Skull Base Cephalometric Changes in Cranial Expansion by Springs

Abstract

The experimental rabbit model was shown to be adequate to the analysis proposed by the study. Under the action of springs, the groups with sagittal and parasagittal osteotomy were found to present a similar distraction of amalgam markers. A concomitant change in cephalometric measurements occurred, suggesting a change in the skull base mediated by expansible springs placed both in the sutural and nonsutural sites.

Development and testing of an absorbable spring for cranial expansion in rabbits

“…Unlike in previous studies (Gewalli et al, 2001;David et al, 2002;Davis et al, 2009b;Dornelles et al, 2010;de Faria Valle Dornelles et al, 2011), expansion was greatest not at parietal bone markers but, rather, at frontal ones. This occurred at least partly because our craniectomy extended beyond the coronal suture and the implant was placed on top of it, thus distributing force more anteriorly.…”

“…of rabbits (1.4 mm) is similar to that of patients undergoing surgery for craniosynostosis (1.8 mm) (Mooney et al, 1998;Gewalli et al, 2001;David et al, 2002;Guimaraes-Ferreira et al, 2002;Sanger et al, 2007;Davis et al, 2009a;de Faria Valle Dornelles et al, 2011). The mortality rate was high in the control and intervention groups.…”

“…Unlike in experimental protocols using a smaller (2015) 1e8 6 ostectomy and spring, there was no bone bridge formation; the defect was bridged by connective tissue alone (Persing et al, 1986;Gewalli et al, 2001;Davis et al, 2009a, Dornelles et al, 2010de Faria Valle Dornelles et al, 2011). There were major differences between the control and intervention groups in neovascularization, giant cells, and mature collagen production.…”

“…In vitro strength measurements were similar to those of metal springs used in other studies (Gewalli et al, 2001;Sanger et al, 2007;Davis et al, 2009a, Dornelles et al, 2010de Faria Valle Dornelles et al, 2011). These measurements were obtained approximately 7 days before implantation.…”

“…The mortality rate was high in the control and intervention groups. The high periprocedural mortality is likely attributable to the need for a wide craniectomy for implant placement, whereas the craniectomy used for metal spring placement is generally smaller (2 mm wide and bounded by the lambdoid and coronal sutures) (Persing et al, 1986;Gewalli et al, 2001;Davis et al, 2009a, Dornelles et al, 2010de Faria Valle Dornelles et al, 2011). Extension of craniotomy posterior to the lambdoid suture caused major intraoperative bleeding in all animals, which led to three immediate fatalities and one delayed death (two due to hypovolemic shock and two due to intracranial hemorrhage).…”