Purpose: This anatomic biomechanical study was undertaken to gain insight into the underlining mechanism of tipping of the maxillary segments during transverse expansion using tooth-borne and bone-borne distraction devices. Materials and Methods: An anatomic biomechanical study was performed on 10 dentate human cadaver heads using tooth-borne and bone-borne distraction devices. Results: The amount of tipping of the maxillary halves was greater in the tooth-borne group, but the difference was not significant. Four of the specimens demonstrated an asymmetrical widening of the maxilla. Conclusions: Segmental tipping was seen in both study groups. In this anatomic model, tooth-borne distraction led to greater segmental tipping compared with bone-borne distraction. Keep in mind, however, that this anatomic model by no means depicts a patient situation, and any extrapolation from it must be done with great care. The fact that the tooth-borne group demonstrated greater tipping might reflect the general opinion that bone-borne distraction causes less segmental angulation than tooth-borne distraction. Some tipping was seen in the bone-borne group, suggesting that overcorrection to counteract relapse will be necessary with this treatment modality.

dx.doi.org/10.1016/j.joms.2007.11.026, hdl.handle.net/1765/25051
Journal of Oral and Maxillofacial Surgery
Erasmus MC: University Medical Center Rotterdam

Koudstaal, M.J, Smeets, J.B.J, Kleinrensink, G.J, Schulten, A.J.M, & van der Wal, K.G.H. (2009). Relapse and Stability of Surgically Assisted Rapid Maxillary Expansion: An Anatomic Biomechanical Study. Journal of Oral and Maxillofacial Surgery, 67(1), 10–14. doi:10.1016/j.joms.2007.11.026