Limited Bone Loss Research Articles

Influence of metronidazole loaded into silver nanoparticle microcapsules on efficacy of alginate gel in correction of structural and functional disorders of dental support apparatus in rats with periodontitis

Objective: To evaluate the effect of metronidazole loaded into silver impregnated alginate microcapsules on the structural and functional disorders of the dental support apparatus in periodontitis. Material and methods. The studies were carried out on 30 white male rats randomly divided into two groups. Comparison group — 15 animals with an experimental model of periodontitis, which underwent applications of a gel containing microcapsules without additional loading with active substances. The experimental group included 15 animals with periodontitis, which were subjected to applications of gel with microcapsules containing metronidazole on inflamed gums. To assess the morphological changes in the supporting apparatus of the tooth, the mandible was taken with subsequent histological examination. Results. Results. Application of a gel containing microcapsules with silver nanoparticles loaded with metronidazole on the gums of animals with periodontitis leads to partial reduction of structural disorders. Thus, local disorganization of the fibers of the circular ligament of the tooth in the experimental group was observed only 5 cases, signs of limited bone loss — in 2 cases out of 15. In the comparison group, all 15 animals showed bone resorption and in 13 of 15 cases there was diffuse fiber alteration throughout the circumferential ligament of the tooth. Conclusion. The inclusion of alginate microcapsules with silver nanoparticles metronidazole leads to a significant decrease in destructive processes occurring in the near-tooth tissues during periodontitis.

Schnurri-3 inhibition suppresses bone and joint damage in models of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease that leads to systemic and articular bone loss by activating bone resorption and suppressing bone formation. Despite current therapeutic agents, inflammation-induced bone loss in RA continues to be a significant clinical problem due to joint deformity and lack of articular and systemic bone repair. Here, we identify the suppressor of bone formation, Schnurri-3 (SHN3), as a potential target to prevent bone loss in RA. SHN3 expression in osteoblast-lineage cells is induced by proinflammatory cytokines. Germline deletion or conditional deletion of Shn3 in osteoblasts limits articular bone erosion and systemic bone loss in mouse models of RA. Similarly, silencing of SHN3 expression in these RA models using systemic delivery of a bone-targeting recombinant adenoassociated virus protects against inflammation-induced bone loss. In osteoblasts, TNF activates SHN3 via ERK MAPK-mediated phosphorylation and, in turn, phosphorylated SHN3 inhibits WNT/β-catenin signaling and up-regulates RANKL expression. Accordingly, knock-in of a mutation in Shn3 that fails to bind ERK MAPK promotes bone formation in mice overexpressing human TNF due to augmented WNT/β-catenin signaling. Remarkably, Shn3-deficient osteoblasts are not only resistant to TNF-induced suppression of osteogenesis, but also down-regulate osteoclast development. Collectively, these findings demonstrate SHN3 inhibition as a promising approach to limit bone loss and promote bone repair in RA.

Anterior shoulder instability: comparison between Latarjet open procedure and arthroscopic capsuloplasty.

Latarjet surgery and capsuloplasty are both valid alternatives for the treatment of anterior shoulder instability with limited glenoid bone loss, although in literature there is extensive discussion on it. The purpose of this study was to compare the outcomes of these procedures in patients with similar lesions. Between January 2000 to October 2020, 59 nonconsecutive patients suffering from anterior shoulder instability were treated, 33 had arthroscopic capsuloplasty (Group 1) and 26 had open Latarjet procedure (Group 2). The Group 1 was composed by 12% of female and 88% of males with the mean age at surgery 25.6 +/- 9.07 (15-49 years). In the Group 2, the 100% of patients were males with mean age 32.42 +/- 10.74 (16-56).Rowe Score, UCLA score and WOSI score were used to test patients. Only UCLA (average was 22.18 ± 6.13 for the Capsuloplasty and 26.76 ± 6.57 in the Latarjet, p = 0.01) and ROWE scores (average was 70.15 ± 24.75 in Latarjet and 50.15 ± 24.70 in Capsuloplasty, p = 0.002) showed a statistically significant difference between the two procedures, while the WOSI (mean results of Latarjet 0.31 ± 0.16 against 0.24 ± 0.09 of the capsuloplasty, p = 0.069) there was no significant difference between the two groups in question. Apparently, the Latarjet surgery is better in terms of instability recurrence compared to capsuloplasty but has higher rate of shoulder joint osteoarthtritis. However, there are no significant differences that could decree which procedure is better. (www.actabiomedica.it).

