Possible Clues:

• Canines
• Some canines
• Canines often metaphorically sacrificed
• Organs of sight in the mouth?
• They're between the incisors and the premolars
• Canines watch where ball starts and heads for the hole
• Canine bones in upper jaw - visualise them
• Four pointed structures in the mouth
• Canines one would sacrifice if in real want?
• Canine bones in upper jaw, under the optic