A rare incidence of mandibular metastasis of papillary thyroid carcinoma: A case report and review of literature.

Papillary Thyroid Carcinoma (PTC) primarily metastasizes via regional lymphatics making its spread to the oral cavity exceedingly rare. Although this disease remains the most common endocrine malignancy, comprising roughly 85%-90% of all thyroid cancers, its occurrence within the oral cavity happens in less than 1% of oral malignancies. This study identifies a case involving a 77-year-old male with a history of well-differentiated PTC that was initially treated with a total thyroidectomy and adjuvant radioactive iodine. Five years after his initial treatment, surveillance imaging demonstrated a 3 cm expansile mass of the left mandible. An incisional biopsy then confirmed the diagnosis of metastatic PTC. A segmental resection of his mandible was completed with final reconstruction utilizing a fibula free flap. Given the limited number of cases involving metastatic spread of PTC to the oral cavity, a standardized treatment algorithm does not exist. Thus, this case serves to provide a documented report of this rare occurrence and to review literature that may help other clinicians treat patients with this malignancy type. There remains a need for future studies to create risk stratification models for patients with metastatic PTC that consider margin analysis, genetic characteristics, and risk factors to tailor individual treatment plans.

Buccally or Lingually Tilted Implants in the Lateral Atrophic Mandible: A Three-Year Follow-Up Study Focused on Neurosensory Impairment, Soft-Tissue-Related Impaction and Quality of Life Improvement.

Background and Objectives: In the severely resorbed posterior mandible, implant placement requires either bone regenerative procedures, subperiosteal implants or short implant placement with drawbacks including morbidity and increased treatment costs and duration. To overcome these inconveniences, some unconventional alternatives have been suggested, such as buccally or lingually tilted implants in the lateral mandible, bypassing the inferior alveolar nerve. The aim of the present retrospective study was to evaluate the three-year survival rate of implants inserted in the posterior atrophic mandible, bypassing the inferior alveolar nerve. The assessment was focused on the occurrence of postoperative complications related to neurosensory impairment and soft tissue impaction, as well as overall improvement in quality of life. Materials and Methods: Patients with severe bone atrophy in the lateral area of the mandible were included in the present study. Only the implants tilted either buccally or lingually to bypass the inferior alveolar nerve were analysed. The relation between peri-implant soft tissue and the healing abutment was assessed and a secondary revision surgery was performed when indicated. The Semmes-Weinstein pressure neurological test was used for qualitative assessment of inferior alveolar nerve function and the Geriatric Oral Health Assessment Index (GOHAI) was used for evaluating Oral-Health-Related Quality of Life (OHRQoL). Results: Fourteen implants were placed in nine patients during the evaluation period. Survival rate was 100%, temporary paraesthesia occurred in one patient and a limited definitive paraesthesia was seen in another patient. Mild or significant discomfort related to soft tissue impaction with healing abutment was observed in six out of nine patients. A statistically significant OHRQoL improvement was observed in all patients. Conclusions: Despite the limited number of patients and observation time, insertion of implants buccally or lingually bypassing the inferior alveolar nerve is a predictive treatment option for patients with severe bone atrophy in the posterior mandible.

Prospective Phase II Open-Label Randomized Controlled Trial to Compare Mandibular Preservation in Upfront Surgery With Neoadjuvant Chemotherapy Followed by Surgery in Operable Oral Cavity Cancer.

PURPOSE: The objective of this study was to explore the potential role and safety of neoadjuvant chemotherapy (NACT) in tumor shrinkage and resultant mandibular preservation in oral cancers compared with conventional surgical treatment. METHODS: This study was a single-center, randomized, phase II trial of treatment-naive histologically confirmed squamous cell carcinoma of the oral cavity with cT2-T4 and N0/N+, M0 (American Joint Committee on Cancer, seventh edition) stage, necessitating resection of the mandible for paramandibular disease in the absence of clinicoradiologic evidence of bone erosion. The patients were randomly assigned (1:1) to either upfront surgery (segmental resection) followed by adjuvant treatment (standard arm [SA]) or two cycles of NACT (docetaxel, cisplatin, and fluorouracil) at 3-week intervals (intervention arm [IA]), followed by surgery dictated by postchemotherapy disease extent. All patients in the IA received adjuvant chemoradiotherapy, and patients in the SA were treated as per final histopathology report. The primary end point was mandible preservation rate. The secondary end points were disease-free survival and treatment-related toxicity. RESULTS: Sixty-eight patients were enrolled over 3 years and randomly assigned to either SA (34 patients) or IA (34 patients). The median follow-up was 3.6 years (interquartile range, 0.95-7.05 years). Mandibular preservation was achieved in 16 of 34 patients (47% [95% CI, 31.49 to 63.24]) in the IA. The disease-free survival (P = .715, hazard ratio 0.911 [95% CI, 0.516 to 1.607]) and overall survival (P = .747, hazard ratio 0.899 [95% CI, 0.510 to 1.587]) were similar in both the arms. Complications were similar in both arms, but chemotherapy-induced toxicity was observed in the majority of patients (grade III: 14, 41.2%; grade IV: 11, 32.4%) in the IA. CONCLUSION: NACT plays a potential role in mandibular preservation in oral cancers with acceptable toxicities and no compromise in survival. However, this needs to be validated in a larger phase III randomized trial.

