Biomedical subjects

Kiyoshi Harada

Publications and source records attributed to Kiyoshi Harada.

15 recordsLinked to original sources

PubMed2006

Effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on bone consolidation on distraction osteogenesis: a preliminary study in rabbit mandibles.

AIM: To examine the effectiveness of administering recombinant human bone morphogenetic protein-2 (rhBMP-2) in distraction osteogenesis. MATERIAL AND METHODS: Twenty-one mature male Japanese white rabbits underwent unilateral mandibular osteotomy. After 5 days, the osteotomized mandibles were distracted 1mm/day for 10 days. On the first day (groups A-1 [n=4] and A-2 [n=4]) or on the last day (group B [n=5]) of distraction, rhBMP-2 mixed with collagen gel was injected into the distraction zone. In control groups (groups C-1 [n=4] and C-2 [n=4]), the mandibles were distracted without rhBMP-2 injection. At the end of the distraction period (groups A-1 and C-1) and after 2 weeks of consolidation (groups A-2, B, and C-2), the distracted mandibles were harvested and examined with soft radiographs, peripheral quantitative computed tomography (pQCT), and microscopy. RESULTS: Radioopacity was more marked in the distraction zone of the groups with rhBMP-2 than in control groups. The mineral density of the cortical bone (BMD) was higher in groups B and A-2 than in group C-2. Histologically, bone formation was more advanced in groups A-2 and B than in group C-2. The cortical BMD was higher in group A-1 than in group C-1. Histologically, bone formation was more advanced in groups A-2 and B than in group C-2. CONCLUSION: These results suggest that rhBMP-2 promotes bone formation in distraction osteogenesis.

Absorptiometry, Photon↗

PubMed2006

A new evaluation method for neurosensory disturbance in the chin of patients undergoing mandibular sagittal split ramus osteotomy: an application of the heat flux technique.

OBJECTIVE: To examine neurosensory changes in the chin following bilateral sagittal split ramus osteotomy (BSSRO) using the heat flux technique. STUDY DESIGN: Twelve healthy adults (C-group) and 23 patients undergoing BSSRO (P-group) were examined. The warm sense threshold (WHF) and cold sense threshold (CHF) in the chin of these patients were measured by the heat flux technique. In the P-group, touch sensation also was measured with a visual analog scale (VAS) and the Semmes-Weinstein monofilament test (SW test). RESULTS: Both WHF and CHF were significantly larger in the P-group than in the C-group (P = .024). Touch sensation (VAS and SW test) were damaged in some patients of the P-group. However, no correlation was revealed between thermal sensation (WHF and CHF) and touch sensation (VAS and SW test) in the P-group. CONCLUSIONS: These results suggest that the thermal sensation in the chin was damaged after BSSRO. The heat flux technique appears to be one of the useful methods for the examination of neurosensory disturbance in the chin.

Adult↗

PubMed2006

Long-term maxillomandibular skeletal and dental changes in children with cleft lip and palate after maxillary distraction.

Long-term skeletal and dental changes were examined in 8 children with cleft lip and palate who underwent maxillary distraction to allow the maxilla to catch up to their mandibular growth at the treatment point. Changes in the overjet (OJ), overbite (OB), and positions of the anterior nasal spine (ANS), upper incisors (U1), pogonion (Pog), and lower incisors (L1) were measured on preoperative to 36 months postoperative lateral-cephalograms. In most of the children, the long-term changes after the maxillary distraction resulted in an inferior growth of the maxilla and anteroinferior growth of the mandible. This seems to suggest that maxillary distraction performed during childhood needs considerable overcorrection. However, if the maxilla is distracted to an adult position during childhood, the masticatory functions of the children will markedly deteriorate until their jaws grow. Therefore, we believe that one goal of maxillary distraction during childhood can be to allow the maxilla to catch up to the mandibular growth of the children at the treatment point.

Adolescent↗

PubMed2006

Orthognathic surgery for a patient with trichorhinophalangeal syndrome type I: a case report.

Trichorhinophalangeal syndrome (TRPS) type I is characterized by slowly progressing systemic osseous dysplasia, exhibiting craniofacial and other skeletal deformities. However, there have been few reports describing this syndrome after undergoing orthognathic surgery. In this report, we present a patient with TRPS I who successfully underwent orthognathic surgery. In addition, we examined the skeletal stability of the patient for 2 years after the surgery.

