1. Acute pulpitis Toothache often manifests as paroxysmal spontaneous pain, which is aggravated at night, more intense after hot or cold stimulation, and pain radiates to the head and temporal area, which cannot be localized. When suffering from purulent pulpitis, the pain is aggravated by hot stimulation, while the pain is reduced or disappeared by cold stimulation. Pulpitis is often developed from caries, but can also be caused by cryptic fracture, dental trauma, periodontal disease, etc. 2.Acute periapical inflammation is caused by the development of acute pulpitis or trauma and other factors. The patient can correctly point out the diseased tooth, and if the patient percusses the diseased tooth, it causes pain, and at this time, there is no excitation pain because the nerve of the diseased tooth is necrotic. 3, acute periodontitis The nature of toothache is similar to that of acute periapical inflammation. The diseased tooth not only has chewing pain and floating sensation, but also has formed periodontal pockets and loosened teeth. The gum tissue may appear repeatedly swollen and painful and bleeding. 4, periodontal abscess The further development of periodontal tissue inflammation can cause purulent inflammation. Pain is intense when abscesses are formed, and local fluctuations occur after abscess formation. After the formation of periodontal abscess, the pain can be significantly reduced or relieved. 5.Dental hypersensitivity is often caused by tooth wear, gingival recession, wedge-shaped defects and dental defects. At this time, cold, hot, sweet and acidic stimuli can appear pain, but the pain can disappear after the stimulation stops. 6, gingival papillitis is due to mechanical or chemical stimulation of the interdental space such as food embedding, bad restorations, etc. caused by the inflammation of the interdental gingival papillae. It is manifested as individual gingival papillae are red, swollen, painful to touch, and bleed easily when probed or sucked, with obvious spontaneous pain and painful stimulation to hot and cold in acute attacks, and only swelling pain in chronic cases. 7. Dry socket pain appears 3 to 4 days after tooth extraction and radiates to the auriculotemporal region, submandibular region or the top of the head. The extracted tooth socket is empty, or there is a residual blood clot of decay and necrosis, and there is a foul smell if the contents are dipped in cotton balls. There are also such as gum and jaw bone tumors as well as trigeminal neuralgia, which can also cause pain in the corresponding area of the ipsilateral tooth.