1.Atmospheric pollen counts of ceder(cryptomeria japonica) and cypress(chamaecypanis obtsusa) in Yanai city, Yamaguchi prefecture, Japan.
Keiko NISHIKAWA ; Masutoshi NISHIKAWA ; Satoru KANDA ; Akiko TAKAMURA
Journal of the Japanese Association of Rural Medicine 1988;37(2):92-95
The atmospheric pollen counts of Ceder (Cryptomeria japonica) and Cypress (Chamaecypanis obtsusa) were measured with Durham's standard devices installed on the roofs and ground in Yanai city, Yamaguchi prefecture, during the period between 1984 and 1987, and the following results were obtained.
1) The number of atmosphreic pollen counts changed significantly every year. There was a large quantity of pollen counts recorded in 1984 and 1986, but a small quantity in 1985 and 1987. 2) Scattering period of atmospheric pollen counts also changed every year. In 1987 the atmospheric pollen began early in February. In 1985 and 1986, it began in late February and in 1984 in late March.
3) The atmospheric pollen counts on the roofs were recorded 3 times as much as those on the ground. But there were no substantial difference between those on the roofs and ground concerning the scattering peroid of atmospheric pollen and the daily change of it's counts. There was observed significant correlation between those on the roofs and ground.(coeffecient of multiple correation=0.987)
2.A safe, stable, and convenient three-dimensional device for high Le Fort I osteotomy
Keisuke SUGAHARA ; Masahide KOYACHI ; Kento ODAKA ; Satoru MATSUNAGA ; Akira KATAKURA
Maxillofacial Plastic and Reconstructive Surgery 2020;42(1):32-
Background:
Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots.
Results:
A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery.
Conclusions
This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.
3.A safe, stable, and convenient three-dimensional device for high Le Fort I osteotomy
Keisuke SUGAHARA ; Masahide KOYACHI ; Kento ODAKA ; Satoru MATSUNAGA ; Akira KATAKURA
Maxillofacial Plastic and Reconstructive Surgery 2020;42(1):32-
Background:
Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots.
Results:
A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery.
Conclusions
This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.
4.Computed Diffusion-Weighted Imaging in Prostate Cancer: Basics, Advantages, Cautions, and Future Prospects.
Yoshiko R UENO ; Tsutomu TAMADA ; Satoru TAKAHASHI ; Utaru TANAKA ; Keitaro SOFUE ; Tomonori KANDA ; Munenobu NOGAMI ; Yoshiharu OHNO ; Nobuyuki HINATA ; Masato FUJISAWA ; Takamichi MURAKAMI
Korean Journal of Radiology 2018;19(5):832-837
Computed diffusion-weighted MRI is a recently proposed post-processing technique that produces b-value images from diffusion-weighted imaging (DWI), acquired using at least two different b-values. This article presents an argument for computed DWI for prostate cancer by viewing four aspects of DWI: fundamentals, image quality and diagnostic performance, computing procedures, and future uses.
Magnetic Resonance Imaging
;
Prostate*
;
Prostatic Neoplasms*
5.Novel condylar repositioning method for 3D-printed models
Keisuke SUGAHARA ; Yoshiharu KATSUMI ; Masahide KOYACHI ; Yu KOYAMA ; Satoru MATSUNAGA ; Kento ODAKA ; Shinichi ABE ; Masayuki TAKANO ; Akira KATAKURA
Maxillofacial Plastic and Reconstructive Surgery 2018;40(1):4-
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.
Chin
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Congenital Abnormalities
;
Equidae
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Glenoid Cavity
;
Humans
;
Jaw
;
Joints
;
Mandible
;
Mandibular Condyle
;
Mandibular Osteotomy
;
Maxilla
;
Methods
;
Oral and Maxillofacial Surgeons
;
Orbit
;
Orthognathic Surgery
;
Osteotomy, Sagittal Split Ramus
;
Surgery, Oral
;
Temporomandibular Joint
6.Mixed reality for extraction of maxillary mesiodens
Yu KOYAMA ; Keisuke SUGAHARA ; Masahide KOYACHI ; Kotaro TACHIZAWA ; Akira IWASAKI ; Ichiro WAKITA ; Akihiro NISHIYAMA ; Satoru MATSUNAGA ; Akira KATAKURA
Maxillofacial Plastic and Reconstructive Surgery 2023;45(1):1-
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 HoloLens® 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.