ヒト イントウ キョキングン ノ キシ ソウコウ ナラビニ テイシ ニ カンスル ニクガン カイボウガクテキ ケンキュウ

Using 50 cadavers, the pharyngeal longitudinal muscles, the palatopharyngeus, salpingopharyngeus and stylopharyngeus, were bilaterally dissected out as the full length of muscles. Using another 5 cadavers, the arrangement of muscles in the soft palate and around the epiglottic vallecula (EV) and the piriform fossa (PF) was histologically observed. The palatopharyngeus formed the base of the soft palate. The muscle was divided into superficial and deep portions. The superficial portion penetrated the soft palate by the levator veli palatini muscle (LVP) to be subdivided into four, A1 to A4, origins of muscle. The four origins gathered to form the palatopharyngeal arch and descended to EV and PF. A1 arose from the median plane between the aponeurosis palatini (AP) and LVP, and A2 arose from AP, both of which ran caudally on the oral side of LVP. A3 arose from AP with the intervention of connective tissue on the nasal side of LVP, and A4 arose from the lateral margin of the uvula posterior to LVP. The deep portion arose from AP on the nasal side of A1 and A2, and ran on the oral side of LVP and then surrounded the pharyngeal isthmus to finally reach the pharyngeal raphe. The salpingopharyngeus arose from the Eustachian tube cartilage and immediately joined the superficial portion of the palatopharyngeus, from which finding the salpingopharyngeus was regarded as one of the origins of the superficial portion. The stylopharyngeus arose from the styloid process and entered the submucous layer of the pharynx to join the superficial portion of the palatopharyngeus. The muscle bundle formed by the two muscles had four insertions. Insertion 1, derived from the stylopharyngeus, descended to reach submucous layers of EV. Insertion 2, derived from the stylopharyngeus and palatopharyngeus, descended to attach to the posterior border of the thyroid cartilage. Insertions 3 and 4, derived from the palatopharyngeus, descended inside the pharyngeal constrictors to reach the submucous layer of the posterior pharyngeal wall and the pharyngeal raphe, respectively, in PF. The insertions of the stylopharyngeus and palatopharyngeus were arranged to surround EV and PF, from which finding the two muscles were suggested to have the action of moving the mucous membranes of EV and PF to help the passage of food, in addition to the sphincter action of the pharyngeal isthmus, the depression of the soft palate, and the elevation of the pharynx

Measurement of the zygomatic bone and pilot hole technique for safer installation of zygomaticus implants

The zygomaticus implant (Brånemark system, Nobel Biocare, Gotebörg, Sweden) was developed for patients with severe bone resorption of the posterior maxilla, which may eliminate or minimize the need for bone grafting. Although the zygomaticus implant has had a remarkable success rate in a difficult patient population, the method requires an advanced surgical technique and carries increased risk of complications, such as the perforation of the orbital floor or infratemporal fossa. Although it is important to have a detailed understanding of the anatomy of the zygomatic bone when performing the installation, there have been few anatomic studies on the zygomatic bone for installation of zygomaticus implants. In this study, we measured the height and thickness of the zygomatic bone for the installation. The thickness at a 90-degree angle point, where the upper margin of the zygomatic arch and the temporal margin of the frontal process of the zygomatic bone intersect and where the apex of the implant penetrates, according to the original method, was 1.8 ± 0.4 mm, which gradually increased inferiorly and anteriorly. In conclusion, the penetration point of the apex of the zygomaticus implant should be located more inferoanterior to the 90-degree angle point, as the thickness of the 90-degree angle point is thinner than the diameter of the implant. Based on these results, we have proposed a newer and safer installation method for the zygomaticus implant using a drill guide, which can be easily made

Courses of the Human Sublingual Artery

The purpose of the present study was to classify the courses of the human sublingual artery. For this purpose, the arteries supplying the floor of the mouth and the tongue were gross anatomically investigated, using 101 sides of 53 cadavers. The courses were divided into three categories: those passing medial or lateral to the hyoglossus (Categories M and L) and that piercing the mylohyoid (Category P), which were subdivided into five types. Category M had one type regarded as the usual type in which the lingual artery took the usual pattern of distribution. Categories L and P, in which the sublingual artery arose from the facial or submental artery, had the respective two types and were collectively regarded as the unusual type. Sixty-one and 36 of the 101 sides were of the usual and unusual types, respectively, the latter of which included 17 of Category L and 19 of Category P. The remaining four were variations of the lingual artery itself. On examining the types by gender, the usual type was more often found in females (75.6%), whereas the unusual type was more often found in males (48.1%). Bilateral occurrence of the same type was often found in both the usual type (77.4%) and the unusual type (65.0%). Existence of the sublingual artery branch significantly increased the thicknesses of the submental arteries. The classification proposed here will conceivably contribute to safer dental implant surgery and more accurate interpretation of angiographic images of arteries in the floor of the mouth

マウス臼歯萌出後における線維芽細胞受容体 (Fgfr) 1, -2c, -3c 転写産物の発現

A previous study suggested that fibroblast growth factor (FGF) signaling plays an important role in dentin formation during tooth development. In this study, to examine dentin formation after tooth eruption involving secondary and tertiary dentin, we analyzed the expression patterns and expressing cells of Fgfr1, -2c, and -3c in mouse maxillary first molars (M1). Since it is difficult to recover the mRNAs from mineralized tissues, we tested methods for extraction after fixation and decalcification of teeth. We successfully obtained consistent results with quantitative real-time PCR (qPCR) using β-actin transcripts for validation. qPCR for Dentin sialo phosphoprotein (Dspp), Fgfr1, -2c, and -3c transcripts was performed on mice at ages of 2-20 weeks. The results showed that the highest expression levels of Dspp and Fgfr2c occurred at 2 weeks old followed by lower expression levels after 4 weeks old. However, the expression levels of Fgfr1 and Fgfr3c were constant throughout the experimental period. By in situ hybridization, Dspp, Fgfr1, and Fgfr3c transcripts were detected in odontoblasts at ages of 2 and 4 weeks. Also, Dspp and Fgfr1 transcripts were detected in odontoblasts facing reactionary dentin at 8 weeks old. These results suggest that FGF-FGFR signaling might be involved in the regulation of odontoblasts even after tooth eruption, including secondary and tertiary dentin formation. Moreover, our modified method for extracting mRNA from mineralized tissues after fixation and decalcification successfully produced consistent results.By utilizing our modified RNA extraction method, we determined the expression of FGFRs after tooth eruption, which suggested the commitment of FGF signaling to the homeostasis of odontoblasts