The most likely cause
of oral malodour is the accumulation of food debris
and dental bacterial plaque on the teeth and tongue,
resulting from poor oral hygiene and resultant gingival
(gingivitis) and periodontal (gingivitis/periodontitis)
inflammation. Although most types of gingivitis and
periodontitis can give rise to malodour, acute necrotising
ulcerative gingivitis (Vincent’s disease, trench
mouth) causes the most notable halitosis.