Related Experiment Video
Updated: Mar 20, 2026

Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Association between Tooth Loss and Degree of Temporomandibular Disorders: A Comparative Study
Adriana Santos Malheiros1, Stéphanye Tavares Carvalhal1, Teonnes Lima Pereira1
1Department of Dentistry, University CEUMA, São Luis Maranhão, Brazil.
Objective:
The aim of this study was to evaluate the association between tooth loss and the signs and symptoms of temporomandibular disorders (TMDs).
Materials And Methods:
One hundred fifty patients with an average age of 49.2 (±14.06) years were divided into three groups (n = 50/group) according to the degree of tooth loss: GI (dentate -control), GII (edentulous), GIII (partially dentate). After performing anamnesis and clinical examination, a questionnaire was used, so that the patients could fill in information on signs and symptoms of TMD. After analyzing this information, it was possible to classify the degree of severity of TMD. As age is a confounding variable to the level of TMD, an analysis of covariance (ANCOVA) was used to check for differences in the degree of TMD between groups (covariate = age). A post hoc test (Bonferroni) was performed to compare the groups two by two (5% significance level).
Results:
The mean level of TMD according to the groups was GI - 1.95; GII - 2.15; GIII - 2.55. There were significant differences between the study groups (p > 0.05). A post hoc test (Bonferroni) confirmed the difference between edentulous patients and the other groups.
Conclusion:
The tooth loss is directly related to the signs and symptoms of TMD. The degree of TMD was significantly higher in edentulous patients.
Related Concept Videos
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...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
The Oral Microbiota
Assessment of the Mouth
Mouth Inspection
The inspection begins with visually examining the mouth for symmetry, color, and size.
Structural Joints: Fibrous Joints
Suture
All the bones of the skull, except for the mandible, are joined to each other by a fibrous joint called a suture. The fibrous connective tissue found at a suture strongly unites the adjacent skull bones and thus helps to protect the brain and form the face. In...
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...

