Table 3: Exclusion Criteria and Number of Excluded Articles According to the Reason for their Exclusion

Exclusion Criteria Nr of Excluded Articles
Subject not relevant to orthodontics 74
Subject not relevant to orthodontics - Cleft lip and palate 6
Letter to the editor 1
Book Reviews 1
Protocol for a Cochrane review 1
Report of cases & Systematic review 1
Short survey 1
Comments on other articles 11
Original studies 19
Narrative reviews 14
Systematic reviews 41
Sum 170