口腔領域混合感染症の発生機序および病原性に関する研究

私は歯性感染症が発症、進展する上で、起炎菌どうしの相互作用が大きな役割を果たしているものと考え、研究を行った。基礎的研究を行うにあたり、まず臨床検体からの菌の分離状況に注目した。その結果、Streptococcus、Peptostreptococusといったグラム陽性球菌とPrevotella、Fusobacteriumといった嫌気性グラム陰性桿菌との組み合わせが、重症症励に多いことを見いだした。そこで特に分離頻度の多い通性嫌気性グラム陽性球菌であるStreptococcus constellatus、偏性嫌気性グラム陰性桿菌であるFusobacterium nucleatum、Prevotella intermediaに注目し、マウス膿瘍モデルを用いてこれらの菌の病原性の相乗効果について検討した。その結果、あらゆる組み合わせで、菌の病原性の相乗作用が認められた。次にこうした菌の相乗作用の機構の解明を目的に研究を行った。この研究には、S.constellatus、F.nucleatumを用いて、2菌間の病原性の相乗作用の機構についてin vivoにて実験を行った。その結果、F.nucleatumの耐熱性の菌体外産生物質がhostの免疫系に作用し、S.constellatusの病原性を増強していることが判明した。一方、S.constellatusは生菌で存在すればF.nucleatumの病原性を向上させるが、その菌体外産生物質はなんらこの相互作用に寄与しないことが判明した。私はこのS.constellatusの働きについて、酸化還元電位に注目した。すなわち、S.constellatusが局所の酸化還元電位を低下させることにより、他の嫌気性菌の発育を向上させるという仮説をたてた。そこで、S.constellatusとF.nucleatum、P.intermediaについてin vitroにて、菌数と酸化還元電位の変動について検討を行った。するとこれらの菌を単独で液体培地にて培養しても、培地の酸化還元電位は低下しないが、S.constellatusと他の嫌気性菌を混合して培養すると、培地の酸化還元電位は低下し、嫌気性菌は単独培養時よりも増加することが判明した。このことから、S.constellatusが生体においても嫌気性菌との共存下において、局所の酸化還元電位を下げ、嫌気性菌の増殖を促進し、このことが病原性の相乗作用の一因となっていることが示唆された。こうした一連の研究から、菌性感染症の発症、憎悪の機構の一部が解明されたと考える。In our previous clinical study, it appeared mixed infection of Steptococcus and anaerobic gram-negative rods was detected in severe odontogenic infections. Thus, we determined the characteristics of microbial interaction of Steptococcus constellatus and Fusobacterium nucleatum, which were the prime pathogens of orofacial odontogenic infection. In the study using murine abscess model, the microbial synergism between S.constellatus and F.nucleatum was found. In this synergism, the product of S.constellatus was not able to enhance F.nucleatum virulence. In contrast, it appeared the heat-stable substance in the product of F.nucleatum could enhance the virulence of S.constellatus. Moreover, it appeared the modulation of host cells function caused by F.nucleatum was one of mechanisms of this microbial synergism. We considered the oxdation-reduction potential (Eh) as the role of enhancement of F.nucleatum virulence caused by S.constellatus. Our in vitro study indicated that the occurrence of mixed infection of the oral region was closely related to the Eh and that the pathogenicity of bacteria was dependent largely on the combination of Viridans streptococci and anaerobes.研究課題/領域番号:07672164, 研究期間(年度):1995-1997出典：「口腔領域混合感染症の発生機序および病原性に関する研究」研究成果報告書　課題番号07672164(KAKEN：科学研究費助成事業データベース（国立情報学研究所）)　　　本文データは著者版報告書より作

Bite Force and Maxillofacial Morphology in Patients With Duchenne-Type Muscular Dystrophy

