In all layers of tissues in the maxillofacial region, such as between muscle and bone, muscle and muscle, there are gaps, when the infection invades into the gap to make the soft tissues enlarged to form suppurative inflammation, it is called interstitial infection. Oral interstitial infections are secondary infections, that is, from other places, the causes of infection are as follows: 1, from the teeth of the infection: for example, the most common wisdom teeth pericoronitis, periapical periodontitis, osteomyelitis of the jaws, etc.; 2, from the salivary glands of the infection: can be due to tonsillitis, salivary gland inflammation, the spread of maxillofacial lymph node inflammation, etc. caused by. 3, the other: such as traumatic infections, infections of medical origin, and also through blood Spread from other parts of the body infection, etc., but now relatively rare.