Ozonotherapy for Treatment of Radiation Therapy-induced Jaw Osteonecrosis and Bisphosphonates: Case Report / Ozonioterapia para o Tratamento de Osteonecrose em Mandíbula Induzida pela Radioterapia Associada com Bisfosfonato: Relato de Caso / Ozonoterapia para el Tratamiento de la Osteonecrosis de la Mordaza Inducida por Terapia de Radiación y Bisfosfonatos: Relato de Caso

Introduction: The inhibition of osteoclastic activity, associated with different treatment modalities in patients with head and neck cancer, make bones unable to respond to repair processes related to physiological traumas or infection and may result in bone necrosis. The present study aims to report a clinical case of osteoradionecrosis in mandible, and how its sequels were controlled by ozonotherapy. Case report: A 73-year-old female patient with infiltrative ductal breast carcinoma with mandibular metastasis was submitted to chemo and radiotherapy at head and neck region associated with bisphosphonate. Three years later, she was diagnosed with hemimandibular osteoradionecrosis that exhibited communication with oral cavity and with a chronic, suppurative and persistent associated infection. It was applied adjuvant therapy with ozone through the cutaneous fistula and the exposed and necrotic bone. Additionally, non-vital bone debridement was proceeded in two surgical steps. The patient is after a 1-year follow-up non-symptomatic. Conclusion: It is supposed that ozonotherapy, due to its antibacterial and immunoregulatory mechanism of action, was an important therapeutic agent for improving the patient's quality of life.

Introdução: A inibição da atividade osteoclástica, associada a diversas modalidades de tratamento utilizadas em pacientes com câncer de cabeça e pescoço, torna o osso incapaz de responder aos processos de reparo relacionados a traumas fisiológicos ou à infecção, e pode resultar em necrose óssea. O presente estudo tem como objetivo relatar um caso clínico de osteonecrose em mandíbula como consequência do uso de bisfosfonato associado à quimioterapia e à radioterapia para tratamento de câncer de mama com metástase para mandíbula, tendo suas sequelas controladas por meio do uso da ozonioterapia. Relato do caso: Paciente do sexo feminino, 73 anos, com história de carcinoma ductal infiltrante de mama com metástase óssea em mandíbula, a qual foi submetida ao tratamento de quimioterapia e radioterapia em região de cabeça e pescoço; três anos depois, foi diagnosticada com osteonecrose da hemimandíbula direita com exposição completa para a cavidade bucal e infecção crônica, supurativa e persistente. Foi realizada terapia adjuvante com aplicação de ozônio nas fístulas cutâneas e no remanescente ósseo exposto e necrosado, além do desbridamento dos sequestros ósseos em duas etapas cirúrgicas. Paciente encontra-se em acompanhamento há 1 ano, sem sintomatologia associada. Conclusão: Observou-se que a ozonioterapia, em razão da sua ação antibacteriana e cicatrizante, foi um importante agente terapêutico para a melhora da qualidade de vida da paciente.

