Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2013 May;131(5):1014-1021.
doi: 10.1097/PRS.0b013e31828e217a.

Quantitative comparison of volume maintenance between inlay and onlay bone grafts in the craniofacial skeleton

Kristoffer B Sugg  1 , Andrew H Rosenthal, Wayne Ozaki, Steven R Buchman
Affiliations
Comparative Study

Quantitative comparison of volume maintenance between inlay and onlay bone grafts in the craniofacial skeleton

Kristoffer B Sugg et al. Plast Reconstr Surg. 2013 May.

Abstract

Background: Nonvascularized autologous bone grafts are the criterion standard in craniofacial reconstruction for bony defects involving the craniofacial skeleton. The authors have previously demonstrated that graft microarchitecture is the major determinant of volume maintenance for both inlay and onlay bone grafts following transplantation. This study performs a head-to-head quantitative analysis of volume maintenance between inlay and onlay bone grafts in the craniofacial skeleton using a rabbit model to comparatively determine their resorptive kinetics over time.

Methods: Fifty rabbits were divided randomly into six experimental groups: 3-week inlay, 3-week onlay, 8-week inlay, 8-week onlay, 16-week inlay, and 16-week onlay. Cortical bone from the lateral mandible and both cortical and cancellous bone from the ilium were harvested from each animal and placed either in or on the cranium. All bone grafts underwent micro-computed tomographic analysis at 3, 8, and 16 weeks.

Results: All bone graft types in the inlay position increased their volume over time, with the greatest increase in endochondral cancellous bone. All bone graft types in the onlay position decreased their volume over time, with the greatest decrease in endochondral cancellous bone. Inlay bone grafts demonstrated increased volume compared with onlay bone grafts of identical embryologic origin and microarchitecture at all time points (p < 0.05).

Conclusions: Inlay bone grafts, irrespective of their embryologic origin, consistently display less resorption over time compared with onlay bone grafts in the craniofacial skeleton. Both inlay and onlay bone grafts are driven by the local mechanical environment to recapitulate the recipient bed.

PubMed Disclaimer

Conflict of interest statement

Disclosure: The authors have no financial interest to declare in relation to the content of this article.

Figures

Fig. 1
Fig. 1
Inlay placement of bone grafts. All grafts were positioned posterior to the coronal suture and on either side of the sagittal suture.
Fig. 2
Fig. 2
Onlay placement of bone grafts. All grafts were positioned posterior to the coronal suture and on either side of the sagittal suture.
Fig. 3
Fig. 3
Three-dimensional micro–computed tomographic representations of inlay and onlay bone grafts at 3, 8, and 16 weeks. All inlay bone grafts, irrespective of embryologic origin, demonstrated actual bone growth and expansion, whereas all onlay bone grafts were consistently resorbed (original magnification, × 40).
Fig. 4
Fig. 4
Volume comparison of membranous cortical (above), endochondral cortical (center), and endochondral cancellous (below) bone grafts in the inlay and onlay positions.
See this image and copyright information in PMC

Comment in

References

    1. Habal MB. Bone grafting in craniofacial surgery. Clin Plast Surg. 1994;21:349–363. - PubMed
    1. Oppenheimer AJ, Tong L, Buchman SR. Craniofacial bone grafting: Wolff’s law revisited. Craniomaxillofac Trauma Reconstr. 2008;1:49–61. - PMC - PubMed
    1. Donovan MG, Dickerson NC, Hellstein JW, Hanson LJ. Autologous calvarial and iliac onlay bone grafts in miniature swine. J Oral Maxillofac Surg. 1993;51:898–903. - PubMed
    1. Phillips JH, Rahn BA. Fixation effects on membranous and endochondral onlay bone graft revascularization and bone deposition. Plast Reconstr Surg. 1990;85:891–897. - PubMed
    1. Lin KY, Bartlett SP, Yaremchuk MJ, Fallon M, Grossman RF, Whitaker LA. The effect of rigid fixation on the survival of onlay bone grafts: An experimental study. Plast Reconstr Surg. 1990;86:449–456. - PubMed

Publication types

MeSH terms