|Heterogeneity of studies|
|Different study designs||Retrospective [36,44], prospective [32,34], randomised [58,64].|
|Different overall aims||Assessment of the molding of the nasal cartilage [27,44], molding of the alveolar possesses [40,42].
|Mixed criteria for evaluating results||Landmarks on casts , cephalometry, facial photographs [43,44], photographs on cast [45,46],
three-dimensional optical scanner on the cast , three-dimensional optical facial scanner [62,63].
|Inadequate sample sizes||Small sample size [17,19], without control group .|
|Inconsistent follow-up period||Before the primary surgery (during the first 18 months), after the primary surgeries [22,23,26].|
|Heterogeneity of appliances||Hotz plate [41,43], Grayson NAM .|
|Variable age of the patient||When the appliance was used, when primary surgeries were performed.|
|Mixed level of surgeon experience |
NAM = nasoalveolar molding.