Residual Bone Research Articles

Is one-stage lateral sinus lift and implantation safe in severely atrophic maxillae? Results of a comparative pilot study

PurposeThe aim of this retrospective comparative study was to evaluate the survival of dental implants placed in the posterior maxilla with a residual bone height less than 3 mm using a one-stage lateral sinus lifting approach. The research question was whether in very severely atrophied maxillary bones (residual height < 3 mm), a sinus lift with simultaneous implant placement would be associated with a higher complication rate compared to single-stage sinus lifts at average residual alveolar process heights.MethodsComplications of 63 implants, where the residual bone height was below 3 mm, were compared to a reference group of 40 implants, which were inserted using a one-stage lateral sinus lift in maxillae with at least 3 mm residual bone height. Implant survival, bleeding-on-probing, the presence of peri-implant mucositis and the occurrence of peri-implantitis were documented.ResultsThe mean follow-up time for implant survival was 80.3 ± 25.9 months. One implant out of 63 was lost in the severely atrophic maxilla group and two implants out of 40 were lost in the reference group. There were no differences in the occurrence of implant loss (p = 0.558), bleeding-on-probing (p = 0.087), peri-implantitis (p = 0.999) and peri-implant mucositis (p = 0.797) between the severely atrophic alveolar ridge group and the reference group.ConclusionsEven in severely atrophic maxillae with < 3 mm residual bone height, a one-stage maxillary sinus lift and immediate implant placement can be carried out safely.Graphical

Guided Lateral Window Osteotomy Using Dynamic Navigation for Maxillary Sinus Augmentation: A Novel Technique.

The size and the position of the sinus antrostomy play a key role in making sinus grafting surgery more predictable and effective with less complications. A cone beam computed tomography and intraoral scan of the maxilla were taken for a patient who is missing maxillary first molar tooth with limited residual bone. Data were exported to the dynamic navigation (DN) system software. Sinus lateral window osteotomy position and dimensions were determined and planned using four 1.5 mm diameter implants placed on the maxillary sinus lateral wall. The osteotomy was initiated following the planned four 1.5 mm implants in a parallel motion to the bone surface using dynamic navigation guidance; thus, creating an outline for the lateral sinus window. Afterword's, the lateral sinus window was greenstick fractured and the membrane was lifted; first molar implant osteotomy done, implant placed, and bone graft material was placed. The flap was sutured, and post-operative instructions and medications were given. No post-operative complications noticed. The outline of the lateral window osteotomy along with implant osteotomy can be accurately planned and executed using DN technology, which may potentially reduce complications and insure accurate placement of the implant and the graft.

Comparing Operators and Imaging Techniques When Performing Trans-Crestal Sinus Augmentation: A Pilot Study.

The aim of this article was to compare baseline residual ridge height using Cone-beam Computed Tomography (CBCT) and panoramic radiographs. A secondary aim was to examine the magnitude of vertical bone gain 6 months after trans-crestal sinus augmentation and compare it between operators. Thirty patients, who underwent trans-crestal sinus augmentation simultaneously with dental implant placement, were included in this retrospective analysis. Surgeries were done by 2 experienced surgeons (EM and EG) using the same surgical protocol and materials. Preoperative residual ridge height was measured on panoramic and CBCT images. The final bone height and the magnitude of the vertical augmentation were measured on panoramic X ray taken 6 months after surgery. Mean residual ridge height measured preoperatively using CBCT was 6.07 ± 1.38 mm, whereas these same measurements on the panoramic radiographs yielded similar results (6.08 ± 1.43 mm), which were statistically insignificant (P = .535). Postoperative healing was uneventful in all cases. All 30 implants were successfully osseointegrated at 6 months. The mean overall final bone height was 12.87 ± 1.39 mm (12.61 ± 1.21 and 13.39 ± 1.63 mm for operators EM and EG, respectively; P = .19). Likewise, mean postoperative bone height gain was 6.78 ± 1.57 mm, which was 6.68 ± 1.32 and 6.99 ± 2.06 mm for operators EM and EG, respectively (P = .66). A moderate positive correlation was found between residual bone height and final bone height (r = 0.43, P = .002). A moderate negative correlation was found between residual bone height and augmented bone height (r = -0.53, P = .002). Sinus augmentation performed trans-crestally produce consistent results with minimal interoperator differences between experienced clinicians. Both CBCT and panoramic radiographs produced similar assessment of the preoperative residual bone height.

