Most of us have been taught that ideal occlusion means canine guidance, or mutually protected occlusion. In fact, that is the preferred occlusal scheme in many instances. It requires the least amount of muscle activity for the mandible to move into excursions when the teeth are touching. It separates the back teeth so they are out of harm's way during parafunction.
Most of us were also taught that group function is BADDD! It causes too much muscle activity and destroys teeth.
So what if we just can't get the canines to touch when the teeth are closed? There are some choices – orthodontics, change the shape of the teeth, and even orthognathic surgery can be a possibility.
Practically though, unless there is a compelling reason to do the other treatments, the easiest thing is to "share the load" with group function. This simply means that when the jaw moves from side to side the guiding teeth may be premolars. The goal is to transition the guidance so that when the jaw moves side to side, even if the guidance begins on premolars it transitions to the canines.
The clinical slide shows this exact instance. Even after braces the canines didn't touch. The solution was to start the guidance on the first premolar and transition it to the canine – group function!