A Multi-Centre Randomized Controlled Trial Comparing Connective Tissue Graft with Collagen Matrix to Increase Buccal Soft Tissue Thickness: A Cone-Beam CT Analysis.

(1) Aim: a cross-linked porcine-derived collagen matrix (CMX) has been developed for soft tissue augmentation. Although this grafting material does not require a second surgical site, recent findings have indicated deeper pockets, more marginal bone loss and more midfacial recession in the short term when compared to connective tissue graft (CTG). Hence, the aim of the present study was to evaluate the safety of CMX based on buccal bone loss over a one-year period. (2) Methods: Patients who were missing a single tooth in the anterior maxilla were included, in whom the failing tooth had been removed at least 3 months prior and who presented a horizontal mucosa defect. All sites had a bucco-palatal bone dimension of at least 6 mm as assessed on Cone-Beam Computed Tomography (CBCT) to ensure complete embedding of an implant by bone. All patients received a single implant and an immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX) to increase buccal soft tissue thickness. All surgeries were performed by means of full thickness mucoperiosteal flap elevation, placing CTG and CMX in contact with the buccal bone wall. Safety was assessed by evaluating the impact of CTG and CMX on buccal bone loss over a one-year period using superimposed CBCT scans. (3) Results: thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48) and 51 (control: 25; test: 26) could be analyzed for buccal bone loss. At 1 mm apical to the implant-abutment interface (IAI), most horizontal resorption was found pointing to 0.44 mm in the control group and 0.59 mm in the test group. The difference of 0.14 mm (95% CI: -0.17-0.46) was not statistically significant (p = 0.366). At 3 mm and 5 mm apical to the IAI, the difference between the groups was 0.18 mm (95% CI: -0.05-0.40; p = 0.128) and 0.02 mm (95% CI: -0.24-0.28; p = 0.899), respectively. Vertical buccal bone loss amounted to 1.12 mm in the control group and 1.14 mm in the test group. The difference of 0.02 mm (95% CI: -0.53-0.49) was not statistically significant (p = 0.926). (4) Conclusions: In the short term, soft tissue augmentation with CTG or CMX results in limited buccal bone loss. CMX is a safe alternative to CTG. Longer follow-up is needed to assess the impact of soft tissue augmentation on buccal bone.

The use of a standard-length conical tapered stem in hip revision arthroplasty to address Paprosky type I–II femoral defects: a prospective study of 87 patients

IntroductionLow-grade femoral defects in revision total hip arthroplasty (rTHA) might be preferably treated with a primary implant. Almost no previous study reported the use of standard-length conical tapered (SLCT) stems in these cases. We analyzed a series of cases using a SLCT stem in rTHA with Paprosky type I–II femoral defects. The purpose of the study was to determine clinical and radiographic outcomes in this series of rTHA.Materials and methodsWe prospectively followed 87 patients undergoing a femoral component rTHA: 53 Paprosky type I and 34 type II femoral defects. Patient-reported measures (Oxford Hip Score, EQ-5D, VAS pain during rest and activity) were administered at baseline, 1 and 2 years post-operatively. Radiographic subsidence overtime was scored. Kaplan–Meier curves were used to evaluate the subsidence over time, the complication-free survival, and the implant survivorship with reoperation and stem revision as endpoints.ResultsThe mean follow-up was 72.5 (SD ± 23.9) months. All PROMs significatively improved over time. The average subsidence was 2.8 (SD ± 3.2), 3.6 (SD ± 4.4), and 4.0 (SD ± 4.9) mm at 4, 12, and 24 months respectively. 6 stems had subsidence > 10 mm. The survival without complication was 0.85 (95% CI 0.94–0.77), while the implant survival without reoperation was 0.83 (95% CI 0.95–0.72). The overall stem survival rate was 93.7% (95% CI 0.91–0.97) at 2 years.ConclusionThe use of a SLCT stem in rTHA with Paprosky type I–II femoral defects demonstrated good survival with low subsidence rates during the first 2 years after surgery. Surgeons should consider the use of this primary prosthesis as a potential treatment during stem revision in cases with limited femoral bone loss.

