Thanks for writing again.
As you provided the detail, it seems that you are suffering from ‘cracked tooth syndrome'.
A symptom of this cracked tooth syndrome includes sharp shooting pain, relieved on biting any object.
The reason behind this is, when biting down, the cracked tooth segments usually move apart resulting in reduction of pressure on the nerves in the dentin of tooth. And as the pressure is released, the segments snap back together sharply, increasing the pressure in the inter-dentin nerves resulting in sharp shooting pain.
The treatment options for cracked tooth syndrome are-
1. Stabilization of tooth by core build up.
2. Composite restoration.
3. Root canal treatment
As you said you have already undergone root canal treatment of your tooth, I will suggest you to visit an endodontist as soon as possible.
If you ignore this condition, you may suffer the following-
1. Severe pain
2. Pulpal death.
4. Loss of tooth.
The sore temples and tight muscles of your face could be related to your fibromyalgia
and chronic fatigue syndrome
, because these conditions can be associated with 'chronic myofacial pain syndrome'.
Hope this answered your query, if you have further any doubt I will be happy to help you.
Dr. Gunjan Gupta