Feeding and Oral Motor Skill development in typical children and management in children with developmental disabilities

Feeding is the first essential function which everyone is concerned about in all new born and young children. Infants and toddlers who are at the risk for developmental difficulties or who have been diagnosed with abnormalities, however, may also have dysfunction in their feeding abilities. This problem can include  poor intake, excessive time needed to feed, unusual feeding characteristics (e.g., abnormal oral-motor patterns or inappropriate progression of feeding skills), and physiological compromises associated with feeding.

Feeding  provides an opportunity for early bonding, and its success strengthens maternal confidence.  Conversely, feeding dysfunction can erode maternal confidence, causing stress that can alter the mother child relationship and interference with bonding.

Occupational therapist working in early intervention programs have the knowledge and skill to make unique contributions to the treatment and management of feeding dysfunction in infants and young children, particularly within the context of the family unit. A background in neuromotor control, in the medical aspects of disease and disability, and in general, child development must be combined with a solid foundation in human interaction and behaviour to effectively manage feeding problems in the population.

Anatomical maturation:

          With growth, changes occur in the size and anatomic relationship of the oral, pharyngeal, and laryngeal structures. These changes are rapid during the first 12-18 months of life, then progress slows  throughout the remainder of childhood period. As the infant matures, the oral cavity enlarges and elongates, and the fatty tissue diminishes. Postural stability, through muscular contraction and the development of more rigid connective tissue, develops to provide the stability for the highly specialized movements of the lips, cheeks, tongue, and jaw, which are involved in the chewing or in sipping from cup.

          As the infant grows, the oral cavity enlarges and there is a downward elongation of the pharyngeal region. The larger oral cavity allows greater mobility of the lips, tongue, and cheeks, which allows the emergence of a wider variety of oral and speech skills. As the pharynx elongates, the hyoid must develop greater mobility to achieve continued protection of the airway. This occurs around 4-6 months of age.

          Infants must have split-second timing between sucking, swallowing, and breathing for safe and efficient feeding. In the sequence of feeding events, the infant takes one to two sucks and then must swallow, suppressing respiration for 0.5-1.0second. The infant then takes a breath, which is typically overlapped with sucking, and the sequence is repeated.  The coordination of breathing with swallowing during feeding continues to play an important role in spoon feeding, sipping from cup, and more matured eating skills.

          Deficits in oral-motor control are common in children with neurologic deficits and can lead to illtimed release of food into the pharynx or release of the bolus in a piecemeal fashion. If food is present in the pharynx before the swallow is triggered, there is the risk of aspiration during nonfeeding times. Children with cerebral palsy have a higher respiratory rate, less regularity to breathing, lower volume per breath, and more difficulty holding their breath than typical children. During eating, children with cerebral palsy also have difficulty in sustaining respiration and timing the integration of swallowing into the respiratory cycle. Coordination of oral skills, swallowing, and breathing remains important for children. Incoordination of these functions can lead to longer feeding times, feeding  inefficiency, physiologic compromise, aspiration, or any combination of these factors.

Sucking:

Sucking develops at 15-18 weeks of gestation.  The well-coordinated, efficient sucking needed for feeding does not generally develop until around 34 weeks of gestation. Infants who are good feeders tend to have sucking patterns that are fast and strong, as well as stable and rhythmic.

 Nutritive and non-nutritive sucking

Characteristics	Nutritive sucking	Non-nutritive sucking
Rate	One suck per second during the sucking burst	Two suck per second
Burst and pause pattern	Initial continuous sucking gradually increasing pauses toward end of feeding	Stable number of sucks per burst (4-13 sucks) and duration of pauses (3-10 seconds)
Suck-to-swallow ratio	1:1 at start of feeding 2-3:1 towards end of feeding	Multiple sucks to one swallow

Normal versus abnormal functions must be considered in the context of the following areas of performances:

1.     Neuromotor performance, including the influence of muscle tone, reflex activity, and motor control on overall posture, position, and oral-motor skills

2.     Sensory responses

3.     Swallowing ability

4.     Physiologic support for feeding

5.     Structural integrity

6.     Behaviour and interaction during feeding.

Neuromotor dysfunction can have a significant impact on the feeding posture. The characteristics of typical feeding posture include:

·        Neutral alignment of the head and neck (or slight neck flexion)

·        Midline orientation

·        Symmetric trunk position

·        Hip flexion (degree varies with the child’s age)

·        Symmetric arm position with the shoulders relaxed and forward

        The body angle during feeding depends on the level of head and trunk control present. Infants with limited head, neck, and trunk control are fed in a semireclined position. Older children who have adequate postural control are fed in an upright position.

Oral-motor control:

          The assessment of oral-motor control includes facial muscle tone, oral reflex activity, and functional oral-motor skills. Oral reflex are often evaluated for their presence or absence. It is highly important to consider their contribution or interference with feeding function.

          The child’s skill in complex activities, such as sucking or chewing, is based on the movement characteristics of each oral structures (i.e., the tongue, jaw, lips , and cheeks), as well as their coordinated function. Both the resting position and movement patterns of each structure must be evaluated. The expectations of movement vary based on developmental age and feeding activity (e.g., cup versus spoon) and are most effectively observed during the feeding time.

Atypical development and functional problems:

-         Hypertonic Muscle Tone

-         Hypotonic Muscle Tone

-         Tongue Retraction

-         Tongue Tip Elevation

-         Tongue Thrust

-         Tonic Biting

-         Jaw Thrust

-         Jaw Instability

-         Lip Retraction

-         Lip and Cheek Instability

-         Lip and Cheek Immobility

Guiding principles of treatment:

1.     Alignment: Proper alignment of the body and the head are crucial to optimal feeding performance. Abnormal alignment of body structures can influence the function of all the oral structures. For example, neck and head extension can lead to tongue retraction or thrusting during feeding.

2.     Proximal stability: Controlled extremity movement requires a stable base. The movements of the tongue and lips for feeding are distal movements, requiring stability of many proximal structures, particularly the jaw. For the mandible to be stable, head and neck stability built on trunk stability is mandatory.

3.     Appropriate movement patterns. Once proper alignment and stability have been achieved, the therapist or caregiver can facilitate appropriate oral movement patterns. Simultaneous application of inhibitory and facilitative techniques elicits the desired movement patterns.

        To achieve proper alignment, stability and appropriate movement patterns, preparation of the child using neurodevelopmental handling techniques before feeding may be beneficial.