injuries poisoning
Fractures of the Mandible and Midface
Introduction
Blunt facial trauma can fracture the jaw and other bones of the midface. Symptoms depend on the location of the fracture. A dental x-ray or CT is diagnostic. Treatment may include surgery and/or external fixation. Fractures of the lower jaw(mandible) are suspected in patients with post-traumatic malocclusion or focal swelling and tenderness over a segment of the mandible. Other clues include defects (stepoff) of the dental occlusal surface, alveolar ridge disruptions, and anesthesia in the distribution of the inferior alveolar or mental nerve. Some fractures result in palpable instability. Fractures of the mandibular condyle usually cause preauricular pain, swelling, and limited opening of the mouth (trismus). With a unilateral condylar fracture, the jaw deviates to the affected side when the mouth is opened. which includes the area from the superior orbital rim to the maxillary teeth, can cause irregularity in the smooth contour of the cheeks, malar eminences, zygomatic arch, or orbital rims. The Le Fort classification (see figure Le Fort classification of midface fractures ) can be used to describe midface fractures. Traumatic malocclusion and upper alveolar ridge fractures may suggest a maxillary fracture that involves the occlusal surface. is suggested by infraorbital nerve anesthesia, enophthalmos, or diplopia. An injury near the orbit requires an eye examination, including, at least, assessment of visual acuity, pupils, and extraocular movements (see also Blowout fracture ). Zygomatic arch fractureis suggested by trismus and a defect on palpation of the zygomatic arch. A depression on the ipsilateral cheek may or may not be visible initially due to swelling. Brain injury and fractured cervical vertebrae are possible when trauma has been severe enough to fracture facial bones. In major impact injuries, hemorrhage and edema due to a facial fracture may compromise the airway. I: only the lower maxilla; II: the infraorbital rim; III: complete detachment of the midface from the skull (craniofacial dissociation). 