In an after coming head the following bone is perforated during craniotomy :
Craniotomy : It consists of perforating the fetal skull, evacuating the contents and then delivering rest of the fetal pas Indications: Delivery of dead fetus in obstructed labour with a cephalic presentation Delivery of the arrested after coming head in vaginal breech delivery Hydrocephalus Ref: Datta Obs 9e pg 544.
Occiput
Parietal
Palate
Frontal
Abnormal labor