He cant be no siamese. But may perhaps be some descendant of Maine coon. Or a Norwegian forest cat...
I would propose the norwegian as the nearest look alike. Not least, they are often bi-color.
Why do yo write he used to have long fangs? Did he lost them?
I agree completely with StefanZ. He can’t be a Siamese because Siamese are colorpointed cats (meaning they’re born white and then develop color on their face, ears, legs, feet, and tail). I think he would be the closest lookalike to a Norwegian Forest Cat, because he has long, thick fur and a triangular head. Technically, without having pedigree papers, he would be considered a black and white bicolor (in the harlequin pattern) Domestic Longhair. He’s very cute!