Tissue-Level Laser-Lok Implants Placed with a Flapless Technique: A 4-Year Clinical Study.

The present study aims to analyze the use of Laser-Lok microtextured neck implants placed with a transmucosal surgical approach. The marginal bone level (MBL) and periodontal parameters were evaluated in a cohort prospective 4-year clinical study. A total of 41 implants were placed in 36 healthy consecutive patients (16 males, 20 females, mean age 60 ± 9 years). Tapered tissue level implants, characterized by a 2.0 mm laser-microtextured neck, were used with a flapless approach. Customized abutments and provisional resin crowns were positioned. Definitive metal-ceramic crowns were cemented approximately 4 months after insertion. Periapical radiographs were taken after 1, 3, 6, 12, 36 and 48 months from implant placement to evaluate MBL. Gingival thickness (thin/thick), plaque score (PS) and bleeding on probing (BoP) were evaluated. After 48 months, all implants were safe from complications. No complications, peri-implantitis, early implant failures or mucositis occurred. The survival rate was 100%. Mean MBL during the follow-up was -0.15 ± 0.18 at T1, -0.29 ± 0.29 at T3, -0.45 ± 0.37 at T6, -0.53 ± 0.45 at T12, -1.06 ± 1.13 at T 36 and -1.10 ± 0.89 at T 48. Implants placed 2-3 months after tooth extraction revealed lower MBL variation when compared to those placed immediately (in fresh extraction sockets) or in completely healed ridges (delayed group). Narrower diameter implants (3.8 mm) showed significantly higher MBL variation when compared to 4.6 diameter implants. Multilevel analysis at T48 revealed that among all the evaluated variables, implant diameter was the factor mostly associated with MBL modifications (p = 0.027). This 4-year clinical study supports the use of Laser-Lok implants placed at tissue level with a flapless approach. A limited bone loss during the 48-month follow-up was observed. Periodontal parameters were stable with no sign of inflammation or soft tissue alteration. The use of Laser-Lok implants with transmucosal surgery represents a suitable technique with a minimally invasive approach.

Monobloc press-fit cups with large-diameter bearings are safe in revision total hip arthroplasty.

Instability is a major cause of failure of revision total hip arthroplasty (THA) which can be avoided with the use of monobloc press-fit cups with large diameter heads (LDH). This consecutive case series analyses whether LDH monobloc components are a safe and clinically beneficial option for revision THA. This consecutive case series includes 47 revision THA with LDH monobloc acetabular cup. Acetabular bone defects were Paprosky type I (42), type IIA (2) and type IIC (3). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Forgotten Joint Score (FJS) and the Patient's Joint Perception (PJP) scores were analysed and a radiographic evaluation for signs of implant dysfunction was performed. After a mean follow-up of 4.5 years, there were 5 (10.6%) acetabular cup re-revisions: 2 loss of primary fixation and 3 instabilities. Implant survivorship at 4-years was 89.4% (95% CI: 89.3 to 89.5). Recurrent hip dislocation was reported in 1 patient (2.1%) and remains under conservative treatment. The mean WOMAC and FJS were 19.5 (16.8; 0.0 to 58.3) and 57.3 (28.9; 6.3 to 100.0), respectively. Regarding the PJP, 3 (8.8%) patients perceived their hip as natural, 8 (23.5%) as an artificial joint with no restriction, 14 (41.2%) with minor restriction and 9 (26.5%) with major restriction. In cases of revision THA with limited bone loss, press-fit primary fixation with LDH monobloc acetabular components are valuable options that offer excellent mid-term out-comes with low re-revision and joint instability rates.

