Bone Reduction Research Articles

LASER-ASSISTED CROWN LENGTHENING: CLINICAL EFFICACY AND ADVANTAGES OVER CONVENTIONAL TECHNIQUES (SYSTEMATIC REVIEW)

Introduction: Crown lengthening is a widely recognized dental procedure with both aesthetic and functional purposes. It involves the reduction of periodontal hard and soft tissues to obtain supracrestal tooth length, resulting in longer clinical crowns and adequate supracrestal tissue attachment. Laser therapy has emerged as a promising alternative that is currently developing in the field of periodontics and offers several advantages. This review aims to synthesize the current research on the clinical efficacy of laser-assisted crown lengthening procedures and highlight their advantages over conventional methods. Review: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted in electronic databases PubMed, Scopus, Embase, and Google Scholar for human studies published from 2017 to April 2023. Out of 213 identified and screened studies, three original articles were included in the analysis. Two clinical trial studies used Er,Cr:YSGG while one study used Er:YAG for crown lengthening procedures involving gingiva and alveolar bone reduction, with a 3-month follow-up period. Compared to conventional crown lengthening, the laser-assisted approach showed comparable increases in clinical crown length. However, the laser-assisted group demonstrated better gingival margin stability, improved soft tissue healing, and minimal damage to adjacent tissues. Furthermore, there was a statistically significant lower bacterial load and less post-surgery pain with laser-assisted crown lengthening compared to the conventional method. Conclusion: In cases where both gingival and bone reduction are required, laser-assisted crown lengthening using Er,Cr:YSGG and Er:YAG can be considered a minimally invasive alternative with several advantages over conventional procedures.

Nerve growth factor receptor limits inflammation to promote remodeling and repair of osteoarthritic joints

Osteoarthritis (OA) is a painful, incurable disease affecting over 500 million people. Recent clinical trials of the nerve growth factor (NGF) inhibitors in OA patients have suggested adverse effects of NGF inhibition on joint structure. Here we report that nerve growth factor receptor (NGFR) is upregulated in skeletal cells during OA and plays an essential role in the remodeling and repair of osteoarthritic joints. Specifically, NGFR is expressed in osteochondral cells but not in skeletal progenitor cells and induced by TNFα to attenuate NF-κB activation, maintaining proper BMP-SMAD1 signaling and suppressing RANKL expression in mice. NGFR deficiency hyper-activates NF-κB in murine osteoarthritic joints, which impairs bone formation and enhances bone resorption as exemplified by a reduction in subchondral bone and osteophytes. In human OA cartilage, NGFR is also negatively associated with NF-κB activation. Together, this study suggests a role of NGFR in limiting inflammation for repair of diseased skeletal tissues.

Morphological and Immunohistochemical Characterization of Bone Structure and Cell–Cell Communication in a Rat Osteoporosis Model

Bone remodeling is essential for maintaining bone health. The imbalance between bone formation and bone resorption leads to bone diseases such as osteoporosis. Connexin43 (Cx43) is a gap junction molecule that plays an important role in bone homeostasis. The present study investigates the morphological characteristics of bone trabeculae and the distribution of Cx43 in bone cells using osteoporotic rat models to explore the relationship between osteoporosis and bone remodeling. Female Sprague–Dawley rats were divided into three groups: sham, ovarectomy with food deprivation (OVX+diet), and ovarectomy with steroid administration (OVX+steroid) for 3 and 12 months to induce osteoporosis. The lumbar vertebrae were processed for histomorphometric and immunohistochemical evaluation of the trabeculae and the distribution of Cx43 in bone cells. The data showed a significant reduction in trabecular bone in both osteoporotic groups. After 12 months, the OVX+diet treatment resulted in reduced mineralization and an increase in unmineralized bone. The percentage of alkaline phosphatase-positive areas in the OVX+diet vertebrae was lower at 12 months compared to the sham group. A significant increase in tartrate-resistant acid phosphatase (TRAP) positive osteoclasts was observed in the OVX+diet group. Both osteoporotic groups showed a decrease in Cx43-positive osteoblasts areas. An increase in the number of osteoclasts positive for Cx43 was detected in the OVX+diet group. The changes in Cx43 distribution in bone cells, together with trabecular mineralization, suggest that Cx43 may play a role in the progression of osteoporosis and could be a valuable target to improve bone remodeling.

Fossils document evolutionary changes of jaw joint to mammalian middle ear.

