What are the defined boundaries of the upper and lower lips for liability purposes?

Primary text

The boundary of the lower lip is defined inferiorly as the part that deviates from the teeth and gums, extending down to where it raises from the skin of the chin. The boundary of the upper lip superiorly extends from what deviates from the teeth and gums up to its connection with the nostrils and the septum. The length of both lips extends along the entire width of the mouth up to the edge of the cheeks (*shadaqayn*), but the edge of the cheeks themselves are not considered part of the lips.