Automatic cerebral computed tomography venographic imaging based on the prior knowledge of cerebral blood circulation

Background and purposeCurrent clinical computed tomography venographic (cCTV) images present limited cerebral venous profiles. Therefore, this study aimed to develop an automatic cerebral CTV imaging technique using computed tomographic perfusion (CTP) images in a cohort of patients with stroke. Materials and MethodsWe retrospectively evaluated 10 (intracerebral hemorrhage) and 2 (acute ischemic stroke) patients who underwent institutional CTP imaging. CTV images were processed with the proposed CTV (pCTV) technique, and pCTV and cCTV images were then independently evaluated by two experienced neuroradiologists blinded to all clinical information using a novel scoring method that considered overall image quality, venous visibility, and arterial mis-segmentation. Venous visibility was separately evaluated for the dural sinus, superficial vein, and deep vein. Then, statistical analysis was performed to determine whether the pCTV technique was superior to the cCTV technique. ResultsIn total, 14 sets of pCTV images were generated and compared with cCTV images. The overall image quality and venous visibility scores of pCTV images were significantly higher than those of cCTV images (all values of p<0.05), especially for the dural sinus (median [25th, 75th percentiles], 14.00 [13.63, 15.50] vs. 7.50 [7.00, 10.88]), and superficial vein (9.00 [8.88, 10.00] vs. 3.25 [1.63, 8.25]), while the difference in arterial mis-segmentation was not statistically significant (p= 0.164). ConclusionsThis study proposed an automatic cerebral CTV imaging technique to eliminate residual bone and soft tissues, minimize the impact of the cerebral arterial system, and present a relatively comprehensive cerebral venous system, which would help physicians assess cerebral venous outflow profiles after stroke and seek imaging markers associated with clinical outcomes.

Biomechanical evaluation of custom-made short implants with wing retention applied in severe atrophic maxillary posterior region restoration: A three-dimensional finite element analysis.

Severe bone atrophy in the maxillary posterior region poses a big challenge to implant restoration. Digitally designed and customized short implants with wing retention provide a safer and minimally invasive implant restoration scheme in such circumstances. Small titanium wings are integrated with the short implant supporting the prosthesis. Using digital designing and processing technology, the wings fixed by titanium screws can be flexibly designed, providing the main fixation. The design of the wings will influence the stress distribution and implant stability. This study analyzes the position, structure, and spread area of the wings fixture scientifically by means of three-dimensional finite element analysis. The design of the wings is set to linear, triangular, and planar styles. Under the simulated vertical and oblique occlusal forces, the implant displacement and stress between the implant and the bone surface are analyzed at different bone heights of 1mm, 2mm, and 3mm. The finite element results show that the planar form can better disperse the stress. By adjusting the cusp slope to reduce the influence of lateral force, short implants with planar wing fixtures can be used safely even if the residual bone height is only 1mm. The results of the study provide a scientific basis for the clinical application of this new customized implant.

Residual Bone Height and New Bone Formation after Maxillary Sinus Augmentation Procedure Using Biomaterials: A Network Meta-Analysis of Clinical Trials.

