■ Part 2. Buttresses of the Craniomaxillofacial Skeleton

Parallels to sanctuary support systems are apparent on inspection of the craniofacial skeleton: vertical buttresses and trajectories, horizontal platforms and shelves, struts, trusses, and out frames (arches) allow offloading of the stress of mastication and the impact of trauma. These features, only slowly comprehended in an historical sense over the centuries, aided development of biomechanical concepts and influenced methods of craniofacial repair after trauma.

Ancient anatomists revered the hand as God’s “most profound creation”6 ^, 7 and generally gave little attention to study of the facial skeleton. Ancient Greeks (distinctly Galen) were exceptions to this focus, and, notably later, during the Renaissance, Leonardo da Vinci and Andreas Vesalius refined skeletal depictions of the cranium and face ( Fig. 1.7A,B ).

Modern awareness and understanding of craniofacial structure was heightened when Rene Le Fort in 1901 described “areas of inherent weakness and comminution” across the bony midface, after impact.8 Le Fort, of Paris, France, perceived bones of the midface to “hang like a curtain,” some “delicate and spongy,” and some in columns or “blades of bone more compact”8 ( Fig. 1.8A ).

Jean-Leo Testut (1849 to 1925), Professor of Anatomy, University of Lyon, France, a decade later, reversed the architecture described by Le Fort. Testut instead pictured a framed assembly of “dense pillars” beneath the cranium. Interspersed between the pillar-like struts, according to his assessment, were “zones of weakness”9 ^– 11 ( Fig. 1.8B,C ).

In either case, the dense condensations of craniomaxillofacial bone, recognized today as buttresses, were not defined in these terms, nor was their role as load-bearing pathways understood. It remained for Henry Cryer of Philadelphia, Pennsylvania, to identify the seven craniomaxillofacial buttresses, “descending,” as he described it, “from the walls of the cranial vault above, to the maxillae [jaws] below.” He recognized four “outer” (anterior) and three “inner” (posterior) buttresses, that strengthened the cranial vault and palate. The anatomic components of each of the seven buttresses are identified in Cryer’s 1916 text, The Internal Anatomy of the Face, published in Philadelphia by Lea & Febiger12 ( Fig. 1.9A,B ).

Cryer perceived the “nasal septum, especially that portion formed by the vomer,” to be a “ flying buttress to the sphenoid bone” and considered the “zygomatic arch a flying buttress that supports the upper jaw.”12 Like Testut before him, Cryer found the bone interspersed between the buttresses and “flying” outjuttings to be delicate, fragile, and, he argued, vulnerable to injury.

Cryer’s original description of the basic craniomaxillofacial architecture has been modified only slightly in the past near-century.13 ^– 22 Sicher ( Fig. 1.10A ), for example, emphasized the pith of horizontal platforms (such as the palate, orbital floors, and orbital roofs) in human facial form.14 ^, 15 Dingman ( Fig. 1.10B ) and Natvig duly noted the buttressing role of the palatine struts.16 And, Ferré and colleagues drew attention to the convergence of structural bone and nonosseous entities at the base of the sphenoid sinus (central cranial base).21 ^, 22

Direct interosseous repair of bone fragments began in 1846, first in the mandible (Buck, Fouchard, Kinloch, Gilmer, Kazanjian) and then in the maxilla (Gillies, Converse, Adams, Rowe, and Dingman). They and Muller, Luhr, Merville, Schilli, Champy, Couly, Michelet, and others in Europe recognized the relevance of reconstitution of the buttresses after craniomaxillofacial trauma.

By applying craniofacial appliances in the proper location, load-bearing forces, it appeared, could be effectively redistributed, and callous-free osteosynthesis could be encouraged. After reports by Huelke, Manson, Donald, Zide, Gruss, Jackson, Munro, Klotch, Van Sickels, Ellis, Alpert, and many others, direct repair became a tenet of craniomaxillofacial repair, with or without comminution23 ^– 92 ( Fig. 1.11 ).