Yoshiyuki Yonehara

Mechanisms involved in an increment of multimodal excitability of medullary and upper cervical dorsal horn neurons following cutaneous capsaicin treatment

BackgroundIn order to evaluate mechanisms that may underlie the sensitization of trigeminal spinal subnucleus caudalis (Vc; the medullary dorsal horn) and upper cervical spinal cord (C1-C2) nociceptive neurons to heat, cold and mechanical stimuli following topical capsaicin treatment of the facial skin, nocifensive behaviors as well as phosphorylation of extracellular regulated-kinase (pERK) in Vc and C1-C2 neurons were studied in rats.ResultsCompared to vehicle application, capsaicin application to the lateral facial skin produced 1 hour later a flare in the skin, and also induced significantly greater nocifensive behaviors to heat, cold or mechanical stimulus of the lateral facial skin. The intrathecal (i.t.) injection of the MEK inhibitor PD98059 markedly attenuated the nocifensive behaviors to these stimuli in capsaicin-treated rats. Moreover, the number of pERK-like immunoreactive (pERK-LI) cells in Vc and C1-C2 was significantly larger following the heat, cold and mechanical stimuli in capsaicin-treated rats compared with vehicle-treated rats. The number of pERK-LI cells gradually increased following progressive increases in the heat or mechanical stimulus intensity and following progressive decrease in the cold stimulus. The ERK phosphorylation in Vc and C1-C2 neurons was strongly inhibited after subcutaneous injection of the capsaicin antagonist capsazepine in capsaicin-treated rats.ConclusionThe present findings revealed that capsaicin treatment of the lateral facial skin causes an enhancement of ERK phosphorylation in Vc and C1-C2 neurons as well as induces nocifensive behavior to heat, cold and mechanical simulation of the capsaicin-treated skin. The findings suggest that TRPV1 receptor mechanisms in rat facial skin influence nociceptive responses to noxious cutaneous thermal and mechanical stimuli by inducing neuroplastic changes in Vc and C1-C2 neurons that involve in the MAP kinase cascade.

Complications associated with gradual cranial vault distraction osteogenesis for the treatment of craniofacial synostosis.

Distraction osteogenesis has become a standard technique for craniomaxillofacial reconstruction. The authors performed gradual cranial vault distraction osteogenesis in 19 patients with craniosynostosis to study the outcome and complications of this procedure. Postoperative infections developed around the shaft puncture wounds in four patients, including one who required surgical removal of the device. Advanced bone was deformed in one patient. In another, the expansion device was exposed, resulting in a postoperative scar. Despite these complications, the cranium was successfully expanded in all patients.

Mandibular lengthening by gradual distraction: analysis using accurate skull replicas

Bone lengthening in the upper and lower extremities by gradual distraction has become an accepted procedure. We have used an extraoral device to lengthen the mandible in four patients with unilateral mandibular hypoplasia. Using an accurate skull replica, the proposed corticotomy line, intended direction of lengthening, and appropriate position for the screws were determined. Following distraction, a significant increase in the dimensions of the affected mandible was obtained in each case. In this series, accurate skull replicas proved very useful for defining the anatomy, for surgical simulation and for pre- and postoperative evaluation.

Treatment of Zygomatic Fractures Without Inferior Orbital Rim Fixation

Zygomatic fractures can be associated with functional and esthetic problems. Recent improvements in surgical techniques and materials have enabled stable fixation of zygmomatic fractures. Multiple-point fixation is most commonly used for internal fixation. Generally, reduction and fixation are performed through lateral brow, subciliary, temporal, or intraoral incisions (three-point fixation). Our experience indicates that postoperative scarring and sensory disturbances are caused by a subciliary incision with inferior orbital rim fixation. It is thus recommended that inferior orbital rim fixation with mini- or microplates be avoided. In patients in whom the fracture does not involve the orbital floor, reduction of the zygoma and zygomatic arch through a temporal incision is performed at this institution. Fixation of the lateral zygomaticomaxillary buttress and anterior wall of the maxilla with miniplates through an intraoral incision is also performed. If necessary, zygomaticofrontal suture fixation with a miniplate or wire is performed through a lateral brow incision. The status of inferior orbital rim reduction is confirmed by palpitation. Inferior orbital rim fixation with mini- or microplates is recommended for reduction of comminuted fractures and orbital floor fractures with herniation of internal orbit components. Patients who did not undergo inferior orbital rim fixation were free of inferior orbital rim deformity, diplopia, and postreduction rotation.

Topical negative pressure using a drainage pouch without foam dressing for the treatment of undermined pressure ulcers.

