Kohei Marukawa

University of Yamanashi, Kōhu, Yamanashi, Japan

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Publications (82)126.64 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to evaluate the postoperative changes in masticatory function in patients with jaw deformities with or without asymmetry treated by orthognathic surgery. Thirty female patients who underwent a Le Fort I osteotomy with sagittal split ramus osteotomy (SSRO) were enrolled. The patients were divided into symmetry and asymmetry groups. The bite force, occlusal contact area, and bite force balance were measured before and at 1, 3, and 6 months and 1 year after surgery; these measurements were compared statistically within and between the two groups. In the symmetry group, there was a significant difference in the preoperative bite force and the 1 month postoperative bite force (P=0.0033). In the asymmetry group, the bite force before surgery was significantly different from that at 1 month (P=0.0375) and at 1 year (P=0.0353) after surgery. Significant differences in the bite force were also observed between the following time points: 1 month and 1 year (P=0.0003), 3 months and 1 year (P=0.0034), and 1 month and 6 months (P=0.0486). The occlusal contact area, bite force, and occlusal balance tended to change after Le Fort I osteotomy with SSRO, with a significantly improved bite force in patients with asymmetry before surgery. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
    International Journal of Oral and Maxillofacial Surgery 04/2015; DOI:10.1016/j.ijom.2015.03.015 · 1.36 Impact Factor
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    ABSTRACT: Purpose The purpose of this study was to evaluate the relationship between lip closing force, occlusal contact area and occlusal force after orthognathic surgery in skeletal Class III patients. Subjects and Methods The subjects consisted of 54 patients (28 female and 26 male) diagnosed with mandibular prognathism who underwent sagittal split ramus osteotomy with and without Le Fort I osteotomy. Maximum and minimum lip closing forces, occlusal contact area and occlusal force were measured pre-operatively, 6 months and 1 year post-operative. Results Maximum and minimum lip closing forces, occlusal contact area and occlusal force increased with time after surgery, however a significant increase was not found in the occlusal contact area in women. In increased ratio (6 months/pre-operative and 1 year/pre-operative), the maximum lip closing force was significantly correlated with the occlusal contact area (P<0.0001). Conclusions This study suggested that orthognathic surgery could improve the occlusal force, contact area and lip closing force, and an increase ratio in maximum lip closing force was associated with an increased ratio in occlusal contact area.
    Journal of Cranio-Maxillofacial Surgery 10/2014; 42(7). DOI:10.1016/j.jcms.2014.01.047 · 2.60 Impact Factor
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    ABSTRACT: Objectives The purpose of this study was to examine the changes with time in lip pressure after orthognathic surgery for skeletal Class III patients. Study design The subjects consisted of 63 patients (32 female and 31 male) diagnosed with mandibular prognathism who underwent sagittal split ramus osteotomy with and without Le Fort I osteotomy. Maximum and minimum lip closing forces were measured with Lip De Cum®. The changes with time were compared statistically. Results The maximum and minimum lip closing force increased time-dependently in men and women after surgery and there were significant differences between men and women with changes with time in the maximum lip closing force (P=0.0086) and the minimum lip closing force (P=0.0302). After 1 year, the Class III group maximum lip closing force was significantly smaller than the control group in both men (p<0.0001) and women (p<0.0001). Conclusions This study suggests that there was significant difference in over time in the lip closing force between men and women in Class III patients. Although the maximum lip closing force increased with time, it did not reach the level of the control group after 1 year.
    Journal of Cranio-Maxillofacial Surgery 09/2014; 42(6). DOI:10.1016/j.jcms.2014.01.007 · 2.60 Impact Factor
  • Journal of Oral and Maxillofacial Surgery 09/2014; 72(9):e139. DOI:10.1016/j.joms.2014.06.250 · 1.28 Impact Factor
  • Journal of Oral and Maxillofacial Surgery 09/2014; 72(9):e126. DOI:10.1016/j.joms.2014.06.225 · 1.28 Impact Factor
  • Journal of Oral and Maxillofacial Surgery 09/2014; 72(9):e231. DOI:10.1016/j.joms.2014.06.415 · 1.28 Impact Factor
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    ABSTRACT: The purpose of this study was to compare the recovery period of lower lip hypoesthesia between hybrid fixation and conventional fixation using absorbable plates and screw systems following sagittal split ramus osteotomy (SSRO).
