Online ISSN : 1884-5185
Print ISSN : 0300-9149
Current issue
Displaying 1-6 of 6 articles from this issue
Original Article
    2024 Volume 91 Issue 1 Pages 1-7
    Published: March 31, 2024
    Released on J-STAGE: May 27, 2024

      In patients with bilateral cleft lip and palate (BCLP), they sometimes need reposition premaxilla which is severely protruded and twisted as functional and aesthetic treatment. We introduce a surgical method of premaxillary fixation during alveolar bone grafting (ABG) with premaxillary osteotomy (PO). We included 9 patients with BCLP and a patient with bilateral cleft lip and alveolus who underwent ABG with PO in our institution between 2002 and 2020. They usually underwent two-stage ABG from the iliac crest with PO. Contralateral ABG was performed approximately 1 year after initial surgery. It is important to divide the surgery into two stages to perform the surgery more safely and surely. Premaxilla fixation was performed at bone-level from the anterior nasal spine to the maxillary sinus anterior wall with an absorbable plate and on dentition by wiring teeth to the labial archwire. This method provides firm fixation and facilitates feeding and dental cleaning without serious complications.

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  • NAGAI Takahiko, SHIBA Takahiko, KOMATSU Keiji, MATSUMURA Shunsuke, KOY ...
    2024 Volume 91 Issue 1 Pages 8-18
    Published: March 31, 2024
    Released on J-STAGE: May 27, 2024

      Introduction : Dental implants are crucial for treating missing teeth, while a dysbiotic microbiome often causes biological implant complications leading to implant loss.

      Materials and Methods : To clarify the bacterial community profiles of a healthy implant (HI), peri-implant mucositis (MI), and peri-implantitis (PI), 25 subgingival plaques each were collected and analyzed by 16S rRNA gene amplicon sequencing.

      Results : Bacterial diversity at the MI and PI sites was higher than that at the HI site, while no difference was observed between MI and PI sites. Desulfomicrobium and Saccharibacteria (TM7) [G-1] bacterium HMT 349 showed a significantly higher abundance at the MI site than at the HI site, suggesting that these bacterial taxa might be associated with the induction of peri-implant inflammation. Well-known disease-associated bacteria such as Porphyromonas gingivalis, Treponema, and Fusobacterium nucleatum subsp. vincentii exhibited significantly higher abundance at the PI site compared to the HI site. Furthermore, Capnocytophaga granulosa and Prevotella sp. HMT 304 were more abundant at the PI site than at the MI site.

      Conclusion : These bacteria appeared to be involved in the pathogenic state of dental implants, especially peri-implantitis. Our study highlights the microbial intricacies in healthy implants and peri-implant diseases, providing insights for diagnostic and therapeutic strategies.

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    2024 Volume 91 Issue 1 Pages 19-28
    Published: March 31, 2024
    Released on J-STAGE: May 27, 2024

      Introduction : The consumption of a high-fat diet (HFD) during pregnancy can adversely affect offspring development. Excess weight resulting for overconsumption of energy is associated with increased risk of cancer, morbidity, and mortality. In this study we examined the effects of HFD consumption during pregnancy and lactation in two-generation on the duct cell morphology and the expression of connexin 32 (Cx32) and connexin 43 (Cx43) in the submandibular gland (SMG).

      Materials and Methods : Six pregnant 11-week-old Wistar rats were assigned to the standard diet (SD) or HFD groups (n=3/group). Rats in the SD group were fed a SD, whereas those in the HFD group received an HFD from day 7 of pregnancy throughout the lactation period. Male offspring in both SD and HFD groups were divided into four groups : weaning-SD (WSD ; 3-week-old), weaning-HFD (WHFD ; 3-week-old), adult SD (ASD ; 9-week-old), and adult HFD (AHFD ; 9-week-old).

      Results : The findings demonstrated that the duct cell nuclei were more aligned in adult rats than those in weaned rats. Duct nuclei size was significantly affected by age in the SD group. In contrast, the HFD fed groups had similar nuclei sizes. Immunohistochemical staining showed that Cx32 and Cx43 were expressed in the ductal cells.

      Conclusions : The consumption of a HFD during pregnancy and lactation periods appears to affect duct cell morphology in weaned and adult offspring. The expression of Cx32 was significantly lower in the AHFD group compared to weaned groups ; however, the expression of Cx43 was increased with HFD although insignificant.

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  • ASANO Sayaka, YAMAMOTO Hirotoshi, MAEDA Shigeru
    2024 Volume 91 Issue 1 Pages 29-34
    Published: March 31, 2024
    Released on J-STAGE: May 27, 2024

      Introduction : Orthognathic surgery (OGS) is widely performed in Japan. Although the number of upper and lower jaw surgeries is increasing, the average amount of blood loss is decreasing.