金沢大学医学部附属病院歯科口腔外科Purpose: The purpose of this study is to evaluate maxillofacial morphology and bite force in patients with severe Duchenne-type myodystrophy. Patients and Methods: The subjects included 24 men (average age, 21.5 years; range, 17 to 30 years) with Duchenne-type muscular dystrophy receiving treatment in National Ioh Hospital. Lateral and axial cephalograms were used to assess the morphology in this study. The maximum bite force on the first molar and the maximum mouth opening distance were measured. Results: The anterior open bite was visualized in most patients on the lateral cephalogram. The upper and lower arch lengths in the patients were significantly smaller than those in the controls (P < .05). In contrast, the upper and lower arch widths in the patients were significantly larger than those in the controls (P < .05). The maximum bite force and maximum mouth opening distance in the patients were significantly lower than those in the controls (P < .05). Conclusion: These results appear to be very useful for improving the care and treatment of patients with Duchenne-type muscular dystrophy. © 2007 American Association of Oral and Maxillofacial Surgeons

Use of self-setting α-tricalcium phosphate for maxillary sinus augmentation in rabbit

金沢大学医薬保健研究域医学系Purpose: The purpose of this study was to histologically and immuno-histochemically evaluate tissue changes in the maxillary sinus after bone screw implantation and maxillary sinus augmentation using self-setting α-tricalcium phosphate (α-TCP; BIOPEX®-R) in rabbit. Study design: Adult male Japanese white rabbits (n=15, 12-16 weeks, 2.5-3kg) were used. The sinus lift was made from the nasal bone of a rabbit. Bone screws (Dual top auto-screw®) were implanted into the nasal bone, and after BIOPEX®-R was implanted into the left elevated space (operated side) an atelocollagen sponge (ACS: Teruplug®) was implanted into the right elevated space (control side). The rabbits were sacrificed at 4, 12 and 24 weeks postoperatively, and formalin-fixed specimens were embedded in acrylic resin. The specimens were stained with hematoxylin and eosin. For immune-histochemical analysis, the specimens were treated with bone morphogenetic protein-2 (BMP-2) antibodies. Finally, these were evaluated microscopically. Results: Tight bonding without fibrous tissue continued between the bone screw and BIOPEX®-R, and the rigidity of the bone screw in the nasal bone was retained for 24 weeks in all cases. The area ofnew bone formation increased gradually on both sides; however, there was no significant difference between both sides at 4, 12 and 24 weeks. The number of BMP-2-stained cells on the experimental side was significantly larger than that on the control side after 4 weeks (P=0.0361). Conclusion: This study suggested the usefulness of self-setting α-TCP (BIOPEX®-R) to maintain the rigidity of implanted bone screws from an early period, and the result of BMP-2 expression suggested that BIOPEX®-R could have bone-conductive activity in the maxillary sinus augmentation. © 2010 John Wiley & Sons A/S

The change of stress distribution on the condyle after mandibular setback surgery

金沢大学医学部附属病院歯科口腔外科The rigid-body spring model (RBSM) theory was incorporated into a model as a discrete method for analysing problems of limit, such as the stress distribution on the condyle. The purpose of this study was to evaluate the two-dimensional RBSM for determining stress on the temporomandibular joint (TMJ) in patients after orthognathic surgery. Thirty-two patients (five males and 27 females, mean age 21.4 ± 4.9 years) with mandibular prognathism underwent bilateral sagittal split ramus osteotomy (SSRO) and setback; 48 subjects were recruited as controls. Anatomical landmarks were traced from pre- and post-operative lateral cephalograms and the information was processed using the Fortran analysis program. The force vector on the condyle, its degree, its direction, and the displacement co-ordinates (x, y) and rotation (θ) at the gonial angle were calculated. When muscular power was assumed to be 1, the post-operative degree of the force vector was higher than the pre-operative value (P < 0.05). The X co-ordinate, x, and rotation, q, of the displacement vector in the pre-operative patients with mandibular prognathism were significantly higher than those in the control subjects (P < 0.05). There were still significant differences between the displacement values post-operatively between the patients and controls (P < 0.05). The results suggest that the degree and direction of the force vector and the resulting displacement co-ordinates can be used as parameters in a surgical model. The RBSM may also be useful in evaluating the pre- and post-operative skeletal morphology of jaw deformities. © The Author 2006. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved

Simplified stress analysis on the temporomandibular joint in Class III patients with and without mandibular asymmetry using a rigid body spring model

