Mouth infections, also known as oral infections, are a group of infections that occur around the oral cavity. They include dental infection, dental abscess, and Ludwig's angina.[1] Mouth infections typically originate from dental caries at the root of molars and premolars that spread to adjacent structures. In otherwise healthy patients, removing the offending tooth to allow drainage will usually resolve the infection. In cases that spread to adjacent structures or in immunocompromised patients (cancer, diabetes, transplant immunosuppression), surgical drainage and systemic antibiotics may be required in addition to tooth extraction. Since bacteria that normally reside in the oral cavity cause mouth infections, proper dental hygiene can prevent most cases of infection. As such, mouth infections are more common in populations with poor access to dental care (homeless, uninsured, etc.) or populations with health-related behaviors that damage one's teeth and oral mucosa (tobacco, methamphetamine, etc.).[2] This is a common problem, representing nearly 36% of all encounters within the emergency department related to dental conditions.[3]
Patients with mouth infections usually complain of pain at the affected tooth with or without fevers. The inability to fully open one's mouth, also known as trismus, suggests that the infection has spread to spaces between the jaw and muscles of mastication (masseter, medial pterygoid, and temporalis). If an abscess has formed, swelling, redness, and tenderness will be present. Depending on the location of the abscess, it will be visible intraorally, extraorally, or both. Severe infections with significant swelling may cause airway obstruction by shifting/enlarging soft tissue structures (floor of mouth, tongue, etc.) or by causing dysphagia that prevents adequate clearance of saliva. This is a medical emergency and may require endonasal intubation or tracheotomy to protect one's airway. The development of stridor, shortness of breath, and pooling oral secretions may indicate impending airway compromise due to a worsening mouth infection. Other rare but dangerous complications include osteomyelitis, cavernous sinus thrombosis, and deep neck space infection.[2]