Different factors may affect new bone formation following maxillary sinus floor augmentation for the rehabilitation of posterior edentulous maxilla. The purpose of this study was to determine the influence of residual bone height (RBH) on new bone formation after lateral sinus augmentation utilizing different biomaterials, through a network meta-analysis (NMA). PUBMED, Scopus, and Web of Science electronic databases were searched until 31 December 2022 to obtain relevant articles. A hand search was also conducted. Randomised controlled studies on maxillary sinus augmentation comparing different grafting materials in patients with atrophic posterior maxilla, in need of prosthetic rehabilitation, were included. The risk of bias was assessed following the guidelines of the Cochrane Collaboration. The primary outcome was new bone formation (NBF), assessed histomorphometrically. The statistical analysis was performed by splitting the data according to RBH (<4 mm and ≥4 mm). A total of 67 studies were eligible for conducting NMA. Overall, in the included studies, 1955 patients were treated and 2405 sinus augmentation procedures were performed. The biomaterials used were grouped into: autogenous bone (Auto), xenografts (XG), allografts (AG), alloplasts (AP), bioactive agents (Bio), hyaluronic acid (HA), and combinations of these. An inconsistency factor (IF) seen in the entire loop of the XG, AP, and Bio+AP was found to be statistically significant. The highest-ranked biomaterials for the <4 mm RBH outcome were XG+AG, XG+AP, and Auto. Similarly, the surface under the cumulative ranking curve (SUCRA) of biomaterials for ≥4 mm RBH was Auto, Bio+XG, and XG+Auto. There is no grafting biomaterial that is consistently performing better than others. The performance of the materials in terms of NBF may depend on the RBH. While choosing a biomaterial, practitioners should consider both patient-specific aspects and sinus clinical characteristics.

OSSEOINTEGRATION OUTCOMES FOLLOWING AMPUTEE LENGTHENING

Percutaneous EndoProsthetic Osseointegration for Limbs (PEPOL) facilitates improved quality of life (QOL) and objective mobility for most amputee's discontent with their traditional socket prosthesis (TSP) experience. Some amputees desiring PEPOL have residual bone much shorter than the currently marketed press-fit implant lengths of 14-16 cm, potentially a risk for failure to integrate. We report on the techniques used, complications experienced, the management of those complications, and the overall mobility outcomes of seven patients who had femur distraction osteogenesis (DO) with a Freedom nail followed by PEPOL.Retrospective evaluation of a prospectively maintained database identified nine patients (5 females) who had transfemoral DO in preparation for PEPOL with two years of follow-up after PEPOL. Six patients had traumatic causes of amputation, one had perinatal complications, one was performed to manage necrotizing fasciitis and one was performed as a result of osteosarcoma.The residual femurs on average started at 102.2±39.7 mm and were lengthened 58.1±20.7 mm, 98±45% of goal (99±161% of the original bone length). Five patients (56%) had a complication requiring additional surgery. At a mean of 3.4±0.6 (2.6-4.4) years following osseointegration six patients had K-level &gt;2. The 6 Minute Walk Test remained unchanged (267±56 vs 308 ± 117 meters). Patient self-rating of prosthesis function, problems, and amputee situation did not significantly change from before DO to after osseointegration. Six patients required additional surgery following osseointegration: six to remove fixation plates placed to maintain distraction osteogenesis length at osseointegration; two required irritation and debridement for infection.Extremely short residual femurs which make TSP use troublesome can be lengthening with externally controlled telescoping nails, and successfully achieve osseointegration. However, it is imperative to counsel patients that additional surgery to address inadequate regenerate or to remove painful hardware used to maintain fixation may be necessary. This may improve the amputee's expectations before beginning on a potentially arduous process.

The Gradual Release of Alendronate for the Treatment of Critical Bone Defects in Osteoporotic and Control Rats.

