Related Experiment Video
Updated: Mar 12, 2026
Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model
Published on: November 4, 2025
Age- and gender-related incisor changes in different vertical craniofacial relationships
1Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia.
Objective:
To investigate the age- and gender-related changes in upper and lower incisors' position and inclination in different vertical craniofacial relationships.
Materials And Methods:
A retrospective study on patients' records of age 8-48 years. The sample was divided based on Frankfort mandibular plane angle into three groups; normal, high, and low angle groups. It was then subdivided according to age. Upper and lower incisors' inclinations and positions were assessed from lateral cephalometric radiographs. Gender and age associations and effects size were calculated using two-way ANOVA tests. Significance level was set at P < 0.05.
Results:
Four hundred and twenty records (F = 272, M = 148) were included; 115 had normal, 81 low, and 250 had high vertical relationships with no significant age and gender distribution differences (P > 0.05). All significant associations and effects were found in the low angle group only. A significant association was found between gender and upper incisor inclination (P < 0.05) with medium effect size (0.13 ≤ ηp2 < 0.26). An association is also found between age × gender interaction and upper incisor inclination and lower incisor position (P < 0.05) with large effect size (0.26 ≤ ηp2).
Conclusion:
Age- and gender-related upper and lower incisor changes were found to be significant in subjects with decreased vertical skeletal pattern only. The upper incisor inclination and the lower incisor position were the most affected variables with age and gender.
Related Concept Videos
01:15Teeth
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...
01:09Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
01:22Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
01:29Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into ...
01:27Cranial Bones: Lateral View
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
01:21Tooth 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...