American Journal of Orthodontics and Dentofacial Orthopedics最新文献

Introduction: This study aimed to analyze the image quality of standard dose orthopantomograms (sd-PAN), extracted PAN from standard dose cone-beam computed tomography (CBCT [extr-PAN]), and from reduced-dose ultra low dose-low dose CBCT (rd-PAN).

Methods: Image pairs, sd-CBCT and sd-PAN, of patients were selected if taken within 6 months of each other. From the sd-CBCT, an extr-PAN was extracted, and a simulated rd-PAN (sim rd-PAN) was constructed using a filtering technique. Three experienced orthodontists assessed image quality by means of 9 yes-and-no statements. For subjective statements (1-5), observers' opinions of technical acceptability and visibility of anatomic structures, observers indicated their disagreement or agreement. For objective statements (6-9), regarding comparability to a gold standard, observers indicated the presence of dental structures. Positive response rates were calculated for the subjective statements. Agreement rates with the gold standard were calculated for the objective statements. Thresholds for acceptable image quality were if ≥2 observers agreeing with the subjective statements or agreeing with the gold standard (objective statements) for 90% for sd-PANs and 85% for both extr-PANs and sim rd-PANs.

Results: In total, images of 43 patients were included. For the subjective statements, only the sd-PAN met the threshold for technical adequacy (95.3%) and suitability for orthodontic treatment planning (95.3%). For objective statements 6, 7, and 9, extr-PAN and sim rd-PAN images met the threshold for acceptable quality, whereas the sd-PAN met the threshold for statements 6 and 9. Differences in agreement with the gold standard among images were small (85.7%-87.8%).

Conclusions: Sd-PAN images demonstrated superior image quality. Although extr-PAN and sim rd-PAN showed reduced diagnostic image quality for orthodontic diagnosis, differences among the 3 types of PAN regarding the gold standard were small.

Introduction: The Carriere Motion 3D appliance (CMA) is gaining popularity for the correction of Class II dentoalveolar relationships. Recently, Gilad's Modified Corrector (GMC), a simple, "do-it-yourself" alternative, was introduced. This study evaluated the effectiveness of the GMC in treating Class II malocclusions and compared it with the CMA.

Methods: A retrospective comparative analysis was conducted on 42 adolescent patients: 21 were treated using the GMC and 21 using the CMA. Cephalometric radiographs were taken pretreatment and after achieving a Class I posterior relationship. They were analyzed, and statistical comparisons were made between the 2 groups.

Results: Both appliances effectively corrected the Class II molar relationship. The changes were primarily dentoalveolar in nature. The maxillary first molar was distalized, tipped distally, and also derotated by the 2 appliances. Both appliances mesialized the mandibular dentition, causing minimal proclination and protrusion of the mandibular incisors. The treatment duration was comparable for both groups.

Conclusions: The GMC and CMA effectively correct Class II malocclusions probably through similar mechanisms. The GMC appliance may offer a practical alternative to the CMA.

Introduction: The primary aim of this study was to establish a correlation between the maturation of the midpalatal suture (MPS), bone density (BD), and transverse dimensions of the maxilla. The secondary goal was to evaluate whether BD or transverse dimensions of the maxilla could serve as quantitative methods for assessing MPS maturation.

Methods: A retrospective observational study was conducted on 114 cone-beam computed tomography (CBCT) records divided into 4 groups according to chronological age: group 1 (10-13 years), group 2 (14-17 years), group 3 (18-21 years), and group 4 (22-25 years). The MPS maturation stage, BD in 5 areas along the MPS, quantified using CBCT with gray values converted to Hounsfield units (HU), and transverse dimensions of the maxilla were assessed. Principal component analysis synthesized BD measurements into a composite gray score, with the first principal component (F1) capturing >90% of the variance. The data were then subjected to statistical analyses.

Results: BD was highest in all regions in stage E and the lowest in stage B. A strong positive correlation was observed between MPS maturation stage, BD, and intermolar width. A weak correlation was observed for the intercanine width. The classification and regression tree analysis showed that a synthetic BD >687.93 HU would be classified as stage E, whereas those with a BD measurement <290.83 HU would be categorized as stage B. Females showed early maturation of the MPS compared with males.

Conclusions: Quantitative assessment of MPS BD, synthesized via principal component analysis from CBCT measurements across 5 regions, and maxillary transverse dimensions reliably indicate MPS maturation stages.