Dynamic Anterior Stabilization Using Transosseous Bone Tunnel Technique With the Adjustable Loop Length Cortical Button Incorporating High-Strength Suture Augmentation for Recurrent Shoulder Instability

Dynamic anterior stabilization using the long head of the biceps tendon is a recently described technique in the management of recurrent shoulder dislocation with subcritical bone loss. This technique involves the transfer of the long head of the biceps to the glenoid, providing sling and hammock effect. The long head of the biceps (LHB) tendon fixation can be accomplished with a variety of implants. We present a modified fixation technique of LHB tendon using transosseous bone tunnel with the adjustable loop length cortical button, incorporating high-strength suture augmentation device in a patient with recurrent glenohumeral instability with limited glenoid bone loss and an engaging Hill-Sachs defect in the humeral head.

Limited marginal bone loss in implant-supported fixed full-arch rehabilitations after 5 years of follow-up.

The aim of the present study was to evaluate the 5-year results in terms of marginal bone level (MBL) around implants supporting fixed full-arch metal-ceramic restorations in a series of cases of patients who had lost their teeth in that dental arch because of severe periodontal disease. A retrospective cohort study was designed to evaluate the 5-year MBL results of OsseoSpeed™ Astra Tech TX implants with internal tapered conical connection. Age, gender, bone substratum, smoking habits, history of periodontitis, and prosthetic features were recorded. Mixed linear model was used to determine the influence of the different variables on MBL. In this series, a total of 160 implants placed in 19 patients were evaluated. No implant failure was reported during the 5 years of follow-up. Only 14 (8.75%) implants had more than 2 mm of MBL. Abutment height, F(3,142)=6.917, p < .001, and implant diameter, F(1,141)=15.059, p < .001, were determined to be statistically associated with MBL. No other effect was significant. Pairwise comparisons showed that MBL was larger for abutment height=1 (MBL=-0.987, SE=0.186) compared with the remaining heights [-0.335 (0.171), -0.169 (0.192) and -0.247 (0.267), 2, 4 and 6 mm, respectively]. MBL was larger for narrow (-0.510, SE=0.169) than for wide implants (-0.364, SE=0.190). The current study demonstrates that the vast majority of internal conical connection implants supporting fixed full-arch metal-ceramic restorations do not suffer from relevant MBL after 5 years in function. Particularly, those implants with transmucosal abutments longer than 2 mm show less than 0.5 mm from the implant shoulder to the marginal bone.

Biological Activity of Copaiba in Damage to the Alveolar Bone in a Model of Periodontitis Induced in Rats.

Several studies have investigated the effects of natural products in the treatment of diseases. Traditional Amazonian populations commonly use copaiba due to its well-known anti-inflammatory, antibacterial, and healing properties. In this study, we aimed to investigate the effects of systemic administration of copaiba oleoresin (Copaifera reticulata Ducke) on ligature-induced periodontitis in rats. To do so, 21 adult rats were divided into three groups (n = 7 each): a control group, ligature-induced periodontitis group, and ligature-induced periodontitis group treated with copaiba oleoresin (200 mg/kg/day). The ligature remained from day 0 to 14, and the copaiba oleoresin was administered via oral gavage during the last seven days. On day 14, the animals were euthanized, and mandibles were collected for histopathological evaluation and microcomputed tomography analysis. Our data showed that the administration of copaiba considerably reduced the inflammatory profile. Moreover, copaiba oleoresin limited alveolar bone loss, increased trabecular thickness and bone-to-tissue volume ratio, and decreased the number of trabeculae compared with those of the untreated experimental periodontitis group. Our findings provide pioneering evidence that supports the potential of copaiba oleoresin in reducing periodontitis-induced alveolar bone damage in rats.

