Aggressiveness toward humans or other dogs. The head is proportionate to the size of the dog, clean-cut, and without exaggeration of any sort. When viewed from the side, the skull and muzzle are approximately equal in length, and joined by a moderate stop that is defined, in part, by the moderately well-defined supraorbital arches over the eyes. The skull is broad, but without exaggeration. There may be a slight median furrow between the eyes at the forehead, and the occipital bone is not conspicuous.
Cheeks are clean.
The bridge of the muzzle is straight and on a parallel plane with the top line of the skull. Viewed from the top or the side, the muzzle is slightly deeper and wider at the stop than at the tip. Lips fall away in a curve toward the throat, and are neither pendulous nor squared off. Removal of whiskers is permitted but not preferred. The Labrador Retriever has a complete set of evenly spaced, white teeth meeting in a scissors bite.