Osteoporosis is a severe health problem with social and economic impacts on society. The standard treatment consists of the systemic administration of drugs such as bisphosphonates, with alendronate (ALN) being one of the most common. Nevertheless, complications of systemic administration occur with this drug. Therefore, it is necessary to develop new strategies, such as local administration. In this study, emulsion/dispersion scaffolds based on W/O emulsion of PCL and PF68 with ALN, containing hydroxyapatite (HA) nanoparticles as the dispersion phase were prepared using electrospinning. Scaffolds with different release kinetics were tested in vitro on the co-cultures of osteoblasts and osteoclast-like cells, isolated from adult osteoporotic and control rats. Cell viability, proliferation, ALP, TRAP and CA II activity were examined. A scaffold with a gradual release of ALN was tested in vivo in the bone defects of osteoporotic and control rats. The release kinetics were dependent on the scaffold composition and the used system of the poloxamers. The ALN was released from the scaffolds for more than 22 days. The behavior of cells cultured in vitro on scaffolds with different release kinetics was comparable. The difference was evident between cell co-cultures isolated from osteoporotic and control animals. The PCL/HA scaffold show slow degradation in vivo and residual scaffold limited new bone formation inside the defects. Nevertheless, the released ALN supported bone formation in the areas surrounding the residual scaffold. Interestingly, a positive effect of systemic administration of ALN was not proved. The prepared scaffolds enabled tunable control release of ALN. The effect of ALN was proved in vitro and in in vivo study supported peri-implant bone formation.

Revision cochlear implant surgery for clinical reasons.

To report the authors' experience in a series of patients treated with cochlear implant (CI) revision surgery due to medical problems. Revision CI surgeries performed in a tertiary referral centre for medical reasons not related to skin conditions were reviewed; patients were included if device removal was required. 17 cochlear implant patients were reviewed. The main reasons requiring revision surgery with device removal were: retraction pocket/iatrogenic cholesteatoma (6/17), chronic otitis (3/17), extrusion in previous canal wall down procedures (2/17) or in previous subtotal petrosectomy (2/17), misplacement/partial array insertion (2/17) and residual petrous bone cholesteatoma (2/17). In all cases surgery was performed through a subtotal petrosectomy. Cochlear fibrosis/ossification of the basal turn was found in 5 cases and uncovered mastoid portion of the facial nerve in 3 patients. The only complication was an abdominal seroma. A positive difference was observed between the number of active electrodes and comfort levels before and after revision surgery. In CI revision surgeries performed for medical reasons, subtotal petrosectomy offers invaluable advantages and should be considered as first choice during surgical planning.

HISTOLOGICAL STUDY TO COMPARE THE APPROPRIATE PARTICLE SIZE OF BETA TCP FOR SOCKET PRESERVATION

Background: One the most used and potent synthetic bone graft substitute which is not only osteoconductive, but also osteoinductive which has been recently discovered and gain popularity is the β-tricalcium phosphate (β-TCP). Along with its cell-mediated resorption propertybeta TCP allow regeneration of full bone defect. Its clinical outcome is sometimes considered to be “unpredictable”, possibly due to a poor understanding of β-TCP physico-chemical properties. Histological evaluation and effects of of bet AIM: a TCP small and large particle at the site of defect in cases of grossly decayed teeth, bone defect and other required areas. Total of 20 cases we Material and Methods: re included in the study (10 cases each of small and large particle). Trephine biopsy was performed and sent for histological evaluation. Histological evaluation depicted the results Results: on the basis of new none formation with residual bone graft material. Vascularity is studied in both the cases with areas of inammation. Conclusion: Production of Mesenchymal stem cells progenitors plays a potent role in elucidating the effects of small Beta TCP particle and is responsible for the production of new bone.

Papillary Thyroid Carcinoma Arising in Thyroglossal Duct Cyst and Locally Infiltrated to Hyoid Bone: Issue of Individualized Management