Abnormalities, Multiple↗

PubMed2005

Long-term skeletal and dental changes in patients with cleft lip and palate after maxillary distraction: a report of three cases treated with a rigid external distraction device.

We examined long-term skeletal and dental changes in three patients with cleft lip and palate who underwent maxillary distraction using a rigid external distraction device. Two were children, and one was an adult. Changes in the overjet (OJ), overbite (OB), and positions of the anterior nasal spine (ANS), upper incisors (U1), pogonion (Pog), and lower incisors (L1) were measured on preoperative to 36 months postoperative lateral-cephalograms. In the adult, the positions of all examination points were relatively stable from 6 to 36 months postoperatively, and the OJ and OB were maintained at over 2 mm at 36 months. In the children, the positions of ANS and U1 changed inferiorly, Pog and L1 changed anteroinferiorly, and OJ and OB tended to decrease from 6 to 36 months postoperatively. Long-term skeletal and dental stability following maxillary distraction was relatively well maintained in the adult patient. In the children, the maxillomandibular growth was observed after maxillary distraction, but the mandibular overgrowth might have been inhibited by the correction of class III dentoskeletal deformity resulting from the maxillary distraction.

Adult↗

PubMed2004

Blood-flow and neurosensory changes in the maxillary dental pulp after differing Le Fort I osteotomies.

PURPOSE: The objective of this study was to examine changes in blood flow and the recovery of sensibility in the maxillary dental pulp after two different types of maxillary osteotomies. Study design Nine patients (C-group) who underwent a combined of Le Fort I and horseshoe osteotomy and 14 patients (NC-group) who underwent a single-segment Le Fort I osteotomy were compared. Thirty-two (C-group) and 54 (NC-group) maxillary incisors were examined preoperatively and at 1-7 days, 14 days, and 3, 6, and 12 months postoperatively. The pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and the pulpal sensibility (PS) was investigated by electrodiagnostics. RESULTS: In both groups, the PBF dropped to its lowest value at 1 day after surgery and increased thereafter. Though a temporary drop of the PBF was observed in the NC-group on day 4, the PS recovered earlier in the NC-group than in the C-group. CONCLUSION: These results suggest that the method of maxillary osteotomy influences the postoperative change of the PBF and recovery of the PS in the maxillary teeth.

Adult↗

PubMed2004

Blood-flow change and recovery of sensibility in the maxillary dental pulp during and after maxillary distraction: a pilot study.

OBJECTIVE: To examine the change in blood flow and recovery of sensibility in the maxillary dental pulp during and after maxillary distraction. STUDY DESIGN: The subjects included 5 patients undergoing high Le Fort I osteotomy and maxillary distraction (D-group) and a reference group of 14 patients who underwent a common single-segment Le Fort I osteotomy, 1-stage maxillary advancement, and mandibular setback surgery (C-group). Eleven (D-group) and 54 (C-group) maxillary incisors were assessed preoperatively and at 1-7 days, 14 days, and 3 months postoperatively. Pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and pulpal sensibility (PS) was investigated by electrodiagnostics. RESULTS: From postoperative days 1 to 5 (the latency period), the PBF tended to be higher in the D-group than in the C-group. From day 6 to 3 months postoperatively (during and after maxillary distraction), the PBF values of the 2 groups were similar. The PS remained negative up to 14 days postoperatively in both groups. However, at 3 months after the operation, a higher proportion (90.9%) of teeth in the D-group was positive for PS. CONCLUSION: These results suggest that maxillary distraction is a favorable technique for maintenance of PBF and recovery of PS in the maxillary teeth after surgery.

Adolescent↗

PubMed2004

Maxillary distraction in patients with cleft deformity using a rigid external distraction device: a pilot study on the distraction ratio of the maxilla to the device.

We examined the ratio between actual maxillary distraction and the distraction of the rigid external distraction device (Rigid external distraction (RED) system) used for maxillary distraction in patients with a cleft deformity. Twelve patients were examined. The amount of maxillary advancement was measured on lateral cephalograms and divided by the activation amount on the RED system. The value obtained was represented as the distraction ratio of the maxilla to the system. The mean ratio in 10 patients with complete cleft lip, palate, and alveolus (complete cleft) was 0.24. However, the ratios in two patients with cleft lip and alveolus or soft cleft palate (incomplete cleft) were considerably higher than the mean ratios in patients with complete cleft. When the maxilla is distracted in patients with complete cleft using the RED system, the amount of activation on the system needs to be about four times the amount of planned maxillary distraction. However, the distraction ratio may be affected by the type of cleft.

