Note: if you use Natural Cycles with an Oura Ring, wearing a retainer will not affect your temperature. Please refer to the Oura section of Cyclerpedia for more information on using Natural Cycles with an Oura Ring.
If you need to wear a retainer or mouth guard when you sleep, you can still measure your temperature with a basal thermometer in the morning.
The retainer may not affect your temperature if you're consistently wearing it, and you are measuring in the sublingual pocket as described in our guidelines.
We recommend that you don't take the retainer out before measuring in the morning.
If you notice that your temperatures are fluctuating as a result of wearing the retainer, you may decide to measure your temperature vaginally or rectally instead (learn more here). If this is an option for you, you could also switch to tracking your temperature data with an Oura Ring.