Asis Kumar Ghosh BPT, NDT(UK)

Definition

Rhythmic movements of an infant’s mouth & tongue either on the bottle or breast to obtain nourishment or on a pacifier, hand, or other object to modulate state or explore the environment.

• In utero: 15to 18 weeks of gestation*

• In extra uterine environment: 27 to 28 weeks, disorganized , weak, immature, random pattern

• 32 weeks: stronger sucking, emerging burst-pause pattern

• 34-35 weeks: stable rhythm**

*Iannirubero,A.,& E.Tajani.1981Ultrasonographic study of fetal movements. Seminars in Perinatology 5:175-181

**Hack,M. et.al., 1985,Development of sucking rhythms in preterm infants. Early infant development 11:133-40

Biomechanics of suckingSucking pressureMouth acts a pump

Positive pressure: tongue compresses the nipple

Negative pressure: closed oral cavity or suction pulls fluid into the mouth

Biomechanics contd.Motor components Tongue • Anteriorly seals against the nipple, compresses the nipple• Posteriorly seals against the soft palate until the palate is

lifted for swallowing, creates negative intra-oral pressure• Creates “central groove” in the antero-posterior

direction, stabilizes the nipple & channels the bolus toward the pharynx

Biomechanics contd.

JawStable base for movements of tongue, lips, and cheeks

Creates intra-oral negative pressure with downward movement

Biomechanics contd.

LipsSeals the nipple with the tongueStabilize nipple position

Biomechanics contd.

CheeksFat pads provide stabilityProvides lateral boundaries for food on the tongue, thus aiding in bolus formation

Biomechanics contd.Palate• Hard palate works with the tongue to

compress the nipple & maintain nipple position

• Soft palate with the tongue creates the posterior seal for the oral cavity

• Elevates during swallowing to allow passage of the bolus, seal the nasal cavity & prevent nasal reflux

Sequence of sucking• Central groove of the tongue receives the nipple• Lateral portions of the tongue in contact with

palate• Lips & tongue close around the nipple• Posterior tongue elevates to maintain contact

with soft palate• Cheeks approximate tongue & nipple• Medial portion of tongue produces wave like

motion antero-posteriorly• Posterior portion of tongue is depressed• Enlarged oral cavity, negative pressure, suction• Propel bolus to pharynx• Mandible moves with the tongue in an ant.-inf.&

post.-sup. direction

Etiologies of sucking abnormalitiesDysfunction in 1.GI system2.Cardiorespiratory3.SwallowingAnatomic defects1.Cleft lip and/ or palate2.Micrognathia(recessed jaw & posteriorly

placed tongue)3.Macroglossia4.Hemangiomas or a mass in the tongue

Etiologies…….

Poor muscular control Secondary to a neurological deficit

1. Asphyxia 2. Cranial hemorrhages 3. Down syndrome 4. CP

Etiologies…….

Oral pain 1. Trauma or lacerations 2. Thrush

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