1. Under the condition of the original chronic gingivitis and periodontitis, due to some factors, the number of anaerobic Fusobacterium and spirochetes in the lesion increased, and invaded the gingival tissue, directly or indirectly causing gingival necrosis and inflammation . At this time, the number of Gram-negative bacilli such as Prevotella intermedia also increased in the affected area.
2. Psychosomatic factors are related to the disease. Often due to busy study and work, lack of rest, or mental stimulation. The mechanism may be that the blood circulation of the gums, the metabolism of connective tissue and the flow of saliva are changed by the excessive secretion of corticosteroids and the influence of autonomic nerves, so that the local resistance is reduced.
3. Some malnutrition or wasting diseases, such as cancer, blood disease, radiation disease, and severe digestive tract diseases are prone to occur.
4. Most of the patients smoke. Smoking can constrict the blood vessels of the gingival tubules and reduce the function of white blood cells, thereby aggravating gingival disease.