Thyroglossal duct cyst (TGDC) is the most common developmental anomaly of the thyroid gland, while TGDC carcinoma with local infiltration to the hyoid bone is extremely rare. The reported case of papillary thyroid carcinoma (PTC) was diagnosed in TGDC along with local infiltration to the hyoid bone and needed individualized management. A 70-year-old male patient presented with a history of PTC arising in TGDC and locally infiltrated to the hyoid bone followed by total thyroidectomy and radical sistrunk operations and was referred to National Institute of Nuclear Medicine and Allied Sciences (NINMAS) for radioactive iodine therapy (RAIT). His post-operative ultrasound of the neck revealed an irregular shaped, fungating, grossly non-homogenous mixed echogenic mass lesion invading the hyoid bone, measuring about 25 X 28 mm. Radioactive iodine(131I) of 150 mCi was administered because the residual hyoid bone mass was inoperable and he was on thyroxine suppression therapy. The post-therapy 131I scan (RxWBS) showed two intense foci of radiotracer concentration (RTC) in the upper area (above the thyroid bed) and an intense focal RTC in the fundal region of the stomach. The activity in the stomach region was evaluated by ultrasound imaging, which revealed a soft tissue mass or thickening of the mid-region of the posterior wall of the stomach (3.3 cm X 1.6 cm). A CT scan of the chest was also performed to rule out metastasis, and it revealed multiple nodular lesions in both lung fields (most likely secondary) as well as tiny subcentric lymphnodes in the lower pre- and right paratracheal regions after nearly one month of RAIT when the patient was stable for examination. EBRT is still under consideration as adjuvant therapy. Tyrosine kinase inhibitors (TKI) may be considered in cases of refractoriness to radioiodine and disease progression. Bangladesh J. Nuclear Med. 26(1): 67-70, 2023

Reconstruction of massive bone defects after femoral tumor resection using two new-designed 3D-printed intercalary prostheses: a clinical analytic study with the cooperative utilization of multiple technologies

BackgroundTo reconstruct massive bone defects of the femoral diaphysis and proximal end with limited bilateral cortical bone after joint-preserving musculoskeletal tumor resections, two novel 3D-printed customized intercalary femoral prostheses were applied.MethodsA series of nine patients with malignancies who received these novel 3D-printed prostheses were retrospectively studied between July 2018 and November 2021. The proximal and diaphyseal femur was divided into three regions of interest (ROIs) according to anatomic landmarks, and anatomic measurements were conducted on 50 computed tomography images showing normal femurs. Based on the individual implant-involved ROIs, osteotomy level, and anatomical and biomechanical features, two alternative 3D-printed prostheses were designed. In each patient, Hounsfield Unit (HU) value thresholding and finite element analysis were conducted to identify the bone trabecula and calcar femorale and to determine the stress distribution, respectively. We described the characteristics of each prosthesis and surgical procedure and recorded the intraoperative data. All patients underwent regular postoperative follow-up, in which the clinical, functional and radiographical outcomes were evaluated.ResultsWith the ROI division and radiographic measurements, insufficient bilateral cortical bones for anchoring the traditional stem were verified in the normal proximal femur. Therefore, two 3D-printed intercalary endoprostheses, a Type A prosthesis with a proximal curved stem and a Type B prosthesis with a proximal anchorage-slot and corresponding locking screws, were designed. Based on HU value thresholding and finite element analysis, the 3D-printed proximal stems in all prostheses maximally preserved the trabecular bone and calcar femorale and optimized the biomechanical distribution, as did the proximal screws. With the 3D-printed osteotomy guide plates and reaming guide plates, all patients underwent the operation uneventfully with a satisfactory duration (325.00 ± 62.60 min) and bleeding volume (922.22 ± 222.36 ml). In the follow-up, Harris Hip and Musculoskeletal Tumor Society scores were ameliorated after surgery (P < 0.001 and P < 0.001, respectively), reliable bone ingrowth was observed, and no major complications occurred.ConclusionsTwo novel 3D-printed femoral intercalary prostheses, which achieved acceptable overall postoperative outcomes, were used as appropriate alternatives for oncologic patients with massive bone defects and limited residual bone and increased the opportunities for joint‐preserving tumor resection. Several scientific methodologies utilized in this study may promote the clinical design proposals of 3D-printed implants.

Two-Step Progressive Transcrestal Sinus Augmentation Using a 4.5 mm Unloaded Implant as a "Temporary Implant" in Highly Atrophic Ridge: Case Report.

