Biomechanical Analysis of the Effect of Intracranial Pressure on the Orbital Distances in Trigonocephaly

Objective This biomechanical study aims to elucidate differences in how skulls with trigonocephaly, normal skulls, and postoperative trigonocephalic skulls respond to intracranial pressure and how this affects the orbital distances. Materials and Methods For 10 patients with trigonocephaly (8.2 ± 4.5 months), simulation models were produced based on the computed tomographic data of the skulls. These models were categorized as the Trigono group. For each model, a 15-mm Hg pressure was applied to the neurocranium to simulate the intracranial pressure. The interorbital distances expanded in response to the applied pressure. The amount of the change in the orbital distance was calculated using finite element analysis. The same processes were repeated for 10 models simulating normal skulls (the Control group) and postoperative trigonocephalic skulls (the Remodeled group). The changes in the orbital distance were compared among the three groups. Results The changes in the orbital distance were significantly smaller for the Trigono group than for the Control group. However, changes were significantly greater for the Remodeled group than for the Control group. Conclusion The expansion of interorbital distances in response to the cranial pressure is restricted in skulls with trigonocephaly. This restriction is eliminated by performing remodeling of the skull. These findings explain why spontaneous correction of hypotelorism occurs postoperatively in trigonocephaly.

[1]  A Yanai,et al.  Can Dog-Ear Formation Be Decreased When an S-Shaped Skin Resection Is Used Instead of a Spindle Skin Resection? A Three-Dimensional Analysis of Skin Surgery Techniques Using the Finite Element Method , 2000, Plastic and reconstructive surgery.

[2]  T. Nagasao,et al.  The Dynamic Role of Buttress Reconstruction after Maxillectomy , 2005, Plastic and reconstructive surgery.

[3]  L. Olson,et al.  Presurgical Finite Element Analysis from Routine Computed Tomography Studies for Craniofacial Distraction: II. An Engineering Prediction Model for Gradual Correction of Asymmetric Skull Deformities , 1998, Plastic and reconstructive surgery.

[4]  Gang Shen,et al.  Biomechanical Effects of Rapid Palatal Expansion on the Craniofacial Skeleton with Cleft Palate: A Three-Dimensional Finite Element Analysis , 2007, The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association.

[5]  L A Whitaker,et al.  Analysis and treatment of severe trigonocephaly. , 1999, Plastic and reconstructive surgery.

[6]  C G Ullrich,et al.  Pre-surgical CT/FEA for craniofacial distraction: I. Methodology, development, and validation of the cranial finite element model. , 1998, Medical engineering & physics.

[7]  T. Nagasao,et al.  The Effect of Striking Angle on the Buckling Mechanism in Blowout Fracture , 2006, Plastic and reconstructive surgery.

[8]  T. Nagasao,et al.  Effectiveness of Additional Transmalar Kirschner Wire Fixation for a Zygoma Fracture , 2007, Plastic and reconstructive surgery.

[9]  J. McNamara,et al.  The neurocranial basis for facial form and pattern. , 2009, The Angle orthodontist.

[10]  J. Jane,et al.  Surgical approaches for the correction of metopic synostosis. , 1986, Neurosurgery.

[11]  K. Oh,et al.  Uncomplicated trigonocephaly. A radiographic affirmation of conservative therapy. , 1981, Radiology.

[12]  M. Choux,et al.  Skull base in trigonocephaly. , 1991, Pediatric neurosurgery.

[13]  Min S. Park,et al.  Surgical correction of metopic synostosis , 2005, Child's Nervous System.

[14]  Carsten J. Beller,et al.  Role of Aortic Root Motion in the Pathogenesis of Aortic Dissection , 2004, Circulation.

[15]  S. Sonnad,et al.  Evolution of Operative Techniques for the Treatment of Single-Suture Metopic Synostosis , 2007, Annals of plastic surgery.

[16]  D H Enlow.  Growth and the problem of the local control mechanism. , 1973, The American journal of anatomy.

[17]  I. Munro,et al.  Trigonocephaly‐Associated Hypotelorism: Is Treatment Necessary? , 1996, Plastic and reconstructive surgery.

[18]  M. Egnor,et al.  Decompressive craniectomy in pediatric patients with traumatic brain injury with intractable elevated intracranial pressure. , 2006, Journal of pediatric surgery.

[19]  A. Shuper,et al.  The incidence of isolated craniosynostosis in the newborn infant. , 1985, American journal of diseases of children.

[20]  K. Katada,et al.  Magnitude and Role of Wall Shear Stress on Cerebral Aneurysm: Computational Fluid Dynamic Study of 20 Middle Cerebral Artery Aneurysms , 2004, Stroke.

[21]  D. Rénier,et al.  Craniofacial Surgery for Craniosynostosis Improves Facial Growth: A Personal Case Review , 1985, Annals of plastic surgery.

[22]  I. Mathijssen,et al.  Bitemporal Depressions After Cranioplasty for Trigonocephaly: A Long-Term Evaluation of (supra) Orbital Growth in 92 Patients , 2008, The Journal of craniofacial surgery.

[23]  K. Muraszko,et al.  Early Development of Infants with Untreated Metopic Craniosynostosis , 2005, Plastic and reconstructive surgery.

[24]  T. Nagasao,et al.  Appropriate diameter for screws to fix the maxilla following Le Fort I osteotomy: an investigation utilizing finite element analysis. , 2007, Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery.

[25]  C. Lauritzen,et al.  Spring-Assisted Correction of Hypotelorism in Metopic Synostosis , 2007, Plastic and reconstructive surgery.

[26]  D. Richardson,et al.  Craniofacial surgery for orbital malformations , 2006, Eye.