Trench mouth, formally known as Necrotizing Ulcerative Gingivitis (NUG), is a severe, intensely painful infection of the gums. The disease causes the soft tissue to rapidly break down, characterized by bleeding and a distinct foul odor. This condition results from an overgrowth of bacteria combined with a compromised defense system, not simply poor hygiene.
Specific Bacteria Responsible for Trench Mouth
The direct cause of Trench Mouth is a polymicrobial infection, involving the synergistic action of several different types of bacteria. These microorganisms are typically present in the mouth as part of the normal oral flora but become pathogenic when conditions allow for rapid proliferation. The most frequently implicated bacteria are spirochetes, such as Treponema species, and fusiform bacteria, such as Fusobacterium species. Other species, including Prevotella intermedia and Selenomonas, also contribute to the infection, but a weakened immune response is necessary for them to become overwhelmingly infectious.
Systemic and Environmental Contributing Factors
A major factor enabling the bacterial overgrowth is a lack of proper oral hygiene, which allows for the accumulation of dental plaque and pre-existing gingivitis. Plaque provides the anaerobic environment—lacking oxygen—that the implicated bacteria require to thrive and multiply. This buildup is often the first step in creating the conditions necessary for NUG to develop.
High levels of psychological stress significantly weaken the body’s immune system, making it less effective at controlling oral bacteria. Stress can reduce blood flow to the gum tissue and depress immune cell function, increasing susceptibility to infection. Smoking and tobacco use are also strongly associated with NUG, as they impair circulation and the local immune response, limiting the ability of gum tissue to fight off invading bacteria.
Systemic health plays a large role, as a weakened immune system is a common predisposing condition. Conditions such as HIV/AIDS, which severely compromise immune function, significantly increase the risk of developing NUG. Nutritional deficiencies and inadequate sleep also contribute by lowering the body’s overall resistance to infection.
How the Infection Progresses
Once the opportunistic bacteria proliferate, the infection progresses rapidly, characterized by the destruction of soft tissue. The bacteria produce toxins and enzymes that initiate tissue necrosis, which is the death of gum cells, most noticeable at the interdental papillae (the gum tissue between the teeth). The characteristic clinical sign is the formation of “punched-out” craters at the papillae tips, covered by a gray or yellowish-white pseudomembrane. This destructive process is responsible for the intense pain, bleeding, and overwhelmingly foul breath (fetor oris) associated with the condition.