The dual jaw joint of Morganucodon1,2 consists of the dentary-squamosal joint laterally and the articular-quadrate one medially. The articular-quadrate joint and its associated post-dentary bones constitute the precursor of the mammalian middle ear. Fossils documenting the transition from such a precursor to the mammalian middle ear are poor, resulting in inconsistent interpretations of this hallmark apparatus in the earliest stage of mammaliaform evolution1-5. Here we report mandibular middle ears from two Jurassic mammaliaforms: a new morganucodontan-like species and a pseudotribosphenic shuotheriid species6. The morganucodontan-like species shows many previously unknown post-dentary bone morphologies1,2 and exhibits features that suggest a loss of load-bearing function in its articular-quadrate joint. The middle ear of the shuotheriid approaches the mammalian condition in that it has features that are suitable for an exclusively auditory function, although the post-dentary bones are still attached to the dentary. With size reduction of the jaw-joint bones, the quadrate shifts medially at different degrees in relation to the articular in the two mammaliaforms. These changes provide evidence of a gradual loss of load-bearing function in the articular-quadrate jaw joint-a prerequisite for the detachment of the post-dentary bones from the dentary7-12 and the eventual breakdown of the Meckel's cartilage13-15 during the evolution of mammaliaforms.

Digitally planned surgical crown lengthening: a novel bone reduction strategy to correct a gummy smile.

This report describes the bone reduction guide which was digitally obtained to improve diagnosis, treatment outcome and follow-up. Treatment of gingival smiles due to altered passive eruption should include interdisciplinary planning and smile design to facilitate the prediction of treatment outcome. Crown lengthening surgery can be supported by digital tools to improve surgical planning and follow-up. A 30-year-old female patient was referred to a private dental clinic seeking solutions for her gingival smile. Based on the anatomical crown length, a smile design was created, and the patient was presented with a simulated smile before treatment. In the surgical phase, a full-thickness flap was raised in the upper jaw to achieve the desired outcome. Using cone-beam computed tomography to determine cementoenamel junction for smile design and treatment planning brings many benefits. Patients and clinicians can foresee treatment results. From there, appropriate changes can be made. The bone reduction guide is designed to rest on the bone to help the clinician cut the bone accurately and thoroughly follow the established plan.

Experimental research based on robot-assisted surgery: Lower limb fracture reduction surgery planning navigation system.

Lower extremity fracture reduction surgery is a key step in the treatment of lower extremity fractures. How to ensure high precision of fracture reduction while reducing secondary trauma during reduction is a difficult problem in current surgery. First, segmentation and three-dimensional reconstruction are performed based on fracture computed tomography images. A cross-sectional point cloud extraction algorithm based on the normal filtering of the long axis of the bone is designed to obtain the cross-sectional point clouds of the distal bone and the proximal bone, and the optimal reset target pose of the broken bone is obtained by using the iterative closest point algorithm. Then, the optimal reset sequence of reset parameters was determined, combined with the broken bone collision detection algorithm, a surgical planning algorithm for lower limb fracture reset was proposed, which can effectively reduce the reset force while ensuring the accuracy of the reset process without collision. The average error of the reduction of the model bone was within 1.0 mm. The reduction operation using the planning and navigation system of lower extremity fracture reduction surgery can effectively reduce the reduction force. At the same time, it can better ensure the smooth change of the reduction force. Planning and navigation system of lower extremity fracture reduction surgery is feasible and effective.

Systematic analysis of anthropobiomechanical and pathological conditions of dancers’ feet

The article examines the anthropometric, biomechanical and pathological conditions of dancers’ feet, which are taken into account when designing shoes for various purposes and their corrective devices. An analysis of the work of the lower limbs of classical choreography dancers is presented. The basis of ballet movements is the inversion of the legs (rotation of the legs in the hip joints with the feet turned outward), characterized by high-amplitude hip retraction, unfoldment of the knee and ankle joints, which contradicts the natural vertical position of the human body, reduces the area of foot support, but at the same time gives a feeling of greater stability of ballet posture. The qualities of the «ballet foot» due to professional necessity are considered: flexibility, elasticity, sufficient strength and strength endurance. In the process of studying body movement when performing various elements of classical ballet dance, information about the features of the basic positions of most dance movements is systematized. Due to the specific loads constantly acting on the foot, injuries and pathologies inherent in ballet dancers arise. Biomechanical disorders, occupational injuries and pathological conditions of dancers’ feet, characteristic only for ballet dancers, have been studied: thickening of the compact substance of the metatarsal bones, valgus deviation of the thumb (deformation of the first ray of the foot, characterized by reduction of the first metatarsal bone (inside) and deviation of the big (first) toe (outside), deforming arthrosis of the first metatarsal joint, the development of cyst-like restructuring of the head of the I-th metatarsal bone, etc. The connection of the occurrence of transverse and longitudinal flat feet with the constant wearing of soft or rigid ballet shoes is presented. A systematic analysis of occupational injuries and pathological conditions of ballet dancers’ feet is presented, including the cause, methods of diagnosis and prevention, and a schematic image. It is determined that in almost every case, the prevention of the occurrence of certain pathological conditions is the wearing of rational shoes, orthopedic and shoes with corrective devices, including the processes of rehabilitation of the dancer. The systematized information about the work of the lower extremities, pathological conditions, injuries and deformations of the dancers’ feet allowed us to identify the necessary parameters of everyday shoes for the prevention of various diseases. The article is part of a series of publications within the framework of scientific work