Introducción: La inhibición de la actividad osteoclástica, asociada con las diversas modalidades de tratamiento utilizadas por los pacientes con cáncer de cabeza y cuello, hace que el hueso no pueda responder a los procesos de reparación relacionados con traumas o infecciones fisiológicas y puede provocar necrosis ósea. El presente estudio tiene como objetivo informar un caso clínico de osteonecrosis mandibular como consecuencia del uso de bisfosfonato asociado con quimioterapia y radioterapia para tartar el cáncer de mama con mandíbula metastásica, controlando sus secuelas mediante el uso de la terapia con ozono. Relato del caso: Paciente de 73 años con antecedentes de carcinoma ductal mamario infiltrante con metástasis en la mandíbula ósea fue sometida a quimioterapia y radioterapia en la región de la cabeza y el cuello. Tres años después, le diagnostica con osteonecrosis hemimandibular derecha con exposición completa a la cavidad oral e infección crónica, supurativa y persistente. La terapia adyuvante se realizó con la aplicación de ozono en las fístulas cutáneas y en el remanente óseo expuesto y necrótico, además del desbridamiento de los secuestros óseos en dos etapas quirúrgicas. El paciente ha estado bajo seguimiento durante 1 años in síntomas asociados. Conclusión: Debido a su acción antibacteriana y curativa, la ozonioterapia fue un importante agente terapéutico para mejorar la calidad de vida del paciente.

Effects of Drynaria Total Flavonoid on the Microstructure of the Mandible in Ovariectomized Rats.

BACKGROUND The aim of this study is to investigate the effects of Drynaria total flavonoids (DTF) on mandible microarchitecture, serum estrogen (E2), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL) levels in an ovariectomy-induced osteoporosis rat model. MATERIAL AND METHODS Thirty female Sprague-Dawley rats were divided into 5 groups (n=6 per group): sham surgery, ovariectomy (OVX), and low-dose, middle-dose, and high-dose DTF. Mandibular osteoporosis was induced by ovariectomy; an equal amount of ovary-sized fat tissue was removed from the sham group. The DTF-treated groups were given DTF gavage at different doses for 12 weeks; the sham and OVX groups were given saline. After the treatment phase, the effects of DTF on the microarchitecture of the mandible were evaluated by measuring bone density, maximum load, morphometric parameters, and histopathological alterations. Serum E2, OPG, and RANKL levels were measured. RESULTS The OVX group showed obvious osteoporosis in the mandible and decreased serum E2 levels and OPG/RANKL ratio. The low-dose group did not show significant improvement in mandibular microstructure. The middle-dose group showed significantly ameliorated osteoporosis. The high-dose group had further improvement in bone microstructures and increase of OPG/RANKL over the middle-dose group. Furthermore, ovariectomy significantly decreased serum E2, but DTF treatment failed to restore serum E2 levels. CONCLUSIONS Ovariectomy can cause significant bone loss in the rat mandible and a decrease in serum E2 and OPG/RANKL. DTF significantly improved the mandibular microstructure and restored OPG/RANKL balance, but it did not restore the decreased serum E2 concentration following ovariectomy.

Effects of 4-Week Diacutaneous Fibrolysis on Myalgia, Mouth Opening, and Level of Functional Severity in Women With Temporomandibular Disorders: A Randomized Controlled Trial.

OBJECTIVE: The purpose of this study was to assess the effects of 4-week protocol of diacutaneous fibrolysis (DF) compared with simulated DF (sham-DF) on myalgia and mouth opening. METHODS: In a sham randomized controlled trial, 34 women with temporomandibular disorders and myofascial pain were randomly divided as intervention group (IG) and sham-DF group (SG). The IG received 4 weeks of real DF, and the SG received sham. Pain was assessed through the visual analog scale and pressure pain thresholds (PPTs) on the temporomandibular joint (TMJ), and over the temporal and masseter muscles. The Mandibular Function Impairment Questionnaire was used to classify the participants regarding to the severity of the functional limitation related to TMD. RESULTS: Pain scores decreased for both groups, but the IG showed lower values at week 4, with between-group differences. Bilateral temporal PPT showed higher values at week 4, with between-group differences. The SG had lower PPTs but the IG had higher PPTs, both compared to baseline results. The time-by-group interaction and the frequency of participants above 40 mm of mouth opening showed a significant difference for the IG over time with higher results at the 4-week assessment compared to its own baseline. Both groups showed lower MFIQ scores from baseline to 4-week assessment. There was a lower frequency of a moderate level of severity for the IG. No differences were observed for TMJ or for the masseter muscles PPT. CONCLUSION: Improvements were observed for visual analog scale scores and PPTs on temporal muscles. There was a group-by-time interaction in the IG, suggesting a possible potential use of DF for mouth opening.

Otx2b mutant zebrafish have pituitary, eye and mandible defects that model mammalian disease.

