The aim of the study was to analyze the incidence of short sublingual frenulum in newborns of the Hospital Nostra Senyora de Meritxell of the Principat of Andorra.

Thus, the objective of this study was to determine the incidence of AG in newborns of the Hospital Nostra Senyora de Meritxell of the Principat of Andorra, as well as the relationship with auxological data, associated malformations or diseases and hereditary component of the newborn.

A random sample of 2167 individuals is enough to estimate, with a confidence of 95% and an accuracy of +/- 1 percentage units, a population percentage that is projected to be around 6%. The percentage of replenishment required is projected to be 0%. With this sample, it will be sufficient to estimate the children who have ankyloglossia, the % of relatives who also have it (a population percentage that is projected to be around 25%). Confidential and anonymous collection of data from patients' medical records for a period of 2 years and 8 months, and write them down in a database to finally correlate them and see if there is any association with the parameters studied.

Inclusion Criteria:

- The inclusion criteria are patients born from July 2018 to February 2021 (both inclusive) and of both genders.

Exclusion Criteria:

• The exclusion criteria are all those who were born abroad and who after 24 hours go to the Hospital of Andorra, those urgently transferred to other foreign centers after birth, as well as those who present medical records with lack of information.

A random sample of 2167 individuals is enough to estimate, with a confidence of 95% and an accuracy of +/- 1 percentage units, a population percentage that is projected to be around 6%. The percentage of replenishment required is projected to be 0%.