Intermittent Hypoxic Therapy Inhibits Allogenic Bone-Graft Resorption by Inhibition of Osteoclastogenesis in a Mouse Model

Systemic Intermittent Hypoxic Therapy (IHT) relies on the adaptive response to hypoxic stress. We investigated allogenic bone-graft resorption in the lumbar spine in 48 mice. The mice were exposed to IHT for 1 week before surgery or 1 week after surgery and compared with controls after 1 and 4 weeks. Complete graft resorption was observed in 33–36% of the animals in the control group, but none in the preoperative IHT group. Increased bone-graft volume was demonstrated by micro-computed tomography in the preoperative IHT group after 1 week (p = 0.03) while a non-significant difference was observed after 4 weeks (p = 0.12). There were no significant differences in the postoperative IHT group. Increased concentration of immune cells was localized in the graft area, and more positive tartrate-resistant acid phosphatase (TRAP) staining was found in controls compared with IHT allogenic bone grafts. Systemic IHT resulted in a significant increase of the major osteoclast inhibitor osteoprotegerin as well as osteogenic and angiogenic regulators Tgfbr3, Fst3l, Wisp1, and Vegfd. Inflammatory cytokines and receptor activator of nuclear factor kappa-B ligand (RANKL) stimulators IL-6, IL-17a, IL-17f, and IL-23r increased after 1 and 4 weeks, and serum RANKL expression remained constant while Ccl3 and Ccl5 decreased. We conclude that the adaptive response to IHT activates numerous pathways leading to inhibition of osteoclastic activity and inhibition of allogenic bone-graft resorption.

Radiographic Union of Evans Osteotomy Without Fixation

Category: Hindfoot; Other Introduction/Purpose: The Evans osteotomy is a lateral column lengthening procedure of the calcaneus that is commonly used to correct flexible flatfoot deformities. There is no consensus on whether fixation is needed to avoid nonunion and calcaneocuboid subluxation when performing this osteotomy. We assessed the nonunion rate and correlated extent of subluxation with graft size in an unfixed Evans osteotomy with an allograft wedge and no pinning of the calcaneocuboid joint at any point in the largest series of the procedure to date. Surgeries were performed in patients undergoing flexible flatfoot reconstruction. Methods: We retrospectively reviewed 120 consecutive patients who had undergone 145 unfixed Evans osteotomies by a single surgeon with allogenic bone graft for flatfoot reconstruction between January 2013 and October 2017, with a mean follow-up of 62.5 (range 9.4-266.7) weeks. The calcaneocuboid joint was not pinned during the procedure. Data were collected using clinical and radiographical examination during regular follow-up. Results: A total of 137 feet (94.5%) underwent a double calcaneal osteotomy with an associated medial displacement calcaneal osteotomy (MDCO). There was one nonunion (0.69%). The mean time to union was 10.8 (range, 6.7-17.9) weeks. There was significant improvement in all radiographic parameters postoperatively, including calcaneal pitch, talonavicular uncoverage, anteroposterior and lateral talo-first metatarsal angle, lateral column length, and naviculocuboid overlap (p<0.05). Minor postoperative calcaneocuboid joint subluxation (1.51 +- 2.3 mm) occurred in 72 of 118 feet (61.0%) and had no correlation with wedge size (r=0.06; 95% CI, -0.13, 0.24; p=0.6). Conclusion: An unfixed Evans osteotomy for symptomatic flatfoot deformity resulted in a significant improvement in the radiographic alignment of the foot with an exceptionally rare nonunion rate. Detectable calcaneocuboid subluxation was common but minimal in extent and was not correlated with wedge size in this series in which wedges were less than 12 mm in the maximum dimension. This report represents the largest series of the Evans procedure to date.

Post-Operative Outcomes of Radiological and Histopathological Findings after Hydroxyapatite and Allogenic Bone Graft among Jaw Cyst Patients: A Randomized Clinical Trial

