A comparative study of facial growth following cleft lip repair with or without soft-tissue undermining: an experimental study in rabbits.

The present study was performed in rabbits to test the hypothesis that incisions in the sulcus and soft-tissue undermining at the time of cleft lip repair contribute more to midfacial growth inhibition and aberrations than lip repair only. The design of this study, using three control groups, permitted assessment of the effects of soft-tissue undermining independently of the other surgical procedures. This study revealed that lip repair combined without soft-tissue undermining. Direct cephalometry on the skulls indicated that anteroposterior facial growth was most severely affected mean quantitative assessment revealed that anteroposterior facial growth inhibition was significantly greater when lip repair was combined with soft-tissue undermining than without. Maxillary width was found to be the greatest in groups 3 and 4 compared with the other two groups. Mean quantitative assessment revealed that lip repair with or without soft-tissue undermining was shown to overcorrect normal transversal growth. Significant growth aberrations also were found in maxillary height, posterior facial height, and nasal deflection. Constant high lip pressure can be explained as a result of an interaction of lip repair and scar contraction from soft tissue undermining. Results of this study cannot be readily transferred to the clinical setting, but they present the first documented evidence elucidating the influence of soft-tissue undermining on facial growth. Further experimental and clinical research is needed to determine the extent of growth inhibition that may be related to the use of this procedure.