65 Trismus INITIAL PRESENTATION This condition is characterized by an inability to open the mouth or catch balls and carry sticks. Swelling or atrophy of masticatory muscles, a stiff jaw, swollen head and pain on opening the mouth may be seen. INTRODUCTION Trismus is a forced closure of the mouth. It may be referred to as ‘lockjaw’. It results from increased muscle tone • Seizures • Tetanus, strychnine poisoning • Hypocalcaemic tetany • Myotonia. or masticatory muscle contracture • Inflammation, e.g. masticatory muscle myositis (MMM) • Fibrosis, e.g. end-stage MMM, muscular dystrophy. Pain on opening the mouth mimics trismus but represents an unwillingness to open the mouth rather than a physical inability to do so. Pain on opening the mouth suggests a lesion of the retrobulbar area, temporomandibular joint, ear canal, parotid gland, pharynx or masticatory muscles. Any structure that moves or is compressed during jaw movement has the potential to cause pain. An animal with oral pain may attempt prehension but drop the object. Source of pain 1. Dental: trauma, foreign bodies 2. Masticatory muscle: spasm; inflammation- immune-mediated; polymyositis 3. TMJ: craniomandibular osteopathy 4. Retrobulbar: abscess, inflammation 5. Tympanic bulla: osteomyelitis; tumour (e.g. multilobular osteochondrosarcoma) 6. Caudal pharyngeal lesion Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Metabolic encephalopathy: hepatic encephalopathy Meningioma Behaviour change – an introduction Idiopathic facial paralysis Stay updated, free articles. Join our Telegram channel Join Tags: Saunders Solutions in Veterinary Practice Small Animal Neurology Sep 3, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Trismus Full access? Get Clinical Tree Get Clinical Tree app for offline access Get Clinical Tree app for offline access
65 Trismus INITIAL PRESENTATION This condition is characterized by an inability to open the mouth or catch balls and carry sticks. Swelling or atrophy of masticatory muscles, a stiff jaw, swollen head and pain on opening the mouth may be seen. INTRODUCTION Trismus is a forced closure of the mouth. It may be referred to as ‘lockjaw’. It results from increased muscle tone • Seizures • Tetanus, strychnine poisoning • Hypocalcaemic tetany • Myotonia. or masticatory muscle contracture • Inflammation, e.g. masticatory muscle myositis (MMM) • Fibrosis, e.g. end-stage MMM, muscular dystrophy. Pain on opening the mouth mimics trismus but represents an unwillingness to open the mouth rather than a physical inability to do so. Pain on opening the mouth suggests a lesion of the retrobulbar area, temporomandibular joint, ear canal, parotid gland, pharynx or masticatory muscles. Any structure that moves or is compressed during jaw movement has the potential to cause pain. An animal with oral pain may attempt prehension but drop the object. Source of pain 1. Dental: trauma, foreign bodies 2. Masticatory muscle: spasm; inflammation- immune-mediated; polymyositis 3. TMJ: craniomandibular osteopathy 4. Retrobulbar: abscess, inflammation 5. Tympanic bulla: osteomyelitis; tumour (e.g. multilobular osteochondrosarcoma) 6. Caudal pharyngeal lesion Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Metabolic encephalopathy: hepatic encephalopathy Meningioma Behaviour change – an introduction Idiopathic facial paralysis Stay updated, free articles. Join our Telegram channel Join Tags: Saunders Solutions in Veterinary Practice Small Animal Neurology Sep 3, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Trismus Full access? Get Clinical Tree
