ジカコツ オ モチイタ サイナス リフト ノ ジュツシキ ト ヨゴ ニツイテ

Treatment of the atrophic edentulous posterior maxilla with implant supported prosthesis is often difficult, because bone volume is insufficient and the bone quality is poor due to resorption of the alveolar ridge and due to increasing pneumatization of the maxillary sinus. Internal augmentation of the maxillary premolar and molar region (sinus floor elevation) was introduced to provide appropriate amounts of bone in a severely absorbed maxilla. Sinus floor elevation became widely accepted as a routine method to improve the amount of bone volume before implant placement. We applied this procedure for patients with atrophic edentulous posterior maxilla from 2000, and we treated the patients in order to restoration of mastication function in safety. In this paper, we give an explanation of operative procedure of sinus floor elevation with autogenous bone for details, and we also comment on the other graft materials, complication of the sinus floor elevation and resorption of autogneous bone grafted on sinus floor

INHIBITION OF IFN-γ PRODUCTION BY SOLUBLE FACTORS DERIVED FROM ORAL CANCER CELLS

The streptococcal antitumor agent OK-432 is commonly used as an immunopotentiator for immunotherapy in various types of malignant tumors including oral cancer. It has been demonstrated that OK-432 elicits an antitumor effect by stimulating immunocompetent cells, thereby inducing multiple cytokines including interferon (IFN)-γ, interleukin (IL)-2 and IL-12. Serum concentrations of IFN-γ in patients with oral cancer were examined 24 h after administration of OK-432. Serum concentrations of IFN-γ in patients with advanced cancer were significantly lower than those in patients with early cancer. These results suggested that some soluble factors produced by cancer cells may inhibit IFN-γ production with OK-432. Thus, in the present study, an in vitro simulation model was established for the immune status of patients with oral cancer by adding conditioned medium (CM) derived from oral cancer cell lines into a culture of peripheral blood mononuclear cells (PBMCs) derived from a healthy volunteer. We investigated whether soluble factors derived from oral cancer cells affected IFN-γ production from PBMCs following stimulation with OK-432. PBMCs stimulated with OK-432 produced a large amount of IFN-γ; however, both IFN-γ production and cytotoxic activity from PBMCs induced by OK-432 were inhibited by the addition of CM in a dose-dependent manner. In order to examine these inhibitory effects against IFN-γ production, the contribution of inhibitory cytokines such as IL-4, IL-6, IL-10, transforming growth factor-β and vascular endothelial growth factor was investigated. However, neutralization of these inhibitory cytokines did not recover IFN-γ production inhibited by CM. These results indicated that unknown molecules may inhibit IFN-γ production from PBMCs following stimulation with OK-432

CSC MARKERS IN OSCC AND THEIR ASSOCIATION WITH CLINICAL FACTORS

Cancer stem cells (CSCs) exhibit self-replication, self-differentiation, drug resistance and immune evasion activities. In recent years CSCs have become increasingly important for the treatment of malignant tumors. CSCs express specific markers, including cluster of differentiation (CD)44, CD44 variant 9 (CD44v9), ATP-binding cassette sub-family G member 2 (ABCG2), CD24, B lymphoma Mo-MLV insertion region 1 homolog (BMI-1) and aldehyde dehydrogenase 1 (ALDH1). However, the prognostic value of their expression in patients with oral squamous cell carcinoma (OSCC) are not well known. The present study evaluated these markers in stage I and II patients with OSCC and examined the association between T classification, histological differentiation, classification of invasion mode, lymph node metastasis and disease-free survival rate. Tissue specimens were obtained from 70 patients with stage I or II OSCC following either surgery or biopsy. Immunohistochemistry was performed and positive staining was defiend as 10% positive cells. CD44 and CD44v9 expressions were strongly detected in all OSCC tissues compared with normal epithelial cells. A total of 22 (31.4%) cases expressed ABCG2 and there was a significant association between ABCG2 expression and invasion. A total of 41 cases (59.0%) expressed CD24 and there was a significant association between CD24 expression and invasion. A total of 33 cases (47.1%) expressed BMI-1 and there was a significant association between BMI-1 expression and the disease-free survival rate. A total of 18 cases (25.7%) expressed ALDH1. Although there was no association between ALDH1 expression and T classification, there were significant associations between ALDH1 expression and histological differentiation, invasion mode, metastasis and the disease-free survival rate. Multivariate analysis revealed that ALDH1 expression was the only prognostic factor for disease-free survival rate. The results of the present study suggest that the positivity of ALDH1 detected in patients with OSCC correlates with the number of cells undergoing epithelial mesenchymal transition and metastasis. These findings indicated that the expression of ALDH1 may be an effective prognostic marker indicating the survival of patients with stage I and II OSCC