Bone formation in large/moderate gap after immediate implantation in response to different treatments: a pre-clinical study in the canine posterior mandible.

This study aims to investigate different treatments on new bone formation around immediate implants in the canine posterior mandible with varying sized mesial-distal gap. The 4th premolar and the 1st molar of six Labrador dogs were extracted from the mandible, and 4 dental implants were placed 1mm below the level of the buccal bone crest. Moderate/large mesial-distal gaps between the implants and the sockets were treated with one of four methods and divided into the following groups: (1) the blank group, (2) the collagen membrane (CM) group, (3) the deproteinized bovine bone mineral (DBBM) group, and (4) the DBBM + CM group. Sequential fluorescent labeling was performed at 4, 8, and 10 weeks after the operation. After 12 weeks, the dogs were euthanized, and specimens were collected for micro-CT scanning and histological analysis. The survival rate of immediate implant was 100%. Micro-CT showed significant differences in bone mineral density (BMD) and bone volume fraction (BVF) among groups (P = 0.040, P = 0.009); other indicators were not significantly different among groups. Histological analysis showed the proportion of new bone formation and bone-to-implant contact were not significantly different among groups. No significant difference in bone reduction height around dental implant among four groups and varied mesial-distal gap size. Owing to the restricted sample size, this pilot study lacks conclusive findings. Within the limitation, this study demonstrated that although DBBM significantly increase BMD and BVF, the use of DBBM/CM didn't significantly improve bone formation and healing in extraction sockets around the implants in both moderate and large mesial-distal gap. The use of deproteinized bovine bone in conjunction with collagen is a common practice in immediate implantation procedures in the posterior mandible. However, there is a lack of conclusive evidence regarding the timing and circumstances under which they should be employed.

Osteology and phylogenetic position of Plagiosaurus depressus (Temnospondyli: Plagiosauridae) from the Late Triassic of Germany and the repeated loss of dermal bones in plagiosaurids

Abstract The skull and postcranium of the Late Triassic plagiosaurid temnospondyl Plagiosaurus depressus from Halberstadt (Germany) are redescribed in detail. Plagiosaurus possesses two autapomorphies, the abbreviated tabular and the broad contact between the postorbital and parietal. A comprehensive phylogenetic analysis of Plagiosauridae finds a clade Plagiosaurinae consisting of Plagiosaurus and Gerrothorax. Among other characters, both taxa share the solid box-like sides of the low pectoral girdle, the short but robust humerus with small deltopectoral crest and well-developed supinator process, and an anterodorsally directed lateral line sulcus close to the mandibular symphysis. Compared with Gerrothorax, the skull of Plagiosaurus is deeper and more slender, and the postfrontal is absent, meaning that the parietal forms the posteromedial margin of the enlarged orbit. This new interpretation of the bone configuration shows that reduction of circumorbital bones associated with orbital enlargement occurred three times independently within Plagiosauridae, albeit probably in different functional contexts. Our phylogenetic analysis further reveals the Plagiosuchinae (Plagioscutum + Plagiosuchus) as the most basal plagiosaurid clade, which, in turn, forms the sister group to Plagiosaurinae and Plagiosterninae (Plagiorophus + (Plagiosternum + Megalophthalma)). The mentioned shared derived characters of Plagiosaurinae in the pectoral girdle, forelimbs, and mandibular lateral lines suggest a similar benthonic lifestyle.