    Journal of Cranio-Maxillofacial Surgery 06/2014; 42(8). DOI:10.1016/j.jcms.2014.06.019 · 2.60 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the factors affecting the recovery period of lower lip hypoesthesia after sagittal split ramus osteotomy (SSRO) in mandibular prognathism patients using multivariate analysis, retrospectively.
    Journal of Cranio-Maxillofacial Surgery 06/2014; 42(8). DOI:10.1016/j.jcms.2014.06.010 · 2.60 Impact Factor
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    ABSTRACT: This study evaluated bone regeneration by periosteal elevation using conventional orthodontic wire and an unsintered hydroxyapatite (u-HA)/poly-l-lactic acid (PLLA) mesh in rabbit frontal bone. Thirty two rabbits (12-16 weeks: 2.5-3.0 kg) were used in this study. In the experimental group, 1 week after the mesh was inserted under the periosteal membrane, it was elevated by traction using the mesh connected with wire and two anchor screws. In the control group, the mesh was kept inserted under the periosteal membrane. Four animals were killed in each period in both groups, at 2, 3, 5 and 9 weeks postoperatively. Operated parts in the frontal bone were removed and prepared for radiological and histological assessment. The distance between the mesh and pristine bone (elevation length), the bone area and the expression of BMP-2 were evaluated. The value in the experimental group was significantly higher when compared to the control group (length P < 0.0001, bone area P < 0.0010, BMP-2 P = 0.0015). The BMP-2 labelling index after 3 weeks tended to be the largest in both groups. This study suggests that bone regeneration can be induced by periosteal elevation using a conventional orthodontic wire and an uHA/PLLA mesh.
    Journal of Cranio-Maxillofacial Surgery 06/2014; 42(8). DOI:10.1016/j.jcms.2014.06.009 · 2.60 Impact Factor
  • 01/2014; 27(2):146-149. DOI:10.15214/jsodom.27.146
  • 01/2014; 27(1):22-26. DOI:10.15214/jsodom.27.22
  • 01/2014; 27(2):154-157. DOI:10.15214/jsodom.27.154
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    ABSTRACT: Sinusitis of dental origin is a relatively frequent entity, and odontomas are considered to be the most common odontogenic tumors of the oral cavity. Eruption and infection of odontomas are extremely rare. Here, we report an interesting case where odontoma was found in the wake of the maxillary sinusitis onset.
    12/2013; 2013:834715. DOI:10.1155/2013/834715
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    ABSTRACT: The purpose of this study was to evaluate bony change in an overlapped cortical bone area at the anterior site of the proximal segment after modified plate fixation with a bent plate in sagittal split ramus osteotomy (SSRO). The subjects were 66 patients (132 sides) who underwent bilateral SSRO setback surgery. After the surgery in SSRO, an overlapped area of cortical bone at the anterior site of the proximal segment was not removed to keep the contact area between the proximal and distal segments intact, and was fixed with a bent plate and 4 screws in each side of the mandible. At the posterior site, a 3-7 mm gap was maintained between the proximal and distal segments to prevent inward-rotation of the condylar long axis. Ramus width, lateral cortex width and lateral cortex step angle were assessed in a coronal image immediately after the surgery, and 1-year postoperative by computed tomography (CT). Ramus width after 1-year was significantly larger than that before surgery and smaller than that immediately after surgery in both sides (P < 0.0001). Lateral cortex width after 1-year was significantly larger than the preoperative value and smaller than that immediately after surgery in both sides (P < 0.0001). Lateral cortex angle after 1-year was significantly larger than the preoperative value in both sides (P < 0.0001). The above findings suggested that the overlapped cortical bone decreased thickness and the cortical bone step disappeared following favourable bone remodelling after 1-year, even though the cortical bone was not removed at the anterior site of the proximal segment.
    Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 09/2013; 42(5). DOI:10.1016/j.jcms.2013.08.009 · 2.60 Impact Factor
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    ABSTRACT: To compare bone regeneration between local implantation of statin and low-intensity pulsed ultrasound (LIPUS), and the combination of statin with LIPUS in rabbit nasal bone using histological and immunohistochemical methods. Thirty-two adult male Japanese white rabbits (age: 12-16 weeks, weight: 2.5-3.0 kg) were used in this study. Two bone circular defects (5 mm in diameter) per rabbit were created in the nasal bone while preserving the nasal membrane. The two defects in each rabbit were filled with 2.5 mg/ml simvastatin in 0.2 ml water with an atelocollagen sponge (ACS) and ACS alone respectively. Sixteen rabbits (32 sides) received the LIPUS application; the remaining 16 rabbits (32 sides) did not. Therefore, the subjects composed of 4 groups, namely, (1) LIPUS + ACS + simvastatin (the LAS group), (2) LIPUS + ACS (the LA group), (3) ACS + simvastatin (the AS group) and (4) ACS alone (the A group). Four animals were killed in each period, at 1, 2, 4 and 8 weeks postoperative. The parts that had been operated on were removed and prepared for histological assessment. The expression of BMP-2 and the bone area ratio were evaluated using histological and immunohistochemical methods. Bone square in the LAS group was significantly larger than that in the AS group after 1 (P < 0.0001) and 2 week (P = 0.0113). The bone square in the LA group was significantly larger than that in the A group after 1 (P < 0.0001) and 2 weeks (P = 0.0090). However, there was no significant difference between the LAS and LA groups. In the number of cells that stained positive for BMP-2, the LAS group was significantly larger than that in the AS group after 1 (P < 0.0001) and 2 weeks (P = 0.0113). This study suggests that bone regeneration can be promoted by LIPUS alone and statin alone, respectively. However the combination use of LIPUS with statin does not differ from LIPUS alone or statin alone.
    Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 08/2013; 42(3). DOI:10.1016/j.jcms.2013.05.002 · 2.60 Impact Factor
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    ABSTRACT: Objective: The purpose of this study was to evaluate bone regeneration by periosteal expansion using conventional orthodontic wire and an unsintered hydroxyapatite (u-HA) / poly-L-lactic acid (PLLA) mesh in rabbit nasal bone. Method: Thirty two adult male Japanese white rabbits (12–16 weeks: 2.5–3.0 kg) were used in this study. In the expansion group, 1 week after the mesh was inserted under the periosteal membrane, it was expanded by traction using the mesh connected with ‚‡wire and two bone screws as anchors. In the control group, the mesh was kept inserted under the periosteal membrane. Four animals were killed in each period in both groups, at 2, 3, 5 and 9 weeks postoperatively. Operated parts in the nasal bone were removed and prepared for histological assessment. The distance between the mesh and mother bone (expansion length), the bone area ratio and the expression of BMP-2 were evaluated using histological and immune-histochemical methods. Result: The expansion length and the bone area in the expansion group was significantly increasedmore than that in the control group in the time-course change (length P<0.0001, bone area P<0.0010). Significant difference was found in the BMP-2 labeling index between the expansion group and the control group in the time-course change (P=0.0015), although the value after 3 weeks tended to be the largest in both groups. Conclusion: This study suggests that bone regeneration can be induced by periosteal expansion using a conventional orthodontic wire and an uHA/PLLA mesh.
    IADR Asia/Pacific Region (APR) Regional Meeting and Co-Annual Scientific Meeting of IADR Divisions 2013; 08/2013
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    ABSTRACT: Objective: The purpose of this study was to examine the changes in border movement of the mandible before and after mandibular ramus osteotomy in patients with prognathism. Method: The subjects were 73 patients with mandibular prognathism who underwent sagittal split ramus osteotomy (SSRO with and without Le Fort I osteotomy. Border movement of the mandible was recorded with a mandibular movement measure system (K7) preoperatively and at 6 months postoperative. Maximum vertical opening, maximum antero-posterior movement from the centric occlusion, maximum lateral deviation on the left and right, and centric occlusion to maximum opening were compared between the pre and post-operative states, and the differences analyzed statistically. Result: There was no significant difference between SSRO alone and SSRO with Le Fort I osteotomy in the time-course change. The values at 6 months postoperative were significantly lower than the pre-operative values in the maximum vertical opening (P=0.0066), maximum antero-posterior movement from the centric occlusion (P=0.0425) and the centric occlusion to the maximum opening (P=0.0300). Conclusion: This study suggests that postoperative temporary reduction of the border in mandibular movement could recover by 1.5 years postoperative, and additional procedure of Le Fort I osteotomy did not affected the recovery of mandibular motion after SSRO.
