Going by owlbear illustrations in the Monster Manuals (or edition equivalent), most have serrated beaks.
clearly serrated: 1e, 2e compendum, 4e essentials, 5.0e, 5.5e
unclear, maybe serrated: 2e MM, 4e
single tomial tooth and notch: 3.Xe
probably no tomia: OD&D
OD&D Greyhawk Supplement -...