The difficulty a patient experiences with pronouncing specific sounds in phonetics often indicates issues related to the placement of the artificial teeth, the contour of the denture base, or the accuracy of the occlusal vertical dimension (OVD).
Here is what trouble with those specific sounds may indicate:
Trouble with ‘S’ sounds (/s/, /z/, /c/)
The distinct ‘/s/’ sound helps establish the correct OVD. The sound is produced by the passage of air through a small space between the tongue and the anterior palate.
| Sound Issue | Indicated Problem | Solution/Adjustment |
|---|---|---|
| Lisping on /s/ | The space between the tongue and the anterior palate is too small. May indicate that the mandibular anterior teeth are placed too far lingually. During maintenance, it can indicate too much room for the tongue between the upper bicuspids. | If too much room (lisping during maintenance), add wax palatal to the bicuspids to test correction. |
| Whistle on /s/ | Caused by the absence of sufficient space for the tongue between the upper bicuspids. | Remove and relocate the denture bicuspids toward the buccal, or, if space allows, grind out more area for the tongue. |
| Inability to enunciate distinct /s/ | Helps determine if the OVD is correct. | Use the sound to help establish the correct OVD. |
Trouble with ‘T’, ‘D’, ‘G’ sounds (/t/, /d/, /g/, /th/, /ch/, /j/)
These sounds rely on the tongue contacting the palate and teeth.
| Sound Issue | Indicated Problem | Solution/Adjustment |
|---|---|---|
| Indistinct /t/ or /th/ | Indicates excessive thickness of the anterior region of the palate (for the /t/ sound). Indistinct /th/ and /t/ can be corrected by thinning out the palatal area of the anterior. | Thin out the palatal area of the anterior denture. |
| Difficulty saying /g/ | May be caused by excessive thickness of the posterior palatal seal. This occurs because the dorsum of the tongue must contact the posterior palate to articulate /g/ and /k/ sounds, and excessive denture thickness impedes this. | Adjust the thickness of the posterior palatal seal area. |
| Difficulty with /t/, /d/, /l/, /r/ | These sounds rely on the ability of the dorsum of the tongue to seal against the posterior palate. | (Implies issues with posterior denture contour or fit in this area). |
Trouble with ‘P’ and ‘B’ sounds (/p/, /b/, /m/, /n/)
The sounds p, b, m, and n are verbalised while the upper and lower lips are touching each other.
| Sound Issue | Indicated Problem |
|---|---|
| Difficulty with /p/ and /b/ | Indicates insufficient vertical height (meaning the OVD is too closed/over-closed). |
Trouble with ‘F’, ‘V’, and ‘Ph’ sounds (/f/, /v/, /ph/)
To produce the sounds f, v, and ph, the lower lip is brought into contact with the incisal edges of the upper anterior teeth. These labiodental sounds are considered an excellent test for determining the proper plane of occlusion and placement of the anterior teeth.
| Sound Issue | Indicated Problem |
|---|---|
| Inability to enunciate /f/ or /v/ | Indicates that the anterior teeth are either too far above or below the functional plane of occlusion. It is caused by incorrect antero-posterior position of the maxillary incisors relative to the lower lip. |
| General difficulty with /f/, /v/, /ph/ | Used to test the proper plane of occlusion and the placement of the anterior teeth. |