Dental anatomy, MDS Entrance Examinations, Prosthodontics, Tips for Dental Students

Classification of Sounds and Importance in Prosthodontics and Dentistry

Various types of sounds are produced by the oral cavity with the help of coordination of several parts of the oral cavity like the tongue, lips, teeth, palate which work in coordination to produce the sounds.

These sounds are very important in the fabrication of Complete denture which helps in determining the correct Vertical dimension, labial and lingual inclination of the teeth, deep bit open bite etc.

The patient is asked to spell these sounds after denture fabrication to determine and make required corrections in the Complete denture.

Classification of Sounds and importance in DentistryTypes of Sounds as Classified as:

  1. Labial Sounds
  2. Labio-Dental sounds
  3. Linguo Dental Sounds
  4. Linguo Palatal Sounds (anterior)
  5. Linguo Palatal sounds (Posterior)
  6. Linguo Palatal (Soft Palate)
  7. True Palatal
  8. Nasal Sounds
  9. Vowel Sounds

Labial Sounds: 

  • The Labial Sounds are ” B, P, M”
  • Produced by: When upper and lower lips meet together and air pressure is built up behind the lips which releases with or without a voice sound
  • Importance of Labial Sounds in Prosthodontics/Complete Denture: Labiolingual position of the anterior teeth and the thickness of the labial flanges of the dentures can affect the sounds b & p. Cleft lip or in-component upper lip can affect labial sounds

Labio Dental Sounds:

  • The Labio Dental Sounds are “F, V, 5 and PH”
  • Produced by: When the upper incisors and the posterior one third of the lower lip meet together to produce these sounds
  • Importance of Labio Dental Sounds: Abnormal position of both upper and lower teeth affects labio dental sounds sounds. If the upper teeth are too long, the “F” sound will be like “V” and if the upper teeth are too short “V” sound will be like “T”

Linguo Dental Sounds:

  • The Linguo Dental Sounds are “TH”
  • Produced by: When the tip of the tongue extends outside the upper and lower anterior teeth
  • Importance of Linguo Dental Sounds: When the tip of the tongue is not visible, the anterior teeth are too far forward except in class II occlusion. If more than 1/4th of the tip of the tongue is visible then teeth are placed too far lingually. Excessive vertical overlap (overbite) also does not provide sufficient space for the tip of the tongue which affects these sounds.

Linguo Palatal Sounds (Anterior Palate): 

  • The Linguo Palatal Sounds are “C (soft), D, T, N, Z and R”
  • Produced by: When the tip of the tongue contacts the anterior portion of the palate or the lingual side of anterior teeth.
  • Importance of Linguo Palatal Sounds: When the denture base in the Rugal area is too thick and can produce a similar effect. “S” sounds produced by the position of the tongue so that air stream released through a small gap between tongue and rugae, “S” will sound as “SH” when anterior teeth are anterioposteriorly displaced.

Linguo Palatal Sounds (Posterior): 

  • The Linguo Palatal Sounds are “I, R, J, CH and SH” 
  • Produced by: When the tongue forms a valve when it contacts the palate and the release of air helps in producing these sounds
  • Importance of Linguo Palatal Sounds: Helps in positioning the anterior teeth as when these sounds are spelt the anterior teeth come very close to each other but do not meet.

Linguo Palatal sounds (Soft Palate) also called as “Velar Sounds”

  • The linguo palatal sounds are “C (hard), K, G, NG”
  • Produced by: When the tongue forms a valve similar to the other linguo palatal sounds but posteriorly than the others.
  • Importance of Linguo Soft palate sounds: In case of Cleft lip or palate the sounds are affected. Artificial Dentures do not affect these sounds

True Palatal Sounds: 

  • True Palatal Sounds are YEAR, SHE, VISION
  • Produced by: The tongue does not come in contact with the palate the sounds is produced by the tongue and Palate coming close together but not touching at any point.
  • Importance: Artificial Dentures do not affect these sounds

Nasal Sounds: 

  • Nasal Sounds are “M, N, NG”
  • Produced by: These sounds are produced from the nose even when the mouth is closed. but if the nose is close we cannot produce these sounds

Vowel sounds: 

  • Vowel Sounds are “A,E, I, O, U”
  • Importance of Vowel Sounds: The alteration in the size of the mouth and the changes in the shape and size of the lip opening gives the various sounds these characteristic sounds


  1. Very sound dental theory and advice. When I was in dental school theories like this are a gem to me. Until now, these sound principles still guide me in my dental clinic in Australia. Fitting some dentures can be very complicated. You can’t afford to have any mistakes, that’s why paying attention to the sounds will help you both in prosthodontics and even sedation dentistry. Sydney libraries and dental clubs offer more details on these dental sounds you mentioned. Awesome post.

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