|Year : 2020 | Volume
| Issue : 2 | Page : 52-58
Determination of the comparative accuracy of manual, semi-digital, and fully digital cephalometric tracing methods in orthodontics
Rajat Mitra1, Adarsh Chauhan1, Sahil Sardana1, Sanjay Manohar Londhe2, Balakrishnan Jayan1, RajKumar Maurya1
1 Army Dental Centre (Research and Referral), Delhi, India
2 Dte Gen Dental Services, New Delhi, India
|Date of Submission||25-Apr-2020|
|Date of Decision||11-May-2020|
|Date of Acceptance||13-May-2020|
|Date of Web Publication||15-Jul-2020|
Army Dental Centre (Research and Referral), Delhi - 110 010
Source of Support: None, Conflict of Interest: None
Introduction: The present study was aimed at comparing the accuracy of cephalometric tracing in by the manual, semi-digital, and fully digital cephalometric tracing methods in orthodontics.
Materials and Methods: The present study was conducted in the department of orthodontics of a tertiary care government hospital with clearance from the Institutional Ethical Committee. Thirty lateral cephalograms were evaluated using three different method: Group I-Print of lateral cephalogram was traced manually on an acetate sheet. Group II-the digital images of cephalograms were traced on screen using the NNT (NewTom Image Viewer) software. Group III-digital images traced using Nemoceph™ software. Ten angular and eight linear variables were measured. Inter-group comparison was made using one-way ANOVA measure followed by post hoc Tukey's Honest Significant Difference test.
Results: Intra-class correlation coefficients showed acceptable agreement in all three groups, i.e., Group I (0.281), Group II (0.11), and Group III (0.056). The one-way ANOVA test revealed a significant difference between groups for two variables. i.e., “EL-Max” and “EL-Mand.” The difference was present between Groups I and II i.e., “EL-Max” (P < 0.000) and “EL-Mand” (P < 0.02) respectively.
Conclusion: The present study found no significant difference between manual, semi-digital, and fully digital cephalometric tracing with good agreement among all variables except two linear variables, which were traced more accurately in semi-digital method. The preference of using on particular technique can be based on the availability, expertise, and ease of availability.
Keywords: Cephalometry, digital, manual, NemoCeph
|How to cite this article:|
Mitra R, Chauhan A, Sardana S, Londhe SM, Jayan B, Maurya R. Determination of the comparative accuracy of manual, semi-digital, and fully digital cephalometric tracing methods in orthodontics. J Dent Def Sect. 2020;14:52-8
|How to cite this URL:|
Mitra R, Chauhan A, Sardana S, Londhe SM, Jayan B, Maurya R. Determination of the comparative accuracy of manual, semi-digital, and fully digital cephalometric tracing methods in orthodontics. J Dent Def Sect. [serial online] 2020 [cited 2020 Dec 3];14:52-8. Available from: http://www.journaldds.org/text.asp?2020/14/2/52/289749
| Introduction|| |
Since the introduction of “Cephalostat,” hand traced manual cephalometric analysis on traditional radiographic films has been the gold standard for the use of cephalogram. Traditional cephalometric analysis has been performed by tracing radiographic landmarks on an acetate sheet, using the landmarks to measure the desired linear and angular values with a ruler and protractor. However, it has been associated with a high risk of error during hand tracing, landmark identification, and measurements, which could be avoidable with constant practice and knowledge.
The development of computers and information technology led to digitization of radiography, including cephalometry, since the late 1970s. With the introduction of digital science, automated and semi-automated landmark identification have been possible, leading to reduce the need for manual cumbersome tracing of radiographs and remove operator level sensitivity. Digitization also facilitated enhanced quality of imaging, reduced radiation exposure, teleradiology, ability to duplicate radiographs at lesser expenses, sharing, and safe archival.
Expansion of the virtual world of technology in late twentieth and early twenty first century led to mushrooming of software programs that are capable for cephalometric measurements on digital cephalograms. Some of the widely used programs are as mentioned i.e., Dolphin Imaging™, Nemoceph™, Autoceph, VistaDent, QuickCeph etc.
One of the objectives of digitization and automation in cephalometry was to reduce errors of measurements and ease in reproducibility. Richardson reported a manual tracing method inferior to computer-assisted cephalometry measurement in one of the earliest comparative studies between the manual and computerized cephalometric measurement in 1981. On the contrary, Macrì and Wenzel and Tourné concluded that the reliability of landmark location on digital images was inferior to conventional film., Subsequently, Segura et al. reported no significant difference between manual and digital tracing methods using “NemoCeph” which had also been confirmed by the manual and Dolphin tracings by Huja et al., Baskin and Cisneros, and Yitschaky et al.