      Materials and Methods : Using multivariate analysis, the present, retrospective, observational study examined factors affecting intraoperative bleeding in OGS performed in the past 13 years in the Department of Oral Surgery of Tokyo Metropolitan Tama Medical Center.

      Results : In total, 157 patients were included : the mean blood loss was 205.7 ml, and the mean operative time was 236.4 minutes. Female patients comprised 104 cases of surgery in total, which included 78, 30, and 27 cases of maxillary surgery, total intravenous anesthesia, and tranexamic acid therapy, respectively. Multiple regression analysis revealed that operative time had the strongest effect on blood loss. Male sex was also associated with blood loss of approximately 60 ml. In contrast, tranexamic acid therapy reduced blood loss by approximately 70 ml. The difference in the type of surgery was a confounding factor of operative time rather than an independent factor.

      Conclusion : Even a sagittal split ramus osteotomy alone carries the risk of increased blood loss if the operative time is prolonged. Among multifaceted approaches of reducing blood loss, prophylactic tranexamic acid administration may be effective if prolonged operative time is anticipated.

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  • OKABE Saki, NAKAGAWA Yasuhiro, SATO Yu, WAKITA Ryo, MAEDA Shigeru, IKO ...
    2024 Volume 91 Issue 1 Pages 35-46
    Published: March 31, 2024
    Released on J-STAGE: May 27, 2024

      The local anesthetic lidocaine exhibits an analgesic effect by inhibiting the activity of sodium-ion channels in nerve cells. However, intraoral application may also paralyse the motor nerves, resulting in biting of the lip, tongue, and buccal mucosa. Lidocaine has a short blood half-life of approximately 1.5 to 2 hours, and the extension of postoperative analgesic time is required. Therefore, in this study, lidocaine and capsaicin were co-encapsulated in biocompatible poly (lactic-co-glycolic acid) microparticles using an emulsion-solvent evaporation technique to achieve specific targeting of the sensory nerves. Capsaicin opens the TRPV1 channel, which is expressed exclusively on sensory nerve C fibers, enabling selective internalisation of lidocaine into sensory nerves. Microparticles with an average diameter of 3.4±0.3 μm had a smooth and uneven surface. The drug loading of lidocaine in PLGA was constant (≈4%), but that of capsaicin varied from 0.6 to 2.2%, depending on the initial loading amounts. The entrapment efficiency of capsaicin in PLGA was higher than that of lidocaine owing to differences in hydrophobicity. The glass-transition temperature of PLGA decreased depending on the drug loading, where the decrease was greater for capsaicin. In vitro studies showed a gradual release of both lidocaine and capsaicin over 10 h, with no initial burst. The release profiles of both drugs from PLGA microparticles followed the Higuchi model. Furthermore, kinetic analyses indicated that capsaicin was released from the PLGA microparticles at a faster rate than lidocaine.

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  • YOKOSE Mako, KOMATSU Keiji, SHIBA Takahiko, TANAKA Daiki, TAKEUCHI Yas ...
    2024 Volume 91 Issue 1 Pages 47-65
    Published: March 31, 2024
    Released on J-STAGE: May 27, 2024

      Gnetin-C is a resveratrol dimer that is reported to have various health-promoting effects, including anti-inflammatory, anti-oxidant, and anti-cancer effects. Gnetin-C promoted alveolar bone healing in periodontal tissues in animal experiments. However, its effects on bacteria have not been investigated. In this study, we compared the effects of gnetin-C with those of monomeric resveratrol and Melinjo seed extract, the source of gnetin-C, on the periodontopathic bacterium Porphyromonas gingivalis (P. gingivalis) and examined its mechanism of action. The results illustrated that gnetin-C strongly inhibited bacterial growth, bacterial cell adhesion, and biofilm binding compared to monomeric resveratrol. Melinjo seed extract displayed greater effectiveness than monomeric resveratrol but was less effective than gnetin-C treatment. In addition, cell surface irregularities and cell membrane ruptures were observed after gnetin-C treatment by scanning electron microscopy, suggesting that bactericidal effect by gnetin-C.

      RNA sequencing analysis and quantitative polymerase chain reaction revealed marked changes in the gene expression profiles of P. gingivalis after gnetin-C treatment. In particular, the expression of genes related to fimbriae, iron metabolism, proteases, and amino acid and vitamin metabolic pathways was significantly suppressed, whereas that of oxidative stress-related genes was significantly increased. Reactive oxygen species levels were significantly decreased by gnetin-C treatment in P. gingivalis. These results indicate that gnetin-C inhibits the growth and virulence of P. gingivalis. This study demonstrates the potential of gnetin-C in the treatment and prevention of periodontal disease. Gnetin-C can be applicable as a self-medication agent for prevention or treatment of periodontal diseases.

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