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jaw dislocation has been reported in the literature as a rare complication of bronchoscopy , intubation , transesophageal echocardiogram , and otolaryngology and dentistry procedures [ 1 , 2 , 3 , 4 ] .
however , temporomandibular joint ( tmj ) dislocation is not commonly recognized by gastroenterologists as a potential complication of esophagogastroduodenoscopy ( egd ) [ 5 , 6 , 7 , 8 , 9 , 10 ] . in this report , we present a patient with temporomandibular displacement after egd and discuss how to identify this complication , the differential diagnosis of postendoscopy jaw pain , and the methods for prevention .
we will also review the literature regarding other cases involving temporomandibular displacement following upper endoscopy to assist in the future identification of this complication .
a 48-year - old woman with hypertension , rheumatoid arthritis , seasonal allergies , and long - standing solid food dysphagia presented to our gastroenterology clinic with progressively worsening dysphagia and transient food impaction .
the patient reported approximately 7 years of solid food dysphagia , but prior to this , has had no upper gastrointestinal symptoms , trouble swallowing , or dietary modification .
she had sought prior gastrointestinal evaluation , and an endoscopy 2 years after symptom onset showed rings and furrows , but biopsies were not obtained and dilation was not performed . though no specific treatments were initiated , the patient did note an improvement in her ability to swallow following the procedure .
one year prior to her presentation , she developed recurrent solid dysphagia which progressively worsened .
solid foods , particularly bread and meat , would get stuck in the upper chest and resulted in transient impactions 23 times per week . in most instances , if she waited , the food would ultimately pass ; however , in some cases , she would have to regurgitate the food .
she reported eating slowly , taking small bites , chewing thoroughly , and drinking a lot of liquids during meals .
because of suspicion of eosinophilic esophagitis ( eoe ) , she was placed on a proton pump inhibitor ( omeprazole 20 mg twice daily ) , and repeat endoscopy was performed .
she was given propofol for sedation , and the endoscopy went smoothly , but it was noted that she was yawning multiple times during the procedure . immediately after the procedure , the patient experienced severe left - sided facial pain . on examination , there was a spasm over the left masseter muscle , and she was unable to close her mouth . in an attempt to control her pain and relax her muscle spasm , the patient was given 25 g of fentanyl and a 30-mg dose of propofol , but these were not successful . given the severity of her pain and her inability to close her mouth , she was referred to the emergency department for suspicion of jaw dislocation . in the emergency department , the patient required additional doses of fentanyl for pain control .
a maxillofacial ct showed an anterior dislocation of the left tmj without a mandibular fracture ( fig . 1 , 2 ) . the initial attempt at jaw reduction using a 2-mg intravenous dose of midazolam sedation was unsuccessful .
the oral maxillofacial surgery team was consulted and successfully reduced the jaw dislocation following administration of a 100-mg dose of ketamine .
she remained in the jaw strap and on a mechanical soft diet for 7 days .
she was closely followed over the next several days and rapidly improved to her baseline .
further history was obtained and while she has had no prior jaw dislocation , she did report intermittent jaw pain . of note , the results of the biopsy from her endoscopy confirmed the diagnosis of eoe , which will require the patient to undergo future endoscopies .
anterior dislocation of the tmj is the most common type of jaw dislocation with multiple potential etiologies .
superior and posterior dislocations are rare and almost exclusively associated with trauma and fracture . while anterior dislocation may occur as a result of a dystonic reaction to drugs and seizures , a majority of anterior dislocations occur with extreme opening of the mouth .
these causes may include eating , singing , laughing , vomiting , or even yawning , as was noted for the patient presented here . in a retrospective study of 96 cases of tmj dislocation , extreme mouth opening while yawning was identified as the most common cause of dislocation , representing approximately 46% of reported cases .
several reports discuss tmj dislocation as a complication of bronchoscopies , dental procedures , induction of anesthesia , and transesophageal echocardiograms [ 1 , 2 , 3 , 4 ] . amongst the potential iatrogenic causes ,
several additional factors have been identified as potential sources for increasing the risk of jaw dislocation in cases outside of gastroenterology .