Epistaxis and its management: A prospective study in a Teritiary Care Centre

Background: Epistaxis ( nose bleed) is one of the most common ear, nose and throat (ENT) emergencies that present to the tertiary care center. Management of Epistaxis is challenging and most are managed conservatively and some by surgical intervention. There is always a need to find the prevalence of Epistaxis and to identify the etiological factors in management of Epistaxis, by different methods such as medical treatment, anterior and posterior nasal packing, and surgical intervention that includes endoscopic cauterization, endoscopic arterial ligation, SMR and Nasal bone reduction. In our study we will determine the various etiologies of epistaxis and its management options. Methodology: A prospective study was done in the Department of ENT, for duration of 18 months, total of 70 patients of both genders in age group of 18 - 60 years with clinical features of nasal bleed were enrolled in the study, and were subjected to clinical examination and history regarding onset and predisposing factors. Patients who are willing to undergo investigations to identify the cause and treatment are enrolled for the study after obtaining the written informed consent. Results: A total of 70 patients were examined in this study. Males were affected more than females. The patients distribution across different age groups shows maximum at age of 46-60 years followed by 36-45 years. The most common cause was found to be trauma followed by hypertension, rhinosinusitis, deviated nasal septum and idiopathic. In most cases, anterior nasal bleeding was observed.Majority of the cases managed conservatively 71.5% while 28.5% patients required surgical intervention. Conclusion: The study on epistaxis and its management provides valuable insights into effective strategies for addressing this common medical condition. This study emphasizes the importance of a medical and surgical approaches based on the severity and underlying causes of epistaxis. Anterior epistaxis is more common than posterior bleeds. Majority of cases of epistaxis are manageable by conservative measures and only few require surgical intervention. Overall, this study contributes to the ongoing efforts to enhance our understanding of epistaxis and refine therapeutic approaches for better patient outcomes.

Hard and soft tissue alterations using dual-zone concept versus connective tissue graft at maxillary immediate implant placement: A 1-year randomized clinical and volumetric trial.

To evaluate the esthetic outcome, as well as clinical, radiographic, and volumetric tissue alterations 1 year after immediate implant placement (IIP) with connective tissue grafting (CTG) versus dual-zone concept (DZ) at sites with thin labial bone in the esthetic zone. This randomized clinical trial included 30 patients treated with IIP simultaneous with either CTG or DZ (n = 15 each). Pink esthetic score (PES) was assessed 6 months after crown placement as the primary outcome. Amount of bone labial to the implant, labio-palatal ridge reduction, and crestal bone changes were measured via CBCT after 1 year. Volumetric analysis of linear labial soft tissue contour, interdental, and mid-facial soft tissue level changes, and total volume loss (mm3) were measured after 1 year. Similar PES was observed in the CTG (12.53 ± 1.13) and DZ (12.13 ± 1.55) groups, with no significant difference (p = 0.42). Likewise, there were no statistically significant differences found between the two groups in labio-palatal bone reduction (mm&%), interdental papillae, and mid-facial gingival levels (p > 0.05). However, the mean vertical crestal bone changes in the CTG and DZ groups were -1.1 ± 0.6 mm and 0.2 ± 1.0 mm, respectively, with a statistically significant difference (p = 0.0002). Moreover, CTG revealed less linear and total volume (mm3) loss in the labial soft tissue which was statistically significant compared to DZ (p = 0.007). Both groups demonstrated the same PES, nevertheless, volumetric analysis revealed twice total labial volume loss in DZ compared to CTG. It might be concluded that the use of CTG with IIP caused less horizontal reduction in the supra-implant complex compared to the DZ.

Impact of molar teeth distalization by clear aligners on maxillary alveolar bone thickness and root resorption: a three‑dimensional study

ObjectiveThis study aimed to evaluate the impact of molar teeth distalization movement by clear aligners on changes in the alveolar bone thickness and orthodontically induced inflammatory root resorption (OIIRR) in maxillary molars using conebeam computed tomography (CBCT).Materials and methodsThree-dimensional CBCT scans of 35 adult patients (one hundred forty maxillary molars) with pre-designed selection criteria and a mean age of 24.4 ± 7.1 years were included. The measured parameters, including alveolar bone thickness for maxillary molars and root resorption (OIIRR), were analyzed using pre-and post-treatment CBCT (T0 and T1, respectively) with Invivo 6.0 software.ResultPost-treatment, relevant statistically significant changes included deposition of bone in the average palatal surface of the 1st molars. The reduction of bone was seen in the average buccal surface of the first molars and both surfaces of the second molars. Regarding root length after treatment, the average maxillary 1st molar roots showed significant OIIRR (p < 0.001).ConclusionClear aligner treatment could effectively reduce the incidence of alveolar bone thickness reduction and OIIRR in treating Class II malocclusions compared to conventional braces, as shown in previous studies. This research will aid in fully grasping the benefits of clear aligners.

