Zygomatic fractures



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ZYGOMATIC FRACTURES



HYSTORY


  • 1751 duVerney reported 2 cases. took advantage of the mechanical forces of the masseter and temporalis muscles on the zygoma in a unique approach to closed reduction technique

  • 1906 Lothrop devised the transantral approach.

  • 1909 Keen categorized zygomatic fractures as those of the arch, the body, or the sutural disjunction. He was the first to describe an intraoral approach to the zygomatic arch in which an incision is made in the gingivobuccal sulcus.

  • 1927 Gillies described an original approach to reduce a depressed malar bone. He was the first to reach the malar bone through an incision made behind the hairline and over the temporal muscle. Gillies further described the use of a small, thin elevator that is slid under the depressed bone, thus enabling the surgeon to use the leverage of the elevator to reduce the fracture. The Gillies method remains in use today to elevate the arch. the nasal approach

  • 1942 Adams first used suspension wires for reduction and fixation

  • 1950 Fryer reported using Kirschner wires for stabilization

  • 1972 Michelet and Festal first reported rigid fixation for fractures of the midface

ANATOMY


  • Sicher and DeBrul were the first to depict facial anatomy in terms of structural pillars or buttresses.

  • This concept allows consideration of an approach for reduction of midface fractures and ultimately the production of a stable reconstruction.

  • Manson have elucidated this concept further by emphasizing the idea that the mid face is made of sinuses that are supported fully and fortified by vertical and horizontal buttresses of bone.

  • maxilla and the associated bones of the mid face are oriented to resist the vertical forces of mastication. This is accomplished through 3 paired vertical buttresses (from anteromedial to posterolateral): the nasomaxillary buttress, the zygomaticomaxillary buttress, and the pterygomaxillary buttress. An additional unpaired midline support is the frontoethmoid-vomerine buttress

  • These buttresses help give the zygoma an intrinsic strength such that blows to the cheek usually result in fractures of the zygomatic complex at the suture lines, rarely of the zygomatic bone.

  • The superior and inferior orbital rims and alveolar ridge constitute a group of weaker horizontal buttresses.

  • While these structures provide some protection against horizontal forces, they can withstand much less force than the vertical buttresses. Therefore, vertical impact tends to be better absorbed within the facial skeleton, which resists fracture, while horizontal impact tends to overcome the weaker horizontal buttresses and shear through the vertical pillars.

Principle vertical buttresses

    1. Frontoethmoid-vomerine buttress

    2. Medial or nasomaxillary buttress

      • extends from the cuspid and anterior portion of the maxillary alveolus along the piriform aperture, the medial side of the orbit, through the anterior lacrimal crest, and the nasal process of the maxilla to the superior orbital rim and nasoethmoidal region

    3. Lateral or zygomaticomaxillary buttress.

      • extends from the maxillary alveolus across the anterior molar to the zygomatic process of the frontal bone and laterally to the zygomatic arch.

    4. Posterior or pterygomaxillary

      • attaches the maxilla posteriorly to the pterygoid plates of the sphenoid bone.



  • Restoration of the zygomaticomaxillary buttress prevents the inferior deviation of the orbit and provided good zygomatic contour.

  • Restoration of the nasomaxillary buttress prevents the superior and posterior deviation of the alar base of the nose

  • Restoration of the pterygomaxillary buttress prevented the superior and posterior deviation of the upper lip.

Horizontal buttress

Principle buttresses



  1. Supraorbital bar

  2. Infraorbital rim

  3. Maxillary alveolar ridge and palate

  4. Mandible




    • 2 types of horizontal buttress – coronal and sagittal.

    • The central part of the face lacks a sagittal buttress and thus projection is often loss with trauma here





  • The zygomaticomaxillary complex has 4 sutures

  1. zygomatico-frontal suture

  2. zygomatico-temporal suture

  3. zygomatico-maxillary suture

  4. zygomatico-sphenoidal suture

  • even though a ZMC fracture is commonly referred to as a trimalar or tripod fracture, a “complete ZMC fracture” technically should be really called a tetrapod fracture. The reason being that ZM and ZS sutures are often considered together as one unit






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