Differential diagnosis and treatment of periodontitis-mimicking actinomycosis
A 46-year-old female was referred to the Department of Periodontics of Seoul St. Mary's Hospital (Seoul, Korea) for treatment of chronic periodontitis, particularly in the mandibular molar area (). She complained of throbbing pain on the right first and second molars of the mandible. The pain lasted three days. The patient's medical and dental histories were taken, and clinical assessments and examination, including probing depths, tooth mobility, and bleeding on probing, were performed. The patient was a nonsmoker and went to the Department of Cardiology of Seoul St. Mary's Hospital for rheumatic mitral insufficiency; she had been taking an anticoagulant (Warfarin, 2 mg Cuparin tablets; Hana Pharm Co., Seoul, Korea) for 3 years. Intraoral examination revealed generalized chronic periodontitis and particularly deep probing pocket depths: 7 to 8 mm on the distal area of the left second molar, right first molar, and right second molar of the mandible. Her oral hygiene status was relatively good. Her cardiologist was consulted for operability, and the cardiologist recommended continuing anticoagulant therapy.\nThe initial cause-related therapy consisted of thorough full-mouth scaling and root planing in the quadrants under local anesthesia. This procedure was performed using a combination of hand and ultrasonic instrumentation. The patient received detailed oral hygiene instructions on using a soft toothbrush and floss.\nThree weeks after her final root planing treatment, she made an unscheduled visit to the clinic. She complained of recurrence of throbbing pain on the right first molar of the mandible. An intraoral examination was performed to exclude pulpitis or cracked tooth syndrome. There was no swelling, redness, fever, or suppuration. The right first and second molars of the mandible had positive responses for percussion, cold, and electric pulp testing. The possibility of pulpitis or cracked tooth syndrome was ruled out. She complained of an unusual throbbing pain, which was relieved when she bit tightly. The probing pocket depth of the distal area on the right first molar was 7 mm. There was no swelling, redness, fever, or suppuration. The right first and second molars of the mandible had positive responses for percussion, cold, and electric pulp testing. The mobility was within normal range. A periodontal flap procedure was planned to aid in the diagnosis.\nAnesthesia was performed using 2% lidocaine containing 1:100,000 epinephrine. A sulcular incision was made around the right posterior teeth of the mandible to preserve the papillae, and the mucoperiosteal buccal and lingual access flaps were elevated (). Granulation tissue adherent to the teeth and the alveolar bone was removed. A round, hard, floating, bluish-gray fragment in the interproximal area between the right first and second molar of the mandible was seen. The remaining area was debrided and irrigated with a saline solution. The resulting interproximal crater defect was filled with a xenograft bone material (Bio-Oss, Geistlich Pharma AG, Wolhusen, Switzerland). The flap was replaced and sutured with nylon 5-0. An analgesic (300 mg acetaminophen, 300 mg Endapen tablet; Chodang Pharm Co., Seoul, Korea) at 3 times a day, and an antimicrobial drug (625 mg amoxicillin with clavulanate, 625 mg Moxicle tablet; Daewoong Co., Seoul, Korea), 3 times a day, were prescribed for 5 days. The patient was also instructed to abstain from brushing and flossing around the surgical area for 2 weeks, to use a 0.1% chlorhexidine (Hexamedine Solution, Bukwang Pharm Co., Seoul, Korea) solution rinse, and to consume a diet of soft food until suture removal. The follow-up visits after the surgical procedure were scheduled for each week of the first month after surgery.\nThe mass removed from the interproximal alveolar bone was stored in 10% formalin, and was sent to the Department of Pathology of Seoul St. Mary's Hospital for diagnosis. Five days after biopsy, the pathologist concluded that the fragment was aggregates of bacterial colonies and needed a special stain for diagnosis. After one week, the results of the Gram, silver, and periodic acid-Schiff (PAS) stain were positive, and the differential diagnosis was actinomycosis (-).\nGram positive colonies of actinomyces and inflammatory cell infiltration can be observed (). The actinomycotic aggregate presented an isolated mass of bacterial filaments in the center and periphery, the so-called sun-ray effect ( and ). The bacterial colonies appeared to be club-shaped. Histologic examination revealed fragments of fibrous tissue containing inflammatory cell infiltrates.\nThe healing was uneventful, and the patient reported mild discomfort, but was satisfied with the absence of throbbing pain. Based on the histologic result, the patient was prescribed to continue taking amoxicillin and clavulanate (625 mg three times a day for 4 weeks). The patient was monitored weekly for the first month and then monthly for four months. The patient did not report any symptoms, and she is now scheduled for ongoing follow-up.