Clinical evaluation of a dental color analysis system: The Crystaleye Spectrophotometer®

AbstractPurposeTo evaluate the clinical performance of the Crystaleye Spectrophotometer®, a dental color analysis system.MethodsThree color-measuring devices (Crystaleye Spectrophotometer®, CAS-ID1, MSC-2000) were tested and the differences in color measurements among them were evaluated using Scheffe's F-test. Color measurements with the Crystaleye Spectrophotometer® were repeated 10 times by the same operator. The color difference (ΔE) between the first and tenth measurements was calculated. The Crystaleye Spectrophotometer® was used to measure the color of the maxillary left central incisor under two conditions (light and dark) and the effect of exterior lighting was analyzed to assess the accuracy of measurements. Furthermore, five different operators performed color measurements, and ΔE among the three devices was calculated. The ΔE between the target tooth and the crown of a single maxillary central incisor crown fabricated using data from the Crystaleye Spectrophotmeter® was calculated. Color differences between prebleaching and postbleaching were also analyzed with the Crystaleye Spectrophotometer® using the parameters ΔE, ΔL*, Δa*, and Δb*.ResultsThe data from the three spectrophotometers were not significantly different. The ΔE during repeated color measurements by the same operator was 0.6. The ΔE between light and dark conditions was 0.9. The data from the five operators were not significantly different. The mean ΔE value between the target tooth and the fabricated crown was 1.2±0.4, and the mean ΔE value between prebleaching and postbleaching was 3.7±1.0.ConclusionsThe Crystaleye Spectrophotometer® is an easy-to-use color analysis system producing accurate color measurements under clinical conditions

Real-time monitor of geomagnetic field in the near-pole regions as an index of magnetospheric electric field

Solar wind electric field that penetrates into the magnetosphere is an important key for causes of magnetosphenc disturbances. Since PC index, produced from the variation of the magnetic field in the near-pole regions is known to be a good indicator of magnetospheric electric field, monitoring the magnetic activity in the near-pole regions in real-time is useful for nowcasting/forecasting space weather. From the comparison of horizontal components of the magnetic field data between two stations, Eureka and Thule, it is found that the correlation between these two stations are quite high except for the summer months. This result suggests that magnetic field variations in the near-pole region are uniform, and the index can be produced throughout the year using magnetic field data in the northern and southern near-pole region

Noncommutative Gauge Theory on Fuzzy Sphere from Matrix Model

We derive a noncommutative U(1) and U(n) gauge theory on the fuzzy sphere from a three dimensional matrix model by expanding the model around a classical solution of the fuzzy sphere. Chern-Simons term is added in the matrix model to make the fuzzy sphere as a classical solution of the model. Majorana mass term is also added to make it supersymmetric. We consider two large $N$ limits, one corresponding to a gauge theory on a commutative sphere and the other to that on a noncommutative plane. We also investigate stability of the fuzzy sphere by calculating one-loop effective action around classical solutions. In the final part of this paper, we consider another matrix model which gives a supersymmetric gauge theory on the fuzzy sphere. In this matrix model, only Chern-Simons term is added and supersymmetry transformation is modified.Comment: 31 pages, more investigations of the theory in the commutative limit and references adde

Indications for cytoreductive surgery plus HIPEC in patients with colorectal cancer and peritoneal metastasis.

