Facial suture plating alters sutural interdigitation in Sus scrofa

Objective: The role of facial sutures during growth is not completely understood.  In order to further investigate their role, the present study analyzed the effect of rigid plating of circummaxillary sutures on suture development.

Methods: Sus scrofa female pigs from 10 birth cohorts of 3 sibs (total n=30, 2 months old) were randomly divided into three groups.  The experimental group (n=10) had rigid pediatric miniplates affixed across the zygomaticomaxillary and nasofrontomaxillary sutures bilaterally using monocortical screws.  A sham group (n=10) had screws inserted but no plates affixed, and a control group (n=10) did not undergo surgery.  All environmental variables, including diet, were kept constant.  At six months, the pigs were euthanized and their skulls were prepared.  2 pigs (1 sham, 1 control) did not survive to six months and were not analyzed.  Each skull underwent computed tomographic scanning.  Vitrea® software was used to quantify suture interdigitation for all zygomaticomaxillary and nasofrontomaxillary sutures.  Suture interdigitation was measured as a ratio of true suture length divided by shortest distance between external and internal surfaces.   Interdigitation between groups was compared using one-way ANOVA with post-hoc Tukey-Kramer's test (a<0.05) utilized when sizes differed among groups analyzed.

Results: Interdigitation of the average experimental (plated) zygomaticomaxillary sutures was found to be significantly less (1.7±0.08, p<0.0001) than interdigitation of sutures from either the sham (3.08±0.37) or control (3.35±0.45) groups. Interdigitation of the average experimental nasofrontomaxillary suture was found to be significantly less (2.70±0.72, p<0.0001) than interdigitation of sutures from either the sham (4.03±0.56) or control (4.06±0.51) groups.  No significant differences existed between the sham and control groups for both zygomaticomaxillary and nasofrontomaxillary sutures.

Conclusion: Rigidly fixating zygomaticomaxillary and nasofrontomaxillary sutures in Sus scrofa alters suture growth and anatomy reflected in significantly reduced circumfacial sutural interdigitation. Support: T32 DEO14678-05.