# Three dimensional palatal morphology and dentoalveolar differences after extraction and non extraction treatment in class II malocclusion

## TL;DR

This study compares how tooth extraction and non-extraction treatments affect the shape and volume of the palate in patients with Class II malocclusion using 3D digital models.

## Contribution

The study provides new insights into palatal remodeling differences between extraction and non-extraction orthodontic treatments in Class II malocclusion.

## Key findings

- Extraction protocols caused maxillary incisor retrusion, while non-extraction led to protrusion.
- Anterior palatal volume and surface area increased in all groups.
- Dentoalveolar displacement was linked to palatal remodeling, but angular and vertical dental variables had limited influence.

## Abstract

Digital technologies have transformed orthodontics by enabling precise three-dimensional (3D) assessment of treatment outcomes; however, the effects of extraction versus non-extraction strategies on palatal morphology in Class II malocclusions remain underexplored. This study quantified segmental palatal volume and surface changes, along with skeletal–dentoalveolar outcomes, using digital model analysis integrated with cephalometrics. Records of 69 post-pubertal patients treated with fixed appliances (Class II, n = 34; Class I controls, n = 35) were retrospectively analyzed, each subdivided into extraction and non-extraction protocols. Maxillary casts were scanned with Sirona inEos X5 and segmented in Materialise 3-Matic to compute palatal volume and surface area, while cephalometric variables were derived from lateral radiographs (Dolphin Imaging). Group comparisons were performed using non-parametric tests (p < 0.05). Multivariable regression analyses were conducted to identify dentoalveolar predictors of palatal remodeling. Intra-examiner repeatability was excellent, as indicated by a high intraclass correlation coefficient (ICC ≥ 0.90). Skeletal changes were minimal and comparable across groups. Dentoalveolar findings demonstrated significant maxillary incisor protrusion in non-extraction protocols and retrusion in extraction protocols (p < 0.05). Anterior palatal volume and surface area increased across all groups. Overall, measurable differences in total palatal volume and surface area were observed between extraction and non-extraction treatment strategies. Regression analyses indicated that sagittal dentoalveolar displacement was associated with palatal remodeling, whereas angular and vertical dental variables showed limited independent influence. Extraction and non-extraction treatment protocols were associated with measurable differences in three-dimensional palatal volume and surface area, reflecting distinct dentoalveolar and palatal remodeling patterns between treatment strategies.

The online version contains supplementary material available at 10.1038/s41598-026-37842-y.