Anteroposterior Diameters
Mnemonic:
- Larger the alphabets, larger the diameter (V>F>B)
- Diameters with “sub” prefix are smaller than counterpart without it.
- mento-Vertical: 14 cm
- SUB-mento-Vertical: 11.5 cm
- occipito-Frontal: 11.5 cm
- SUB-occipito-Frontal: 10.5 cm
- sub-occipito-Bregmatic: 9.5 cm
- sub-mento-Bregmatic: 9.5 cm
Transverse Diameters
Mnemonic: MTP (Medical Termination of Pregnancy) in increasing order.
- bi-Mastoid: 7.5 cm
- bi-Temporal: 8 cm
- bi-Parietal: 9.5 cm
Very useful information
why is submentovertical diameter less than mentovertical
Because it is measured from a closer point to the back of the head.
Bcz it is made by God n we can not change it
submento is from the side of the chin to vertex.so that is why it is smaller than mento vertical.
Pic is informative, could have been more clear graphically