    IADR Asia/Pacific Region (APR) Regional Meeting and Co-Annual Scientific Meeting of IADR Divisions 2013; 08/2013
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    ABSTRACT: Objective: Inferior alveolar nerve (IAN) impairment is widely known as typical accident of dental implant treatment. The aim of this study was to examine whether immediate removal of implants promotes histological recovery after IAN injury caused by bone screw placement close to mental foramen in rabbit using histological and immuno-histochemical methods. Methods: 14 adult male Japanese white rabbits were used. Right side and left side were divided as the retention side and the removal side. On the retention side, a self-drilling bone screw was kept implanted at the superior site closely to the mental foramen. On the removal side, soon after implantation at a similar site, the screw was removed. Rabbits were sacrificed at 1, 2 and 4weeks postoperatively, and the IAN was extracted and prepared for assessments using the hematoxylin-eosin stain and immuno-histochemical β-nerve growth factor (β-NGF) stain. Results: There were significant differences between the retention side and the removal side in ratio of destruction of nerve fibers only at 2weeks, and in mean diameter of nerve fibers only at 4weeks, statistically (P<0.05). Neither number of nerve fibers nor ratio of disappearance of axons showed a significant difference between both sides in each period. Ratio of β-NGF positive cells did not show a significant difference between both sides either. Conclusion: This study suggested that IAN impaired by dental implant tends to recover histologically without implant removal.
    IADR Asia/Pacific Region (APR) Regional Meeting and Co-Annual Scientific Meeting of IADR Divisions 2013; 08/2013
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    ABSTRACT: Objective: To compare bone regeneration among local implantation of statin and low-intensity pulsed ultrasound(LIPUS), and the combination of statin with LIPUS in rabbit nasal bone using histological and immunohistochemical methods. Method: Thirty two adult male Japanese white rabbits were used in this study. Two bone circular defects (5 mm in diameter) per rabbit were created in the nasal bone while preserving the nasal membrane. The two defects in each rabbit were filled with 2.5 mg/ml simvastatin in 0.2 ml water with an atelocollagen sponge (ACS) and ACS alone respectively. Sixteenrabbits (32 sides) received the LIPUSapplication, the remaining 16 rabbits (32 sides) did not. Therefore, the subjects composed of 4 groups, namely, (1) LIPUS +ACS{simvastatin (the LAS group), (2) LIPUS+ACS(the LA group), (3) ACS{simvastatin (the AS group) and (4) ACS alone (the A group). Four animals were killed in each period, at 1, 2, 4 and 8 weeks postoperative. The parts that had been operated on were removed and prepared for histological assessment. The expression of BMP-2 and the bone area ratio were evaluated using histological and immunohistochemical methods. Result: Bone square in the LAS group was significantly larger than that in the AS group after 1 (P<0.0001) and 2 week (P=0.0113). The bone square in the LA group was significantly larger than that in the A group after 1 (P<0.0001) and 2 weeks (P=0.0090). However, there was no significant difference between the LAS and LA groups. In the number of cells that stained positive for BMP-2, the LAS group was significantly larger than that in the AS group after 1 (P<0.0001) and 2 weeks (P=0.0113). Conclusion: This study suggests that bone regeneration can be promoted by LIPUS alone and statin alone, respectively. However the combination use of LIPUS with statin does not differ from LIPUS alone or statin alone.5
    IADR Asia/Pacific Region (APR) Regional Meeting and Co-Annual Scientific Meeting of IADR Divisions 2013; 08/2013
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    ABSTRACT: The purpose of this study was to examine the changes in border movement of the mandible before and after mandibular ramus osteotomy in patients with prognathism. The subjects were 73 patients with mandibular prognathism who underwent sagittal split ramus osteotomy (SSRO) with and without Le Fort I osteotomy. Border movement of the mandible was recorded with a mandibular movement measure system (K7) preoperatively and at 6 months postoperatively. Of the 73 patients, 21 had measurements taken at 1.5 years postoperative. Data were compared between the pre- and postoperative states, and the differences analyzed statistically. There was no significant difference between SSRO alone and SSRO with Le Fort I osteotomy in the time-course change. The values at 6 months postoperative were significantly lower than the preoperative values for maximum vertical opening (P=0.0066), maximum antero-posterior movement from the centric occlusion (P=0.0425), and centric occlusion to maximum opening (P=0.0300). However, there were no significant differences between the preoperative and 1.5 years postoperative measurements. This study suggests that a postoperative temporary reduction in the border movement of the mandible could recover by 1.5 years postoperative, and the additional procedure of a Le Fort I osteotomy does not affect the recovery of mandibular motion after SSRO.
    International Journal of Oral and Maxillofacial Surgery 08/2013; DOI:10.1016/j.ijom.2013.07.740 · 1.36 Impact Factor