Severe atrophic posterior maxillary ridge (residual bone height < 3 mm) could be a challenging situation to place dental implants. Several treatment options have been proposed, but some of them may require advanced surgical skills to achieve best results. In this article, we present a novel and easier technique to allow implant placing in localized areas of severe atrophy. In a first step, a 4.5-length extra-short (unloaded) implant is placed after a transcrestal maxillary sinus floor augmentation (MSFA). After the gained apical bone consolidation, this "temporary implant" is atraumatically removed and a longer and wider definitive implant is placed to support the definitive single restoration. The case of a 45-year-old female treated with this approach is also presented. The patient suffered a severe resorption in the upper right molar area after a tooth extraction. Four months after the "temporary implant" placement and MSFA grafting with plasma rich in growth factors and autologous bone, 3 mm of dense apical bone gain could be observed. In a second surgical time, the 4.5 mm-length "temporary implant" was removed, and a 5.5 mm-length "definitive implant" was placed. This second implant was placed in a denser type 1 (1,000 Hounsfield Unit) new formed apical bone. Four months later, the implant was loaded with a screw-retained crown over a transepithelial (intermediate abutment). After 1-year follow-up, the implant was in health and no mechanical or biological complications were noticed. The satisfactory results of this case encourage the realization of new studies to elucidate its reproducibility.

Novel resorbable bone wax containing β-TCP and starch microspheres for accelerating bone hemostasis and promoting regeneration.

Traditional non-resorbable bone wax has been used in clinical surgery for more than 100years. However, residual bone wax has been proven to cause numerous complications. In this study, a novel resorbable bone wax was designed to overcome the disadvantages of traditional non-resorbable bone wax. Alkylene oxide copolymers were used as the main component of resorbable bone wax; additionally, β-tricalcium phosphate and starch microspheres were added to enhance bone regeneration and hemostatic ability. This novel resorbable bone wax has a high potential for clinical translation and is expected to be developed as a substitute for traditional bone wax.

Bismuth-coated 80S15C bioactive glass scaffolds for photothermal antitumor therapy and bone regeneration.

Background: Malignant bone tumors usually occur in young people and have a high mortality and disability rate. Surgical excision commonly results in residual bone tumor cells and large bone defects, and conventional radiotherapy and chemotherapy may cause significant side effects. In this study, a bifunctional Bi-BG scaffold for near-infrared (NIR)-activated photothermal ablation of bone tumors and enhanced bone defect regeneration is fabricated. Methods: In this study, we prepared the Bi-BG scaffold by in-situ generation of NIR-absorbing Bi coating on the surface of a 3D-printing bioactive glass (BG) scaffold. SEM was used to analyze the morphological changes of the scaffolds. In addition, the temperature variation was imaged and recorded under 808nm NIR laser irradiation in real time by an infrared thermal imaging system. Then, the proliferation of rat bone mesenchymal stem cells (rBMSCs) and Saos-2 on the scaffolds was examined by CCK-8 assay. ALP activity assay and RT-PCR were performed to test the osteogenic capacity. For in vivo experiments, the nude rat tumor-forming and rat calvarial defect models were established. At 8weeks after surgery, micro-CT, and histological staining were performed on harvested calvarial samples. Results: The Bi-BG scaffolds have outstanding photothermal performance under the irradiation of 808nm NIR at different power densities, while no photothermal effects are observed for pure BG scaffolds. The photothermal temperature of the Bi-BG scaffold can be effectively regulated in the range 26-100°C by controlling the NIR power density and irradiation duration. Bi-BG scaffolds not only significantly induces more than 95% of osteosarcoma cell death (Saos-2) in vitro, but also effectively inhibit the growth of bone tumors in vivo. Furthermore, they exhibit excellent capability in promoting osteogenic differentiation of rBMSCs and finally enhance new bone formation in the calvarial defects of rats. Conclusion: The Bi-BG scaffolds have bifunctional properties of photothermal antitumor therapy and bone regeneration, which offers an effective method to ablate malignant bone tumors based on photothermal effect.

