Diagnostic challenges of nonodontogenic toothache
A 50-year-old female was referred for evaluation of pain on #15, the upper left second premolar. She complained sharp pain on #15 when chewing that started 2 weeks ago. To resolve her discomfort, she visited her general dental practitioner and root canal therapy was started on this tooth. The patient was subsequently referred to the Department of Conservative Dentistry, Kyungpook National Dental Hospital when the pain was not resolved.\nClinical examination revealed that tooth #15 was restored with temporary filling material. The tooth was positive to percussion and periodontal probing depths on distopalatal area of was more than 7 mm. Pain could be elicited by bite test of the tooth. All adjacent teeth responded within normal limits to percussion, palpation and bite test and showed positive response to vitality tests with cold spray and electronic pulp tester. No noticeable pathologies were observed on the radiographs except alveolar bone resorption on distopalatal area of #15 (). On the basis of clinical findings and history of pain, a diagnosis of acute apical periodontitis was suspected. Root canal treatment was performed on this tooth ().\nOn follow-up 2 week later, the patient was still experiencing what she described as 'sharp pain' from her lower right tooth not from tooth #15. At this time she pointed to tooth #45 and insisted that sharp pain resulted when chewing. Tooth #45 was slightly sensitive to percussion and pain could be elicited by bite test of the tooth. Tooth #45 responded within normal limits when tested with cold and electronic pulp tester. A caries cavity was observed at the distal surface of #45 on the radiograph (). Intraligamental injection on #45 area resulted in relieving the pain. A definitive diagnosis could not be made from the clinical findings. Distal caries on #45 was removed and the tooth was restored with composite resin ().\nOn follow-up 1 week later, the patient informed us that the sharp pain on chewing had not resolved. The failure of standard dental tests to ascertain the cause of pain necessitated further investigation. Palpating of the right masseter muscle, medial pterygoid muscle, lateral pterygoid muscle and temporalis muscle was performed. When palpating of the right lateral pterygoid muscle, the pain was elicited. Based on contributing factors of the pain that were chewing on #45 and palpation of the right lateral pterygoid muscle and the pattern and nature of the pain, a possible diagnosis of myofascial pain or trigeminal neuralgia was suspected. The patient was referred to the Department of Oral Medicine, Kyungpook National Dental Hospital. Further questioning revealed the pain episodes consisted of 'severe stabbing pain' that radiated to the right cheek and continued less than 1 minute. The pain could be elicited by chewing right side and tooth brushing. The presenting complaint was diagnosed as trigeminal neuralgia, and carbamazepine was recommended as the treatment of choice. 200 mg of carbamazepine, taken twice daily, was prescribed. The patient's symptoms resolved within 2 weeks.