The forces exerted by the perioral musculature and the effects observed in subjects with adverse swallowing patterns accompanied by demonstrable mentalis habits were compared with a control group of "normal" subjects by the following methods:

1. Study casts of upper and lower arches were obtained for a morphological evaluation of denial structures.

2. Measurements of lip pressures against the teeth were recorded for the following:

a. Drinking water

b. Volitional and spontaneous swallows

c. Designated speech sounds

d. Maximum effort pressure

3. Measurements of inter-lip pressures were recorded at the center and corner of the mouth for the following:

a. Maximum pressures

b. Volitional swallow

The recording instrument consisted of a cast rubber pressure sensing cushion coupled to a pressure-sensitive transducer by small, relatively inelastic tubing. The system was hydraulically activated. The signals from the transducer were recorded by a two-channel recorder equipped with strain gauge amplifiers.

From the records accumulated, this investigation has shown evidences that point to the following:

  1. Persons with a "normal" swallowing pattern generally exert greater pressures of lips against teeth and gums in both upper and lower arches during speaking and swallowing.
  2. The pressures resulting from the pill exerted by the mentalis and associated muscles is not primarily against the mandibular incisors and adjacent gum area.
  3. Persons with abnormal swallowing patters accompanied by mentalis habit exert greater inter-lip pressures.
  4. Since malocclusion is such a constant accompaniment of the mentalis habit, it is thought possible that the repetitive eversion of the lower lip associated with the mentalis habit may be contributory.

LLU Discipline





Graduate Studies

First Advisor

Thomas J. Zwemer

Second Advisor

Kenneth R. Lutz

Third Advisor

Walter H. B. Roberts

Fourth Advisor

Robert B. Pearson

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Deglutition Disorders



Page Count

vi; 56

Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website



Loma Linda University. Del E. Webb Memorial Library. University Archives