金沢大学医薬保健研究域医学系To cite this article: Ueki K, Takeuchi N, Nakagawa K, Yamamoto E: Simplified stress analysis on the temporomandibular joint in Class III patients with and without mandibular asymmetry using a rigid body spring model Orthod Craniofac Res 2009;12:312-318 Structured AbstractAuthors - Ueki K, Takeuchi N, Nakagawa K, Yamamoto E Objective - Aim of this study was to investigate the differences in stress on the temporomandibular joint (TMJ) between Class III patients with and without mandibular asymmetry using a rigid body spring model (RBSM). Design - Menton (Me), the centre point of occlusal force on the line that connected the bilateral buccal cusps of the second molars and the most lateral, superior and medial points of the condyle were plotted on frontal cephalograms, and stress on the condyles was calculated with the 2-dimensional RBSM program of fortran. Setting and Sample Population - Eighty Japanese patients with diagnosed mandibular prognathism were divided into two groups, a symmetry group and asymmetry group on the basis of the Mx-Md midline position. Outcome measure - The degree (force partition) of the resultant force, the direction (angulation) and displacement (X, Y) of each condyle were calculated. The horizontal displacement vector (u), the vertical displacement vector (v) and rotation angle (θ) of the mandibular body at Menton were also calculated. Results - There were significant differences between the deviated and non-deviated sides of both groups regarding resultant force (symmetry group: p = 0.0372, asymmetry group: p = 0.0054), X (symmetry group: p < 0.0001, asymmetry group: p = 0.0001) and Y (symmetry group: p = 0.0354, asymmetry group: p = 0.0043). For angulation, there was a significant difference between the deviated and non-deviated sides in the asymmetry group (p = 0.0095). Conclusion - The results of this study suggest that difference in stress angulation on the condyles could be associated with asymmetry in mandibular prognathism. © 2009 John Wiley & Sons A/S

Incidence and bacteriology of bacteremia associate with various oral and maxillofacial surgical procedures

金沢大学大学院医学系研究科Objective. The aim of this study was to determine the incidence and bacteriology of bacteremia associated with various oral and maxillofacial surgical procedures. Methods. A total of 237 patients who underwent oral and maxillofacial surgery were included in this study. Blood samples were obtained for bacteriological examination immediately after the essential steps of the surgical procedure had been performed. Results. Bacteremia was detected in patients who underwent surgery for tumor, infection and trauma, and surgical reconstruction of jaw. In particular, decortication for osteomyelitis and tooth extraction resulted in a higher incidence of bacteremia compared with other surgical procedures. The incidence of bacteremia was not affected by oral hygiene, gingival inflammation, blood loss, and duration of surgery. Furthermore, concerning tooth extraction, there was no statistical difference in the incidence of bacteremia with respect to the number of teeth extracted and the method of extraction. Extraction of teeth with odontogenic infection (periodontitis, periapical infection, and pericoronitis) did however produce a significantly increased incidence of bacteremia compared with infection-free teeth (P <. 01). Viridans streptococci were the predominant group of bacteria isolated from the bacteremias. Conclusion. Oral and maxillofacial surgery involving transoral incision produces bacteremia, regardless of the extent and degree of surgical invasion. In particular, surgical procedure at infected sites is more likely to result in bacteremia compared with infection-free sites

Use of the Sonopet ultrasonic curettage device in intraoral vertical ramus osteotomy

金沢大学医学部附属病院歯科口腔外科This study was designed to evaluate the usefulness of the Sonopet UST-2001 (Miwatec Co., Ltd., Kawasaki, Kanagawa, Japan) ultrasonic curettage device, and to assess the outcome after intraoral vertical ramus osteotomy (IVRO). Thirteen Japanese adults (age range 20-41 years, mean age 29.6 years) presented with jaw deformities diagnosed as mandibular prognathism and asymmetry; they all underwent IVRO of the mandible. This procedure was followed by ultrasonic bone curettage using the Sonopet to make a guiding notch or groove in the lateral cortex of the ramus without damaging the vessels and nerves. After surgery, the osteotomy line was evaluated by three-dimensional computed tomography. In all patients, osteotomy with the Sonopet device was achieved safely, with minimal bleeding and no major complications. The distal segment could be moved into its ideal position and all patients achieved their ideal profiles. Ultrasonic bone curettage is a safe method for making a guiding groove, without damage to surrounding tissue, prior to complete IVRO. © 2007 International Association of Oral and Maxillofacial Surgeons

