According to the USDA, heavy cream can be stored in the refrigerator (opened or unopened) for up to a month. 1  This assumes that it has been kept at a constant refrigerator temperature and not left out on the counter for stretches of time. Discard any cream with mold or an off odor.
However, one of the most common causes of lockjaw, as already mentioned, is TMJ disorder. TMJ disorder refers to a syndrome that affects the temporomandibular joint, commonly called the TMJ, which connects the jaw with the bottom of the skull.
The causes of TMJ dysfunction fall into two categories: tight muscles and damaged joints. Anything that causes the jaw muscles to tighten up can cause TMJ dysfunction, including stress and dental disease. Damage to the TMJ can result from trauma or disease such as arthritis. Less common causes of joint problems include fusion of bones or calcification of ligaments (ankylosis), looseness of the jaw caused by stretched ligaments, and birth abnormalities. Treatment is based on cause.