these include prolonged procedure time , increased age , and relaxation of the musculature caused by sedating medications .
this is an unusual complication of egd , and we have only been able to identify 6 cases reported within the last 30 years in patients ranging from 23 to 83 years of age [ 5 , 6 , 7 , 8 , 9 , 10 ] . in these cases ,
the endoscopies were uncomplicated , but immediately following each procedure , the patients complained of facial pain and the inability to close their mouth ( similar to our case ) , with two exceptions .
the first was a patient who was intubated prior to the procedure and unable to communicate symptoms ; the second was a patient who presented the following day with facial pain and the inability to close her mouth appropriately .
another consistent finding amongst these cases and our patient is that all had anterior dislocations .
however , the ability to reduce these displacements varied based on the degree or laterality of dislocation and patient experience with prior displacements .
for example , in the report from lacy et al . , a patient who had no prior history of dislocations experienced a bilateral displacement which required additional sedation for successful reduction .
however , in a report of a young woman with only a unilateral displacement and a well - documented history of tmj dislocations , the patient was able to reduce the displacement herself with the assistance of her endoscopist requiring no further sedation .
while a prior history of dislocation is a risk factor for jaw displacement following egd , the lack of a predisposing history does not exclude patients from the possibility of having a tmj dislocation .
of the 6 reported cases , only 2 patients reported a prior history of tmj displacement [ 6 , 10 ] .
anesthesia is frequently cited as a risk factor for tmj dislocation because it relaxes the masseter and temporalis muscles , which usually act as stabilizers .
while propofol was used in our case , in the other reports of jaw dislocation following egd , a benzodiazepine , midazolam or diazepam , was used for sedation [ 5 , 6 , 7 , 8 , 9 , 10 ] .
while most reported cases of tmj displacement from a gastroenterology procedure occur as a complication of egd , 2 cases of jaw dislocation have been reported following endoscopic retrograde cholangiopancreatography , and 1 was noted after percutaneous endoscopic gastrostomy tube placement [ 13 , 14 , 15 ] . while jaw dislocation was felt to be the most likely source of this patient 's jaw pain following endoscopy , reduction was not immediately attempted due to concern for other possible causes .
when patients suffer from tmj dislocation , they will often be unable to close their mouth and have drooling and garbled speech along with pain .
for this reason , acute stroke was part of the differential diagnosis and should always be considered in the correct clinical context .
another factor considered in this case was a pathologic fracture . while the diagnosis of tmj dislocation is made based upon clinical examination , radiographic imaging
the disadvantage of delayed reduction is an increased risk of developing muscular spasms , which ultimately makes reducing the dislocation more challenging .
. she will require additional upper endoscopies for surveillance of treatment response given her new diagnosis of eoe .
however , no specific recommendations exist at this time regarding measures that can prevent jaw dislocation during an endoscopy . given that most jaw dislocations seem to occur as a result of anesthesia , appropriate surveillance of patients who may be over- or undersedated can be important in preventing complications from endoscopy . while it is important to note if a patient has a prior history of tmj dislocation , the lack of such a history should not diminish monitoring for displacement after the procedure . while jaw dislocation is a very rare complication of upper endoscopy , it is important for gastroenterologists to be aware of this possibility , recognize it in the recovery area , and appreciate the differential diagnosis .
similar to previous recommendations [ 9 , 10 ] , as a part of routine evaluation , it may be beneficial to observe patients during mastication after the procedure .
this case report presents an unusual complication of upper endoscopy , resulting in jaw dislocation . 
 temporomandibular joint dislocation is commonly reported in association with anesthesia and intubation , but it is not widely recognized as a complication of gastrointestinal endoscopy . 
 this report also reviews the current literature regarding this complication and discusses the potential causes of dislocation , differential diagnoses for jaw pain following endoscopy , and recommendations for prevention .