How good are we at estimating crowding and how does it affect our treatment decisions?

Area of Science:

• Dental Science
• Orthodontics
• Clinical Practice

Background:

• Accurate assessment of dental crowding is crucial for effective orthodontic treatment planning.
• Variability in clinical judgment can impact treatment outcomes and patient satisfaction.

Purpose of the Study:

• To evaluate how orthodontists estimate dental crowding using study models.
• To assess orthodontists' subsequent choices regarding tooth extractions.
• To determine the reliability and consistency of these estimations and decisions over time.

Main Methods:

• Sixty-two orthodontists quantified crowding on eight lower arch study models using their preferred methods.
• Extraction choices were recorded for each model.
• Eleven orthodontists repeated the assessment after nine months to evaluate reliability.
• Intermolar and intercanine widths, clinical scenarios, and curve of Spee were standardized across models.

Main Results:

• Direct visualization was the preferred method for estimating crowding, but estimates were highly variable.
• For 7.5mm of crowding, estimates ranged from 5mm to 20mm.
• Extraction choices were less variable than crowding estimates and shifted from second to first premolars as crowding increased.
• Estimates and decisions varied significantly upon re-evaluation after nine months.
• Crowding estimates were not correlated with the orthodontists' clinical experience.

Conclusions:

• Orthodontists' estimations of dental crowding and subsequent extraction decisions exhibit considerable variability, both initially and over time.
• Despite variability, extraction decisions became more likely and shifted towards first premolar extraction with increasing crowding.
• The study's limitations include its laboratory-based nature and focus solely on the lower arch.
• Understanding these variations is critical due to potential medico-legal implications.