Kazumi Ohkubo

Evaluation of 15 mandibular reconstructions with Dumbach Titan Mesh-System and particulate cancellous bone and marrow harvested from bilateral posterior ilia

This study reports on 15 mandibular reconstructions using the Dumbach Titan Mesh-System and particulate cancellous bone and marrow harvested from bilateral posterior ilia. All cases showed segmental defects. Eleven cases involved patients with malignant tumor. Six patients had received irradiation of 40-50 Gy. Reconstructions were performed immediately in 1 patient and secondarily in the remaining 14 patients. In 13 cases, mandibles were successfully reconstructed. Of these 13 patients, 9 reconstructions were completed without complications, whereas the other 4 cases showed complications. In 2 cases, reconstruction failed completely. Overall success rate was 87%. Statistical analysis revealed the extent of mandibular defect, but not malignancy of the original disease or radiotherapy of <or=50 Gy, as a significant factor in the occurrence of postoperative complications. Although no significant correlation was identified, cases in which mandibular continuity was lost at the time of reconstruction tended to show a higher postoperative complication rate. These results suggest that for the management of patients with malignant disease, resected mandible and soft tissue should be properly reconstructed using the metal plate and soft tissue flap at the time of cancer ablation surgery to reduce postreconstructive complications. Preoperative fabrication of the titanium mesh using a 3-dimensional skull model is expected to improve surgical outcomes.

A novel method for designing and fabricating custom-made artificial bones

Artificial bones are useful for tissue augmentation in patients with facial deformities or defects. Custom-made artificial bones, produced by mirroring the bone structure on the healthy side using computer-aided design, have been used. This method is simple, but has limited ability to recreate detailed structures. The authors have invented a new method for designing artificial bones, better customized for the needs of individual patients. Based on CT data, three-dimensional (3D) simulation models were prepared using an inkjet printer using plaster. The operators applied a special radiopaque paraffin wax to the models to create target structures. The wax contained a contrast medium to render it radiopaque. The concentration was adjusted to achieve easy manipulation and consistently good-quality images. After the radiopaque wax was applied, the 3D simulation models were reexamined by CT, and data on the target structures were obtained. Artificial bones were fabricated by the inkjet printer based on these data. Although this new technique for designing artificial bones is slightly more complex than the conventional methods, and the status of soft tissue should also be considered for an optimal aesthetic outcome, the results suggest that this method better meets the requirements of individual patients.

Evaluation of Mandibular Hypoplasia in Patients With Hemifacial Microsomia: A Comparison Between Panoramic Radiography and Three-Dimensional Computed Tomography

Objective To compare the accuracy of three-dimensional computed tomography (3D-CT) and panoramic radiography in the evaluation of mandibular hypoplasia in patients with hemifacial microsomia (HFM). Design Retrospective study of imaging data. Setting Images selected from the archives of the University of Tokyo Hospital. Subjects Twenty patients with unilateral HFM who had undergone both panoramic radiography and 3D-CT in the same period. Method Mandibular deformities were classified according to the Pruzansky classification; eight patients had Grade I deformity and 12 patients had Grade II deformity. Ramus heights were measured on both panoramic radiographs and 3D-CT. Main outcome measures Magnification in panoramic radiographs and extent of mandibular asymmetry as estimated by the affected/unaffected side ratio based on two methods were examined. The Pearson product-moment correlation coefficient was used to estimate correlations between parameters. Results The magnification of ramus heights on panoramic radiographs showed large variations in Grade II patients. The affected/unaffected side ratio estimated by the two methods showed a strong correlation in Grade I patients (correlation coefficient 0.99; p < .0001). Conversely, a weak correlation was seen in Grade II patients (correlation coefficient 0.77; p = .0036), and affected/unaffected side ratios from panoramic radiographs were both over- and underestimated. Conclusions The accuracy of evaluation using panoramic radiography was fairly reliable in Grade I patients. Conversely, accuracy was poor in Grade II patients, and evaluation using 3D-CT seems preferable. The combination of two methods with careful consideration is recommended for clinical applications.

Submucous cleft palate: variations in bony defects of the hard palate

We have analysed bony defects of the hard palate in patients with submucous cleft palate to find out whether velopharyngeal insufficiency (VPI) is dependent on the extent of these defects. We evaluated the maxillofacial structures associated with cleft palate by 3-dimensional computed tomography (CT) in 23 children diagnosed with submucous cleft palate. Bony defects of the hard palate were divided into Type I, defined as absent posterior nasal spine (n=12), Type II, V-shaped bony notch (moderate, n=7), and Type III, as bony defect extending into the incisive foramen (severe, n=4) defects, respectively. VPI was found in 10, 3, and 4 patients, respectively. Neither VPI nor the degree of bifid uvula was significantly associated with the types of bony defects.

Treatment of ankylosed maxillary central incisors by single-tooth dento-osseous osteotomy and alveolar bone distraction

When tooth ankylosis occurs in growing children, the ankylosed tooth fails to erupt and gradually positions itself below the occlusal plane. This causes functional and esthetic problems, and orthodontic treatment is often impossible. To clarify this problem, we developed a new treatment protocol for the movement of ankylosed teeth. This consists of single-tooth dento-osseous osteotomy and alveolar bone distraction using orthodontic multibracket appliances. A special distraction device is not required, thus reducing the burden to patients. Two cases in which an ankylosed maxillary central incisor was successfully treated with this protocol are presented.