Combined pituitary hormone deficiency (CPHD) is a genetically heterogeneous disorder caused by mutations in over 30 genes. The loss-of-function mutations in many of these genes, including orthodenticle homeobox 2 (OTX2), can present with a broad range of clinical symptoms, which provides a challenge for predicting phenotype from genotype. Another challenge in human genetics is functional evaluation of rare genetic variants that are predicted to be deleterious. Zebrafish are an excellent vertebrate model for evaluating gene function and disease pathogenesis, especially because large numbers of progeny can be obtained, overcoming the challenge of individual variation. To clarify the utility of zebrafish for the analysis of CPHD-related genes, we analyzed the effect of OTX2 loss of function in zebrafish. The otx2b gene is expressed in the developing hypothalamus, and otx2bhu3625/hu3625 fish exhibit multiple defects in the development of head structures and are not viable past 10 days post fertilization (dpf). Otx2bhu3625/hu3625 fish have a small hypothalamus and low expression of pituitary growth hormone and prolactin (prl). The gills of otx2bhu3625/hu3625 fish have weak sodium influx, consistent with the role of prolactin in osmoregulation. The otx2bhu3625/hu3625 eyes are microphthalmic with colobomas, which may underlie the inability of the mutant fish to find food. The small pituitary and eyes are associated with reduced cell proliferation and increased apoptosis evident at 3 and 5 dpf, respectively. These observations establish the zebrafish as a useful tool for the analysis of CPHD genes with variable and complex phenotypes.

Mandibular resorption and vocal cord paralysis: a catastrophic form of systemic sclerosis.

Sudden respiratory distress in association with severe weight loss are unusual features of systemic sclerosis (SSc). We report the case of a 56-year-old Caucasian woman with a 9-year history of a diffuse form of SSc who presented with acute stridor due to vocal cord paralysis and required an emergency tracheostomy. She had sought medical attention only after 4 years of disease onset, presenting with a mask-like face, diffuse skin thickening, acro-osteolysis and severe interstitial lung disease. Even though skin tightness improved after immunosuppressive treatment, several spontaneous facial fractures and episodes of dysphagia and choking occurred in the years that followed. At the time of stridor, she was severely malnourished and a percutaneous endoscopic gastrostomy was required for feeding. Permanent vocal cord damage in combination with severe loco-regional bone resorption resulted in severe disability and impaired nutrition. We hereby highlight the features of SSc for which therapy remains challenging.

Hide and seek: Impacted maxillary and mandibular canines from the Roman period Croatia.

OBJECTIVE: The aim of this paper was to analyse the dental remains of an adult male with three impacted canines from the Roman period cemetery in Osijek, Croatia. MATERIALS: The dental remains of an adult male aged 35-45 years at the time of death were analysed. METHODS: Macroscopic analysis of dental remains was accompanied by radiographic examination. RESULTS: The individual also had additional dental pathologies (carious lesion, antemortem tooth loss). A total of 21 permanent teeth were present in maxillae and mandible. Eighteen of them were normal fully erupted dentition, while three were impacted: left maxillary canine and both mandibular canines. The left maxillary and mandibular canines were mesially inclined, and the right mandibular canine was relatively horizontally positioned. CONCLUSION: A case of non-syndrome impaction in which the lack of eruptive force in combination with the unfavorable position of the tooth bud might have resulted in multiple impacted teeth is presented. SIGNIFICANCE: Current clinical knowledge reports low frequency of this anomaly, with maxillary impaction occurring more often than mandibular. Furthermore, canine impaction is even more rarely reported in the archaeological material. The presented case is the only one from the archaeological setting with impaction present both in maxillae and mandible. LIMITATIONS: In modern populations multiple impactions are often associated with various syndromes. Since the majority of syndromes affect soft tissue, their association with impaction cannot be confirmed in archaeological populations.

970 nm low-level laser affects bone metabolism in orthodontic tooth movement.

