Tires â Retreading is less expensive than new tires and is a large portion of this cost. Although mere pennies per mile, an average tire can cost over $250 and annual tire expenses can exceed $4,000 ($0.03 per mile), enough to purchase 16 new tires annually, but still not enough to replace every tire of an 18-wheeler.
With the head in a forward position, a passive tensile force is created in the hyoid muscles resulting in hyoid muscle tension, causing the mandible to be depressed and translated posteriorly. The patient is therefore forced to contract the temporalis and masseter muscles to keep the mouth closed.
The Six Movements are Listed Below: 1  Neck Retraction â Bring the head straight back, keeping your eyes forward then return to a neutral position. 2  Head Drop â Tip your head back as far as it can comfortably go pointing your chin toward the ceiling. Return to a neutral position.