Soft tissue movements after mandibular reconstruction using the vascularized iliac flap: patterns and predictions.

Abstract

To investigate soft-to-hard tissue response following mandibular reconstruction and to develop a predictive model for projecting soft tissue movement. In this retrospective study, 18 patients receiving mandibular reconstruction using a vascularized iliac flap were enrolled. Various indicators for characterizing the movement of tissues were considered to identify the effective predictors for projecting soft tissue movements. Face-region-specific linear regression models for prediction were constructed and evaluated. The arithmetic mean of hard tissue movement in an extended area had the strongest correlation with the movement of the focal soft tissue, while the arithmetic mean in a regional area (Ram) was a more effective predictor. The linear regression model using Ram, global extrema and distances between them as the predictors performed the best in the lower margin of the face, with an average error of 1.51 ± 1.38mm. Soft tissue movement in the alveolar process was not correlated with the existence of dentition, only can be predicted by the soft tissue movement below it. The area of the masseter was strongly correlation with Ram, but no other factors. An accurate prediction of soft tissue movements in the lower margin and the alveolar process of the face can be achieved by considering hard tissue and adjacent soft tissue movements. No effective predictor in the masseter area was identified. We investigated the relationship between hard tissue movements and the soft tissue responses in the facial area. Through building predictive models for projecting postoperative soft tissue movements, we derive insights for the aesthetic outcome of face surgeries. This study was registered on the Chinese Clinical Trial Registry (registration number: ChiCTR2100054103).