Temporal trends in ankyloglossia and frenotomy in British Columbia, Canada, 2004-2013: a population-based study

Background: Routine surveillance of congenital anomalies has shown recent increases in ankyloglossia (tongue-tie) in British Columbia, Canada. We examined the temporal trends in ankyloglossia and its surgical treatment (frenotomy).

Methods: We conducted a population-based cohort study involving all live births in British Columbia from Apr. 1, 2004, to Mar. 31, 2014, with data obtained from the province's Perinatal Data Registry. Spatiotemporal trends in ankyloglossia and frenotomy, and associations with maternal and infant characteristics, were quantified using logistic regression analysis.

Results: There were 459 445 live births and 3022 cases of ankyloglossia between 2004 and 2013. The population incidence of ankyloglossia increased by 70% (rate ratio 1.70, 95% confidence interval [CI] 1.44-2.01), from 5.0 per 1000 live births in 2004 to 8.4 per 1000 in 2013. During the same period, the population rate of frenotomy increased by 89% (95% CI 52%-134%), from 2.8 per 1000 live births in 2004 to 5.3 per 1000 in 2013. The 2 regional health authorities with the lowest population rates of frenotomy (1.5 and 1.8 per 1000 live births) had the lowest rates of ankyloglossia and the lowest rates of frenotomy among cases with ankyloglossia, whereas the 2 regional health authorities with the highest population rates of frenotomy (5.2 and 5.3 per 1000 live births) had high rates of ankyloglossia and the highest rates of frenotomy among cases of ankyloglossia. Nulliparity, multiple birth, male infant sex, birth weight and year were independently associated with ankyloglossia.

Interpretation: Large temporal increases and substantial spatial variations in ankyloglossia and frenotomy rates were observed that may indicate a diagnostic suspicion bias and increasing use of a potentially unnecessary surgical procedure among infants.