How long can I leave teeth that need root canal or extraction without doing anything. Dont wanna extract coz afraid face shape will change. Wut to do?

Dental infection. Its highly unlikely that your face shape will change with dental extraction long term. There can be mild swelling after the procedure that subsides with time. It is important to take care of broken, damaged or infected teeth as soon as possible as they can lead to much more serious infections.
Infection Rx. Teeth that require root canal treatment or extraction are infected. The infection travels through your blood stream and damages other organ systems. Infection requires immediate treatment. Either root canal treatment/crown or extraction/bridge or implant will prevent facial change. Talk to your Dentist about alternatives instead of making up disaster scenarios.