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

Effectiveness of Newly Developed Water-Equivalent Mouthpiece during External Beam Radiotherapy for Oral Cancer

The objective of this study was to research the effectiveness of newly developed water-equivalent mouthpiece during external beam radiotherapy for oral cancer. In external beam radiotherapy for cancer of the tongue, floor of the mouth, and lower gingiva, it is possible to prescribe a low dose to the upper gingiva and hard palate at an open mouth position using a mouthpiece. However, the inhomogeneity correction resulting from the air cavity and the mobility of the tongue produced by an open mouth position should be considered. Therefore, a new mouthpiece was designed to be fixed by the dental arch, and the air cavity of the mouth can be filled with water-equivalent material. In 30 patients with previously treated oral cancer, the simulated homogeneity index of the calculated water-equivalent mouthpiece by a treatment-planning system was significantly better than that of a conventional mouthpiece (p = 0.004). This new mouthpiece facilitates excellent dose distribution while attaining immobilization of the tongue in patients with oral cancer

Reconstruction of rabbit mandibular bone defects using carbonate apatite honeycomb blocks with an interconnected porous structure

Carbonate apatite (CO3Ap) granules are useful as a bone substitute because they can be remodeled to new natural bone in a manner that conforms to the bone remodeling process. However, reconstructing large bone defects using CO3Ap granules is difficult because of their granular shape. Therefore, we fabricated CO3Ap honeycomb blocks (HCBs) with continuous unidirectional pores. We aimed to elucidate the tissue response and availability of CO3Ap HCBs in the reconstruction of rabbit mandibular bone defects after marginal mandibulectomy. The percentages of the remaining CO3Ap area and calcified bone area (newly formed bone) were estimated from the histological images. CO3Ap area was 49.1 ± 4.9%, 30.3 ± 3.5%, and 25.5 ± 8.8%, whereas newly formed bone area was 3.0 ± 0.6%, 24.3 ± 3.3%, and 34.7 ± 4.8% at 4, 8, and 12 weeks, respectively, after implantation. Thus, CO3Ap HCBs were gradually resorbed and replaced by new bone. The newly formed bone penetrated most of the pores in the CO3Ap HCBs at 12 weeks after implantation. By contrast, the granulation tissue scarcely invaded the CO3Ap HCBs. Some osteoclasts invaded the wall of CO3Ap HCBs, making resorption pits. Furthermore, many osteoblasts were found on the newly formed bone, indicating ongoing bone remodeling. Blood vessels were also formed inside most of the pores in the CO3Ap HCBs. These findings suggest that CO3Ap HCBs have good osteoconductivity and can be used for the reconstruction of large mandibular bone defects

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

Prevalence and imaging characteristics of palatine tonsilloliths evaluated on 2244 pairs of panoramic radiographs and CT images

Objectives: Palatine tonsilloliths incidentally detected on diagnostic imaging should be differentiated from pathologic calcifications to enable correct diagnosis and treatment. The aim of this study is to clarify the prevalence and imaging characteristics of palatine tonsilloliths on panoramic radiographs. Materials and Methods: We retrospectively reviewed 2,244 individuals who underwent pairs of consecutive panoramic radiography and computed tomography (CT) of the head and neck region. The imaging characteristics of palatine tonsilloliths on panoramic radiography were compared with the findings from CT, which was considered the gold standard. Results: Tonsilloliths were detected in 300 (13.4%) and 914 (40.7%) of the 2,244 individuals on panoramic radiographs and CT, respectively. On panoramic radiographs, tonsilloliths were superimposed over the ramus of the mandible at the level coincident with and inferior to the soft palate in 176 (7.8%) and 90 (4.0%) individuals, respectively. Tonsilloliths were also superimposed over the surrounding soft tissue inferior to the body of the mandible, postero-inferior to the angle of the mandible, and posterior to the ramus of the mandible in 33 (1.5%), 26 (1.2%), and 28 (1.3%) individuals, respectively. A significant correlation was observed between the detectability on panoramic radiographs and the size (Spearman r=1.000) and number (Spearman r=0.991) of tonsilloliths, as revealed by CT images. Conclusions: The present results suggest that tonsilloliths are commonly detected on panoramic radiographs. Furthermore, they can be superimposed on both the mandible and the surrounding soft tissue. Clinical Relevance: Clinicians should include tonsilloliths among the differential diagnoses when calcified bodies are detected on panoramic radiographs

