Mixed reality for extraction of maxillary mesiodens

Yu Koyama,Masahide Koyachi,Kotaro Tachizawa,Akira Iwasaki,Ichiro Wakita,Akihiro Nishiyama,Satoru Matsunaga,Akira Katakura,Keisuke Sugahara 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background Mesiodentes are the most common supernumerary teeth. The cause is not fully understood, although proliferations of genetic factors and the dental lamina have been implicated. Mesiodentes can cause delayed or ectopic eruption of permanent incisors, which can further alter occlusion and appearance. Careful attention should be paid to the position and direction of the mesiodentes because of possible damage to adjacent roots in the permanent dentition period, errant extraction in the deciduous and mixed dentition periods, and damage to the permanent tooth embryo. To avoid these complications, we applied mixed reality (MR) technology using the HoloLens® (Microsoft, California). In this study, we report on three cases of mesiodentes extraction under general anesthesia using MR technology. Results The patients ranged in age from 6 to 11 years, all three were boys, and the direction of eruption was inverted in all cases. The extraction approach was palatal in two cases and labial in one case. The average operative time was 32 min, and bleeding was minimal in all cases. No intraoperative or postoperative complications occurred. An image was shared preoperatively with all the surgeons using an actual situation model. Three surgeons used Microsoft Holo- Lens® during surgery, shared MR, and operated while superimposing the application image in the surgical field. Conclusions The procedure was performed safely; further development of MR surgery support systems in the future is suggested.

A PREDICTION MODEL FOR CONDENSATION OF BINARY REFRIGERANT MIXTURES INSIDE A HORIZONTAL SMOOTH TUBE

Shigeru Koyama,Akira Ishibashi,Jian Yu 대한기계학회 1996 KSME/JSME THERMAL and FLUID Engineering Conference Vol.3 No.1

Clinical Findings, Response to Steroid Treatment, and Recurrence Rate in Alopecia Areata Patients with or without a Nonsynonymous Variant of Coiled-Coil Alpha-Helical Rod Protein 1

Satoshi Koyama,Nagisa Yoshihara,Atsushi Takagi,Etsuko Komiyama,Akira Oka,Shigaku Ikeda 대한피부과학회 2023 Annals of Dermatology Vol.35 No.5

Background: Alopecia areata (AA) is considered complex genetic and tissue-specific autoimmune disease. We recently discovered a nonsynonymous variant in the coiled-coil alphahelical rod protein 1 (CCHCR1) gene within the AA risk haplotype. And a water avoidance stress test on CCHCR1 knockout mice induced AA-like lesions. Objective: To investigate the difference clinical findings of AA in patients with the CCHCR1 variant and without. Methods: We conducted a retrospective analysis of the data from 142 AA patients. Among these patients, 20 (14.1%) had a variant of CCHCR1. We evaluated the sex distribution of the patients, age at onset, distribution of the clinical types, prevalence of a positive family history of AA, prevalence of association of AA with atopic dermatitis, response to steroid therapy, and recurrence rate. We used multivariate logistic regression analysis and Fisher’s exact test for statistical analysis. We also investigate electron microscopic observations of hair samples with the CCHCR1 variant and without. Results: The results showed a significant correlation between the CCHCR1 variant and the recurrence rate compared with the variant-negative group (p=0.0072). Electron microscopy revealed abnormalities in the hair shaft structure and hair cuticle in patients with the CCHCR1 variant (p=0.00174). Conclusion: Our results suggest that AA with CCHCR1 variant is clinically characterized by a high recurrence rate and hair morphological abnormality

A clinico-statistical study of factors associated with intraoperative bleeding in orthognathic surgery

Keisuke Sugahara,Yu Koyama,Masahide Koyachi,Akira Watanabe,Kiyohiro Kasahara,Masayuki Takano,Akira Katakura 대한악안면성형재건외과학회 2022 Maxillofacial Plastic Reconstructive Surgery Vol.44 No.-

Background: Excessive bleeding is a major intraoperative risk associated with orthognathic surgery. This studyaimed to investigate the factors involved in massive bleeding during orthognathic surgeries so that safe surgeriescan be performed. Patients (n=213) diagnosed with jaw deformities and treated with bimaxillary orthognathicsurgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) in the Department of Oral andMaxillofacial Surgery at the Suidobashi Hospital, Tokyo Dental College between January 2014 and December 2016were included. Using the patients’ medical and operative records, the number of cases according to sex, age at thetime of surgery, body mass index (BMI), circulating blood volume, diagnosis of maxillary deformity, direction ofmaxillary movement, operative duration, incidence of bad split, injury of nasal mucosa, and blood type were analyzed. Results: The results revealed that BMI, circulating blood volume, nasal mucosal injury, and operative time wereassociated with the risk of intraoperative massive bleeding in orthognathic surgeries. Chi-square tests and binomiallogistic regression analyses showed significant differences in BMI, circulating blood volume, direction of maxillarymovement, operative duration, and injury to the nasal mucosa. Operative duration emerged as the most important riskfactor. Furthermore, a >4-mm upward migration of the posterior nasal spine predicted the risk of massive bleeding inorthognathic surgery. Conclusions: The upward movement of the maxilla should be recognized during the preoperative planning stage as arisk factor for intraoperative bleeding, and avoiding damage to the nasal mucosa should be considered a requirementfor surgeons to prevent massive bleeding during surgery