Single-Tooth Immediate Placement and Provisionalization with Subcrestally Angulated Implants in Sites with Hard and Soft Tissue Facial Dehiscence in the Esthetic Zone: An Observational Study with 2 to 5 Years of Follow-up.

This study evaluated the survival and esthetic outcome of flapless postextraction placement and provisionalization in compromised single tooth sites in the esthetic area. Ten patients were included in the study, and 10 subcrestally angled (SCA) tapered implants were placed. Only maxillary central or lateral incisors and canines were included. Implants showed 100% survival rate, a limited mean marginal bone loss of 0.43 ± 0.23 mm, and a mean gain in coronal gingival level of 1.6 ± 1.17 mm; the mean vertical alveolar bone gain was 4.0 ± 1.5 mm, and the average pink esthetic score was 12.5 at a mean 3.5-year follow-up (range: 2 to 5 years). These results show that immediate replacement and restoration of a tooth with compromised hard and soft tissue condition in the esthetic area, with simultaneous use of connective tissue, bone graft, and membrane, could be a valid alternative to a more complex staged approach.

Protective Effect on Bone of Nacre Supplementation in Ovariectomized Rats

ABSTRACTNacre has emerged as a beneficial natural product for bone cells and tissues, but its effect was only studied by gavage in the ovariectomized mouse model. We sought to assess the antiosteoporotic effect of nacre through a nutritional supplementation in the ovariectomized rat model. Sixteen‐week‐old female Wistar rats were either Sham‐operated or bilateral ovariectomized (OVX) and then fed with standard diet (Sham and OVX groups) or standard diet supplemented with either 0.25% CaCO3 or nacre (OVX CaCO3 and OVX Nacre group, respectively) for 28 days (n = 10/group). The bone microarchitecture was assessed at appendicular and axial bones by micro‐computed tomography (μCT). Histomorphometric analysis was performed to determine cellular and dynamic bone parameters. Bone metabolism was also evaluated by biochemical markers and gene expression levels. Nacre‐based diet prevented the OVX‐induced bone loss better than that of the CaCO3 supplement, given the significant changes in trabecular bone volume fraction (BV/TV) both at the femoral distal metaphysis (difference, 35%; p = 0.004) and at the second lumbar spine (difference, 11%; p = 0.01). Trabecular osteoclast surfaces (Oc.S/BS) were also 1.5‐fold lower at the tibial proximal metaphysis in OVX Nacre group compared with OVX CaCO3 group (p = 0.02). By principal component analysis (PCA), OVX Nacre group formed a cluster away from OVX group and with a trend closest to Sham group. These data were consistent with biological measurements demonstrating a positive profile related to nacre supplementation, which blunted an increase in serum CTX level and enhanced serum P1NP secretion 14 days post‐OVX compared with CaCO3 supplementation. Bmp2 mRNA expression in OVX Nacre group was +1.76‐fold (p = 0.004) and +1.30‐fold (p = 0.20) compared with OVX and OVX CaCO3 groups, respectively. We conclude that supplementation with nacre could effectively limit bone loss induced by estrogen deficiency just after OVX in rats by modulating the negative imbalance of bone turnover. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

What is the failure rate of constrained liners in complex revision total hip arthroplasty?