The Scalloped Surgical Guide as an Alternative to Flat Bone Reduction Guide in Full-arch Implant Restoration.

The goal of this clinical report was to present an alternative to traditional flat bone reduction guides, using a custom-designed 3D printed guide according to the future gingival margin of the planned dentition. A 61-year-old female with concerns regarding her smile appearance was presented. The initial examination revealed excessive gingival show accompanied by excessive overjet. The dentition was in a failing situation. The proposed treatment plan, relying on the sufficient amount of bone and keratinized tissue, consisted of re-contouring of the alveolar ridge and gingiva and placement of six implants and a FP-1 prosthesis after extraction of all remaining maxillary teeth. Digital smile design was completed, and a fully-digitally-guided surgery was planned. This consisted of utilizing three surgical guides. Starting with the fixation pin guide and continuing with the scalloped hard and soft tissue reduction guide and finally, the implant placement template. Following the surgery, the patient received a temporary restoration and on the 4-month follow-up, a new poly-methyl meta-acrylate temporary prosthesis was delivered. The patient's 7-month follow-up is presented in the paper. The report of this triple-template guided surgery indicated that digital 3D planning is a considerably predictable tool to properly establish and evaluate future occlusal plane, smile line, and lip support. Scalloped guides seem to be an excellent alternative to conventional bone reduction guides since they require less bone removal and improve patient comfort during surgery.

Association between asthma and periodontitis.

The association between asthma and periodontitis is of interest. 20 periodontitis patients with asthma (asthma group) and 20 patients without asthma (non-asthma group) were included based on inclusion and inclusion criteria. Periodontitis was classified according to 2017 periodontal classification and periodontal parameters such as tooth loss, pocket depth, clinical attachment loss, alveolar bone loss, bone reduction index, plaque index, bleeding index and periodontal risk were assessed. Effect of anti-asthmatic drugs and asthma control on periodontal parameters was also assessed. Inter-group comparison of all the continuous variables was done using independent "t" test. Comparison of categorical variables was done using Chi-square test. P value <0.05 was considered statistically significant. Results showed greater severity and higher grade of periodontitis with asthma group as well as with patients on anti-asthmatic drugs and patients with poor controlled asthma. Hence, there is an association between asthma and periodontitis.

Virtual registration of comminuted bone fracture and preoperative assessment of reconstructed bone model using the Procrustes algorithm based on CT dataset.

A research work was undergone in a virtual bone reduction process for reconstruction of the comminuted pelvic bone fracture using a CT scan dataset of patients. This includes segmentation, 3D model optimization and bone registration technique. The accuracy of the reconstructed bone model was validated using Finite Element Method. Analysed and applied various segmentation techniques to segregate the injured bone structure. The ICP (Iterative Closest Point), Procrustes algorithm and Canny edge detection algorithm were applied to understand the bone registration process for surgery in detail. The average RMS error, mean absolute distance, mean absolute deviation, and mean signed distance of the reconstructed bone model using proposed algorithms involving 10 patient datasets in a group were found to be 1.77, 1.48, 1.51 and -0.31 mm respectively. The calculated RMS error value proved minimal error in semi-automatic registration than other existing automatic registration techniques. Therefore, the proposed approach is suitable for virtual bone reduction for comminuted pelvic bone fracture. This method could also be implemented for various other bone fracture reconstruction requirements.

In Vitro Assessment of Compression Patterns Using Different Methods to Achieve Interfragmentary Compression during Tibial Plateau Levelling Osteotomy.

The aim of this study was to evaluate and characterize different methods to achieve interfragmentary compression during tibial plateau levelling osteotomy (TPLO). TPLO was performed in 20 canine tibia models (Sawbones, Vashon, Washington, United States) using 3D-printed guides for standardization. Interfragmentary compression was assessed using pressure-sensitive films (Prescale, Fujifilm, Atherstone, United Kingdom). Seven compression methods were tested: (1) Kern bone holding forceps clamping the craniodistal aspect of the TPLO plate to the caudal aspect of the tibia (K); (2) using the distal TPLO plate dynamic compression hole (P); (3) pointed bone reduction forceps engaging the caudal aspect of the proximal bone fragment and the cranial aspect of the tibial crest (F); (4) K + P; (5) K + F; (6) F + P; and (7) K + F + P. Five measurements were obtained for each method, and each bone model was used for two measurements (single method, ± plate). The interfragmentary surface was digitalized and divided into quadrants for standardization and pixel density calculation: Q1, craniomedial; Q2, craniolateral; Q3, caudomedial; and Q4, caudolateral. One-way analysis of variance (ANOVA) and post hoc tests were used for statistical analysis. Mean pressures per quadrant differed significantly between methods (p < 0.001). Methods K, F, and P produced more craniomedial, craniolateral, and caudal compression, respectively. Method K resulted in loss of caudal compression (p < 0.001). Method F + P provided the most even distribution of high interfragmentary compression forces. The addition of method K to this construct (K + F + P) marginally increased cranial compression (p = 0.189 for Q1; p < 0.001 for Q2), but reduced compression caudally (p < 0.001). Method F + P provided more even interfragmentary compression. If method K were used, then combined use with method F + P would be recommended.

