Oral causes have been proposed to be responsible for the
majority of halitosis complaints, accounting for 85–90% of all
cases.6,9,16 This estimate is based mainly on the results of one
study of 260 patients with halitosis in which 87% of patients
were said to have an oral cause (periodontitis, gingivitis, or
tongue coating), 8% had an ear-nose-and-throat (ENT) related
cause, and 5% had an unknown cause.17 In contrast, another
similar study reported that 26% of patients with halitosis had
ENT related disorders, 23% had dental problems, 18% had oral
discomfort, and 10% exhibited gastrointestinal pathology (or a
combination of these conditions), while 31% had no clinically
detectable problems