AI-AIDED VOLUMETRIC ROOT RESORPTION ASSESSMENT FOLLOWING PERSONALIZED FORCES IN ORTHODONTICS: PRELIMINARY RESULTS OF A RANDOMIZED CLINICAL TRIAL

Abstract

Introduction

External apical root resorption (EARR) is an undesirable loss of hard tissues of the tooth root frequently affecting to the maxillary incisors. The magnitude of orthodontic forces is a major treatment-related factor associated with EARR occurrence in orthodontics. The primary aim of the present randomized clinical trial was (i) to quantify the impact of a sequence of personalized force archwires on EARR compared to the conventional standard of care and (ii) compare the 3D-quantification of EARR using two quantification methods (manual or automated AI-aided segmentation).

Material and Methods

A superiority two arms-parallel-randomized clinical trial (RCT) was conducted to quantify the EARR of two regime forces [CONSORT-guidelines]. A total of 18/43 patients were randomly assigned [block-size: 4] to Control Group [Ni-Ti archwires sequence] or Experimental Group [selective individualized force archwires]. After 142 days sectorial CBCT were obtained; upper incisors were segmented manually and with AI and the volume/length of root quantified. Method error/descriptive statistics (mean; SD; range) and Student t-test were used to assess the differences between groups (Post hoc adjustment for confounders [95% CI; P < .05]).

Results

The total root volume loss detected by AI was 2.44 ± 6.59 mm³ / 2.42 ± 4.75 mm³ (P > .05) and the mean root length loss was 0.20± 0.23mm/0.42 ± 0.43 mm (P = .045) for control/test group, respectively. Despite length loss showed similar changes when it was quantified with both methods, manual and automatic segmentations (P > .05), differences are observed at volume loss. The results demonstrated greater volume loss detection with manual segmentation than with AI-aided segmentation at the global level, volume by thirds, and 4 mm from the apex. However, as we approached apically, the differences equalized and even diminished, resulting in a greater loss with automatic segmentation 1 mm from the apex in the EG (P = .011).

Conclusions

A non direct-force-dependent effect over EARR (6 months) was observed. Individualized force induces slightly higher root resorption at the apical third at 1-2 mm.