Dettoni was born in Manassas, Virginia, United States, and started playing soccer at the age of four.
[4] On August 13, 2024, Dettoni was called-up with the Bayern Munich senior team as an unused substitute for their last friendly match of the 2024–25 pre-season, a 3–0 win against Austrian Bundesliga club WSG Tirol.
[5] Dettoni was called-up with the Bayern Munich senior team for a friendly match on January 6, 2025, after the 2024 winter break concluded, in which he substituted Eric Dier at the 63rd minute of a 6–0 win over Austrian Bundesliga club Red Bull Salzburg.
[6] On January 28, 2025, he joined Grasshopper Club Zürich of the Swiss Super League on loan for the rest of the season.
[8] Dettoni holds Italian passport, making him eligible to play for Italy as well as his native United States.