OPEN-MOUTH POSTURE AND MAXILLARY ARCH WIDTH IN YOUNG-CHILDREN - A 3-YEAR EVALUATION

A large biracial sample of children were assessed for open mouth postu re and maxillary arch width once a year for 3 years. Analyses revealed that although the youngsters exhibited open-mouth posture at high lev els, over time, there was a significant decrease in this behavior. Rac ial and gender differences, as well as a race-by-time interaction, wer e also evidenced. The children displayed a significant increase in max illary arch width across time, with gender and racial differences seen in this growth pattern. Finally, when the youngsters were classified as exhibiting primarily open-mouth or closed-mouth posture, it was obs erved that children with open-mouth posture displayed a significantly slower pattern of maxillary growth compared with children who display anterior lip seal posture. The implications of the findings were discu ssed.