OBJECTIVE: During orthodontic tooth movement (OTM), the speed of movement depends on the rate of bone turnover. In this study, we used a rat model to investigate the effect of 970 nm low-level laser therapy (LLLT) on OTM under different dose and frequency protocols. METHODS: We first compared the OTM rates between the OTM only control and the OTM + LLLT group (1250 J/cm2) in Experiment 1 and showed that LLLT significantly increased OTM. In Experiment 2, we employed 3 different LLLT protocols: the low-dose group and the high-dose group receiving 5 doses of 750 J/cm2 and 15,000 J/cm2 of LLLT every 3 days, respectively, and the early high-dose group which received 5 daily doses at 15,000 J/cm2 at the beginning of the experiments. The OTM-only control group received no LLLT. Tooth movement rate was measured through sequential silicone impressions. MicroCT was also performed to evaluate bone de-mineralization rate. Bone histmorphometry was used to compare the bone turnover rate between LLLT group and control group. Finally, TRAP, Osteocalcin, and VEGF expression is evaluated by immunohistochemistry (IHC) in tissue sections. RESULTS: When LLLT treatment was given every three days, both the 1250 J/cm2 and 15,000 J/cm2 groups showed significantly increased OTM compared to the control group. No significant difference was observed in the 750 J/cm2 group, or in the early irradiation group, when compared with controls, although 750 J/cm2 showed the same trend of accelerating OTM. The MicroCT result of rat maxilla demonstrated that LLLT increased bone remodeling and showed decreased bone mineral density and bone volume/total volume in the furcation areas of the maxillary first molars at the end of experiment. LLLT without OTM increased bone turnover as evidenced by fluorochrome incorporation. Immunohistochemistry analyses revealed high osteocalcin expression at later stages of OTM in the LLLT group, while VEGF expression was highly induced in the LLLT + OTM group at an early stage. CONCLUSION: Our results suggest that the 970 nm LLLT increases the rate of OTM in a dose-sensitive and frequency-dependent manner. Further animal and human studies are needed to determine the optimal timing and dosage of LLLT for OTM acceleration.

Benign fibro-osseous lesion of the mandible in a Middle Bronze Age skeleton from Southern Russia.

A discrete dysplastic lesion of the mandible found in a skeleton of a young adult male of the Middle Bronze Age in the Northern Caucasus/Russia is described. The periapical lesion of the right lower canine alveolus was examined by digital microscopy, plain radiology, and plain and polarizing microscopy. Its macroscopic, radiologic and microscopic characteristics are discussed in reference to different fibro-osseous lesions arising from the odontogenic apparatus and maxillofacial skeleton. Periapical osseous dysplasia was considered to be the most likely diagnosis.

Effect of expanded bone marrow-derived osteoprogenitor cells seeded into polycaprolactone/tricalcium phosphate scaffolds in new bone regeneration of rabbit mandibular defects.

The purpose of this study was to assess and evaluate new bone formation in rabbit marginal mandibular defects using expanded bone marrow-derived osteoprogenitor cells seeded in three-dimensional scaffolds of polycaprolactone/tricalcium phosphate (PCL/TCP). Bone marrow was harvested from the rabbit ilium and rabbit bone marrow-derived osteoprogenitor cells were isolated and expanded in standard culture medium and osteogenic medium supplement. The cells were then seeded into the PCL/TCP scaffolds and the cell/scaffold constructions were implanted into prepared defects in rabbit mandibles. PCL/TCP scaffold alone and autogenous bone graft from the mandible were also implanted into the other prepared defects. The specimens were evaluated at 4 and 8 weeks after the implantation using clinical, radiographic, and histological techniques. The results of the experimental group demonstrated more newly formed bone on the surface and in the pores of the PCL/TCP scaffolds. In addition, the osteoblasts, osteocytes, and new bone trabeculae were identified throughout the defects that were implanted with the cell/scaffold constructions. The PCL/TCP alone group was filled mostly with fibrous cells particularly in the middle region with less bone formation. These results would suggest that the derived osteotoprogenitor cells have the potential to form bone tissue when seeded onto PCL/TCP scaffolds.

Treatment of obstructive sleep apnoea-hypopnea syndrome by mandible advanced device reduced neuron apoptosis in frontal cortex of rabbits.

