A Comparison of Short-Term Treatment Outcomes with Non-extraction and Extraction Orthodontic Treatment Modalities in Borderline Class I and Mild Class II Malocclusions

Abstract

Extraction (EX) and non-extraction (NEX) decisions impact various treatment outcomes, including soft tissue and incisor positions. Increasing desirability for more protrusive lips requires for an update in esthetic preferences. Borderline cases are critical when attempting to discern EX and NEX treatment effects. This retrospective study used Discriminant Analysis to identify 30 EX and 30 NEX borderline cases, analyzing soft tissue, incisor, and occlusal changes. Assessment of profile and incisor inclination preferences were conducted by 90 laypeople (LP), 40 orthodontists (OR), and 40 general dentists (GP). EX cases showed increased nasolabial angle, more ideal overbite, and lip and incisor retraction, with no significant differences in molar relationship and overjet. Linear regression of survey results indicated OR preference for EX profiles, GP preference for NEX profiles, and all groups favouring more upright incisors. LP’s preferences more aligned with GP. Conflicting GP preferences emerged, desiring protrusive lips and acute nasolabial angle (NEX-associated), yet more strongly preferring upright incisors (EX-associated).