AbstractComprehensive treatment (COMPT) consisting of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) improves survival in selected patients with peritoneal metastasis (PM) from colorectal cancer (CRC). The aim of the present study was to clarify clinicopathologic parameters that are indications to perform COMPT in CRC-patients with CRC-PM.Between 2006 and 2021, 447 patients were selected as eligible for COMPT among 906 CRC-patients with PM. Clinicopathologic parameters contributing to long-term survival and cure were analyzed.Results: A log-rank test showed a significant survival difference for peritoneal cancer index (PCI) (≤12 vs. ≥13), completeness of cytoreduction (CCR) score (CCR-0 vs. CCR-1), small bowel (SB)-PCI (≤2 vs. ≥3), liver/lung metastasis (LLM) (negative vs. positive), histologic type (differentiated type vs. signet ring cell (SRC) subtype), number of involved peritoneal sectors (≤6 vs. ≥7), HIPEC (done vs. not done) and postoperative complication (grade 0, 1, or 2 vs. grade 3, 4, or 5). Muti-variate analyses revealed that CCR score (CCR-0 vs. CCR-1), SB-PCI score (≤2 vs. ≥3), LLM (negative vs. positive), and HIPEC (performed vs. not done) were independent prognostic factors. The incidence of postoperative grade 3, 4 or 5 complication was 19.0% (85/447) and the mortality rate was 2.0% (9/447). One hundred and seventy patients fulfilled the following clinicopathologic factors,PCI ≤12, SB-PCI ≤2, number of involved peritoneal sectors ≤6, no LLM, differentiated histologic type and CCR-0. The MST of these patients was 5.5 years, and 5- and 10-year survival rates were 57.8% and 24.6%, respectively. Postoperative grade 3, 4, and 5 complications in these 170 patients occurred in 9 (5.3%), 15 (8.8%) and 1 (0.6%), respectively. Cured patients were defined as those alive without recurrence more than 5 years after CRS. All of the cured patients underwent CCR-0 resection. The PCI and SB-PCI of these 23 patients were ≤12 and ≤2, respectively

歯科用金属アレルギーが疑われる患者の調査

Patients with metal allergy have been increasing due to various metals being used in the daily environment. Therefore, we performed patch tests in 40 patients with suspected metal allergy whose initial visit from April 1992 to march 1996. The medical route to our department and symptoms at the initial consultation at our department were evaluated in all the patients, and the association with oral metals was examined in patients positive for patch tests. The course after treatment was also analyzed. The results were as follows: 1. Fifty percents of the patients were referred to our department from the hospital affiliated to Iwate Medical University. 2. The major symptoms at the initial consultation at our department were eruptions (60.0%), oral mucosal inflammation (23.3%), and tongue pain (13.3%) 3. Patch tests were positive in 27 (67.55%) of the 40 patients. 4. According to metal elements, patch tests were most frequently positive for palladium (10 patients), followed by nickel and cobalt (9 patients each). 5. The positive metal in patch tests was consistent with the oral metal in 20 patients but inconsistent in the other 7. 6. Due to removing antigen metals in the 20 patients , three patients were cured completely, however, rest of the patients showed reduced and recurrent symptoms

歯根破折歯に対して抜歯後即時埋入インプラントを行った1症例

Immediate implant placement following extraction is suggested as a method of implant treatment. As this method is associated with almost no gingival recession or absorption of alveolar bone in the extraction socket, and as the period of treatment can be shortened, its usefulness has been widely reported. In this case, implant placement was performed immediately after extraction of an upper left first premolar in which a root fracture had been discovered, with porcelain fused to a metal crown used as the superstructure. Through implant placement immediately following extraction, postoperative gingival recession and bone absorption were kept to a minimum, and esthetic recovery was achieved. Moreover, the period of treatment up to functional recovery was shortened, showing that this can be an effective method of treatment in prosthetic dentistry when applied to suitable cases

当科における5年間の顎機能異常者の調査

Clinical findings of 351 out patients having temporomandibular disorders (TMD) treated in the Department of Fixed Prosthodontics, Iwate Medical University Dental Hospital, from 1999 to 2003 were surveyed as to. number of patients every year, gender ratio, age distribution, past treatment history, chief complaints, initial symptoms, initiating factors and accessory signs. The number of TMD patients varied from 52 to 95 each year Peak age distribution was in the 20\u27s followed by the 30\u27s. The male-female ratio was 1 . 2.8, which showed significant difference compared to the clinic as a whole, which has a ratio of 1:1 5 (p<0.05; chi-square test) Referred patients comprised 76.6% of the total number of TMD patients in the surveyed period Although a temporomandibular joint (TMJ) sound was the main initial symptom, TMJ pain was the most common symptom in the chief complaint category. This result implies that the single symptom of TMJ sound does not lead a patient to seek treatment at a dental clinic, however, pain in the TMJ and/or masticatory muscle is the key to initiate treatment

Reliability and validity of the patient disability-oriented diagnostic nomenclature system for prosthetic dentistry