Objective: To investigate effects of mandible advanced device (MAD) therapy for obstructive sleep apnoea-hypopnea syndrome (OSAHS) on the neuron apoptosis and acetylcholine esterase activity in frontal cortex. Materials and methods: Thirty male New Zealand white rabbits were randomly divided into three groups (n = 10 in each group): group OSAHS, group MAD, and control group. Hydrophilic polyacrylamide gel was injected into soft palate of the animals to induce OSAHS in group OSAHS and group MAD. The group MAD animals wore MAD to relief the obstructiveness. The control group was not given any treatment. Computed tomography (CT) examination of the upper airway and polysomnography (PSG) recordings were performed in supine position. All rabbits were induced to sleep in a supine position for 4 to 6 hours every day and were observed for consecutive 8 weeks. The frontal cortices of three groups were dissected and the neuron apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and flow cytometry. Acetylcholine esterase (AchE) activity in the frontal cortex was measured by spectrophotometry. Results: The group OSAHS exhibited high neuron apoptosis rate and low AchE activity than those of group MAD and control group. The blood oxygen saturation was negatively correlated with neuronal apoptosis rate and positively correlated with AchE activity. Applying MAD in OSAHS animals significantly improve the neuronal damage and function deficits by apnoea-hypoxia caused by narrowed upper airway. Conclusion: This study provided evidence that MAD therapy for OSAHS can significantly decrease neuronal apoptosis and increase AchE activity in the frontal cortex.

Curcumin photodynamic effect in the treatment of the induced periodontitis in rats.

This study assessed the effect of curcumin as a photosensitizer in antimicrobial photodynamic therapy (aPDT) for the treatment of induced periodontitis in rats. Periodontitis was induced via a ligature around the mandibular first molar on the left side of 96 rats. The ligature was removed 7 days later, and the animals were randomized into four groups: NT, no local treatment; CUR, irrigation with curcumin solution (40 µM); LED, irradiation with a light-emitting diode (LED, InGaN, 465-485 nm, 200 mW/cm2, 60 s); and aPDT, irrigation with curcumin solution (40 µM) followed by irradiation with LED. Eight animals from each group were euthanized at 7, 15, and 30 days post-treatment. Treatments were assessed using alveolar bone loss (ABL) in the furcation region using histological, histometric, and immunohistochemical analyses. Rats treated with aPDT exhibited less ABL at 7 days compared to the NT group, moderate pattern immunolabeling for osteoprotegerin at 30 days, and a pattern of immunolabeling for RANKL from moderate to low. Treatments resulted in smaller numbers of TRAP-positive cells compared to the NT group. aPDT as monotherapy using curcumin as a photosensitizer and LED as the light source was effective in the treatment of induced periodontitis in rats.

Effect of strontium citrate on bone consolidation during mandibular distraction osteogenesis.

OBJECTIVES/HYPOTHESIS: Mandibular distraction osteogenesis (MDO) involves a lengthy consolidation phase where complications can occur. Strontium is an element that has been shown to improve bone healing. The objective of this study was to determine whether strontium citrate can be used to enhance bone healing during MDO in a rabbit model. STUDY DESIGN: Prospective animal model study. METHODS: Custom-made MDO devices were placed on 20 New Zealand White rabbits. After a 7-day latency period, distraction was performed at 1 mm/day for 5 days. The study group rabbits (n = 10) received oral strontium citrate; the other 10 rabbits served as controls. Mandibles were removed at the end of the consolidation period (4 weeks). Formation and healing of new bone were evaluated with microcomputed tomography, histology, and a three-point bending mechanical test. RESULTS: New bone formed in all animals, but the consolidation process was enhanced in rabbits that received strontium. The histological analysis showed that study group rabbits had more mature bone. Microcomputed tomographic images demonstrated significantly higher bone density for study group animals, and the three-point bending test results demonstrated that the maximum load of the study group specimens was significantly greater than that of the control group mandibles. CONCLUSIONS: Strontium citrate improved the formation of new bone in the current rabbit model of MDO. The prolonged consolidation period may be shortened with strontium citrate, which may also have the potential to reduce complications. LEVEL OF EVIDENCE: NA Laryngoscope, 127:E212-E218, 2017.

Bone Degeneration and Its Recovery in SMP30/GNL-Knockout Mice.

Senescence marker protein-30 (SMP30) decreases androgen-independently with aging and is a lactone-hydrolyzing enzyme gluconolactonase (GNL) that is involved in vitamin C biosynthesis. In the present study, bone properties of SMP30/GNL knockout (KO) mice with deficiency in vitamin C synthesis were investigated to reveal the effects of SMP30/GNL and exogenous vitamin C supplementation on bone formation. Mineral content (BMC) and mineral density (BMD) of the mandible and femur of SMP30/GNL KO and wild-type mice at 2 and 3 months of age with or without vitamin C supplementation were measured by dual-energy X-ray absorptiometry. Body and bone weight of both age groups decreased and became significantly lower than those of wild-type mice. The bones of SMP30/GNL KO mice were rough and porous, with BMC and BMD significantly below wild-type. Oral supplementation with vitamin C eliminated differences in body weight, bone weight, BMC, and BMD between SMP30/GNL KO and wild-type mice at each age. These results indicate that bone degeneration in SMP30/GNL KO mice was caused by lack of vitamin C, and that this mouse strain is an appropriate model for bone metabolism in humans, which have no ability to synthesize vitamin C.

