Comparison of 2- and 3-dimensional radiologic evaluation of secondary alveolar bone grafting of clefts: a systematic review

Objective. Secondary alveolar bone grafting (SABG) has become the principal means of treating alveolar cleft defects. We reviewed the literature on 2-dimensional (2-D) and 3-dimensional (3-D) radiographic evaluation of SABG in patients with cleft lip and alveolus (CLA) and those with cleft lip and palate (CLP), with a focus on outcomes. Study Design. We searched several electronic databases to the end of 2018. The inclusion criteria were nonsyndromic CLA or CLP treated with SABG at an optimal age and evaluation performed no earlier than 3 months postoperatively. Study quality was evaluated by using the Methodological Index for Non-Randomized Studies and the Cochrane Collaboration tool. Results. We identified 282 articles from 3 databases. Full texts of 102 articles were analyzed, and finally 11 articles were included for qualitative analysis. 2-D and 3-D radiographic evaluations were performed in each study. Traditional 2-D radiographic imaging tended to overestimate success; bone resorption in the labiopalatal direction was inaccurate in 2-D views. Most articles were observational in nature and of moderate methodologic quality. Conclusions. 2-D evaluation tended to overestimate SABG outcomes; 3-D evaluation was more precise and reliable than 2-D radiography. A gold standard 3-D evaluation protocol is required for quantitative comparisons in the future.