As the saying goes, “A headache is a headache, a foot is a foot,” and also “A toothache is not a disease, but a pain can kill you.” . Many diseases are especially “insidious” and require advanced diagnostic techniques and advanced equipment to make a clear diagnosis. For example, in clinical practice, we can often see many patients who have had their teeth extracted or have undergone root canal treatment, but the patients still feel pain, or even “toothache”. Therefore, it can be seen that toothache can not only be caused by the disease of the tooth itself, but also many other diseases can cause toothache, which should be paid attention to. A. Acute and chronic maxillary sinusitis Maxillary sinusitis often causes pain in the maxillary molars and premolars. This pain is light in the morning and worsens in the afternoon or after sitting for a long time. Most patients do not have any damage to their teeth and most patients have a previous history of colds. Positive maxillary sinus anterior wall toothache is often accompanied by headache, nasal congestion and runny nose. Oral and maxillofacial tumors Oral and maxillofacial swellings are most common with odontogenic tumors. Clinically, when encountering unexplained toothache, loose teeth, or loss of teeth, do not assume that it is definitely periodontitis, and do not hastily pull out the teeth, but carefully search for the real cause of toothache or loose teeth. Clinically, I have also encountered an elderly female patient who visited the clinic with loose teeth and was diagnosed by an inexperienced physician as having “adult periodontitis” and extracted. As a result, one month after the extraction, the wound did not heal and a “new organism” grew, and the pathological biopsy showed squamous cell carcinoma of the gums. In this case, there is a high risk of medical disputes. Gum cancer is not a short-term growth, so why was it not recorded in the medical record when the tooth was extracted? Why didn’t the doctor remind the patient to take a case biopsy earlier? Therefore, once a lawsuit is filed, the physician or hospital will have a higher possibility of compensation. Trigeminal neuralgia Clinically, some trigeminal neuralgia is often manifested as toothache in the early stage. When patients eat, speak or brush their teeth, individual teeth cannot be touched, and they show sharp pain, electric shock-like, knife-like, pinprick-like pain, lasting for several seconds, unbearable pain, precise location, sometimes radiating, relieved at night, ranging from several to dozens of episodes per day. In this case, the physician should consider trigeminal neuralgia, but often many physicians only think about toothache and try to treat the “tooth” and ignore the neuralgia. In many cases, the pain remains even after the tooth has been extracted or root canal treatment has been done. At this moment, “it is time to think about the neuralgia” and “it is time to remind the patient”. The clinical incidence of TMJ disorder reaches about 40%, and the pain is mostly around the temporomandibular joint area and chewing area in front of the ear, which is aggravated when eating. The pain is often “dull” in nature, and some patients also feel pain in the ear or even headache when eating and chewing. Sometimes there is a popping sound in the joint area when opening or closing the mouth, which is mistaken for dental disease. TMJ disorders as one of the four major clinical diseases of the oral cavity (dental caries, periodontitis, malocclusion, and TMJ disorders) should not be forgotten in the treatment of dentists. Glossopharyngeal neuralgia: the nature of pain is similar to trigeminal neuralgia. The pain site mostly occurs in the tonsils, tongue root or soft palate, etc. It can be induced by speaking, coughing, swallowing or head twisting, and sometimes can be misdiagnosed as pain in the teeth. Cardiogenic toothache: coronary heart disease (angina pectoris, myocardial infarction) with toothache as the first symptom is not uncommon in clinical practice. Sometimes there are obvious multiple toothaches (posterior toothache) that are persistent, and the radiating site of the pain is often the left shoulder left arm, neck and face, and the pain increases after exertion and decreases after rest. Psychological toothache: this kind of toothache has nothing to do with organic dental diseases, that is, before the onset of toothache, there is no obvious gingivitis or periodontitis, but is caused by mental factors such as irritation, sadness, tension, etc. It is characterized by the onset of toothache after mood swings. It is mostly seen in emotionally sensitive young and middle-aged people, and is more common in women with introverted personalities. Secondary neuralgia: Also known as symptomatic trigeminal neuralgia. It is trigeminal neuralgia caused by various intracranial and extracranial organic diseases. It appears similar to the manifestation of primary trigeminal neuralgia in facial pain episodes or toothache, but its pain level is milder, and the duration of pain episodes is longer, or it is persistent pain with paroxysmal aggravation. Diagnostic methods: cerebrospinal fluid examination, X-ray skull base photograph, CT scan, MRI, DSA and even nasopharyngeal biopsy. Salpingolithiasis: Salpingolithiasis is a series of lesions caused by calcified masses that occur in the salivary glands and their ducts. It is more common in males than females and can last from a few days to several years or even decades. The clinical diagnosis of submandibular salivary gland complicating submandibular adenitis is based on the swelling of the submandibular gland with pain during feeding, pus overflowing from the duct opening, and the presence of stones in the duct on palpation with both hands. X-ray and CT examination should be done to confirm the diagnosis. Pterygopalatine neuralgia: Pterygopalatine neuralgia, also known as pterygopalatine neuralgia, pterygoductal neuralgia, Sluder’s syndrome, was first discovered and named by Sluder in 1908. It is a relatively rare clinical atypical facial neuralgia, the pathogenesis of which is unclear, the clinical manifestations are complex and atypical, and the diagnosis is difficult. Facial myofascial pain: including myofascial pain, myositis, myospasm, localized myalgia that cannot be classified and myofiber deformation contracture, etc., with myofascial pain being the most common. Myofascial pain, also known as myofascial pain dysfunction syndrome, refers to primary chewing pain, characterized by facial myofascial trigger points, and symptoms such as myalgia and restricted temporomandibular joint movement. Therefore, the statement “toothache is not a disease” should be changed to “toothache may be a very complex disease”.