Adolescent↗

PubMed2003

Changes in bite force and dentoskeletal morphology in prognathic patients after orthognathic surgery.

OBJECTIVE: We sought to evaluate the changes in bite force and dentoskeletal morphology in prognathic patients after orthognathic surgery. STUDY DESIGN: Twenty-four patients underwent orthognathic surgery to correct Class III skeletal and dental malocclusions. Ten patients who underwent Le Fort I and bilateral sagittal split ramus osteotomy of the mandible (ie, surgical correction of 2 jaws) and 14 patients who underwent only bilateral sagittal split ramus osteotomy (ie, surgical correction of 1 jaw) were compared. Bite force was measured preoperatively and at 3, 6, and 12 months postoperatively. The dentoskeletal morphology was assessed through lateral cephalograms obtained preoperatively and 12 months postoperatively. RESULTS: Twelve months postoperatively, the bite force was significantly greater in the patients who underwent surgery on 1 jaw than in the patients who underwent surgery on 2 jaws. Significant decreases in the gonial angle, occlusal plane angle, and anterior facial height were observed postoperatively in the patients with 1 surgically corrected jaw, but not in the patients with 2 surgically corrected jaws. Patients with 2 surgically corrected jaws experienced a greater increase in the Frankfort mandibular plane angle and a greater decrease in the posterior facial height than did those with 1 surgically corrected jaw. CONCLUSION: The difference in the preoperative-to-postoperative change in dentoskeletal morphology between the 2 groups is one of the factors responsible for the significant difference in postoperative bite force between the 2 groups.

Adolescent↗

PubMed2003

Blood-flow change and recovery of sensibility in the maxillary dental pulp after a single-segment Le Fort I osteotomy.

OBJECTIVE: To examine blood-flow change and recovery of sensibility in the dental pulp of maxillary incisors in patients undergoing a single-segment Le Fort I osteotomy. STUDY DESIGN: Fifty-four maxillary incisors in 14 patients were examined preoperatively and at 1 to 7 days, 14 days, 3 months, 6 months, and 12 months postoperatively. The pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and the pulpal sensibility (PS) was investigated by electrodiagnostics. RESULTS: The mean PBF dropped to its lowest value at 1 day postoperatively and subsequently increased except for a temporary drop on day 4. The PS was negative in all the examined teeth from 1 day to 14 days after surgery. Subsequently, the rate of the teeth with positive PS increased. At 3 months postoperatively, the PS recovered in half of the examined teeth. The PBF value on day 1 was significantly higher in the teeth with positive PS at 3 months postoperatively than in those with negative PS at 3 months postoperatively. CONCLUSION: These results suggest that the decrease of the PBF in the maxillary incisors on 1 day after a single-segment Le Fort I osteotomy may affect the recovery of the PS in the short term after surgery.

Adult↗

PubMed2003

Mandibular lengthening by distraction osteogenesis for treatment of obstructive sleep apnea syndrome: a case report.

A 31-year-old man who had been diagnosed with obstructive sleep apnea syndrome (OSAS) due to retrognathia was referred to our hospital. Before treatment, the angle of the sella-nasion-point B (SNB) was 67 degrees. The lowest oxygen saturation (SpO2) during sleep was 77%, the longest-running episode of sleep apnea was 128 seconds, and his apnea index (AI) was 29.9. He underwent bilateral horizontal mandibular distraction osteogenesis using intraoral distraction devices. After mandibular distraction, SNB increased to 72 degrees. The lowest SpO2 during sleep increased to 85%, the longest-running episode of sleep apnea decreased to 40 seconds, and his AI decreased to 4.1 (within normal range). No marked recurrence of OSAS was observed even at one year after mandibular distraction. This report suggests that mandibular lengthening by distraction osteogenesis is an effectual method for the treatment of OSAS due to retrognathia.

Adult↗

PubMed2002

Effect of maxillary distraction osteogenesis on velopharyngeal function: a pilot study.