Background: Post-surgical outcomes of jaw cyst is very crucial. Objective: The purpose of the present study was to observe the radiological and histological finings as postoperative outcomes after hydroxyapatite and allogenic bone graft among jaw cyst patients. Methodology: This single centre, parallel, randomized clinical trial was conducted in the Department of Oral and Maxillofacial Surgery at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from July 2006 to June 2008 for a period of two (02) years. Patients presented with radicular and dentigerous cyst with the size of the lesion between 2 cm to 7 cm. in diameter and relatively non infected cystic lesion were selected as study population. The study population were divided into two groups designed as group A treated with hydroxyapatite alloplastic material and group B treated with allogenic-bone graft after enucleation of the cystic lesion. The standard surgical procedure was to be performed meticulously in sterile environment. Post-operative radiograph were taken after one month, three months and six months. Histopathological examination was done after six month of operation which was done in the department of Pathology, BSMMU. Scintigraphic examination was performed after 6 months of the operation to evaluate the viability of the bone graft in the graft site. Result: A total number of 28 patients were recruited for this study of which 14 patients were treated with hydroxyapatite crystals bone graft in group A and 14 patients were treated with allogenic bone graft in group B. The age of patients of both groups ranged between 14 and 58 years. In histopathological examination marked presence of cementing line, woven bone and osteoblast cell was found in patients who were grafted with hydroxyaptite and this had indicated good osteoblastic activity. Increased technetium-99m labeled diphosphonate uptake was found in the patient with allograft. There was a smaller lesion diameter of hydroxyapatite group in comparison with allogenic bone graft group which had indicated comparatively better healing than that of the hydroxyapatite group. Conclusion: In conclusion hydroxyapatite alloplastic material has better radiological and histopathological outcomes than allogenic bone graft after surgery of jaw cyst. Journal of National Institute of Neurosciences Bangladesh, 2020;6(1): 48-53

Comparison of Rate of Infection during Hydroxyapatite and Allogenic Bone Graft Used In Jaw Cyst: A Randomized Clinical Trial

Background: Post-operative infection can occur after bone grafting among patietns with jaw cyst. Objective: The purpose of the present study was to compare the rate of infection as postoperative outcomes after hydroxyapatite and allogenic bone graft among jaw cyst patients. Methodology: This randomized clinical trial was conducted in the Department of Oral and Maxillofacial Surgery at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh from July 2006 to June 2008. Patients presented with radicular and dentigerous cyst and relatively non infected cystic lesion were selected as study population. The study population were divided into two groups designed as Group A treated with with allogenic-bone graft and Group B treated with hydroxyapatite alloplastic material after enucleation of the cystic lesion. The rate of infection was recorded after surgery in both group A and B. Result: A total number of 28 patients were recruited for this study of which 14 patients were treated with hydroxyapatite crystals bone graft in group A and 14 patients were treated with allogenic bone graft in group B. Post-operative infection was not found in group A and 5(35.7%) in group B (p<0.05). Infection occurred in 1(20.0%) case in one side intact and 4(80.0%) in both side lost. Infection was found in 1(20.0%) case and 4(80.0%) cases in average and poor oral hygiene status respectively. Conclusion: In conclusion more infection occurs in allogenic bone graft group than the group treated with hydroxyapatite alloplastic material Bangladesh Journal of Infectious Diseases 2019;6(2):29-33

Dental Implant for a Patient with Narcolepsy: A Case Report

Narcolepsy is a neurological disorder characterised by cataplexy, sleep paralysis and excessive daytime sleepiness. The literature on dental managements of patients with narcolepsy is lacking with no set guidelines for dental practitioners. A 31-year-old female presented to the dental office with a dull pain related to the maxillary left lateral incisor with Grade 2 mobility and isolated 8 mm periodontal pocket. In addition, there was loss of buccal gingiva with radiographic changes suggestive of caries and fractured crown. The patient had a history of narcolepsy with cataplexy and hypertension controlled with bisoprolol and desvenlafaxine in addition to clonazepam 1 mg/day as needed to prevent episodes of cataplexy. Patient was asked to take 2 mg clonazepam and 600 mg ibuprofen one hour before procedure. The maxillary left lateral incisor was extracted atraumatically and an immediate implant combined with allogenic bone graft and collagen membrane was placed. The procedure was uneventful, and patient left conscious and stable. After three months, the implant was restored with porcelain fused-to-metal crown and followed-up for six months without any complications. This is the first case describing a narcolepsy patient who successfully received a dental implant without developing a cataplexy episode. Clonazepam prophylaxis may be considered prior to dental procedures for similar situations.

Platelet Rich Fibrin for the Treatment of Cleft like Gingival Recession: A Case Report

Background: Gingival recession exposes the tooth’s root with aesthetic disfigurement, frequently brings a patient to a dentist’s office for the objectionable aesthetics caused by the disease. This case report addressed the management of localized cleft like gingival recession in the tooth no 31 with the aid of Platelet Rich Fibrin (PRF). Methods: Mucosal flap was retracted from tooth no 41 to 33 followed by curettage and root planning on the effected tooth (where there was gingival recession). Allogenic bone graft was applied over the affected area, covered with freshly prepared autogenous PRF membrane, flap was repositioned and sutured. Results: Within six month after surgery previously denuded root surface of the treated incisor became entirely covered with mucosa and good aesthetics was regained; which after 4 years, maintained stable gingival contour and aesthetics. Conclusion: The result in the presented case indicate that PRF can be applied when cleft like gingival recession due to malocclusion is necessarily to be treated uneventfully with good aesthetics. Bangladesh Med Res Counc Bull 2018; 44: 168-170