Cranioplasty for Bone Defects after Craniosynostosis Surgery in Pediatric Patient: A Case Report

Background: Craniosynostosis, the premature closure of skull sutures, can cause a misshapen head and neurologic issues. Surgical correction may result in bone defects requiring additional surgery. Case Description: We present a 5-year-old female who underwent cranioplasty for a skull defect and bulging brain after craniosynostosis surgery. Cranioplasty corrected the defect&amp;apos;s functional and cosmetic aspects. CT with 3D reconstruction confirmed findings and aided planning. The patient underwent cranioplasty using mesh over the defect and had an unremarkable recovery. Result: A 5-year-old had residual craniosynostosis bone defect and bulging brain. Cranioplasty used mesh over the defect, had unremarkable recovery. Early intervention and a multidisciplinary approach are key. More research is needed on this condition&amp;apos;s prevalence, causes and management. Conclusion: This case emphasizes early intervention and a multidisciplinary approach for craniosynostosis and related defects. A team approach addressing the condition&amp;apos;s physical and psychological impacts on the child and family is crucial for optimal outcomes. Cranioplasty is critical, and success depends on expertise. This case highlights the importance of timely, appropriate craniosynostosis management and related defect care. We hope this report contributes to literature and improves outcomes for patients undergoing cranioplasty after craniosynostosis surgery.

A large animal model of periodontal defects in bisphosphonate-related osteonecrosis of the jaw: a comparison of clinical and radiological findings.

The objective of this study was to demonstrate the suitability of cone-beam computed tomography (CBCT) for in vivo research in periodontology, with implications for oral implantology, facial traumatology, and all disciplines involved in treating patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ). Halves of the jaws of 9 Swiss mountain sheep, assigned to a control group (n=3), an osteoporosis group (n=3) and a zoledronate-exposed group (n=3), were examined. Clinical and radiological evaluations were conducted using CBCT imaging to assess whether periodontitis and bone defects were observed to a significant extent after surgical tooth extraction. In contrast to the control and osteoporosis groups, the zoledronate group exhibited significant residual bone defects following tooth extraction (P<0.05). CBCT more objectively revealed these effects and enabled a numerical evaluation (in mm3). Evaluating residual defects in bone blocks from sheep using CBCT analysis was found to be as effective as a clinical examination conducted by specialists in oral and maxillofacial surgery. The strong correlation between radiological findings and clinical conditions suggests that CBCT may become increasingly important in the future, particularly in periodontological research related to BRONJ.

Rehabilitation of patient using a patient-specific implant with bar-retained maxillary obturator and orbital prosthesis postoperated rhino-orbital mucormycosis

ABSTRACT The “black fungus” or Mucor mycosis affected a significant number of COVID patients during the pandemic. Aggressive surgical intervention of these cases resulted in large palatal &amp; orbital defects that required prosthetic rehabilitation. This is a painstaking process due to compromised retention and minimum residual bone. In this dental centre, two case was rehabilitated with 3D printed titanium patient specific implants (PSI) followed by prosthetic rehabilitation.A 36-year-old male diabetic COVID patient was diagnosed with mucormycosis and underwent right orbital exenteration &amp; maxillectomy. Upon recovery, a PSI was designed and 3D printed to provide support for orbital and maxillary prosthesis. PSI was fixed to the orbital rims and remaining zygomatic bone for supporting the prostheses and Bar-clip retained prostheses were fabricated using the conventional method.During COVID-19 pandemic, patients who contracted Mucormycosis had a poor prognosis with conventional prostheses since all the supporting structures had been affected by the infection. Conventional prostheses for maxillofacial defects do not have adequate supporting hard &amp; soft tissues to provide retention and support. The PSI with Bar retained protheses have been selected as a treatment option for such types of defects.PSIs can be valuable aids in rehabilitating patients with large maxillofacial defects.

15-Year Retrospective Study on the Success Rate of Maxillary Sinus Augmentation and Implants: Influence of Bone Substitute Type, Presurgical Bone Height, and Membrane Perforation during Sinus Lift.

