Comparison of linear measurements between CBCT orthogonally synthesized cephalograms and conventional cephalograms

Abstract

Objectives: The purposes of the study are to investigate the consistency of linear measurements between CBCT orthogonally synthesized cephalograms and conventional cephalograms and to evaluate the influence of different magnifications on these comparisons based on a simulation algorithm. Methods: Conventional cephalograms and CBCT scans were taken on 12 dry skulls with spherical metal markers. Orthogonally synthesized cephalograms were created from CBCT data. Linear parameters on both cephalograms were measured via Photoshop CS v. 5.0 (Adobe ® Systems, San Jose, CA), named measurement group (MG). Bland-Altman analysis was utilized to assess the agreement of two imaging modalities. Reproducibility was investigated using paired t-test. By a specific mathematical programme "cepha", corresponding linear parameters [mandibular corpus length (Go-Me), mandibular ramus length (Co-Go), posterior facial height (Go-S)] on these two types of cephalograms were calculated, named simulation group (SG). Bland-Altman analysis was used to assess the agreement between MG and SG. Simulated linear measurements with varying magnifications were generated based on "cepha" as well. Bland-Altman analysis was used to assess the agreement of simulated measurements between two modalities. Results: Bland-Altman analysis suggested the agreement between measurements on conventional cephalograms and orthogonally synthesized cephalograms, with a mean bias of 0.47 mm. Comparison between MG and SG showed that the difference did not reach clinical significance. The consistency between simulated measurements of both modalities with four different magnifications was demonstrated. Conclusions: Normative data of conventional cephalograms could be used for CBCT orthogonally synthesized cephalograms during this transitional period.

The Canadian Systemic Sclerosis Oral Health Study IV: oral radiographic manifestations in systemic sclerosis compared with the general population

“…Adobe Photoshop is already widely used in the dental and oral maxillofacial disciplines for measurement. 22,23 Intraoral radiographs were scanned at 1600 dpi, and panoramic radiographs were scanned at 300 dpi and saved as jpeg images.…”

“…Adobe Photoshop is already widely used in the dental and oral maxillofacial disciplines for measurement. 22,23 Intraoral radiographs were scanned at 1600 dpi, and panoramic radiographs were scanned at 300 dpi and saved as jpeg images.The radiographs were evaluated by two trained experienced oral and maxillofacial radiologists (DM, MD) tested for interobserver and intraobserver reliability; 24 the observers performed the assessment on all digital and scanned radiographs under the same conditions. 24 Differences between digital and scanned images were deemed clinically insignificant.…”

Skeletal stability of inter-molar mandibular distraction osteogenesis in growing patients

“…The low-dose spiral CT radiographs from T0 and T1 were imported into SimPlant O&O (V3.0.0.59) by Materialise Dental to produce a constructed lateral cephalogram. The constructed lateral cephalograms were orthogonally synthesized, which has been shown to be comparable to a traditional lateral cephalograms [ 29 ]. The constructed lateral cephalograms and T2 lateral cephalogram were standardised to 50 pixels per centimetre using Adobe Photoshop CS4.…”