THE ability to speak is a complex act. First, the brain issues a command to the lungs to initiate an airstream. Before this airstream can become speech, however, it must pass through, or by, the larynx or voice box, pharynx or throat, tongue, teeth, lips and nose. All these can modify the airstream in various ways.

Sometimes mothers attended the clinic with a child seeking help in relation to speech problems the child may be experiencing. Recently, for example, a woman brought her three-year-old son. She complained that he could not speak as yet because he has “tied tongue”. On examining the child I discovered that indeed he had a short frenulum (the ligament that restrains the tongue from underneath). I explained to the mother that a short frenulum, although inhibits proper articulation does not prevent anyone from speaking. The child, in fact, had a speech disorder.

The front of the tongue is especially plastic and can be controlled with great precision by the nervous system. To pronounce vowels, the tongue, by assuming different positions within the mouth, creates a great variety of resonance chambers, all different from each other, like the shapes of different musical instruments.

To pronounce consonants, the tongue collaborates with the other parts of the mouth to make partial or complete closures, either forcing the air through a narrow constriction ( as in the pronunciation of the “th” sound in breath) or stopping its progress altogether ( as with the “d” sound in breed).

The existence of pathology (disease), either functional or organic, is the basic distinction between true speech disorders and those faulty speech habits which arise from a complex of environmental, cultural, local-regional, educational and socio-economic factors. Another distinction, at the behavioural level, is whether the speech disorder is assessed as a handicap. Speech disorders, both functional and organic, at the handicap level, affect about 50 000 Guyanese or six per cent of the population. Approximately 40 per cent is due to hearing loss, 10 per cent neurological disease and the remaining 50 per cent a range of other causes.

The highest incidence of speech disorders occurs developmentally among children and youth. Functional disorders in articulation are the leading cause, stuttering is the second and hearing impairment with speech defect is the third. Now, voice disorders, or dysphonias, consist of two main types. There are those arising from speech habits, and psychogenic types arising from emotional disturbance. Both types represent either overactive muscular activity, creating harsh, grating speech, or underactive activity, creating subdued or sluggish speech.

Speech impediments include the following three types, Cluttering (tachypnoea) is an erratic, jerky speech. Lisping, or immature speech (dyslalia), may relate to the abnormality of the external speech organs, for example, in tongue, teeth relationships. Stuttering or stammering (dysphemia), once considered a psychogenic disorder, is now known to be caused by neurological deficiencies present at birth or resulting from an injury.
Finally, other functional disorders include those caused by sensory inadequacies in the family setting, such as the presence of deaf parents. Also seen are delayed maturation of motor or brain function, emotional trauma due to parental neglect or abuse as well as institutional deprivations of adverse socio-economic factors, which result in learning disabilities related to the development of speech. So, because the final instrument which produces speech is the mouth, the dentist should always be consulted as part of the treatment team.