ENT causes of trismus
Trismus is inability to open the mouth. Normal mouth opening ranges between 25 - 50mm. Any value less than this is known as trismus. (Roughly the opening should permit a minimum of three fingers when inserted sideways).
ENT causes of trismus:
Inflammatory causes involving oral cavity and throat:
1. Acute tonsillar infections like quinsy can cause inability to open the mouth fully due to spasm of masticatory muscles. This spasm is due to excessive pain due to the inflammation of tonsillar and peritonsillar tissues.
2. Inflammation involving parotid salivary gland. Parotid gland infections cause reflex spasm of muscles of mastication leading on to trismus.
3. Dental infections involving unerupted molar tooth, or dental abscess
4. Submucosal fibrosis (painless trismus)
5. Retro pharyngeal abscess 6. Ludwigs angina
Inflammatory conditions involving external ear:
Inflammations of external auditory canal i.e. furuncle can cause pain on mouth opening there by reducing it.
Otolaryngological tumors causing trismus:
1. Carcinoma cheek
2. Carcinoma mandible
3. Carcinoma maxilla
4. Malignant tumors involving parotid gland
5. Tumors of parapharyngeal spaces
6. Juvenile nasopharyngeal angiofibroma