Related Experiment Video
Updated: Aug 15, 2026

Treatment of Facial Deformities using 3D Planning and Printing of Patient-Specific Implants
Published on: May 23, 2020
Lower lip position and incisor overjet in a 12-year-old Nigerian population
1Department of Preventive Dentistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
Abstract:
Relationship between variation of overjet and different postural positions of the lower lip in 1,016, 12-year old Nigerians was investigated using a modified Jackson classification (1962). The range and mean overjet values tended to decrease as the extent of incisal coverage increased with statistically significant differences in lip positions. Overjet greater than 6 mm was consistently associated with 'trapped' lower lip. The results of this study also indicate that lower lip may provide inadequate lip coverage to the upper incisors when the overjet is greater than 7 mm.
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 and...
Assessment of the Mouth
Mouth Inspection
The inspection begins with visually examining the mouth for symmetry, color, and size.

