The lower eyelid consists of at least four distinct layers: the skin and subcutaneous tissue, the orbicularis oculi muscle, the tarsus (upper 4 to 5 mm of the eyelid) or orbital septum, and the conjunctiva. The upper eyelid consists of five distinct layers from skin to conjunctiva: the skin, the orbicularis oculi muscle, the orbital septum above or the levator palpebrae superioris aponeurosis below, the Müller muscle/tarsus complex, and the conjunctiva. The anatomy of the eyelids and scalp is briefly discussed here for later reference. Because these ideal measurements are not always found, an examination of the contralateral zygoma will determine the correct position of the injured zygoma in every patient who has no craniofacial anomalies.įor complex zygomatic fractures, multiple approaches are often needed for visualizing the fracture sites and applying internal fixation. From a lateral perspective, the globe should be 1 mm anterior to the most prominent portion of the zygoma. The zygomaticotemporal foramen on its medial side transmits the zygomaticotemporal nerve and vessels.įrom a frontal view, the ideal position of the zygomatic prominence is 10 mm lateral and 20 mm inferior to the lateral canthus. On the malar surface is the zygomaticofacial foramen, which provides exit to the nerve and vessels of the same name. The temporalis muscle and the temporalis fascia attach at the temporal process, specifically its posterolateral edge. The body of the zygoma is sturdy, but its articulations are frequently the site of fracture.įive muscles attach to the zygoma: the masseter muscle originates from its temporal surface the zygomaticus major, the zygomaticus minor, and the levator labii superioris originate from its malar surface. It articulates with the zygomatic process of the temporal bone, and together they make up the zygomatic arch. It forms a large portion of the orbit and, together with the sphenoid bone, forms part of the orbital floor. The frontal process is sturdy however, it narrows superiorly as it articulates with the zygomatic process of the frontal bone. The four processes of the zygoma are the frontal, maxillary, temporal, and sphenoid. Because it forms part of the lateral wall and floor of the orbit, fractures of the body of the zygoma usually involve fractures of the floor or the lateral wall of the orbit, or both ( Figure 12-1 ). It is quadrilateral in shape and articulates with four other bones: maxilla, sphenoid, temporal, and frontal bones. Its outer (lateral) surface is convex its inner (temporal) surface, concave. ANATOMYīecause of its prominent position on the facial skeleton, the zygomatic bone is responsible for the anterior and lateral projection of the midface and thus is a very important part of facial aesthetics. ![]() For these reasons, the appropriate diagnosis and treatment of these fractures are important for the functional and cosmetic outcome of facial trauma patients. These fractures occur most commonly as the result of assaults or motor vehicle collisions.ĭisplaced fractures of the zygoma cause obvious deformities of the midface related to the projection of the malar eminence, lateral projection of the arch, and position of the globe, which can affect vision. ![]() ![]() Zygomatic fractures are common in facial trauma and, as is the case with other facial fractures, occur primarily among men in their third decade of life.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |