Abstract
The purpose of the present study was to investigate the development of the masticatory function, the occlusal force and primary canine distance in children with extremely low and very low birthweight (EVLBW).
The subjects were nine children aged 4.3 to 5.8 yrs (mean 5.0 yrs old) who were born with EVLBW and 16 healthy and normal birthweight children as controls with ages matched those with extremely low and very low birthweight. In seven children of the EVLBW the development of mastication had been observed continuously for 1.5 years. Electromyography (EMG) were recorded while chewing from the bilateral temporal and masseter muscles, and the unilateral digastric muscle. The occlusal contact area and the occlusal force were measured using the bite pressure detecting system Dental Prescale®.
The occlusal contact area, occulusal force and bilateral primary canine distance of those with EVLBW were significantly smaller than those with normal birthweight children. However, the muscle activity of those with EVLBW was found to be significantly higher than that of those with normal birthweight children. According to growth and development for 1.5 years, both the values of occulusal contact area and the occulusal force for those with EVLBW significantly increased, whereas muscle activities of those with EVLBW decreased.
In conclusion, it is suggested that the masticatory muscles of those with EVLBW when chewing would be much more activated to compensate for their low occulusal force, but their masticatory function might be caught up in an earlier stage than their general growth.
