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The biomechanical effect of the bipartite zygoma: A Finite Element Analysis of the impact of an auxiliary facial suture in the midface
Author(s) -
Unger Evelyn,
Wang Qian
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.723.4
Subject(s) - zygomatic arch , maxilla , zygomatic bone , fibrous joint , temporal bone , skull , anatomy , mathematics , orthodontics , medicine
Typically the zygoma is a single facial bone bounded by sutures where it abuts the maxilla, frontal, sphenoid, and temporal bones. Rarely, the zygoma is transected by an extra suture arising perpendicularly from the facial aspect of the maxillozygomatic suture and running dorsolaterally to the zygomatic aspect of the temporal fossa giving the bone a bipartite morphology (Incidence of 2.5–6.5% in human populations). In the midface, which is normally under heavy stresses during feeding, the biomechanical effect of bipartite zygoma has so far not been explored. We hypothesized that the bipartite zygoma condition would alter the pattern of stress distribution in the face during mastication. The bipartite zygoma condition was created in a Finite Element Model of a skull from a Tufted Capuchin monkey (USNM518342), and the model was analysed and compared to a model with typical zygoma condition. Results revealed that the bipartite morphology disrupts the normal inferosuperior stress flow from maxilla to frontal through the zygoma. The superior half of the zygoma in the upper face was spared high stress flow at the expense of the inferior half of the zygoma in the midface. In this way, the stresses incurred during normal activities (i.e. feeding) were shunted from the upper facial regions to the relatively gracile yet already heavily stressed temporal arm of the zygomatic arch, suggesting that the bipartite morphology is less optimal than the typical case. How the temporal arm of the zygomatic arch adapts in this situation needs further studies. Grant support: NSF HOMINID BCS‐0725183 and NSF BCS‐0100825 (CT images of USNM518342 courtesy of Dr. James Rossie. www.digimorph.org ).