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Arch length changes from 6 weeks to 45 years
S E Bishara1, J R Jakobsen, J Treder
1College of Dentistry, University of Iowa, Iowa City, USA.
Insights
Maxillary and mandibular arch length significantly increases in early childhood, with continued growth until age 13 and 8, respectively. Both arches show consistent decreases after these ages, impacting dental arch development.
Area of Science:
- Dentistry
- Human Growth and Development
- Orthodontics
Background:
- Understanding longitudinal changes in dental arch dimensions is crucial for diagnosing and treating malocclusions.
- Previous studies have focused on shorter timeframes or specific developmental periods.
Purpose of the Study:
- To longitudinally evaluate changes in maxillary and mandibular arch length over a 45-year period in normal individuals.
- To identify key developmental stages influencing arch length.
- To document long-term dimensional changes in the dental arches.
Main Methods:
- Longitudinal study design using two cohorts of normal individuals.
- Arch length measurements taken at multiple time points from infancy to 45 years.
- High intra- and inter-examiner reliability for measurements (0.25 mm and 0.5 mm).
Main Results:
- Greatest arch length increases occurred during the first two years of life.
- Maxillary arch length increased until 13 years; mandibular arch length increased until 8 years.
- Both arches exhibited significant, consistent decreases in length mesial to the permanent first molars after peak growth.
Conclusions:
- Dental arch length undergoes significant changes throughout human development, with distinct periods of growth and reduction.
- The findings provide valuable normative data for orthodontics and pediatric dentistry.
- Understanding these long-term changes is essential for predicting and managing dental arch stability.
Abstract:
The purpose of this study was to evaluate, on a longitudinal basis, changes in maxillary and mandibular arch length over a 45-year period. Subjects were drawn from two pools of normal individuals. Twenty-eight male and 33 female infants were evaluated longitudinally at 6 weeks, 1 year, and 2 years (before the eruption of the deciduous dentition). Fifteen males and 15 females from the Iowa Facial Growth Study were evaluated at 3, 5, 8, 13, 26, and 45 years. Arch length measurements were obtained independently by two investigators. Intra- and interexaminer reliabilities were predetermined at 0.25 and 0.5 mm, respectively. The greatest incremental increases occurred during the first two years of life. Arch length continued to increase until 13 years in the maxillary arch, and until 8 in the mandibular. Then significant and consistent decreases occurred in both arches mesial to the permanent first molars.