<prompt> Impoance of the plane of midpelvis isSuperior straitInferior straitPlane of least pelvic dimensionsPlane of greatest pelvic dimensions  <response>: The pelvis is described as having four imaginary planes:The plane of the pelvic inlet--the superior strait. 2. The plane of the pelvic outlet--the inferior strait. 3. The plane of the midpelvis--the least pelvic dimensions. 4. The plane of greatest pelvic dimension--of no obstetrical significance.Ref: Williams Obstetrics; 25th edition 