Kissing molars class III detected at a young age

Teruhide Hoshino,Yu Koyama,Akira Katakura 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background Kissing molars (KMs) is defined as a state in which the apex of two impacted molars face opposite directions and the occlusal surfaces touch each other and the crown is in one follicle. Class III KMs have been reported previously; however, reports on class III KMs in young people (< 18 years of age) are limited. Case presentation Here, we present the case of KMs class III confirmed at an early age, supported by a review of the literature. The patient was a 16-year-old female and experienced discomfort in the left molar of the lower jaw and visited in our department. We diagnosed KMs based on an impacted teeth on the buccal side, near the lower jaw wisdom teeth, and a cyst-like low-density area observed around the crown of both teeth, as revealed by computed tomography. We decide to extract the tooth and enucleate the cyst under local anesthesia as the patient experienced discomfort due to occlusion. Furthermore, the cyst-like structure removal and tooth extraction including tooth root were necessary as the patient had KM class III, possibly inducing complicated malocclusion. Although no previous reports recommended timing for KMs tooth extraction, we propose that extraction at an early stage is important regardless of age especially in class III cases. Conclusions We report a case of KM class III detected at an early age.

Fabrication of non-wetting surfaces on aluminum

Hiroki Habazaki,Katsutoshi Nakayama,Akira Koyama,Tomohiro Inoue,Chunyu Zhu,Yoshitaka Aoki 한국표면공학회 2018 한국표면공학회 학술발표회 초록집 Vol.2018 No.6

Novel condylar repositioning method for 3D-printed models

Sugahara, Keisuke,Katsumi, Yoshiharu,Koyachi, Masahide,Koyama, Yu,Matsunaga, Satoru,Odaka, Kento,Abe, Shinichi,Takano, Masayuki,Katakura, Akira Korean Association of Maxillofacial Plastic and Re 2018 Maxillofacial Plastic Reconstructive Surgery Vol.40 No.-

Background: Along with the advances in technology of three-dimensional (3D) printer, it became a possible to make more precise patient-specific 3D model in the various fields including oral and maxillofacial surgery. When creating 3D models of the mandible and maxilla, it is easier to make a single unit with a fused temporomandibular joint, though this results in poor operability of the model. However, while models created with a separate mandible and maxilla have operability, it can be difficult to fully restore the position of the condylar after simulation. The purpose of this study is to introduce and asses the novel condylar repositioning method in 3D model preoperational simulation. Methods: Our novel condylar repositioning method is simple to apply two irregularities in 3D models. Three oral surgeons measured and evaluated one linear distance and two angles in 3D models. Results: This study included two patients who underwent sagittal split ramus osteotomy (SSRO) and two benign tumor patients who underwent segmental mandibulectomy and immediate reconstruction. For each SSRO case, the mandibular condyles were designed to be convex and the glenoid cavities were designed to be concave. For the benign tumor cases, the margins on the resection side, including the joint portions, were designed to be convex, and the resection margin was designed to be concave. The distance from the mandibular ramus to the tip of the maxillary canine, the angle created by joining the inferior edge of the orbit to the tip of the maxillary canine and the ramus, the angle created by the lines from the base of the mentum to the endpoint of the condyle, and the angle between the most lateral point of the condyle and the most medial point of the condyle were measured before and after simulations. Near-complete matches were observed for all items measured before and after model simulations of surgery in all jaw deformity and reconstruction cases. Conclusions: We demonstrated that 3D models manufactured using our method can be applied to simulations and fully restore the position of the condyle without the need for special devices.