OBJECTIVE: The purpose of this study was to examine preoperative and postoperative changes of velopharyngeal function in cleft patients who underwent maxillary distraction osteogenesis using the Rigid External Distraction System. STUDY DESIGN: Six cleft patients followed for a minimum of 12 months after maxillary distraction were examined. Plain and contrast lateral-cephalograms were obtained preoperatively and postoperatively, and speech evaluation was performed by the same authorized speech therapist at the same time points. RESULTS: The mean distraction amount at the anterior nasal spine was 11.7 mm (range, 7.4 mm - 15.0 mm). Both the nasopharyngeal depth and velar length increased after maxillary distraction, but the need ratio (nasopharyngeal depth/velar length) also increased after distraction. Although scores for velopharyngeal closure dropped a few points after maxillary distraction, the rating for hypernasality remained unchanged in all patients but the patient whose distraction amount was 15.0 mm. CONCLUSION: These results suggest that maxillary distraction of less than 15 mm may not markedly affect velopharyngeal function in cleft patients.

Cephalometry↗

PubMed2002

Soft tissue profile changes of the midface in patients with cleft lip and palate following maxillary distraction osteogenesis: a preliminary study.

OBJECTIVE: The purpose of this study was to examine preoperative to postoperative changes of soft tissue profiles in the midface of cleft patients who underwent maxillary distraction. STUDY DESIGN: Nine cleft patients were examined (distraction group). Lateral cephalograms were obtained preoperatively and 6 months after distraction. Changes in the positions of soft and hard tissue landmarks, the nasolabial angle, and facial height were investigated and compared with those in 9 other cleft patients who underwent conventional maxillary advancement (conventional group). RESULTS: Anterior changes of the soft and hard tissue landmarks were significantly larger in the distraction group than in the conventional group. The distraction group tended to have larger increases in the nasolabial angle and subnasal length, as well as a higher anterior movement ratio for soft to hard tissue. CONCLUSIONS: These results suggest that, in the midfacial profile changes of cleft patients who underwent maxillary distraction, not only is advancement of soft and hard tissue large, but also anterior movement ratio for soft to hard tissue is relatively high.

Adolescent↗

PubMed2002

Post-operative stability of the maxilla treated with Le Fort I and horseshoe osteotomies in bimaxillary surgery.

In this study, the post-operative change of the maxilla in six non-cleft patients who underwent combination (Le Fort I and horseshoe) osteotomy for superior repositioning of the maxilla was investigated. In all patients, the maxilla was first osteotomized and fixed with four Luhr plates. No iliac bone graft was applied to the maxilla. A bilateral sagittal split ramus osteotomy of the mandible (BSSRO) was then carried out and titanium screw fixation was performed. No maxillo-mandibular fixation (MMF) with stainless steel wire was used post-operatively in any patient. Lateral cephalograms were obtained pre-operatively, 5 days post-operatively, and 3, 6, and 12 months after surgery. The changes in anterior nasal spine (ANS), point A, upper incisor (U1), and point of maxillary tuberosity (PMT) were examined. The maxillae in the six subjects were repositioned nearly in their planned positions during surgery and no significant post-operative changes in the examined points of the maxilla were found. These results suggest that a combination of a Le Fort I and horseshoe osteotomy is a useful technique for reliable superior repositioning of the maxilla. The post-operative change in the maxilla using this combination osteotomy is comparatively stable.

Adult↗

PubMed2002

Three cases of anterior maxillary osteotomy under orotracheal intubation.

Anterior maxillary osteotomy is frequently applied to skeletal Class II cases with maxillary protrusion. In addition to the anteroposterior problem, these cases are often accompanied with a long midfacial appearance and display of incisors and gingiva during smiling. In the application of anterior maxillary osteotomy to such patients, it is necessary to move the anterior maxillary segments upward as well as backward. Since the upward movement occasionally interferes with the intranasal endotracheal tube, orotracheal intubation is recommended for the operation. Recently, the use of a resin replica of the mandibular dental arch was introduced to place the anterior maxillary segment correctly in the planned position and to obtain the correct occlusion. This article reports on 3 maxillary protrusive skeletal Class II patients with deep overbites and vertical esthetic problems treated by this method. The treatment results show that all 3 patients exhibited large upward and backward movements of the anterior maxillary segments and desirable facial profiles, with a reduction of the deep overbites after the treatment. This case report demonstrates that the anterior maxillary osteotomy under orotracheal intubation with the use of a resin replica is a useful method to treat maxillary protrusive skeletal Class II patients with a large alveolar height.

Adult↗