Table 1. Final article selection.

Author	Study	Sample size	Findings
Amitai et al., 2020.	Pre-conceptional folic acid supplementation: A possible cause for the increasing rates of ankyloglossia. • Retrospective case-control. • Israel.	225 total. • 85 infants with ankyloglossia. • 148 infants in the original control group. The study group was recruited from two pediatric clinics in Ramot, Jerusalem, and consisted of infants that underwent frenotomy for ankyloglossia. The control group was recruited from three different clinics in Jerusalem, and patients with ankyloglossia were excluded.	‘Regular’ preconception folic acid intake was found to be higher in mothers of infants with ankyloglossia, compared to controls (OR 3.41, 95% CI 1.85–6.27, p-value < 0.0001). However, there was no significant difference found between the case and control groups for intake on ‘most days’ (OR 1.67, 95% CI 0.93–3.05, p-value = 0.07) or for ‘any’ intake (OR 1.45, 95% CI 0.77–2.78, p-value = 0.23).