The causes of left zygomatic pain are as follows: 1. Fasciitis: fasciitis occurs in the muscles around the left zygomatic bone, forming local swelling and pain, requiring the application of non-steroidal anti-inflammatory and analgesic creams, oral antibiotics, etc. 2. Acute periapical inflammation: when acute periapical inflammation occurs in the maxillary molar, the root tip produces a large amount of inflammatory secretions that penetrate into the infratemporal space, pterygomandibular space, etc., resulting in redness, swelling, heat and pain around the zygomatic bone. 3, 3. Facial neuritis: When the left facial neuritis is triggered by cold or virus infection, it can cause crooked corners of the mouth, facial twitching and pain around the zygomatic bone. 4. Temporomandibular joint dysfunction syndrome: When long-term lateral chewing induces temporomandibular joint dysfunction syndrome, the chewing muscles around the left zygomatic bone become spasmodic and tonic, causing pain.