Effect of dental metal artifact conversion volume on dose distribution in head‐and‐neck volumetric‐modulated arc therapy

Purpose: During treatment planning for head‐and‐neck volumetric‐modulated arc therapy (VMAT), manual contouring of the metal artifact area of artificial teeth is done, and the area is replaced with water computed tomography (CT) values for dose calculation. This contouring of the metal artifact areas, which is performed manually, is subject to human variability. The purpose of this study is to evaluate and analyze the effect of inter‐observer variation on dose distribution. Methods: The subjects were 25 cases of cancer of the oropharynx for which VMAT was performed. Six radiation oncologists (ROs) performed metal artifact contouring for all of the cases. Gross tumor volume, clinical target volume, planning target volume (PTV), and oral cavity were evaluated. The contouring of the six ROs was divided into two groups, small and large groups. A reference RO was determined for each group and the dose distribution was compared with those of the other radiation oncologists by gamma analysis (GA). As an additional experiment, we changed the contouring of each dental metal artifact area, creating enlarged contours (L), reduced contours (S), and undrawn contours (N) based on the contouring by the six ROs and compared these structure sets. Results: The evaluation of inter‐observer variation showed no significant difference between the large and small groups, and the GA pass rate was 100%. Similar results were obtained comparing structure sets L and S, but in the comparison of structure sets L and N, there were cases with pass rates below 70%. Conclusions: The results show that the artificial variability of manual artificial tooth metal artifact contouring has little effect on the dose distribution of VMAT. However, it should be noted that the dose distribution may change depending on the contouring method in cases where the overlap between PTV and metal artifact areas is large

Can Kampo therapy prolong the life of cancer patients?

Our policy regarding the performance of radiotherapy to squamous cell carcinoma of the uterine cervix has not changed since 1969. We have already reported the treatment results which were as good as those from other institutions. Since 1978, Kampo therapy was first introduced in the treatment of cancer patients in dealing with problems such as the side effects of radiotherapy and chemotherapy and various types of general malaise. We analyzed our treatment results in order to re-evaluate the chemo-radiotherapy in combination with Kampo. Survival rates for 5, 10 and 15 years, respectively, were 90.9%, 71.6% and 71.6% for Stage IB, 78.9%, 61.8% and 41.8% for Stage II, 62.3%, 49.1% and 41.2% for Stage III and 53.1%, 36.5% and 16.7% for Stage IV. The Kampo significantly extended the survival of patients with uterine cervical cancer. We intend to perform further research with more patients to explore how this therapy contributes to the prolonging of patients survival

コウクウ ガク ガンメン アクセイ シュヨウ ノ エンカク テンイ ヒョウカ ニオケル クカンブ CT ケンサ ノ イチズケ

Abdominal CT examinations for the scouting of distant metastasis (DM) of orofacial malignant tumors were retrospectively evaluated, for the purpose of establishing the standard way of examination. Out of 159 patients with oral malignancies, 247 abdominal CT examinations were performed for the purpose of scouting DM. During the examination, intravenous contrast enhancement (CE) was performed in 166 examinations. DM were detected in 13 patients (8.2%). DM were found in 6 at administration, and 8 were late DM. Nine DM were detected out of 166 (5.4%) examinations with CE, and 5 were detected out of 81 (6.2%) examinations without CE. In detecting the DM, no improvement was found by CE. DM attacked lungs in 13, mediastinum in 3, liver in 2, paraaortic lymph nodes in 1, chest wall in 1, and vertebra in 1. Only 2 patients with DM were free from cervical metastasis, and the remainder was combined with cervical metastasis, regardless the status of the primary sites. Conclusions: Abdominal CT was useful for detecting DM. Intravenous CE was not necessary for scouting the DM. Patients with cervical metastasis had a high potential for developing DM