It looks like you are getting the text of the answer back from the datareader; that just doesn't translate to the ID; you have to query the ID as well. Or by answer ID do you mean 1, 2, 3, 4? If that is the case, just hard-code it based on the radio button checked:
If Me.RadioButton1.Checked = True Then
answerId = 1 ' since first radio is checked
Dim answer As Integer = Convert.ToInt32(answerId)
Session("jaw") = answerId