1.
k.gayatri

2.
 DEFINITION: This is a rare variety of cephalic
presentation where
presenting part: is face
attitude: complete flexion of limbs
with extension of spine so
that occiput is in contact
with back
denominator: mentum

3.
RIGHT OCCIPITO POSTERIOR LEFT MENTO ANTERIOR
LEFT OCCIPITO POSTERIOR RIGHT MENTO ANTERIOR
RIGHT OCCIPITO ANTERIOR LEFT MENTO POSTERIOR
LEFT OCCIPITO ANTERIOR RIGHT MENTO POSTERIOR
THE MOST COMMON POSITION IS left mento anterior
AS RIGHT OCCIPITO POSTERIOR IS 5 TIMES MORE COMMON THAN
LEFT OCCIPITO POSTERIOR

4.
MENTO ANTERIOR MENTOPOSTERIOR
LEFTRIGHT

5.
Primary- during pregnancy Secondary- onset of labor
Fetal :
1.congenital malformations
a) anencephaly
b) goitre
c) dolichocephalic head
d) bronchocoele
2.Twist of cord round the
neck
3.Hypertonicity of extensor
group of neck muscles
Maternal:
1. Multiparity with
pendulous abdomen
2. Lateral obliquity of
uterus
3. Contracted pelvis
4. Flat pelvis
5. Pelvic tumours
ETIOLOGY:

6.
PRODUCTION OF FACE
PRESENTATION BY LATERAL
OBLIQUITY OF UTERUS
PRODUCTION OF FACE
PRESENTATION IN FLAT
PELVIS

7.
OCCIPITO ANTERIOR MENTO ANTERIOR
Engagement Engagement
Descent Descent
Flexion Extension
Internal rotation Internal rotation
Extension Flexion
Restitution Restitution
External rotation External rotation
Expulsion by lateral flexion Expulsion by lateral flexion

8.
 Diameter of engagement:
OBLIQUE DIAMETER
Right in LMA LEFT IN RMA
MENTUM One pubic eminence
GLABELLA Opposite sacro iliac joint
ENAGAGING DIAMETER is SUBMENTOBREGMATIC-9.5CM
Engagement is delayed because of long distance between
mentum and biparietal plane i.e. 7cm where as to that of
occiput is 3cm

9.
 Further descent occurs till submentum hinges
under the pubic arch
 INTERNAL ROTATION: occurs through 1/8th of
the circle anteriorly placing mentum bheind
the pubic symphysis

10.
 HEAD IS BORN BY
 Diameter distending the vulval outlet is
submentovertical-11.5cm
RESTITUTION: occurs through 1/8th of circle
Opposite to direction of internal rotation
EXTERNAL ROTATION: occurs further 1/8th
of the circle to the same side of
restitution so that face looks
left thigh right thigh
in LMA In RMA
FLEXION
•CHIN
•FACE
•BROW
•VERTEX
•OCCIPUT
•ANTERIOR
•SHOULDER
•POSTERIOR
•SHOULDER
•TRUNK BY
•LATERAL
•FLEXION
DELIVERING

11.
 The principle differences between
occipitoposterior and mentoposterior are
20-30%cases -anterior rotation of mentum
occurs
70-80% cases
INCOMPLETE
ANTERIOR
ROTATION
NON
ROTATION
SHORT
POSTERIOR
ROTATION
ANTERIOR ROTATION OF THE FETUS FROM
RIGHT MENTOPOSTERIOR POSITION

12.
 Arrest occurs in all these positions with
average size pelvis and foetal head
 In short posterior rotation delivery there is
no possibility of spontaneous delivery in
mento posterior because
short neck cannot clear off the total length
of the sacrum i.e.12cm

13.
 As such thorax is thrust in resulting
BREGAMTICO STERNAL DIAMETER-18CM to
occupy the pelvis as a result labour is
obstructed