Abstract:Topical negative pressure is gaining popularity as an acute and chronic wound management technique. In general, foam dressing is applied to the wound surface to maintain negative pressure. Due to the potential for clogging by the foam dressing, topical negative pressure cannot be used when there is a high volume of necrotic tissue or massive infection present. In this study, topical negative pressure was applied using a drainage pouch without any dressing. Topical negative pressure was applied to 8 patients with 9 pressure ulcers complicated by undermining. This approach was effective in the treatment of all 9 ulcers and allowed the wounds to be visualized while maintaining negative pressure. Since this technique can be performed without foam dressing, it can be used to treat early-stage infectious pressure ulcers in which there is a lot of necrotic tissue. Conclusion:Topical negative pressure without dressing is an extremely effective treatment of pressure ulcers complicated by undermining.

Early correction of the nose in unilateral cleft lip patients using an open method: a 10-year review.

PURPOSE To review a 10-year follow-up of cases with rhinoplasty for a cleft lip-associated nose deformity done during the preschool years. MATERIALS AND METHODS Sixteen patients from 16 to 19 years of age were evaluated with two indices: the nasal index and the lobule portion of the columella index. RESULTS Several years after surgery the results appeared to be reasonably satisfactory. However, as the patients approached their adolescent growth spurt at 15 years of age, undesirable features became obvious. Each patient showed a strikingly bulbous nose. The nasal index of male patients ranged from 68.8% to 82.7% (mean, 75.4%) and that of female patients ranged from 72.7% to 85.0% (mean, 79.2%). The mean value of the nasal index in the Japanese male and female is 58.5% +/- 1.5% and 59.0% +/- 1.0%, respectively. The lobule portion index of male patients ranged from 57.1% to 72.0% (mean, 65.1%) and that of female patients ranged from 62.5% to 82.0% (mean, 74.2%). The lobule portion of the columella constitutes 33% of the total columellar length on average. CONCLUSIONS A possible cause of the undesirable deformities is use of an open surgical method. A second possible cause is mobilization and suspension of the alar cartilages. These undesirable features may occur only in Oriental noses.

Heterotopic gastrointestinal cyst of the oral cavity.

We report a heterotopic gastrointestinal cyst of the oral cavity. Heterotopic islands of gastrointestinal mucosa have been found in the esophagus, the small bowel, and particularly in Meckels diverticulum. However, their occurrence in the head and neck is extremely rare. Previously reported cases and the theories of embryogenesis are reviewed.

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.

Controlled delivery of bFGF to recipient bed enhances the vascularization and viability of an ischemic skin flap

Therapeutic angiogenesis is a promising approach to treat ischemic skin flaps. We delivered basic fibroblast growth factor (bFGF) to the recipient bed of a rat dorsal skin flap by a drug delivery system with acidic gelatin hydrogel microspheres (AGHMs), and assessed augmentation of neovascularization and flap viability. An axial skin flap was elevated on the back of male Sprague–Dawley rats, and bFGF solution or bFGF‐impregnated AGHMs were injected into the recipient bed. The dose of bFGF in the bFGF solution was set to 15 (Sol‐15 group), 50 (Sol‐50 group), or 150 μg (Sol‐150 group). Correspondingly, 2 mg AGHMs were impregnated with 15 (AGHM‐15 group), 50 (AGHM‐50 group), or 150 μg (AGHM‐150 group) bFGF. Other groups of animals received phosphate‐buffered saline (Sol‐Cont group) or phosphate‐buffered saline‐impregnated AGHMs (AGHM‐Cont group) as controls. Seven days later, analyses of the area of necrosis, microangiographic findings, and histological findings in the flap were carried out. The area of necrosis in the AGHM‐150 group was significantly smaller than that in the other groups. Microangiographic and histological analyses showed that neovascularization of the ischemic skin flap significantly increased in the AGHM‐150 group as compared with the Sol‐150 group and the AGHM‐Cont group. These findings suggest that continuous delivery of bFGF to the recipient bed by bFGF‐impregnated AGHMs enhances the viability of an ischemic skin flap.

Distraction of scarred soft tissue before secondary bone grafting : A case report

Mandibular distraction was performed to restore oral function in a 52-year-old man with tongue cancer, in whom a mandibular fracture developed after marginal resection of the mandible. The fracture caused the mandibular dental arch to be shorter than the maxillary arch. An external fixation device was attached to the collapsed mandible. The mandibular soft tissue was expanded by 32 mm. After gradual distraction, a vascularized iliac bone graft was transferred to the lengthened space. Subsequently, vestibuloplasty was performed and implants were inserted. A normal appearance, acceptable occlusion and satisfactory oral function were achieved.