Changes in Occlusal Contact Area and Occlusal Force Obtained from Patients with Various Types of Malocclusion during Retention Using Pressure Sensitive Occlusal Sheets
2002 Volume 22 Issue 2 Pages 137-143
Details
2002 Volume 22 Issue 2 Pages 137-143
The objective of the present study was to compare the changes in the occlusal contact area (OcAr) and the occlusal force (OcFr) longitudinally during retention in patients with various types of malocclusion by the use of pressure-sensitive occlusal sheets (Dental Prescale).
The subjects treated at Showa University Dental Hospital were selected according to the following criteria : 1) clinically normal function of the oral and maxillofacial region; 2) less than 4 mm deviation between the maxillary and mandibular midlines; 3) no congenital craniofacial anomaly such as cleft lip and/or palate; 4) the first and second molars being present and functioning without extensive defects. The subjects were divided into four types : Class I, II, III, and surgical class III (S-Cl. III). All subjects had active treatment completed with or without the extraction of premolars. OcAr and OcFr were recorded by using Dental Prescale at three different (early, middle, late) retention stages.
All types of subjects showed a significant increase in both OcAr and OcFr during retention in female and male. The increasing ratio during retention among four types were ranked in the following order : S-Cl. III>> Cl. I>> Cl. II>> Cl. III in both female and male. Therefore OcAr and OcFr in Cl. III were greater than those in S-Cl. III at an early stage of retention in both female and male. This order was reversed in the late stages of retention. The order of OcAr and OcFr among the four types of malocclusion in female and male were respectively as follows : Cl. I>> Cl. II>>Cl.III≅S-Cl (female); Cl.I≅Cl.III≅S-Cl. III>>Cl. II (male).
These results suggest that OcAr and OcFr obtained from the patients during retention increased time-dependently in female and male. This increase did not depend on the extraction of premolars or on the type of malocclusion.Key words : malocclusion;occlusal contact area;occlusal force;longitudinal study;retention.
