There are many causes for oral malodour, and tongue coating, periodontitis, deep caries and unfitted restorations are main causes of bad breath odour. It is not difficult to reduce oral malodour by careful examination and proper treatment. However, we sometimes encounter oral malodour associated with other problem. Here, we report a case of persistent oral malodor associated with periodontitis caused by tooth perforation. The patient (a 41 year old, female) had visited our breath clinic complaining of a strong breath odor. Oral malodor was detected by several tests including organoleptic test, portable sulfide monitor and gas chromatography. She had consulted two dentists to reduce her breath odor. The dentists performed periodontal treatments including scaling, and root planing. However, her oral malodour did not decrease, and she had been worrying about her breath odor for 15 years. The patient’s oral hygiene was not bad at the first visit. Periodontal condition was not severe except tooth 24, and there were deep pockets in the proximal of the tooth. We performed initial periodontal treatment, but the condition of 24 did not change. We performed a surgical inspection and perforation of the tooth 24 was considered to be the main cause of periodontitis. Large number of periodontopathic bacteria was detected from the saliva and examination revealed the strong oral malodor. After extraction of the causative  tooth, periodontal condition improved, and bacterial number was decreased. The patient’s breath odor was reduced to less than the threshold level and she was free from long-lasting worries on oral malodor. 

Keywords: Oral malodor; Periodontitis; Perforation; Bacterial Examination