Three-dimensional characterization of root morphology for maxillary incisors

Abstract

The aim of this study was to test the reproducibility of three-dimensional (3D) surface models of maxillary incisors and to propose a characterization of root morphology. The sample was comprised of pre-treatment cone-beam computed tomography (CBCT) images of fifty-five patients. The CBCTs were used to construct 3D surface models of the maxillary incisors. The reproducibility of surface models was tested by repeated construction of them by two observers. A 3D surface model that corresponded to the average of all lateral and all central incisors was generated. 3D surface distances and vector differences were calculated for each individual tooth and the average of the teeth considered. The corresponding points on the 3D surface mesh for each subgroup were compared statistically to those of the neutral subgroup using shape analysis MANCOVA and Hotelling’s t-statistic (p < 0.05). Repeated construction of surface models demonstrated adequate inter-rater reproducibility. The distribution of 3D models into root morphology subgroups was: blunt (11% and 26% of the central and lateral incisors, respectively), conical (15% of the central incisors), long (27% and 20% of the central and lateral incisors, respectively), and short (15% and 4% of the central and lateral incisors, respectively). Compared to the neutral average, statistically significant differences in root morphology were found for blunt, long, conical, and short central incisors and for blunt, long, and short lateral incisors. We can conclude that 3D surface models construction for upper incisors is reproducible. 3D shape analysis using CBCT images allows a phenotypic characterization of incisor root morphology.

The Accuracy of Lateral Cephalogram in Representing the Anterior Maxillary Dentoalveolar Position

“…A gradual thinning of the root apically from the CEJ relied on the normal root anatomy [ 21 ]. Ceph presented thinner roots than the CBCT images by 0.4 to 0.5 mm, whereas Ceph was thinner than U2CT by about 0.2 mm.…”

Tooth and root size as determined from 0.25- and 0.30-mm voxel size cone-beam CT imaging when contrasted to micro-CT scans (0.06 mm): An ex vivo study

“…Therefore, it is important to understand the limitations of the imaging parameters when diagnosing and assessing RR. Different ways of measuring RR have been previously described in the literature, from volume and surface reduction to shape change analysis ( Ahlbrecht et al, 2017 ; Puttaravuttiporn et al, 2018 ). The percentage of volume change is the most intuitive for clinicians and, therefore, the most helpful to put the results into perspective.…”

“…This modality has relatively lower contrast and a lower signal-to-noise ratio, which generates challenging situations for the segmentation process ( Liu et al., 2010 ). Even if its quality is not ideal for all types of measurements, including RR, it seems that CBCT voxel sizes are usually in the range of 0.30–0.40 mm ( Ahlbrecht et al., 2017 ). This has logical reasons such as the need for a comprehensive orthodontic diagnostic (lateral cephalogram and panoramic radiography) through a full FOV at the lowest possible ionizing radiation levels.…”

Diagnosis and treatment of a maxillary lateral incisor with two root canals. A case report.

“…[6][7][8][9] The study of internal root anatomy has allowed setting standard patterns regarding the number and configuration of root canals. [10][11][12][13][14][15][16][17] In that sense, among maxillary teeth, the lateral incisors are typically described as singlerooted, with one canal, slightly flattened mesiodistally and with a disto-palatal orientated low curvature. 10,15,18 Although morphological root canal abnormalities of the maxillary lateral incisors are uncommon, [19][20][21] variations are frequently associated with "dens in dente", palatal grooves, gemination or fusion.…”

“…10,16 As well as a thorough knowledge of the root anatomy, a detailed examination of the crown and preoperative radiographs are necessary to detect root canal anomalies. [13][14][15][16][17] An accurate treatment plan must include all present canals to achieve endodontic success. [1][2][3][4][5][6][7][8][9] This article describes a maxillary lateral incisor with two canals managed by nonsurgical endodontic treatment.…”