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.
Rotation describes the action of moving the head from side to side, lateral motion brings the ear to the shoulder, flexion moves the chin to the chest (as in looking down), and hyperextension moves the neck so that the head tilts upward.he muscles of the neck run from the base of the skull to the upper back and work together to bend the head and assist in breathing.