To evaluate the success rate of bone grafts and implants carried out at the Latin American Institute for Research and Dental Education (ILAPEO), considering the following: (i) the different pure bone substitutes (autogenous, xenogeneic, and alloplastic), (ii) the presurgical bone height, and (iii) how the treatment is compromised when membrane perforation occurs during sinus lift in maxillary sinus surgeries. Material and Methods. The initial sample comprised 1040 records of maxillary sinus lifting surgeries. After evaluation, the final sample retained 472 grafts performed using the lateral window technique with a total of 757 implants. The grafts were divided into 3 groups: (i) autogenous bone (n = 197), (ii) xenogenous bovine bone (n = 182), and (iii) alloplastic material (n = 93). One calibrated examiner classified the sample into two groups based on the residual bone height (<4 mm and ≥4 mm) of the area of interest measured on parasagittal sections of tomographic images. Data on membrane perforation occurrences in each group were collected; qualitative variables were described using frequency, expressed as percentages. The Chi-square test was used to analyze the success of the graft types and the survival rate of the implants as a function of the grafted material and the residual bone height. The Kaplan-Meier survival analysis was used to calculate the survival rate of bone grafts and implants according to the classifications adopted in this retrospective study. The success rate of grafts and implants was 98.3% and 97.2%, respectively. There was no statistically significant difference in the success rate among the different bone substitutes (p = 0.140). Only 8 grafts (1.7%) and 21 implants (2.8%) failed. There was a greater success rate for both grafts (96.5%) and implants (97.4%) when the bone height was ≥4 mm. The success rate in the 49 sinuses in which the membrane was perforated was 97.96% for the grafts and 96.2% for the implants. The follow-up periods after rehabilitation ranged from 3 months to 13 years. Within the limitations of the data analyzed in this retrospective study, maxillary sinus lift was a viable surgical technique that enabled implant placement with a predictable long-term success rate, regardless of the type of material used. The presence of membrane perforation did not interfere with the success rate obtained for grafts and implants.

Crestal sinus augmentation in a head back position: Retrospective case series.

To evaluate the clinical efficacy of Crestal Sinus Augmentation (CSA) in a head back position (CSA-HBP) for maxillary sinus mucosa elevation. We enrolled 209 patients, 246 maxillary sinuses, 348 sites in this study. Complications, maxillary sinus mucosal perforation rate and cumulative survival rate (CSR) data were collected to evaluate the clinical efficacy of CSA-HBP. Maxillary sinus mucosal elevation height (EH) and new bone height (NH) were measured by cone-beam computerized tomography and standard periapical radiographs. The implantation sites of residual bone height (RBH) ≤5 mm and RBH >5 mm were marked as Groups A (n = 81) and B (n = 267), respectively. The implantation sites of the second and third molar sites were marked as Group C (n = 134), and the remaining sites were marked as Group D (n = 214). The RBH before implant placement was 6.63 ± 2.10 mm (95% confidence interval [CI] 6.41- 6.85 mm). The mucosal EH was 4.04 ± 1.86 mm (95% CI 3.85 - 4.24 mm). The NH was 2.36 ± 1.20 mm (95% CI 3.85-4.24 mm). No other complications were found except three cases of postoperative swelling and one case of nasal blood secretions. The overall mucosal perforation rate was 1.44% (5/348, 95% CI 0.2%-2.7%) and the rate of RBH ≤ 5 mm (Group A) was 1.49% (2/134, 95% CI 0%-3.50%). The 8-year CSR was 99.71% (347/348, 95% CI 99.2%-100.0%). Mucosal EH and NH were higher in RBH ≤5 mm (Group A) than in RBH >5 mm (Group B) (P = 0.001 and P = 0.001, Mann-Whitney U-test). There were no significant differences in mucosal EH and perforation rate between second and third molar sites (Group C) and other sites (Group D) (P = 0.77, Mann-Whitney U-test, and P = 0.16, Yates' Chi-square independence test). CSA-HBP is a minimally invasive and reliable technique.