Monitoring dental pulp sensibility and blood flow in patients receiving mandibular orthognathic surgery

Aim To investigate the effect of orthognathic surgery, in particular genioplasty, on pulp sensibility and pulp blood flow (PBF). Methodology Pulp blood flow monitoring and CO2 pulp sensibility testing were performed on 101 mandibular anterior teeth from 17 subjects who received mandibular bilateral sagittal split osteotomy (BSSO) with or without genioplasty and other maxillary surgical procedures combined with orthodontic treatment. A laser Doppler flowmeter was used to monitor PBF using customized acrylic splints for each subject. Preoperative baseline scores were recorded from up to 1 week preoperatively, and subsequently monitored for up to 1828 weeks postoperatively. The data were analysed by RMANOVA and pairwise comparisons. Statistical significance was defined as P < 0.05. Results The average PBF in subjects who received genioplasty was not significantly different to those who received no genioplasty (F = 0.076, P = 0.784). In both groups, PBF decreased significantly postoperatively (F = 23.323, P = 0.000) and remained significantly lower (P = 0.000) than preoperative values at all times. PBF decreased markedly for 12 weeks postoperatively in patients who received genioplasty. However, there were no statistical differences between the PBF values at any time postoperatively for either group (P > 0.05). All teeth in both groups responded to CO2 preoperatively. The average number of teeth that responded to CO2 postoperatively in the genioplasty group was lower without significant difference when compared to the group without genioplasty (binomial distribution F = 2.63, P = 0.1256, normal distribution F = 2.98, P = 0.1048). At each progressive period after 12 weeks following surgery, the number of teeth responding to CO2 increased significantly (P < 0.001) in both groups. At the end of the study, in the genioplasty group 81.1% of teeth responded to CO2 compared to all teeth in the group without genioplasty. Conclusion Pulp blood flow decreased and remained significantly lower than preoperative values in mandibular anterior teeth postoperatively with or without genioplasty. At no time was the absence of PBF recorded. The number of teeth that responded to CO2 decreased markedly postoperatively but recovered significantly over time. All teeth regained sensibility in the group without genioplasty at the end of the study. There were neither common trends nor coincidence in the recovery of PBF and pulp sensibility.