Recurrent hip dislocation after multiple revision total hip arthroplasty is a severe complication. Therefore, constrained acetabular liners (CL) have been used during salvage procedures. We report our experience of constrained liners in a re-revision setting with focus on re-dislocation. We also evaluated acetabular and femoral bone loss as potential risk factor. Between January 2013 and December 2016, 65 patients were treated in a single institution for revision and re-revision hip arthroplasty using CL. The indication for using a CL was a high risk of re-redislocation after multiple recurrent hip dislocation including failed Dual Mobility Cups (DMC). Compromising soft tissue defects as well as severe bone defect were therefore regarded as high risks. Thirty-eight patients (77.6%) underwent a minimum of three surgical procedures before the index revision procedure. Sixteen patients (24.6%) were excluded as they were lost to follow-up, expired before minimum follow-up or refused study participation, leaving 49 patients in the analysis (75.4%). The mean follow-up was 62months (44-74; SD = 7.7). We assessed the following potential risk factors for revision or dislocation: type of surgical setting (septic/aseptic), BMI, cup inclination angle, size of liner used and acetabular and femoral bone loss according to Paprosky classification. The primary endpoints were dislocation or repeat revision for any reason. Of the 49 patients, we found an overall re-revision rate of 40.8% (20/49) and a dislocation rate of 30.6% (15/49). There were no significant differences among the surgical re-revision rate or dislocation rate as a factor of patient characteristics. In terms of bone loss, there was a trend towards higher revision rates for increasing acetabular and femoral bone loss, but without statistical significance. We found the use of a constrained liner in a re-revision setting still bears a high risk of re-revision and re-dislocation. Therefore we restrained from using constrained liners in favour of Dual mobility cups. In this study there was no significant higher dislocation rate in the subgroup of periprosthetic infection. Furthermore the rigid design of a constrained liner bears the known risk of structural failure of acetabular reconstruction implants. Severe acetabular or femoral bone defects seem to have an impact on the revision rate, but not on the dislocation rate with regards to the restored offset and center of the hip. Results have to be taken into context such that the study population inherently has a predisposition for poorer outcomes. Indications should be strongly filtered for patients at high risk for recurrent hip joint dislocation including failed DMCs with only limited bone loss and moderate soft tissue defects. Our modification to the existing classification with a high inter and intraobserver reliability will make future studies more comparable regarding revisions and bone stock loss. Still furtherresearch using objective and reproducible parameters is needed to better analyze data especially in the background of complex revision hip arthroplasty.

Four-implant-supported overdenture treatment in the maxilla. Part I: A randomized controlled split mouth trial assessing the effect of microthreads and abutment connection type on 4 years peri-implant health.

According to literature, peri-implant bone loss is minimized on implants with microthreaded neck design and internal type of abutment connection. However, most clinical studies may be biased due to confounding factors. This nonblinded RCT assessed the effect of implant neck (microthreaded vs non-microthreaded) as well as the type of abutment connection (internal conical vs external flat-to-flat) on peri-implant bone stability and peri-implant health after at least 36 months. Twenty-five patients were treated with a maxillary implant-supported bar-retained overdenture on four different implant types: internal connection with microthreads (I-MT), internal connection without microthreads (I-NMT), external connection with microthreads (E-MT), and external connection without microthreads (E-NMT). To control confounding factors, all other design features were similar. A linear mixed-model analysis or mixed-model logistic regression analysis was used to determine the effect of implant type on bone level, probing pocket depth, bleeding on probing, and plaque. Four out of 98 implants (4.1%) placed in 25 patients failed during provisionalization and were replaced. Mean overall bone loss after 6months was 0.39 mm (SD 0.62, range 0.00-3.48) with limited additional bone loss of 0.04 mm (SD 0.54, range -1.80-1.63) after at least 3 years. Microthreads or connection type had no effect on the bone level, probing pocket depth, bleeding on probing, nor plaque. With 96% of implant survival, the maxillary overdenture supported with a bar on four implants yield a predictable outcome and the implant-abutment connection type (internal vs external) and implant neck design (microthreaded vs non-microthreaded) have no influence on peri-implant bone remodeling after initial bone remodeling nor up to 4 years of function. Peri-implant bone levels are within international success standards and peri-implant health is indicative of absence of peri-implantitis.

