The edges of the mouth are called the "commissures." They are the points where the upper and lower lips meet. The commissures play a role in facial expression and speech, contributing to the overall appearance and function of the mouth.
Lips.
It is in Ireland. The river Liffey flows from the Wicklow mountains through to the city centre of Dublin and into the Irish Sea. As it flows through the city it creates a north and south division of the city and county, referred to as the northside and the southside.
A river becomes an ocean when it has flowed to the edge of the land and into the open water; this place is called the mouth of the river.
A bird's mouth is an interior angle or notch cut across a piece of timber for the reception of the edge of another - also called a crow's foot in the United States.
lip
impossible, differant bodies.
border, edge, margin, rim
A leaf's edge is called its margin.
The centre of a circle is simply called the cnetre. The edge may called the perimeter, the circumference or the edge.
The top edge of a glass or cup is called the rim.
The outer edge of a circle is called the circumference.
It is called an edge: there is no special name.