Related Experiment Video
Updated: Feb 10, 2026

Evaluating the Function of the Foot Core System in the Elderly
Published on: March 11, 2022
A study of occlusion in elderly Japanese over 80 years with at least 20 teeth
Haruyo Miyazaki1, Etsuko Motegi, Kenichi Yatabe
1Department of Orthodontics, Tokyo Dental College, Chiba, Japan. miyazaki@tdc.ac.jp
Objectives:
The purpose of this study was to identify the occlusal status of elderly Japanese over 80 years with at least 20 teeth.
Materials And Methods:
The study enrolled 76 elderly Japanese (44 male, 32 female) with a mean age of 82 years and an average of 25.7 remaining teeth. The study consisted of intra-oral examination, intra-oral and facial photographs, radiographs and impressions for study casts.
Results:
No gender difference was observed in age or number of remaining teeth. Anteroposterior occlusal relationship was characterised by maxillary protrusion in 67.6%, acceptable overjet in 31.0%, and anterior crossbite in 1.4%. Vertically, deep bite was noted in 33.8%, acceptable overbite in 64.8%, and open bite in 1.4%. Most of the subjects had either Angle class I (68.4%) or class II (25.7%) canine relationship. Only 3.9% of the subjects had upper anterior crowding. Lower anterior crowding was observed in 23.7%, but tended not to be severe.
Conclusion:
These results indicate that Japanese who attained the goal of '8020' have a relatively good occlusion.
More Related Videos
09:11Performing Permanent Distal Middle Cerebral with Common Carotid Artery Occlusion in Aged Rats to Study Cortical Ischemia with Sustained Disability
Published on: February 23, 2016
09:01Vascular Occlusion Training for Inclusion Body Myositis: A Novel Therapeutic Approach
Published on: June 5, 2010
Related Concept Videos
Imaging Studies I: Kidney, Ureter, and Bladder Studies
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Case Studies
Longitudinal Studies
Observational Studies
There are three types of observational studies – Prospective, retrospective, and cross-sectional.
Prospective Study
Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One...
Studying the Cytoskeleton