Physical and Histological Comparison of Hydroxyapatite, Carbonate Apatite, and β-Tricalcium Phosphate Bone Substitutes

Three commercially available artificial bone substitutes with different compositions, hydroxyapatite (HAp; Neobone®), carbonate apatite (CO3Ap; Cytrans®), and β-tricalcium phosphate (β-TCP; Cerasorb®), were compared with respect to their physical properties and tissue response to bone, using hybrid dogs. Both Neobone® (HAp) and Cerasorb® (β-TCP) were porous, whereas Cytrans® (CO3Ap) was dense. Crystallite size and specific surface area (SSA) of Neobone® (HAp), Cytrans® (CO3Ap), and Cerasorb® (β-TCP) were 75.4 ± 0.9 nm, 30.8 ± 0.8 nm, and 78.5 ± 7.5 nm, and 0.06 m2/g, 18.2 m2/g, and 1.0 m2/g, respectively. These values are consistent with the fact that both Neobone® (HAp) and Cerasorb® (β-TCP) are sintered ceramics, whereas Cytrans® (CO3Ap) is fabricated in aqueous solution. Dissolution in pH 5.3 solution mimicking Howship’s lacunae was fastest in CO3Ap (Cytrans®), whereas dissolution in pH 7.3 physiological solution was fastest in β-TCP (Cerasorb®). These results indicated that CO3Ap is stable under physiological conditions and is resorbed at Howship’s lacunae. Histological evaluation using hybrid dog mandible bone defect model revealed that new bone was formed from existing bone to the center of the bone defect when reconstructed with CO3Ap (Cytrans®) at week 4. The amount of bone increased at week 12, and resorption of the CO3Ap (Cytrans®) was confirmed. β-TCP (Cerasorb®) showed limited bone formation at week 4. However, a larger amount of bone was observed at week 12. Among these three bone substitutes, CO3Ap (Cytrans®) demonstrated the highest level of new bone formation. These results indicate the possibility that bone substitutes with compositions similar to that of bone may have properties similar to those of bone

Tophaceous pseudogout of the TMJ

We report a case of tophaceous pseudogout (i.e., calcium pyrophosphate dihydrate [CPPD] crystal deposition disease) in the temporomandibular joint (TMJ) that extended to the base of the skull. A 38-year-old man was referred to our hospital with mild pain in the right chin and tip of the tongue. Panoramic radiography showed a large calcified mass around the right TMJ. Computer tomography (CT) imaging revealed a large, granular, calcified mass surrounding the right condylar head and extending to the base of the skull. The mass was clinically and radiographically suspected to be a pseudogout lesion. A biopsy specimen was collected under general anesthesia to confirm the diagnosis. The mass histologically contained the deposition of numerous rod-shaped and rhomboid crystals, which suggested tophaceous pseudogout. The deposition was identified as CPPD crystal deposition, based on analysis by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). These two crystallography methods were useful in confirming the diagnosis of CPPD crystal deposition disease in the TMJ

Prevalence and Imaging Characteristics of Palatine Tonsilloliths Detected by CT in 2,873 Consecutive Patients

Tonsilloliths are calcified structures that develop in tonsillar crypts. They are commonly detected in daily clinical practice. The prevalence of tonsilloliths was 16 to 24% in previous reports, but it is inconsistent with clinical experience. The aim of this study is to clarify the prevalence, number, and size distribution of tonsilloliths using computed tomography (CT) in a relatively large number of patients. Materials and Methods. We retrospectively reviewed the scans of 2,873 patients referred for CT examinations with regard to tonsilloliths. Results. Palatine tonsilloliths were found in 1,145 out of 2,873 patients (39.9%). The prevalence of tonsilloliths increased with age, and most commonly in patients of ages 50–69. The prevalence in the 30s and younger was statistically lower than in the 40s and older (P < 0.05). The number of tonsilloliths per palatine tonsil ranged from one to 18. The size of the tonsilloliths ranged from 1 to 10 mm. For the patients with multiple CT examinations, the number of tonsilloliths increased in 51 (3.9%) and decreased in 84 (6.5%) of the tonsils. Conclusions. As palatine tonsilloliths are common conditions, screenings for tonsilloliths during the diagnosis of soft tissue calcifications should be included in routine diagnostic imaging

Histological comparison of three apatitic bone substitutes with different carbonate contents in alveolar bone defects in a beagle mandible with simultaneous implant installation

