Functional and electron-microscopic changes after differential traction injury in the sciatic nerve of a rat / 대한악안면성형재건외과학회지

Background@#During maxillofacial trauma or oral cancer surgery, peripheral nerve might be damaged by traction injury. The purpose of this study was to evaluate functional and histomorphometric changes after traction nerve injury in the sciatic nerve of a rat model. @*Methods@#A total of 24 Sprague-Dawley rats were equally divided into three groups: unstretched (sham/control, group A), stretched with 0.7N (group B) and 1.5N (group C). Traction injury was performed for 10 min in B and C groups. Functional recovery of the sciatic nerve was evaluated by walking track analysis, toe spread test, and pinprick test 2 weeks after injury. The weight of gastrocnemius muscles of both sides was measured to evaluate weight ratio (ipsilateral/contralateral). Total number of axons, axon fiber size, myelin thickness, G-ratio, axon number/mm 2 , diameter of fiber, changes of longitudinal width, and formation of the edema and hematoma were evaluated by transmission electron microscopy. @*Results@#The sciatic function indexes were −11.48±4.0, −15.11±14.84, and −49.12±35.42 for groups A, B, and C, respectively. Pinprick test showed 3.0, 2.86±0.38, and 1.38±0.52 for A, B, and group C. Muscle weight ratios were 0.98±0.13 for group A, 0.70±0.10 for group B, and 0.54±0.05 for group C. There were significant differences in toe spread test, pinprick test, and muscle weight ratio between control group and experimental group (p<0.001). In the experimental group, fiber number, fiber size, G-ratio, fiber number/mm 2 , myelin thickness, diameter of fiber, and longitudinal width were decreased with statistical significance. @*Conclusion@#The present study demonstrated that the nerve traction injury in the rat sciatic nerve damaged the motor and sensory function and axonal integrity. The amount of functional nerve damage was proportional to the amount of traction power and dependent on the initial tensile strengths (0.7N and 1.5N).

Per-oral cross-facial sural nerve graft for facial reanimation / 대한악안면성형재건외과학회지

BACKGROUND: Cross-facial nerve graft is considered the treatment of choice for facial reanimation in patients with unilateral facial palsy caused by central facial nerve damage. In most cases, a traditional parotidectomy skin incision is used to locate the buccal and zygomatic branches of the facial nerve. METHODS: In this study, cross-facial nerve graft with the sural nerve was planned for three patients with facial palsy through an intraoral approach. RESULTS: An incision was made on the buccal cheek mucosa, and the dissection was performed to locate the buccal branch of the facial nerve. The parotid papillae and parotid duct were used as anatomic landmarks to locate the buccal branch. CONCLUSIONS: The intraoral approach is more advantageous than the conventional extraoral approach because of clear anatomic marker (parotid papilla), invisible postoperative scar, reduced tissue damage from dissection, and reduced operating time.

365 nm LED laser treatment on beagle for gingival whitening without gum dermabrasion

PURPOSE: Gingival whitening is one of dental treatment purposes which is close to treating aesthetic disorders. Initial gingival whitening treatment was done by dermabrasion using a high power Diode Laser. However, this treatment method cannot be free from any infection or pain after the treatment. Therefore, we have decided to progress gingival whitening treatment using a low power LED laser. MATERIALS AND METHODS: The laser was irradiated on pork meat then the safety of output power, temperature change and skin denaturalization was measured. Bison 365 nm LED laser was irradiated on oral mucosal pigment of a 15 - 20 kg beagle for 15 min for 1 - 2 weeks, one or two times each. Any pigment loss was checked through Hematoxyline-Eosin staining. RESULTS: The melanin pigments at the area of 365 nm LED Laser irradiation were decreased. CONCLUSION: The 365 nm LED Laser proposed in this study is considered to compensate the bleaching effect achieved by either using Diode laser or surgical methods.

Sweet syndrome initially manifesting odontogenic buccal cellulitis; Report of a case