Influence of low-level laser therapy on the healing process of autogenous bone block grafts in the jaws of systemically nicotine-modified rats: A histomorphometric study.

OBJECTIVE: To analyze the influence of low-level laser therapy (LLLT) on the bone healing process of autogenous bone block grafts installed in nicotine systemically modified rats. METHODS: Seventy-two rats (Wistar) were randomly assigned into 4 groups (n=18). SS-BG: saline application+bone graft. SS-BG/LLLT: saline application+bone graft+LLLT. NIC-BG: nicotine application+bone graft. NIC-BG/LLLT: nicotine application+bone graft+LLLT. After 30days of application of solutions, all animals received autogenous bone block graft in the jaw, with the donation from the parietal bone's calvarial area. Treatment with LLLT was in bed-graft interface, after accommodation of the graft. The animals in each group were sacrificed at 7, 14, and 28days after graft surgery. RESULTS: The histologic analyses of NIC-BG group depicted a delay of osteogenic activity in the recipient bed-graft interface and the irradiation of tissue with LLLT provided better bone healing. The histometric analysis revealed that SS-BG/LLLT and NIC-BG/LLLT groups showed increased bone formation compared to BG-SS and NIC-BG groups, after 14days (SS-BG 24.94%±13.06% versus SS-BG/LLLT 27.53%±19.07% and NIC-BG 14.27%±2.22% versus NIC-BG/LLLT 24.37%±11.93%) and 28days (SS-BG 50.31%±2.69% versus SS-BG/LLLT 58 19%±12.32% and NIC-BG 36.89%±8.40% versus NIC-BG/LLLT 45.81%±6.03%). CONCLUSION: Nicotine harms bone formation in the bed-graft interface and LLLT action can mitigate this.

Excision of recurrent synovial sarcoma of the infratemporal fossa.

Synovial sarcoma is a soft tissue sarcoma especially encountered in the lower extremities. The infratemporal fossa is quite a rare location. Since it is a closed location, combined approaches and multidisciplinary planning always need to be considered. This case emphasizes the high-grade character of synovial sarcoma, which causes it to recur often. The difficulty of clear surgical margins in the infratemporal fossa adds to synovial sarcoma a second challenging issue. Therefore, the need of complementary therapy is essential. In this case, we applied postoperative radiotherapy and we did not observe any sign of local, regional or distant metastasis in the one-year follow-up. In this article, we present a 68-year-old male patient together with totally excised synovial sarcoma in the infratemporal fossa by mandibular swing and transzygomatic technique information on the manifestation, imaging, histopathological features and postoperative complications of previous infratemporal fossa synovial sarcomas.

Providing Flaxseed Oil but Not Menhaden Oil Protects against OVX Induced Bone Loss in the Mandible of Sprague-Dawley Rats.

Higher intakes of polyunsaturated fatty acids (PUFA) are associated with benefits at several skeletal sites in postmenopausal women and in rodent models, but the effect of PUFA-containing oils on tooth-supporting alveolar bone of the mandible has not been studied. Moreover, direct comparison of the effect of flaxseed oil (a source of alpha-linolenic acid (ALA)) and menhaden oil (a source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) is unknown. One-month old female Sprague-Dawley rats (n = 48) were randomized to and fed a diet containing flaxseed oil or menhaden oil from one to six months of age. At three months of age, rats were randomized to receive SHAM or ovariectomy (OVX) surgery (n = 12/diet). The inter-radicular septum below the first molar of the mandible was imaged at 6 months of age (study endpoint) using micro-computed tomography (µCT) at a resolution of 9 µm. As expected, OVX significantly reduced percent bone volume (BV/TV), connectivity density (Conn. D.), trabecular number (Tb. N.), and increased trabecular separation (Tb. Sp.) compared to SHAM rats (p < 0.001). However, post hoc analysis revealed these differences were present in rats fed menhaden oil but not those fed flaxseed oil. These results suggest that providing flaxseed oil, possibly through its high ALA content, provides protection against the OVX-induced alveolar bone loss in rats.