A study to evaluate the extent of bone healing in mandibular distraction osteogenesis using preoperative and postoperative pixel value ratio

Abstract

Background the aim of this study was to investigate the value and potential influencing factors of pixel value ratio (PVR) in early phase of mandible healing by distraction osteogenesis. Methods We performed a retrospective analysis on 342 patients with bilateral mandibular lengthening surgery, measured PVRs in osteotomy position of children before surgery, and monitored PVRs in early stage of bone regenerating at 1st, 2nd and 3rd month respectively after surgery. The potential effects of gender, weight, and age on fixation period were also analyzed. Results PVRs before osteotomy and at 1st, 2nd and 3rd month after osteotomy were (R0.96 ± 0.04, L0.97 ± 0.05), (R0.4 ± 0.1, L0.42 ± 0.1), (R0.68 ± 0.11, L0.71 ± 0.11), (R0.97 ± 0.04, L0.98 ± 0.04) which had significant differences (p < 0.001). We found no significant difference in PVRs by gender. In terms of age, there was a significant difference in PVRs between children aged less than 28 days and older than 120 days before surgery. There were also significant differences between those aged less than 28 days and older than 120 days, and children aged 8–28 days and aged 29–60 days at the 3rd month after surgery. Consider weight, children with birth weight less than 4 kg and those with admission weight less than 2.5 kg were significant different. Conclusion PVRs were gradually increased during the early 3 months after the osteotomy. Gender had no effect on PVRs, while age, birth weight, and admission weight had a greater effect. Our results may inform the assessment of PVRs and potential impact of patients with early bone lengthening.