The reason you can’t smell your own bad breath is a result of olfactory adaptation, also known as olfactory fatigue or acclimatization. This is a natural phenomenon where your nose becomes less sensitive to familiar odors over time. When you produce an odor, such as halitosis (bad breath), your olfactory receptors detect it and send signals to your brain. Initially, the smell is noticeable because it is novel. However, as you continue to produce the odor, your brain becomes accustomed to it, and the signals from the olfactory receptors diminish, leading to a reduced perception of the smell.
Additionally, the act of breathing through your mouth can sometimes reduce the awareness of bad breath because the olfactory receptors are primarily located in the nasal passages, not the mouth. Using mouthwash or sucking on mints might provide a temporary masking effect, but they don’t address the root cause of the bad breath.
To check your breath for halitosis, you can try the following methods:

1. Pulling back your cheeks and lower lip to expose your gums and teeth: Look for any visible signs of film or tartar buildup, which can contribute to bad breath.
2. Sipping on water: Sometimes rinsing your mouth with water can temporarily clear away odors.
3. Using a tissue: Lick the inside of a tissue and then smell it. This can be a more direct way to assess your breath without the olfactory adaptation affecting your perception.
4. Requesting a trusted friend or family member to smell your breath: This is perhaps the most direct method, but it requires someone you feel comfortable asking!

If you’re concerned about persistent bad breath, it’s a good idea to see a dentist or a healthcare professional. They can assess your breath and recommend appropriate treatments or oral hygiene practices to improve your breath odor.