Due to conflict in reported results between digital and manual tracing, it was found that cephalometric tracing can be categorized in three broad categories: tracing on lateral cephalometric film on acetate paper (manual), tracing on digital image lateral cephalometric on computer screen using noncephalometric software (semi-digital), tracing on digital image lateral cephalometric on the computer screen using dedicated cephalometric software such as NemoCeph, Dolphin, etc., which are fully digital. All of the previously reported studies in the literature till date have compared manual tracing and fully automatic digital cephalometric software-based tracing showing either no or some, but not statistically significant difference among them. Although, fully digital method has been reported with the advantage of being time-saving, improved contrast and reduced inter- and intra-observer variability, it comes with the extra cost of the added cost of dedicated software which can be curbed using semi-digital tracing method while retaining their associated advantages hence, present study was aimed to determine the comparative accuracy of manual, semi-digital and fully digital cephalometric tracing methods in orthodontics.
| Materials and Methods|| |
The present study was conducted in the Department of Orthodontics of a Tertiary Care Government Hospital after taking clearance from the Institutional Ethical Committee. Considering the test power of 0.80 (with an allowable error of 15%), calculated for an effect size (r) equal to 0.38 at an ά level of 0.05 and 95% confidence coefficient, the sample consisted of randomly selected lateral cephalograms of 90 lateral cephalograms of the patients, who had undergone orthodontic treatment from 2014 to 2018 in the Department of Orthodontics at Government Tertiary Care Service Hospital, India. Good quality records of all the treated patients were collected and analyzed. The cross sectional study design was carried out on thirty lateral cephalograms, selected from departmental records, and measured once using three different methods, as mentioned below.
- Group I: Printout was taken of each of the lateral cephalogram, and all were traced manually on acetate sheets (0.003-inch thickness) with 0.5 mm soft 3H lead mechanical pencil by a single operator [Figure 1]
- Group II: Digital images of cephalograms were traced on screen using the NNT software (NewTom, Verona, Italy), which gave linear and angular values [Figure 2]
- Group III: Digital images were uploaded in Nemoceph™ software and landmarks identified. The software then generated specific values depending on the analysis run by the operator [Figure 3]a and b].
|Figure 3: (a) Fully digital cephalogram using NemoCeph showing landmark identification. (b) Fully digital cephalogram automated tracing using NemoCeph|
Click here to view
The 18 variables (10 Angular) SNA, SNB, ANB, SN-GOGN, FMA, UI-NA (degree), LI-NB (degree), UI-SN (degree), IMPA, Nasolabial angle and (8 linear) EL-Max, EL-Mand, N Vert-A, N Vert-Pog, UI-NA (Linear), LI-NB (Linear), Upper Lip-E line and Lower Lip-E line were analyzed.
Manual tracing was performed on fine-grain 0.003-inch transparent acetate papers using a 0.3 mm lead pencil in a dark room using a screen viewing box using geometry box measurement tools. Group II digital images of cephalograms were traced on-screen using NewTom NNT analysis software (NewTom, Verona, Italy) on the imaging machine associated stand-alone computer. The manual measurements were carried out on the screen of the computer interface using digital measurement tools. Group III digital image was transferred to NemoCeph NX (Nemotech, Madrid, Spain) and the fully automatic tracing was carried out after calibration of the actual size of each image in millimeters was based on the measurement of the known distance (100 mm) between the two fixed points on the screen. This calibration standardized all images. Landmark identification was carried out manually on digital images using a mouse-driven cursor and stored in the NemoCeph NX (Nemotech, Madrid, Spain).
The selected landmarks were traced with bilateral structures averaged to make a single structure or landmark. The manual, semi-digital, and fully digital measurements were performed by the same investigator (AC). Thirty percent cephalometric measurements were repeated at 3 weeks interval to assess intra observer reliability. All measurements were entered into an Excel spreadsheet (Microsoft, Seattle, WA) for statistical evaluation.
The statistical analysis was carried out using “SPSS” (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY, USA). The mean, standard deviation, and standard error of the difference between the repeated measurements for each method and between the two methods were calculated. The data agreement was determined using Pearson's correlation coefficient (r2). These levels were used to determine the strength of the correlation: r2> 0.8 = strong; 0.5< r2< 0.8= moderate; r2< 0.5 = weak. The one-way ANOVA test was carried out to determine the differences between the three techniques for all variables. The post hoc analysis was carried out to assess the actual difference affected groups. The level of statistical significance was set at P < 0.05.
| Results|| |
The present study was carried out to determine the comparative accuracy of manual, semi-digital, and fully digital cephalometric tracing methods in orthodontics using a cross-sectional method. Intra-observer errors were assessed after repeating 30% randomly chosen measurements at 3 weeks apart and analyzed with intraclass correlation coefficients, which showed acceptable intra-observer agreement. Group I (0.281), Group II (−0.11), and Group III (0.056) [Table 1]a, [Table 1]b, [Table 1]c. The reproducibility of the double determinations of measurements was expressed by the Dahlberg formula, which showed minimal error (within 0.05 mm) that did not affect the reliability of the measurements. The one-way ANOVA test was carried out to determine the differences between the three techniques among all variables. The linear variables, namely “EL-Max” and “EL-Mand” were found to have significant differences between groups [Table 2]a. The post hoc analysis was carried out to assess the difference among affected groups and found that there was a significant difference between Groups I and II for “EL-Max” (P < 0.000) and “EL-Mand” (P < 0.02) [Table 2]b.
