SURGICAL APPROACHES TO THE FACIAL SKELETON

Contents Section I General Principles for Approaches to the Facial Skeleton 1 1 General Principles for Approaches to the Facial Skeleton 3 Section II Periorbita Approaches 7 2 Lower Eyelid Approach 9 3 Transconjunctival Approach 38 4 Supraorbital Eyebrow Approach 51 5 Upper Eyelid Approach 55 Section III Coronal Approach 63 6 Coronal Approach 65 Section IV Transoral Approachs to the Facial Skeleton 95 7 Maxillary Vestibular Approach 97 8 Mandibular Vestibular Approach 109 Section V Transfacial Approaches to the Mandible 121 9 Submandibular Approach 123 10 Retromandibular Approach 139 11 Rhytidectomy Approach 154 Section VI Approaches to the Temporomandibular Joint 161 12 Preauricular Approach 163 Section VII Surgical Approaches to the Nasal Skeleton 187 13 External (Open) Approach 189 14 Endonasal Approach 204 Index 217 xiii S E C T I O N I GENERAL PRINCIPLES FOR APPROACHES TO THE FACIAL SKELETON 1 General Principles For Approaches To The Facial Skeleton aximum success in skeletal surgery depends on adequate access to and exposure of the skeleton. Skeletal surgery is simplified and expedited when the involved parts are sufficiently exposed. In orthopedic surgery, especially of the appendicular skeleton, a basic rule is to select the most direct approach possible to the underlying bone. Thus, incisions are usually placed very near the area of interest while major nerves and blood vessels are retracted. This involves little regard for aesthetics, allowing the orthopedics surgeon greater leeway in the location, direction, and length of the incision. Surgery of the facial skeleton, however, differs from general orthopedics surgery in several important ways. First, the primary factor in incision placement is not surgical convenience but facial esthetics. The face is plainly visible to everyone, and a conspicuous scar may create a cosmetic deformity that can be as troubling to the individual as the reason for which the surgery was performed. Cosmetic considerations are critical in light of the emphasis that Western society places on facial appearance. Thus, as we will see in this text, all of the incisions used on the face must be placed in inconspicuous areas, sometimes very distant from the underlying osseous skeleton on which the surgery is being performed. For instance, placement of incisions in the oral cavity allows superb exposure of much of the facial skeleton with a completely hidden scar. A second factor that differentiates incision placement on the face from that anywhere else on the body is the presence of the muscles and nerve (cranial nerve VII) of facial expression. The muscles are subcutaneous structures, and the facial nerve branches that supply them can be traumatized if incisions are placed in their path. This can result in a “paralyzed” face, which is not only a severe cosmetic deformity but can have great functional ramifications as well. For instance, if the ability to close the eye is lost, corneal damage can ensue, affecting sight. Thus, placement of incisions and dissections that expose the facial skeleton must ensure that damage to the facial nerve is unlikely. Many dissections to expose the skeleton require care and electrical nerve stimulation to identify and protect the nerve. Approaches using incisions in the facial skin must take into consideration the muscles of facial expression. This is especially important for approaches to the orbit, where the orbicularis oculi muscle must be traversed. Closure of some incisions also affects the muscle of facial expression. For instance, if a maxillary vestibular incision is closed without proper reorientation of the perinasal muscle, widening of the nasal base will occur. A third factor in facial incision placement is the presence of many important sensory nerves exiting the skull at multiple locations. The facial soft tissues have more sensory input per unit area than soft tissues anywhere else in the body. Loss of this sensory input can be a great inconvenience to the individual. Thus, the incision and approaches used must attempt to spare the sensory nerves from injury. An example is dissection of the supraorbital nerve from its foramen/notch in the coronal approach. 3 ... - tailieumienphi.vn