Biomaterials and osteoradionecrosis of the jaw: Review of the literature according to the SWiM methodology

ObjectivesTo systematically present and interpret the current literature on research and treatment perspectives for mandibular osteoradionecrosis (mORN) in the field of biomaterials. Material and methodsA systematic review of the literature using the “Synthesis without meta-analysis” (SWiM) methodology was performed on PubMed, Embase and Cochrane, focusing on the implantation of synthetic biomaterials for bone reconstruction in mORN in humans and/or animal models. The primary endpoints were the composition, efficacy on mORN and tolerance of the implanted synthetic biomaterials. ResultsForty-seven references were obtained and evaluated in full-text by two assessors. Ten (8 in humans and 2 in animal models) met the eligibility criteria and were included for analysis. Materials most often comprised support plates or metal mesh (5 of 10 cases) in combination with grafts or synthetic materials (phosphocalcic ceramics, glutaraldehyde). Other ceramic/polymer composites were also implanted. In half of the selected reports, active compounds (molecules, growth factors, lysates) and/or cells were associated with the reconstruction material. The number of articles referring to implantation of biomaterials for the treatment of mORN was small, and the properties of the implanted biomaterials were generally poorly described, thus limiting a thorough understanding of their role. ConclusionIn preventing the morbidity associated with some reconstructive surgeries, basic research has benefitted from recent advances in tissue engineering and biomaterials to repair limited bone loss.

The Potential Repurposing Effect 4‐Aminopyridine in Nerve and Muscle Injury‐induced Bone Loss

Muscle injuries are one of the most common injuries occurring in physical and sporting activities, and account for 10-55% of all injuries. Peripheral nerve injury (PNI) itself accounts for 3-5% of all injuries in trauma patients, and muscle injuries can be concurrent with PNI because of their close proximity. Importantly, the peripheral nervous system is critically involved in bone metabolism, bone mineralization, and bone remodeling, and PNI results in substantial bone loss. While first aid for muscle injuries follows the conservative RICE (Rest, Ice, Compression and Elevation) principle, there is no medical treatment available after the acute phase except anti-inflammatory medications and rehabilitation. The poor healing process in damaged muscle, prolonged muscle disuse, and the lack of therapeutic strategies affect the performance of daily activities and predispose to further risk of muscle injury and bone loss. Therefore, there is an unmet need to develop therapeutic strategies that can help the recovery of damaged muscle and nerve, and limit bone loss. Recently we demonstrated the potential repurposing effect of 4-aminopyridine (4-AP), a potassium channel blocker, on neurogenic muscle atrophy and functional recovery after PNI in mice. However, it is unknown whether these beneficial effects of 4-AP are present in traumatic muscle injury and muscle injury-induced bone loss. This study was thus designed to evaluate the potential therapeutic effect of 4-AP in traumatic muscle healing and PNI-induced bone loss. Standardized crush injury was performed on right sciatic nerve, biceps femoris (BF) muscle (innervated by sciatic nerve), and quadriceps femoris (QF) muscle (innervated by femoral nerve) of adult male mice (6 animals/group). Post-surgical animals were randomly assigned to normal saline and 4-AP. 4-AP (40 µg, intraperitoneal) was given daily for 21 days, and the functional recovery after injury was assessed by sciatic function index (SFI), sensation by von Frey test (VFT), and grip strength test. After 21 days, the muscles at the injury/peri-injury site were processed for histomorphometry and tibial bone density was analyzed using DEXA scanning. We found that 4-AP significantly enhanced SFI, VFT, and hind limb paw grip strength from post-injury day 7, improved BF muscle morphology, cross-sectional area, and minimum ferret diameter, and totally reversed trauma-induced muscle fiber type composition changes (type-1 vs. type-2). 4-AP-induced muscle effects were also associated with a significantly increased number of regenerating stem cells (Pax7+) and proliferating cells (Ki67+) compared with saline group. Of note, 4-AP-induced muscle effects were either less pronounced or nonsignificant in QF muscle. Most importantly, 4-AP treatment significantly reduced PNI-induced bone loss by enhancing bone mineral density and bone mineral content. In conclusion, these interesting findings, for the first time, demonstrate the potential therapeutic effect of 4-AP on the recovery of traumatic muscle and bone loss after mixed muscle and nerve injury.