Mer tyrosine kinase regulates bone metabolism, and its deficiency partially ameliorates periodontitis- and ovariectomy-induced bone loss in mice.

Bone homeostasis is maintained by tightly coordinated activities of bone-forming osteoblasts and bone-resorbing osteoclasts. In the present report, the role of Mer tyrosine kinase (MerTK) in bone metabolism was investigated. The expression of MerTK decreased upon BMP2 stimulation of osteoblast precursors. The femurs of Mertk-deficient mice showed significantly increased bone volume with concomitant increase of bone formation and reduction in bone resorption. These bone phenotypes were attributed to the increased osteoblast differentiation and mineralization accounted by the enhanced β-catenin and Smad signaling in the absence of MerTK in osteoblast precursors. Although the Mertk-deficient bone marrow macrophages were predisposed to enhanced osteoclast differentiation via augmented Ca2+-NFATc1 signaling, the dramatic increase of Tnfsf11b/Tnfsf11 (Opg/Rankl) ratio in Mertk knockout bones and osteoblast precursors corroborated the reduction of osteoclastogenesis in Mertk deficiency. In ligature-induced periodontitis and ovariectomy models, the bone resorption was significantly attenuated in Mertk-deficient mice compared with wild-type control. Taken together, these data indicate novel role of MerTK in bone metabolism and suggest a potential strategy targeting MerTK in treating bone-lytic diseases including periodontitis and osteoporosis.

Management of endo-perio lesion with autologous stem cell therapy

The objective of periodontal therapy is the regeneration of tooth-supporting tissues. Various treatment modalities, such as the use of bone grafting materials, guided tissue regeneration, and delivery of enamel matrix derivatives or growth factors, are applied with large variability in regenerative outcomes. However, a case report was done by utilization of autologous dental pulp stem cells and periodontal ligament stem cell niches in the treatment of bone loss associated with endodontically and periodontally involved teeth. An autologous periodontal ligament stem cells niche adherent to the root and dental pulpal stem cells from dental pulp directly into the selected osseous defect following extraction of the impacted tooth in the same patient. The results of this case reported that the dental pulpal stem cells and periodontal ligament stem cells niche with gelatin sponge resulted in a significant amount of bone fill and reduction in probing pocket depth.

Digital Smile Design, Vast Bone Reduction with Surgical Guide and Intraoral Welding - A Case Report

Digital Smile Design, Vast Bone Reduction with Surgical Guide and Intraoral Welding - A Case Report

Contribution of Signal Transducer and Activator of Transcription 3 (STAT3) to Bone Development and Repair.

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor activated canonically by numerous cytokines and other factors, with significant roles in immunity, immune diseases, and cancer. It has also been implicated in several human skeletal disorders, with loss-of-function (LOF) mutations associated with aberrant skeletal development. To gain further insights, two zebrafish STAT3 lines were investigated: a complete LOF knockout (KO) mutant and a partial LOF mutant with the transactivation domain truncated (ΔTAD). Consistent with other studies, the KO mutants were smaller, with reduced length in early embryos exacerbated by a decreased growth rate from 5 days postfertilization (dpf). They displayed skeletal deformities that approached 80% incidence by 30 dpf, with a significant reduction in early bone but not cartilage formation. Further analysis additionally identified considerable abrogation of caudal fin regeneration, concomitant with a paucity of infiltrating macrophages and neutrophils, which may be responsible for this. Most of these phenotypes were also observed in the ΔTAD mutants, indicating that loss of canonical STAT3 signaling was the likely cause. However, the impacts on early bone formation and regeneration were muted in the ΔTAD mutant, suggesting the potential involvement of noncanonical functions in these processes.