抜歯症例における口腔内模型の重ね合わせのための安定したランドマークとしての第三口蓋ヒダ：後向きコホート研究
Carolina Morsani Mordente1, Lorenna de Souza Dores1, Dauro Douglas Oliveira1
1Pontifical Catholic University of Minas Gerais, Belo Horizonte, Brazil.
Objectives:
To validate the third palatal rugae as stable reference landmarks for the superimposition of maxillary digital models in premolar extraction cases.
Materials And Methods:
Maxillary intraoral scanning digital models of 22 extraction patients, obtained before (T0) and after approximately 4 months of incisor retraction (T1), were superimposed using the automated best-fit of the third palatal rugae and palatine raphe. Voxel-based registration of CBCT scans served as the gold standard. Point-to-point displacements between T0 and T1 of the central incisors and cuspids were calculated for both methods.
Results:
The mean differences (mismatch) between methods in the combined vertical and horizontal perspectives of the central incisors were 0.08 mm (right) and 0.12 mm (left), respectively. For the cuspids, the mean 2D differences were 0.02 mm (right) and 0.07 mm (left). The pure horizontal displacement differences of the maxillary central incisors were 0.13 mm (right) and 0.04 mm (left). For the cuspids, the differences were: 0.05 mm (right) and 0.03 mm (left). No statistically significant differences were found between the intraoral-scan and CBCT measurements for either the central incisors or cuspids after maxillary superimpositions. The differences between the two methods were smaller than 0.2 mm in all comparisons.
Conclusions:
Digital superimposition of the third palatal rugae of models obtained with intraoral scans is a valid method for the 3D evaluation of the short-term (4-month) dental changes in the anterior region of the maxilla in cases of premolar extraction followed by incisor retraction.
Trial Registration:
ClinicalTrials.gov: NCT03089996 and NCT05281588.
