Treatment outcomes of digital nasoalveolar moulding in infants with cleft lip and palate: A systematic review with meta-analysis

The aim of this systematic review was to compare the treatment outcomes of digital nasoalveolar moulding (dNAM) technique with conventional nasoalveolar moulding (cNAM) or non-presurgical intervention protocol in infants with unilateral (UCLP) or bilateral (BCLP) cleft lip and palate. A bibliometric search by MEDLINE (via Ovid), Embase, Cochrane Library, grey literature and manual method was conducted without language restriction until November 2023. Literature screening and data extraction were undertaken in Covidence. The risk of bias was evaluated using the Newcastle-Ottawa Scale and RoB-2. Pooled effect sizes were determined through random-effects statistical model using R-Software, and the certainty of evidence was assessed using the GRADE approach. Among 775 retrieved articles, nine studies were included for qualitative synthesis (6-UCLP, 3-BCLP), with only three eligible UCLP studies for meta-analysis. In the UCLP group, very low certainty of evidence indicated no difference in alveolar cleft width (SMD, 0.13 mm; 95% CI, -0.31 to 0.57; I2, 0%), soft tissue (lip) cleft gap, nasal width, nasal height, and columellar deviation angle changes between dNAM and cNAM. In the BCLP group, qualitative synthesis suggested similar changes in alveolar, lip, and nasal dimensions with dNAM and cNAM. In both cleft groups (UCLP, BCLP), reduced alveolar cleft width was observed in the dNAM group compared to the non-presurgical intervention protocol, along with fewer clinical visits and reduced chairside time for dNAM compared to cNAM. It can be concluded that the treatment outcomes with dNAM were comparable to cNAM in reducing malformation severity and were advantageous in terms of chairside time and clinical visit frequency. However, the overall quality of evidence is very low and standardization is needed for the virtual workflow regarding the alveolar movements and growth factor algorithms. Registration: PROSPERO-database (CRD42020186452).