 0.35 and 84.05 ± 5.15 s). The stride length was significantly reduced (p < 0.001) in aged rats (4.21 ± 0.57 and 4.38 ± 0.61 cm) when compared to young control rats (6.98 ± 0.25 and 7.13 ± 0.70 cm). The histomorphometric data of the aged animals showed a significant reduction in the neuronal diameter (p < 0.001), density (p < 0.001), and volume (p < 0.001) in the SN of aged rats when compared to young rats. Immunohistology demonstrated a marked reduction in the levels of TH enzyme in both the SN and ST of aged animals when compared to young rats. Both structural and functional impairments were reversed in the aged animals after the supplementation of WA (p < 0.001). The present study clearly indicates that WA attenuates the ageing-mediated motor degenerative changes in the SN and ST of aged rats and ascertains its neuroprotective potential.