You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following facial expressions indicate the rest position and explain in detail?
Facial expression: 
The following indicates rest position:

Lips are even anteroposteriorly with slight contact.
Skin around the eyes and chin is relaxed.
Relaxation around the nostrils with unobstructed breathing.

With experience the dentist learns to recognize, these features depicting rest position and will make measurements accordingly.