Physiologische Veränderung der Molarenrelation und Platzverhältnisse während des Übergangs vom Wechselgebiss zum permanenten Gebiss

Establishment of molar relation under physiologic conditions is a
dynamic process during development of the occlusion. For the
clinician it is interesting to be able to predict these
physiological proceedings from an early point of development to
evaluate treatment need for a patient, possible self-corrections
and interference of treatment with ongoing physiological
maturation. AIM OF THIS STUDY: To describe longitudinal changes in
molar relation from the early mixed to the permanent dentition as a
result of normal development and to study associations between the
change in molar relation and different dental parameters with
special focus on the space conditions. MATERIAL AND METHODS: Dental
casts of fifty orthodontically untreated children were evaluated
longitudinally at the age 7, 11 and13 years. A space analysis for
each quadrant was performed and the molar relationship was
registered at each stage. To evaluate the effect of space
conditions and possible molar migration on the existing molar
relationship the upper and lower molars were mentally transferred
to a position in the dental arch, which is neutralizing the
existing surplus or lack of space in each quadrant. The relation of
the lower molar to the upper one in the new position is called
“corrected occlusion”. RESULTS AND CONCLUSION: The mean molar
occlusion has a tendency for developing a less distal relation
during establishment of the permanent dentition. Self-corrections
do occur, but not in a frequency warranting reduced importance of
early initiating of orthodontic screening and treatment. When the
cases were grouped according to variable «corrected occlusion», a
rather good agreement between the early mixed and permanent
dentition was demonstrated; indicating a certain stability of the
molar relation after isolating the effect of the space conditions.