<prompt> Seiberts class IV defect isFaciolingual loss of tissues with normal ridge heightNormal ridge width with loss of ridge heightLoss of height and widthNone of the above  <response>: Seiberts ClassificationClass 0 defects- no defectClass I defects- faciolingual loss of tissue width with normal ridge height. Class II defects- loss of ridge height with normal ridge width.Class III defects- a combination of loss in both dimensions. 