The answer to this question is difficult to provide as it can depend on the underlying cause of the mouth ulcers. For example if someone experiences ulcers due to dental braces rubbing on the inside of their cheeks, the ulcers are likely to take longer to heal as the braces may continue to cause irritation. Additionally the life span of mouth ulcers can depend on their type.
Types of mouth ulcers
A review of Bagan et al (1991) shows that there are three main types of mouth ulcers.
1. Minor aphthae – which are roundish in shape, less than 10mm wide and typically last up to 10 days.
2. Major aphthae – which are larger in size than minor ulcers, hence they take longer to clear up (around 20 -30 days) and may cause scarring.
3. Herpetiform ulcers – which are very small at less than 1mm wide, but tend to appear in multiples and may join together creating a larger ulcerated area of the mouth. These usually clear up within 15 days. In the UK, the NHS (2014) echoes these time frames stating that most ulcers ‘heal within 10-14 days…although severe ulcers may last for several weeks’.
Bagan J.V., Sanchis J.M., Milan M.A., Penarrocha M., Silvestre F.J. Recurrent aphthous stomatitis: a study of the clinical characteristics of lesions in 93 cases. Journal of Oral Pathology and Medicine 1991;20(8):395-7. NHS (2014) Mouth Ulcers – NHS Choices [Online] Available at: http://www.nhs.uk/Conditions/Mouth-ulcer/Pages/Introduction.aspx (Accessed 6th June 2014).