A Study of The Effect of The Eruption of The First Permanent Molar To Occlusion, Occlusal Contact Area and Occlusal Force

1 The Analysis of The First Examination

Abstract

As a part of the study of the development of the occlusal function in children, It was decided that the department of pediatric dentistries of six colleges would work together and examine the longitudinal change of the occlusal contact around the time of the eruption of the first permanent molar four times every six months.
The results obtained at the first examination (with the time of the early occlusion of the first permanent molars, the average age being 7 years and 2 months. ) were as follows.
1) As the occlusal contact area of the mandibular first permanent molar increased, the occlusal force and the occlusal contact area of the deciduous second molar tended to increase. There was no relationship between the occlusal contact area of the mandibular first permanent molar and the occlusal pressure of the mandibular deciduous second molar.
2) In the mandibular first permanent molar, the occlusal force tended to increase and the occlusal pressure tended to decrease, with increase of the occlusal contact area.
3) There was a correlation between the root length and the occlusal force in the mandibular first permanent molar, but there was no correlation in the mandibular deciduous second molar.
4) As the occlusal contact area of the mandibular permanent molars increased, the occlusal contact area and the occlusal force of the total dentition tended to increase. We were not able to show a regular change in the occlusal pressure of the total dentition.