Betty C. Vine


In recent years the attention of specialty groups has been drawn toward the peculiar oral behavior commonly referred to as tongue-thrust. This behavior is not only characterized by multiple symptomatology, but it also has been characterized by multiple terminology.

In addition to the wide variety of views and theories on the tongue-thrust behavior, there is an ever greater discrepancy of opinion concerning the causal factors of this behavior. What is its etiology? Is it a functional disorder? Is it organically based or a combination of the two?

The purpose of the study was to attempt to organize the most prevalent body of clinical investigation which has been submitted for publication or delivered at speech or dental conferences on the subject of tongue-thrust etiology. The paper endeavored to pursue all etiological possibilities and consider each theory propounded in order to arrive at a point of agreement, reserved agreement or disagreement between scholars who have done validated research and made a significant contribution to the field.

It is important to understand tongue thrust etiology because the tongue-thrust swallowing pattern has a high incidence in the general population primarily among school age children, especially in the lower grades. Increasing number of children with tongue-thrust also have defective speech and therefore serious consideration should be given to the causative factors related to it.

The study reviewed the major etiological possibilities for the deviant swallowing pattern commonly referred to as tongue-thrust. The main theories advanced by leading scholar·s were organized into two categories or organic and functional theories. A chart was formed whereby the various theories were listed and association of the theories with the researchers were coordinated so that at a glance it is possible to identify the harmonious or discordant thinking among leading writers regarding tongue-thrust etiology.

A review of the literature revealed twelve etiological theories pertaining to the tongue-thrust behavior. Of these the highest number of agreements involved 35 percent of the researchers and stated that tongue-thrust could be etiologically attributed to a structural deviancy or a temporary manifestation occurring intermittently during growth and development of the lower face.

Twenty-nine percent felt that early in the years of maturation the performances of swallowing and speech are developed and modified by rapid facial or oral morphological change. Therefore this pattern of infantile swallow will change as a function of growth and development.

Twelve percent of the investigators felt that tongue-thrust was innate at birth, while eight percent felt that the tooth shedding years were responsible when the child learns to fill the space left by departing deciduous teeth with the apex of the tongue, therefore fronting the tongue.

Nine percent agreed with the hereditary thesis that tongue-thrust is genetically transmitted from parent to offspring as was shown by similar dental structures. Upper respiratory disorders was felt by eleven percent to be a causative factor. The most controversial theory of tongue-thrust appeared· under the heading of nursing habits. Eight percent of scholars felt that bottle feeding contributed to a deviant neuromuscular pattern of swallowing. Non-nutritive sucking habits and tonsillitis tissue was felt by eight percent to play a strong role in tongue-thrust and open bites. Three percent felt that neurological involvements might be a cause, while on the theory of oral fixation only two percent of the scholars submitted a reserved agreement regarding the psychic disturbances relative to the tongue-thrust swallow. Surgical defects was felt by only one percent to be a causative factor.

The study should give valuable information both to the field of orthodontics and the field of speech pathology in developing (a) preventive techniques for implementation early in the life of the child who has tendencies towards the forward thrust of the tongue, (b) meaningful counsel to young parents concerning feeding habits of their infants and how to encourage a stronger muscular action within the oral cavity, and (c) more successful therapeutic techniques in the remediation of the abnormal swallowing pattern.

The study also demonstrated the fact that few researchers are willing to conclusively affiliate themselves with a particular theory (perhaps because this is not practical or possible). The study would also have carried more validity if each researcher could have been contacted individually for a more complete view of his etiological convictions and to have given his opinion on other etiological theories which were found in the research materials.

It is obvious by the wide diversity of opinion presented in the study that tongue-thrust etiology is at best poorly understood, inadequately investigated, and indicative of need for further research so that remedial techniques might be more successfully developed.

LLU Discipline

Speech Pathology


Communicative Disorders


Graduate School

First Advisor

Logan W. Barnard

Second Advisor

E. Evelyn Britt

Third Advisor

W. Fletcher Tarr

Degree Name

Master of Science (MS)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Tongue Habits; Speech Disorders



Page Count

v; 44

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