Purpose: The Japan Prosthodontic Society (JPS) has proposed a new diagnostic nomenclature system (DNS), based on pathogenesis and etiology, to facilitate and improve prosthodontic treatment. This systemspecifies patient disability and the causative factor (i.e. ‘‘B (disability) caused by A (causative factor)’’). The purpose of this study was to examine the reliability and validity of this DNS. Study selection: The JPS Clinical Guideline Committee assessed mock patient charts and formulated disease names using the new DNS. Fifty validators, comprising prosthodontic specialists and dental residents, made diagnoses using the same patient charts. Reliability was evaluated as the consistency of the disease names among the validators, and validity was evaluated using the concordance rate of the disease names with the reference disease names. Results: Krippendorff’s α was 0.378 among all validators, 0.370 among prosthodontic specialists, and 0.401 among dental hospital residents. Krippendorff’s α for 10 validators (3 specialists and 7 residents) with higher concordance rates was 0.524. Two validators (1 specialist and 1 resident) with the highest concordance rates had a Krippendorff’s α of 0.648. Common disease names had higher concordance rates, while uncommon disease names showed lower concordance rates. These rates did not show correlation with clinical experience of the validator or time taken to devise the disease name. Conclusions: High reliability was not found among all validators; however, validators with higher concordance rates showed better reliability. Furthermore, common disease names had higher concordance rates. These findings indicate that the new DNS for prosthodontic dentistry exhibits clinically acceptable reliability and validity

Evaluation of Tomographic Technique of Temporomandibular Joint using COMMCAT IS-2000^<TM> Imaging System

COMMCAT IS-2000^は顎顔面領域専用の断層エックス線撮影装置で,顎関節の矢状断および冠状断撮影の機能を有する。本装置の顎関節撮影における有用性をエックス線不透過性の鋼鉄製マーカーを付けた4個のヒト乾燥頭蓋骨を用いて検討した。スライス位置の正確性を調べるため下顎頭の表面中央にマーカーを固定し,マーカー直上,それより近心,遠心にそれぞれ1mm,2mm離れた計5点に対して矢状断撮影を行ったところ,スライス位置の誤差は±1mmの範囲内であった。写真の寸法精度を調べるため,下顎頭の実測値と断層写真上での寸法をデジタルキャリパーを用いて比較した。両者の差は前後径では平均0.43mm,近遠心径では平均0.52mmであった。断層軌道および断層厚さの違いが写真画質におよぼす影響を調べた。同一撮影条件下ではhypocycloidal軌道で1mmの断層厚さで撮影した場合,ぶれや周囲の構造物の写り込みが少ないため,最も写真画質が良好であることがわかった。以上の結果よりCOMMCAT IS-2000^はTMJの骨構造を画像化する上で有用な診断装置であることが示唆された。The COMMCAT IS-2000^ (Imaging Sciences International, Hatfield, PA, USA) is a tomographic machine for scanning the dentomaxillofacial region and is capable of imaging the sagittal and coronal sections of the temporomandibular joint (TMJ). The feasibility and accuracy of tomography for the TMJ were examined by use of the COMMCAT IS-2000^ and four dried human skulls with radiopaque steel markers. To assess the setting accuracy of the slice position, a steel marker was fixed at the center of the superior surface of the condyle, and images of five sagittal sections were taken, i.e., directly above the marker and 1 mm and 2 mm distance from it in both the medial and distal planes. The deviation of the slice position was found to be within ± 1 mm for all test subjects. To evaluate the dimensional accuracy of this method, the difference between the actual value and the graphically observed value with respect to the tomographic image of the condyle was examined using a digital caliper. The difference between values for the anteroposterior distance was 0.43 mm and that for the mediolateral distance was 0.52 mm. The effect of the difference in tomographic motion and slice thickness on the image quality was then evaluated. Under identical exposure conditions, hypocycloidal tube motion and the slice thickness of 1 mm produced the best image quality because blurring of the image and the degree of superimposition of the surrounding structures were minimal. These results suggest that the COMMCAT IS-2000^ is a high-quality diagnostic tool for visualizing the bone structure of the TMJ