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Changes in lower third molar position in the young adult
1Orthodontic Department, School of Dentistry, Royal Victoria Hospital, Belfast, Northern Ireland.
Summary
Unerupted lower third molars showed significant positional changes between ages 18 and 21, despite generally inadequate space. Most molars did not significantly alter their mesiodistal angulation, with few fully erupting.
Area of Science:
- Dentistry
- Orthodontics
- Oral Surgery
Background:
- Unerupted lower third molars are common, and their positional changes during late adolescence can impact oral health.
- Understanding the dynamics of third molar development and eruption is crucial for orthodontic and surgical planning.
Purpose of the Study:
- To examine changes in the position of unerupted lower third molars from age 18 to 21.
- To assess mesiodistal and buccolingual angulation, molar space, and eruption status over this period.
Main Methods:
- Longitudinal study involving 17 men and 24 women with intact lower arches.
- Analysis of 60-degree cephalograms taken at ages 18 and 21.
- Measurement of mesiodistal and buccolingual third molar angulation, molar space, and molar space condition.
Main Results:
- At age 18, average molar space was inadequate by 5.0 mm.
- A statistically nonsignificant average increase in molar space of 0.7 mm was observed.
- Third molar positions varied significantly, with mesiodistal changes from 39 to -46 degrees and buccolingual changes from 24 to -24 degrees.
- Only 10 third molars maintained their mesiodistal angulation; four fully erupted.
Conclusions:
- Significant mesiodistal and buccolingual positional changes occur in unerupted lower third molars between ages 18 and 21.
- Limited eruption and minimal space increase suggest potential impaction or delayed development.
- These findings highlight the dynamic nature of third molar positioning in early adulthood.