A static occlusal analysis based on ideal interarch and intraarch relationships

Area of Science:

• Orthodontics
• Dental Morphology
• Biomedical Engineering

Background:

• Assessing orthodontic treatment outcomes is crucial for evaluating treatment efficacy.
• Quantifying ideal tooth relationships provides an objective measure of occlusal success.
• Longitudinal studies are essential to understand treatment effects over time.

Purpose of the Study:

• To introduce and validate the Ideal Tooth Relationship Index (ITRI) for quantifying orthodontic treatment outcomes.
• To assess the longitudinal changes in tooth relationships throughout orthodontic treatment and retention.
• To compare ITRI scores across different segments of the dentition and malocclusion types.

Main Methods:

• Visual assessment of study models to quantify ideal tooth relationships.
• Development and application of the Ideal Tooth Relationship Index (ITRI) for entire dentition, anterior, posterior, interarch, and intraarch segments.
• Longitudinal data collection at various time intervals for 92 treated orthodontic cases.

Main Results:

• The total ITRI score increased from 26% initially to 52% post-treatment and 59% during retention.
• Anterior segment scores (64%) were higher than posterior segment scores (44%).
• Intraarch anterior relationships showed the highest scores (75%), while posterior lingual cusp relationships had the lowest (35%).
• Different malocclusions showed varying initial ITRI scores but responded similarly to treatment.

Conclusions:

• The ITRI is a valuable tool for objectively measuring orthodontic treatment success.
• Orthodontic treatment leads to significant and sustained improvements in tooth relationships.
• Specific dental segments and relationship types demonstrate varying degrees of improvement, highlighting areas for further focus.