Since bone apatite is a carbonate apatite containing carbonate in an apatitic structure, carbonate content may be one of the factors governing the osteoconductivity of apatitic bone substitutes. The aim of this study was to evaluate the effects of carbonate content on the osteoconductivity of apatitic bone substitutes using three commercially available bone substitutes for the reconstruction of alveolar bone defects of a beagle mandible with simultaneous dental implant installation. NEOBONE®, Bio-Oss®, and Cytrans® that contain 0.1 mass%, 5.5 mass%, and 12.0 mass% of carbonate, respectively, were used in this study. The amount of newly formed bone in the upper portion of the alveolar bone defect of the beagle’s mandible was 0.7%, 6.6%, and 39.4% at 4 weeks after surgery and 4.7%, 39.5% and 75.2% at 12 weeks after surgery for NEOBONE®, Bio-Oss®, and Cytrans®, respectively. The results indicate that bone-to-implant contact ratio was the largest for Cytrans®. Additionally, the continuity of the alveolar ridge was restored in the case of Cytrans®, whereas the continuity of the alveolar ridge was not sufficient when using NEOBONE® and Bio-Oss®. Both Cytrans® and Bio-Oss® that has a relatively larger carbonate content in their apatitic structure was resorbed with time. We concluded that carbonate content is one of important factors governing the osteoconductivity of apatitic bone substitutes

Lingual tonsillolith on PR and CT

Objectives: Lingual tonsilloliths are not as well-known to radiologists than palatine tonsilloliths, although they might be common in clinical practice. The aim of this investigation was to clarify the prevalence and imaging characteristics of lingual tonsilloliths using panoramic radiographs and CT images. Methods: This study included 2244 patients without pathology at the base of tongue who had undergone panoramic radiography and CT of the maxillofacial region. The size, number and position of lingual tonsilloliths relative to the mandible and tongue were evaluated. Results: Lingual tonsilloliths were observed in 33 (1.5%) and 108 (4.8%) of all patients on panoramic radiographs and CT images, respectively. The prevalence was higher in patients aged ≥40 years than in those aged < 40 years (χ2, p < 0.01). They appeared as small, round- or rod-shaped calcified bodies, and they always located closely anterior (1–17 mm) to the anterior border of oropharyngeal airway on panoramic radiographs. Lingual tonsilloliths were superimposed over the surrounding soft tissue inferior to the body of the mandible, posteroinferior to the angle of the mandible and posterior to the mandible in 16 (48.5%), 15 (45.5%) and 1 (3.0%) individual, respectively. A significant correlation was observed between the detectability on panoramic radiographs and size (Spearman’s r = 0.961, p < 0.01) of tonsilloliths, as revealed by CT images. Conclusion: Lingual tonsilloliths commonly appear on CT. They also appear on panoramic radiography and may superimpose the surrounding soft tissue of the mandible. Although lingual tonsilloliths may resemble other pathological calcifications including submandibular sialoliths and lingual osseous cholistoma, they can be differentiated by carefully observing panoramic radiographs. When clinicians detect calcified bodies near the base of tongue, lingual tonsilloliths should be included in the differential diagnoses

Effects of acidic calcium phosphate concentration on setting reaction and tissue response to β-tricalcium phosphate granular cement

Beta-tricalcium phosphate granular cement (β-TCP GC), consisting of β-TCP granules and an acidic calcium phosphate (Ca-P) solution, shows promise in the reconstruction of bone defects as it sets to form interconnected porous structures, i.e., β-TCP granules are bridged with dicalcium phosphate dihydrate (DCPD) crystals. In this study, the effects of acidic Ca-P solution concentration (0–600 mmol/L) on the setting reaction and tissue response to β-TCP GC were investigated. The β-TCP GC set upon mixing with its liquid phase, based on the formation of DCPD crystals, which bridged β-TCP granules to one another. Diametral tensile strength of the set β-TCP GC was relatively the same, at approximately 0.6 MPa, when the Ca-P concentration was 20–600 mmol/L. Due to the setting ability, reconstruction of the rat’s calvarial bone defect using β-TCP GC with 20, 200, and 600 mmol/L Ca-P solution was much easier compared to that with β-TCP granules without setting ability. Four weeks after the reconstruction, the amount of new bone was the same, approximately 17% in both β-TCP GC and β-TCP granules groups. Cellular response to β-TCP granules and β-TCP GC using the 20 mmol/L acidic Ca-P solution was almost the same. However, β-TCP GC using the 200 and 600 mmol/L acidic Ca-P solution showed a more severe inflammatory reaction. It is concluded, therefore, that β-TCP GC, using the 20 mmol/L acidic Ca-P solution, is recommended as this concentration allows surgical techniques to be performed easily and provides good mechanical strength, and the similar cellular response to β-TCP granules