The Use of an Intermaxillary Fixation Screw for Mandibular Setback Surgery

金沢大学医学部附属病院歯科口腔外科Purpose: To assess skeletal stability after mandibular setback surgery with and without an intermaxillary fixation (IMF) screw. Patients and Methods: The subjects were 40 patients with mandibular prognathism. The subjects underwent sagittal split ramus osteotomy with titanium plate fixation and were divided into 2 groups, 1 with and 1 without an IMF screw. A lateral cephalogram was done preoperatively, immediately after surgery, and 1 month, 3 months, and 6 months postoperatively. The 2 groups were then compared statistically. Results: In the comparison of the time-course change between the 2 groups with repeated measure analysis of variance, there were significant differences in occlusal plane (between subjects, F = 2.517; df = 4; P = .0437) and convexity (between subjects, F = 4.048; df = 4; P = .0038). However, there was no significant difference in the other measurements. Conclusion: This study suggested that in most measurements, there was no significant difference between 2 groups with and without an IMF screw in time-course skeletal change. However, use of IMF screws was helpful for orthognathic surgery as a rigid anchor of IMF. © 2007 American Association of Oral and Maxillofacial Surgeons

Stress change on the temporomandibular joint in mandibular prognathism subjects with asymmetry after orthognathic surgery

金沢大学医薬保健研究域医学系The purpose of this study was to evaluate changes in stress on the temporomandibular joint (TMJ) in 80 Japanese subjects (21 males and 59 females, mean age 23.7 years) with mandibular prognathism, with and without asymmetry after orthognathic surgery using the rigid bodies spring model (RBSM). The asymmetric group consisted of 40 subjects whose Mx-Md midline was more than 3 degrees. The remaining 40 subjects formed the symmetric group.The geometry of the stress analysis model was based on frontal cephalograms of the subjects. Menton (Me), the centre point of occlusal force on a line connecting the bilateral buccal cusps of the second molars, and the most lateral, superior, and medial points on the condyle were plotted on a computer display and stress on the condyle was calculated with the two-dimensional RBSM program, Fortran. The degree (force partition) of the resultant force, the direction (angulation), and the displacement (X, Y) of each condyle were calculated and the horizontal displacement (u), the vertical displacement (v), and rotation displacement (θ) of the mandibular body at Me were calculated pre- and post-operatively. The data was analysed using paired and unpaired t-tests.For the vertical (v) and rotational (θ) displacement, the post-operative value was smaller than the pre-operative value (v: P < 0.001, θ: P = 0.0063) in the asymmetric group. For angulation and the X-component, the post-operative value was smaller than that pre-operatively on the deviated (angulation: P = 0.0074, X-component: P = 0.0003) and non-deviated (angulation: P = 0.0024, X-component: P = 0.001) side in the asymmetric group. However, there was no significant difference between the pre- and post-operative value for any parameter in the symmetric group.These findings suggest that surgical correction of mandibular prognathism, with and without asymmetry, could induce an improvement in stress balance on the TMJ in the frontal aspect. © The Author 2010

Changes in occlusal force after mandibular ramus osteotomy with and without Le Fort I osteotomy

金沢大学医学部附属病院歯科口腔外科金沢大学大学院医学系研究科がん細胞学The purpose of this study was to evaluate the differences in bite force changes and occlusal contacts after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) with and without Le Fort I osteotomy. Sixty female patients with diagnosed mandibular prognathism with or without asymmetry were divided into four groups (SSRO, IVRO, SSRO with Le Fort I osteotomy and IVRO with Le Fort I osteotomy). Bite force and occlusal contacts were measured preoperatively and at 1, 3, 6 and 12 months after surgery with pressure-sensitive sheets. The differences among surgical procedures were examined statistically. Maximum bite force and occlusal contacts returned to preoperative levels after between 3 and 6 months. Regarding time-dependent changes in bite force and occlusal contact area, there were no significant differences among the groups. In conclusion, this study suggests that the combination of IVRO or SSRO and Le Fort I osteotomy does not affect postoperative time-dependent changes. © 2006 International Association of Oral and Maxillofacial surgeons