Utilizing a low-cost desktop 3D printer to develop a “one-stop 3D printing lab” for oral and maxillofacial surgery and dentistry fields

Abstract Background In the oral and maxillofacial surgery and dentistry fields, the use of three-dimensional (3D) patient-specific organ models is increasing, which has increased the cost of obtaining them. We developed an environment in our facility in which we can design, fabricate, and use 3D models called the “One-stop 3D printing lab”. The lab made it possible to quickly and inexpensively produce the 3D models that are indispensable for oral and maxillofacial surgery. We report our 3D model fabrication environment after determining the dimensional accuracy of the models with different laminating pitches (; layer thickness) after fabricating over 300 3D models. Considerations were made for further reducing modeling cost and model print time. MDCT imaging was performed using a dry human mandible, and 3D CAD data were generated from the DICOM image data. 3D models were fabricated with a fused deposition modeling (FDM) 3D printer MF-2000 (MUTOH) with a laminating pitch of 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. Each 3D model was then subjected to reverse scanning to evaluate the modeling conditions and deformation during modeling. For the 3D image processing system, Volume Extractor 3.0 (i-Plants Systems) and POLYGONALmeister V2 (UEL) were used. For the comparative evaluation of CAD data, spGauge 2014.1 (Armonicos) was used. Results As the laminating pitch increased, the weight of the 3D model, model print time, and material cost decreased, and no significant reduction in geometric accuracy was observed. Conclusions The amount of modeling material used and preparation cost were reduced by increasing the laminating pitch. The “One-stop 3D printing lab” made it possible to produce 3D models daily. The use of 3D models in the oral and maxillofacial surgery and dentistry fields will likely increase, and we expect that low-cost FDM 3D printers that can produce low-cost 3D models will play a significant role

A case of sacrococcygeal teratoma associated with antenatally acquired urethrovaginal fistula and hydrocolpos

Abstract Background Sacrococcygeal teratomas (SCTs) are known to cause urological complications, but urethrovaginal (UV) fistula as a complication of SCT is rare. We herein report a case of SCT with UV fistula and hydrocolpos. Case presentation A 1-day-old female neonate presented to our department with prominent swelling in the sacrococcygeal region. She was born at 37 gestational weeks via spontaneous vaginal delivery from a 39-year-old woman. The weight of the baby was 2965 g, and her Apgar scores were 4/10 (at 1 and 5 min). An MRI examination confirmed an 11 × 11 cm Altman classification typeII SCT associated with hydrocolpos, a dilated urinary bladder, and bilateral hydronephrosis. When she was 5 days, the SCT was excised totally and a coccygectomy was performed. After the operation, as her urinary output appeared unstable, a cystoscopic examination was performed on the third postoperative day. This revealed that the UV fistula was located approximately 1 cm from the urethral opening. In addition, the proximal urethra was unobstructed and connected to the bladder. The cystoscope allowed for the passage of a urinary catheter through the urethra. After 1 month of catheter placement, she was discharged from the hospital at 57 days of age. Follow-up was uneventful, with neither urinary infection nor retention. Conclusions SCTs are associated with not only trouble with rectal function and lower extremity movement but also urinary complications. The pathogenesis of this UV fistula is thought to be the rapid growth of the SCT that developed in the fetal period, resulting in obstruction of the urethra by the tumor and the pubic bone, which in turn caused urinary retention and the formation of a fistula as an escape route for the pressure. Because SCTs can cause a variety of complications depending on the course of the disease, careful examination and follow-up are necessary

Investigation of the Effectiveness of Infection Control Measures in the Dental Office

Aerosol transmission is an important mode of COVID-19 (SARS-CoV-2) infection. Dentists and dental hygienists, who provide medical treatment and care in the oral cavity, may be exposed to expiratory aerosols of asymptomatic infected persons. To compare the effectiveness of devices in reducing the risk of transmission to dentists and dental hygienists, we conducted experiments in a dental treatment room at Nippon Dental University. The measurements were carried out in five cases: a) the basic case (conventional air conditioning), b) a case with the circulator placed in the center of the room and operated in high air flow mode, c) a case with a circulator placed behind the patient and operated in low air flow mode, d) a case with the circulator blowing from inside to outside, e) a case using an extraoral vacuum, and f) a case with a portable neck fan hanging on the dentist manikin. The results indicated that all measures were effective in reducing the risk of infection, and case e showed the highest reduction in aerosol concentration. However, because extraoral vacuums are expensive, it is important to reduce the risk as much as possible by selecting circulators or portable neck fans according to the budget of each hospital