Oral Testofen, L-Citrulline, Resveratrol, and Caffeine Supplement Drink Improves Sexual Function in Men with Phosphodiesterase 5 Inhibitors: Randomized, Double-Blind, Placebo-Controlled Crossover Pilot Study

Shirai Masato,Miyoshi Yuto,Ogasa Taiki,Miyoshi Miho,Ishikawa Keisuke,Hiramatsu Ippei,Uesaka Yuka,Nozaki Taiji,Koyama Taro,Tsujimura Akira 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Purpose: Sexuality is very important for men’s health. Currently, phosphodiesterase type 5 inhibitors (PDE5i) remain the firstline therapy for erectile dysfunction, and no other oral drugs or drinks are approved and used clinically to treat male libido or orgasm dysfunction. In reference to a pharmaceutical dosage document, growing health consciousness is said to have boosted yearly sales of supplement drinks to more than 170 billion yen (1.58 billion US dollars) in Japan. We have created a supplement drink comprised of testofen, L-citrulline, resveratrol, and caffeine. We hypothesized that our supplement drink would be effective for men with sexual dysfunction, and especially libido dysfunction. Materials and Methods: In this study, men with sexual dysfunction received a placebo drink for 14 days or our supplement drink (testofen, 600 mg/d; L-citrulline, 800 mg/d; resveratrol, 300 mg/d; and caffeine, 40 mg/d) for another 14 days separated by a 7-day washout period. Patients continued on-demand use of PDE5i. The International Index of Erectile Function (IIEF) score and adverse events were assessed. Results: Twenty patients aged 30–47 years old were enrolled in and concluded the study with no adverse events experienced. The IIEF domains of desire frequency, erection frequency, erection firmness, erection confidence, intercourse satisfaction, ejaculation frequency, orgasm frequency, and overall satisfaction were significantly improved with our supplement drink. Conclusions: This is the first study to show that our supplement drink may not only be effective for erection but also for libido, orgasm, and ejaculation.

Retromandibular vein position and course patterns in relation to mandible: anatomical morphologies requiring particular vigilance during sagittal split ramus osteotomy

Keisuke Sugahara,Satoru Matsunaga,Masahito Yamamoto,Taku Noguchi,Sumiharu Morita,Masahide Koyachi,Yu Koyama,Takumi Koyama,Norio Kasahara,Shinichi Abe,Akira Katakura 대한해부학회 2020 Anatomy & Cell Biology Vol.53 No.4

Major bleeding associated with sagittal split ramus osteotomy (SSRO) involves vessels such as the inferior alveolar, facial, and maxillary arteries and veins, and the retromandibular vein (RMV). The present study aimed to clarify and classify the three-dimensional variations in RMV position and course direction in relation to the mandible. Specimens comprised a total of 15 scientific cadavers, and the relationship between RMV and the mandible lateral and posterior views was observed. We identified 3 patterns on the lateral view, the mean distance between the RMV and the posterior border of the ramus was 3.9 mm at the height of the lingula. A total of five course patterns were identified on the posterior view. In no course pattern, the RMV inferior to the lingula was lateral to its position superior to the lingual. The present findings suggest that it may be possible to predict correlations with intraoperative bleeding risk. Further study is planned using contrast computed tomography in patients with jaw deformity for skeletal classification.

Significance of rescue hybrid endoscopic submucosal dissection in difficult colorectal cases

Hayato Yamaguchi,Masakatsu Fukuzawa,Takashi Kawai,Takahiro Muramatsu,Taisuke Matsumoto,Kumiko Uchida,Yohei Koyama,Akira Madarame,Takashi Morise,Shin Kono,Sakiko Naito,Naoyoshi Nagata,Mitsushige Sugimo 대한소화기내시경학회 2023 Clinical Endoscopy Vol.56 No.6

Background/Aims: Hybrid endoscopic submucosal dissection (ESD), in which an incision is made around a lesion and snaring is per-formed after submucosal dissection, has some advantages in colorectal surgery, including shorter procedure time and preventing per-foration. However, its value for rescue resection in difficult colorectal ESD cases remains unclear. This study evaluated the utility of res-cue hybrid ESD (RH-ESD). Methods: We divided 364 colorectal ESD procedures into the conventional ESD group (C-ESD, n=260), scheduled hybrid ESD group(SH-ESD, n=69), and RH-ESD group (n=35) and compared their clinical outcomes. Results: Resection time was significantly shorter in the following order: RH-ESD (149 [90–197] minutes) >C-ESD (90 [60–140] min-utes) >SH-ESD (52 [29–80] minutes). The en bloc resection rate increased significantly in the following order: RH-ESD (48.6%), SH-ESD (78.3%), and C-ESD (97.7%). An analysis of factors related to piecemeal resection of RH-ESD revealed that the submucosal dis-section rate was significantly lower in the piecemeal resection group (25% [20%–30%]) than in the en bloc resection group (40% [20%–60%]). Conclusions: RH-ESD was ineffective in terms of curative resection because of the low en bloc resection rate, but was useful for avoid-ing surgery.