RESUMO
A concern in the current trend toward more aggressive undermining in rhytidectomy and liposuction surgery has been the potential for damage to the marginal mandibular nerve. This study was undertaken in an attempt to clarify the exact peripheral pathway of the marginal mandibular nerve. A series of 22 fresh cadaver heads were studied bilaterally by gross dissection and histologic studies. It was found that dissection superficial to the platysma up to a point 2 cm lateral to the lower lip can be done safely. Medial to this point, dissection is hazardous and is not indicated because the marginal mandibular nerve becomes more superficial as it travels to innervate its effector muscles. Additionally, dissection in this area is technically difficult because of the tight adherence of the skin to the underlying muscles. This adherence generally permits only the formation of fine superficial rhytids that are best treated by chemical peel or dermabrasion.
Assuntos
Tecido Adiposo/cirurgia , Face/cirurgia , Nervo Mandibular/anatomia & histologia , Cirurgia Plástica , Humanos , SucçãoRESUMO
Brow elevations via the indirect temporal lift approach was carried out on a series of 26 cadaver half heads. The purpose of the dissection was to identify the course and depth of plane of the frontalis branch of the facial nerve. Of particular interest was the area superolateral to the brow. Histologic sections were taken along the course of the nerve to determine its exact depth. It was determined that the nerve lay in the superficial musculoaponeurotic system layer of superficial fascia lying above the level of the temporalis fascia. Utilizing this information, a method of dissection in the temporal lift operation is described that safely avoids the frontalis branch of the facial nerve.
Assuntos
Face/cirurgia , Nervo Facial/anatomia & histologia , Testa/anatomia & histologia , Cirurgia Plástica/métodos , Cadáver , Expressão Facial , Traumatismos do Nervo Facial , Testa/inervação , Testa/cirurgia , Humanos , Cirurgia Plástica/efeitos adversosRESUMO
A study was conducted to destroy two specific areas of the cat's visual system in order to determine if these lesions would affect the visual inhibition of calorically-induced vestibular nystagmus. The occipital visual cortex was removed in eight cats and the superior colliculi were removed bilaterally in nine cats. Postoperative vestibular testing revealed no significant change in the electronystagmography tracings and response to visual fixation. These findings suggest that, in cats, the visual inhibition of labyrinthine nystagmus is not dependent upon the integrity of the visual cortex or superior colliculi. The hypothesis is brought forward that the visual inhibition of the vestibular nystagmus is merely a reflex of the brain stem to light stimulus, mediated via the cerebellum.