Correlation Between Functional Lingual Pressure and Oral Cavity Size

Abstract

The hypothesis that pressure by the tongue and lips influence the development of the dental arch and the whole oral cavity is an old one. The " functional matrix " view of facial growth (5), which emphasizes functionally related growth of the orbit, nasal cavity, oral cavity, etc., provided a conceptually new way of looking at form—function interaction. More recently , several writers (1, '7, 9) have expressed the view that resting pressures are more important in determining dental arch form than are functional pressures from such activities as speaking and swallowing. Prof-fit, Chastain and Norton (8) found, for instance, no relationship between increments of lateral growth of the maxillary arch and lateral lingual pressure exerted during swallowing. The low level resting pressures over a long period of time that occur within the oral cavity are technically difficult to measure. However, the high levels of pressure of short duration that occur during swallowing and speaking are comparatively easy to determine. The relationship of these " functional " pressures to oral cavity size will determine if their inclusion in a function-form theory is required. Therefore, the purpose of this study was to determine if a correlation occurs between the lingual pressure exerted against the maxillary arch during speech and swallow and the size of the oral cavity. Method Nine children were selected as subjects for this study from a larger population involved in a longitudinal investigation of lingual pressures and dental occlusion. The subjects were selected who provided a wide range of oral cavity sizes as determined by measurements previously described by Brown and McGlone (2). From cephalograms of each child made with teeth in occlusion, the following measurements, as illustrated in