| Discussion|| |
The present study was conducted to determine the accuracy of three different cephalometric tracing methods. The traditional methods of manual tracing on acetate paper have been known as gold standard procedure and still commonly used; however, it is subjected to increased physical maneuverer, difficulty in locating the landmarks, requirements of proper storage and varying intra- and inter-observer variability. Despite these lacunae, few researchers have reported the superiority of manual tracing in comparison to digital automatic tracing., Since literature in the last two decades have been showing either superiority or no clinically perceptible difference in manual and automatic digital tracing methods, the present study was conducted to determine the comparative accuracy of manual, semi-digital and fully digital cephalometric tracing methods in orthodontics as the fully digital method has been reported advantageous of being time-saving, improved contrast and reduced inter- and intra-observer variability, However, it comes with the extra cost of added cost of dedicated software which can be curbed by using semi-digital tracing method while retaining some associated advantages of both manual tracing and fully digital tracing.
The present study used thirty lateral cephalograms from departmental archives taken digitally and traced by three different techniques each time, i.e., conventional manual acetate paper, semi-automatic digital method using in-built software in computer associated with cephalometric imaging machine and fully digital automatic tracing using dedicated “NemoCeph NX.” The sample size was calculated as per considering the test power of 0.80 (with an allowable error of 15%), calculated for effect size (r) equal to 0.38 at an ά level of 0.05 and 95% confidence coefficient. The 18 cephalometric measurement variables, i.e., 10 angular and 8 linear were chosen for the study as it was frequently used, easy to locate and a high degree of agreement among observers. Similar reliability of the most of included variables have been reported by Tikku et al. from computerized tracing of direct digital radiographs and hand tracing of their digital radiographic printouts and found good agreement among difference between anterior facial height, posterior facial height, upper lip length, lower lip length, anterior cranial base length, posterior cranial base length, maxillary length, mandibular length, lower incisor to NB line (L1 to NB), and lower lip protrusion but were clinically acceptable.
Albarakati et al. reported equal reliability, of conventional and digital cephalometry, i.e., both the digital (scanning a conventional film into digital format), in daily orthodontic routines as the statistically significant differences between both do not appear to be clinically significant. Farooq et al. also reported that most of the commonly used measurements were accurate except few variables, between the digital tracing with FACAD® and manual methods; however, the advantages of digital imaging such as enhancement, transmission, archiving and low radiation dosages makes it to be preferred over conventional method in daily use. Noush and Esmaily also reported that digital cephalometric analysis software is not only reliable but also saves time and reduces manual analysis errors. The similar finding had also been reported by de Abreu et al. who reported comparative accuracy between three tracing methods and found computerized method using the Dentofacial Software, Toronto, Canada showed the highest reliability, followed by the manual method, while the Dolphin Imaging software (Patterson Dental Supply, St. Paul, MN) was the least effective. On contrary, Mahto et al. reported a high level of agreement for cephalometric measurements between both the computerized software Dolphin® and AutoCEPH© in comparison with manual tracings. The present study also find the acceptable degree of agreement among all three-technique; however, semi-digital method was relatively better in linear measurement than the other two. The difference could be due to nonreporting of semi-digital method of tracing as most of the literature comparison has been done either manual versus fully digital software based tracing or two different fully digital software-based tracing.
Paixão et al., reported comparative study between manual and digital cephalometric tracing using Dolphin Imaging software with lateral radiographs measurements and found consistency in all angular and linear measurements. Huja et al. reported the ability to produce comparable superimpositions using hand tracing and digital methods (Dolphin version 10) and found comparable. Naoumova and Lindman compared the accuracy of cephalometric measurements made with FACAD software (Swedish company Ilexis AB, Linköping, Sweden) with equivalent hand-traced measurements and found greater variability in digital cephalometric measurement. Celik et al. reported the low correlation for measurements between digital and hand-tracking methods; most of the commonly used measurements were accurate. The user-friendly and time-saving nature of the computerized method using digital radiographs makes it the preferred option. Vianna-Lara MS evaluated the accuracy of cephalometric measurements obtained with digital tracing software compared with equivalent hand-traced measurements and found comparable results. Ongkosuwito et al. also reported the reproducibility of longitudinal cephalometric measurements between analog and digital methods using two different resolutions and found comparable reproducibility of variables. The present study used NemoCeph as a fully digital tracing method based on availability and its reported accuracy over the period of time.
The present study had limitations of concluding on limited variables and only two soft-tissue landmarks, which can be further tested at a larger level. Inter-observers variability in measurement was not carried out to rule out any bias; however, the same can be considered in future to assess the agreement and reliability among different operators.
| Conclusion|| |
The present study found no significant difference between manual, semi-automatic and fully automatic digital cephalometric tracing with good agreement with all variables. The preference of using on particular technique can be based on the availability, expertise, and ease of maneuver.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]