Relugolix - new treatment for uterine fibroid-related heavy bleeding.

Limited pharmacological treatments for uterine leiomyomata (fibroids) are available. Now, two phase III trials lasting 24 weeks showed marked reduction in leiomyoma-related heavy menstrual bleeding with relugolix, a new orally active gonadotropin-releasing hormone antagonist with add-back oestrogen (to limit bone loss) and progestin (to limit endometrial changes from unopposed oestrogen).

Prospective randomized clinical trial evaluating the effects of two different implant collar designs on peri-implant healing and functional osseointegration after 25 years.

Evaluate the effects of two different machined-collar lengths and designs on peri-implant healing. An implant with a microtextured surface and 3.6mm-long internal-connection machined collar was compared to two implants that had an identical 1.2mm-long external-connection machined collar, but one had the microtextured surface while the other's was machined. Participants received the three implants, with microgap at the crest, alternately at five sites between mental foramen, and a full-arch prosthesis. Peri-implant bone levels were measured after 23 to 26years of function. Keratinized tissue height, plaque, probing depth, bleeding, and purulence were also evaluated. Descriptive and mixed models for repeated\measures analyses were used, with Bonferroni correction for pairwise comparisons. Twenty-two participants (110 implants) were evaluated at the 25-year examination. Microtextured implants with the longer machined collar had significantly greater mean marginal bone loss (-1.77mm±0.18, mean±SE) than machined (-0.85mm±0.18, p < .001) and microtextured (-1.00±0.18mm, p < .001) implants with the shorter machined collar. Keratinized tissue height was greater for internal-connection (0.74mm±0.10) versus external-connection (0.51±0.08, p= 0.01) microtextured implants. No differences were observed for plaque (p=0.78), probing depth (p=0.42), bleeding (p = 0.07), and purulence (p=1.00). Implant survival rate was 99%. Implants with the 1.2mm machined collar limited bone loss to 1mm, while those with the longer machined collar showed>1.5mm loss after 25years of function with microgap at the crest. Internal-connection design and fixture surface microtexturing did not result in greater bone preservation. ClinicalTrials.gov Identifier: NCT03862482.

Feeling the warmth in your bones

Warm ambient temperatures induce gut microbiota to release factors that limit bone loss.

Lateral ridge augmentation in the posterior part of the mandible with an autogenous bone block graft harvested from the ascending mandibular ramus. A 10-year retrospective study

PurposeThe objective of the present retrospective study was to assess the long-term implant treatment outcome and patient satisfaction after lateral ridge augmentation in the posterior mandible with autogenous bone block graft harvested from the ascending mandibular ramus. Materials and methodsSeventy-four lateral ridge augmentation procedures in the posterior mandible with an autogenous bone block graft harvested from the ascending mandibular ramus and delayed placement of 87 implants was conducted in 46 consecutive patients from 2002–2006. Records and radiographs were retrospectively analyzed. Twenty-four patients responded to a 10-years follow-up examination including 39 lateral ridge augmentation procedures and 48 implants. Survival of suprastructures and implants, peri-implant marginal bone loss, patient perception and professional evaluation of the final implant treatment was assessed after 10 years. ResultsThe 10-year survival of suprastructures and implants was 100% as all the implants and suprastructures were present with limited peri-implant marginal bone loss. The patients were highly satisfied with the esthetic and implant treatment outcome. ConclusionLateral ridge augmentation in the posterior mandible with autogenous bone block graft from the ascending mandibular ramus is characterized by high long-term implant survival rate and patient satisfaction.