Direct current stimulation of the coronal suture in rabbits

The purpose of this investigation was to determine whether a constant direct current stimulation applied at the coronal suture would alter sutural morphology and selected cephalometric parameters of the cranial vault and cranial base. In each of six rabbit litters (N = 36), animals were randomly assigned to control, sham, and experimental groups. At 21 days of age, the sham and experimental groups had thin titanium wire cathodes surgically positioned between the fascial layers of the scalp overlying the coronal suture. On this same day and on day 70, all animals had standardized lateral and dorsoventral cephalograms taken and also received lead acetate vital stain injections. The following results were demonstrated: (1) a significantly greater flexure in the cranial base angle (P < 0.01) for the experimental group at day 70; (2) no statistically significant differences for percentage changes (day 70/day 21) in cranial vault length or cranial vault width among the control, sham, and experimental groups (P < 0.05); (3) alterations in sutural morphology at day 70 for the experimental group, including lengthened collagenous fibers, abundant cartilage in the suture, and a twofold increase in the bony modeling of the ectocranial surface. This study concludes that, although the exact mechanisms of action for direct current stimulation remain unknown, this manipulation can indeed alter some parameters of the cranial skeleton and suture morphology.