Cyclooxygenase-2 activity is important in craniofacial fracture repair.

The aim of this study was to examine the effect of cyclooxygenase (COX)-2 on bone repair after craniofacial fracture in mice. A 4-mm fracture was created in the parietal bone of 8-week-old male COX-2 wild-type (COX-2(+/+)) and knockout (COX-2(-/-)) mice. Ribonucleic acid was extracted from the fractured bone and analysed. For morphological and histological analysis, the mice were killed 8 and 12 weeks after treatment, and sections were prepared. Three-dimensional computed tomography was performed, and the sections were stained with hematoxylin-eosin for histological examination. Expression of COX-2 messenger ribonucleic acid was induced in COX-2(+/+) mice, but not in COX-2(-/-) mice. Ossification at the fracture site was almost complete 12 weeks after fracture in COX-2(+/+) mice. In COX-2(-/-) mice, incomplete union had occurred at the fracture site. In both types of mice, the fracture site contained no cartilaginous tissue, and the callus formed from the periosteal side. These results suggest that COX-2 plays an important role in craniofacial fracture repair and that COX-2-selective non-steroidal anti-inflammatory drugs might interfere with fracture repair of the membranous viscerocranium in the clinical setting.

Maxillary Protraction in Patients With Cleft Lip and Palate in Mixed Dentition: Cephalometric Evaluation After Completion of Growth

Objective To clarify the short- and long-term effects of maxillary protraction (MP) in mixed dentition in patients with unilateral cleft lip and palate (UCLP). Design Retrospective study. Setting University of Tokyo Hospital. Patients and Intervention Eleven Japanese patients with UCLP in mixed dentition were treated with MP and followed up until the completion of growth. Multibracket treatment had been performed after MP treatment in all patients. Main Outcome Measure Lateral cephalograms taken before and after MP and after completion of growth were used. Posterior and anterior vertical reference lines (PV, AV) were used to measure the horizontal movements of point A, pogonion, and maxillary first molar (U6). SNA, SNB, ANB, maxillary and mandibular length, mandibular plane angle, Wits value, upper incisor inclination, overjet, and overbite were also measured. Results Large variation was found in the effects of MP, and five patients eventually required orthognathic surgery. In average change with MP, the maxilla showed favorable forward growth. Point A had moved forward from PV but not AV. The mandible rotated backward. However, ANB and the Wits value did not improve. U6 moved forward, and the overjet improved. After MP, the skeletal Class III relationship became severe. Conclusions MP was effective as an early treatment for UCLP patients. However, its effects showed large variation and were in conflict with facial growth. Conscientious explanation of the expected effects and associated problems should be given to the patients/parents before its application.

The efficacy of dental therapy for an adult case of Henoch–Schönlein purpura

Abstract Henoch–Schonlein purpura (HSP) is a disease that involves palpable purpura on the skin, joint pain, and gastrointestinal problems. An acute bacterial infection is one of the causes of HSP. Odontogenic infectious diseases have also been implicated in causing HSP. However, there are only a few reports describing the correlation between HSP and odontogenic infectious diseases. The present study describes a case in which a patient was cured of HSP following dental treatment.

Evaluation and analysis of formation of bone at the palate in patients with cleft lip and palate after palatoplasty based on computed tomograms and three-dimensional data

Abstract There are various techniques for palatoplasty, but no studies of postoperative osteogenesis at the palatal fissure. In the cranial and maxillofacial region it is thought to develop from the periosteum, so palatoplasty with mucoperiosteal flaps may encourage new bone to form at the fissure. We evaluated the status of osteogenesis in the hard palate after palatoplasty on computed tomograms (CT). We studied 29 patients (22 boys and 7 girls) with unilateral cleft lip and palate who had pushback palatoplasty with the use of CT obtained between May 2003 and March 2007. Age at the time of operation was recorded. The width of the palatal fissure at the first premolar, the first molar, and the maxillary posterior region were measured on coronal CT. The mean (SD) age at the time of palatoplasty was 16 (2) months. The mean (SD) width of the fissure at the first molar was 3.96 (3.1) mm, and bony union was seen in four patients. The width of the fissure was significantly less at the first molar than at the other sites (p = 0.006). The shape of the margin of the fissure was irregular in nearly all patients. The width of the fissure at the first molar became significantly less, suggesting that osteogenesis had occurred. In some patients the height of the fissure differed. Given the results of previous studies, bony regeneration from the periosteum most likely happens together with regeneration from the margins of the fissure.

A Case of Odontogenic Infection by Streptococcus constellatus Leading to Systemic Infection in a Cogan’s Syndrome Patient

Odontogenic infection in immunocompromised patients tends to extend systemically beyond the oral cavity. Our case report presents a patient with sepsis due to a Streptococcus constellatus (S. constellatus) odontogenic infection in a 64-year-old-immunocompromised woman with Cogans syndrome. She had been suffering from chronic mandibular osteomyelitis which was thought to have been caused by dental caries and/or chronic periodontitis with furcation involvement of the left mandibular first molar. We suspect that the acute symptoms of the chronic osteomyelitis due to S. constellatus led to the systemic infection. This infection could be accelerated by the use of a corticosteroid and an alendronate. This is the first report which represents the potential association between odontogenic infection and Cogans syndrome.