FACE PRESENTATION

k.gayatri

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

POSITIONRIGHT OCCIPITO POSTERIOR

LEFT MENTO ANTERIOR

LEFT OCCIPITO POSTERIOR RIGHT MENTO ANTERIOR

RIGHT OCCIPITO ANTERIOR LEFT MENTO POSTERIOR

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

MENTO ANTERIOR

MENTOPOSTERIOR

LEFTRIGHT

INCIDENCE: 1 IN 500 BIRTHS

Primary- during pregnancy Secondary- onset of labor

Fetal : 1.congenital malformations a) anencephaly b) goitre c) dolichocephalic

head d) bronchocoele2.Twist of cord round the

neck3.Hypertonicity of extensor

group of neck muscles

Maternal:1. Multiparity with

pendulous abdomen2. Lateral obliquity of

uterus3. Contracted pelvis4. Flat pelvis5. Pelvic tumours

ETIOLOGY:

PRODUCTION OF FACE PRESENTATION BY LATERAL

OBLIQUITY OF UTERUS PRODUCTION OF FACE PRESENTATION IN FLAT

PELVIS

MECHANISM OF LABOUR

THE PRINCIPLE DIFFERENCES BETWEEN OCCIPITOANTERIOR AND MENTOANTERIOR ARE:

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

ENGAGEMENT 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

DESCENT: with increasing extension descent occurs till chin touches the pelvic floor

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

DELIVERY OF HEAD 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

MENTOPOSTERIOR: 20-25% RMP OR LMP 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

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

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

18CMS