|Year : 2022 | Volume
| Issue : 3 | Page : 333-337
Evaluation of the accuracy of measurements made at probable implant site using cone-beam computed tomography: A retrospective in vivo study
Hasan Sarfaraz1, Mallika Shetty1, K Harini1, Sanath K Shetty1, Sazia Amreen2, Rachana Prabhu3
1 Departments of Prosthodontics, Crown and Bridge, Yenepoya Dental College, Karnataka, India
2 Departments of Periodontics, Crown and Bridge, Yenepoya Dental College, Karnataka, India
3 Departments of Oral Medicine and Radiology, Crown and Bridge, Yenepoya Dental College, Karnataka, India
|Date of Submission||19-Dec-2021|
|Date of Decision||16-Aug-2022|
|Date of Acceptance||04-Sep-2022|
|Date of Web Publication||26-Sep-2022|
Yenepoya Dental College, Deralakatte, Mangaluru, Karnataka - 575 018
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: Computed Tomography (CT) was the most used 3D radiographic diagnostic technique for years, but cone-beam computed tomography (CBCT) was created to reduce radiation exposure, costs, and accessibility issues. Aim: To evaluate the accuracy of CBCT measurements made at probable implant sites. Materials and Methodology: This was a retrospective study that compared panoramic reconstructed CBCT with RVG measurements at 77 probable implant sites, especially mandibular posterior tooth-bounded edentulous areas. Measurements made were the mesiodistal width of the edentulous area at the crest and at the highest point of the adjacent tooth's contour and the length of the natural teeth in the mandibular first molar region from the highest cusp to the apex next to the edentulous area. Statistical analysis was done with the Statistical Package for the Social Sciences (SPSS) and the independent t-test. Results: The mean difference between CBCT and radiovisiography (RVG) readings for mesiodistal width at the crest and highest contour of the edentulous bounded two neighboring teeth was −0.21039 and 0.02961, respectively, which was not statistically significant. The mean difference between CBCT and RVG readings along the tooth was 0.80481, which was statistically significant (P = 0.018). RVG outperformed CBCT (SD = 1.7) in estimating tooth length. Conclusion: Conventional RVG radiographic measurements were similar to real tooth length, whereas CBCT panoramic reconstructions underestimated the lengths by 15% but were clinically acceptable. Clinical CBCT application requires operator abilities and knowledge with software. It is critical to pay close attention to the calibration of data obtained from clinical examination and CBCT.
Keywords: Accuracy, CBCT, linear measurements, RVG Key Messages: A retrospective study compared panoramic reconstructed CBCT with RVG measurements at 77 potential implant sites, focusing on mandibular posterior tooth-bounded edentulous regions. Conventional RVG radiography measures matched tooth length, but CBCT panoramic reconstructions underestimated lengths by 15% but were clinically acceptable. In the clinical area, however, CBCT requires the operator's experience and understandin
|How to cite this article:|
Sarfaraz H, Shetty M, Harini K, Shetty SK, Amreen S, Prabhu R. Evaluation of the accuracy of measurements made at probable implant site using cone-beam computed tomography: A retrospective in vivo study. J Indian Acad Oral Med Radiol 2022;34:333-7
|How to cite this URL:|
Sarfaraz H, Shetty M, Harini K, Shetty SK, Amreen S, Prabhu R. Evaluation of the accuracy of measurements made at probable implant site using cone-beam computed tomography: A retrospective in vivo study. J Indian Acad Oral Med Radiol [serial online] 2022 [cited 2022 Dec 10];34:333-7. Available from: http://www.jiaomr.in/text.asp?2022/34/3/333/356966
| Introduction|| |
Proper diagnosis and treatment planning are critical parameters for the implants to have a high survival rate. Until the 1980s, the most prevalent 3D radiographic modality for assessment was computed tomography (CT). Because of the increased radiation exposure and cost of CT, cone-beam computed tomography (CBCT) was created to solve these difficulties. CBCT is an appropriate diagnostic tool for 3D preoperative treatment planning for implant placement. In comparison to conventional CT, dimensions were either underestimated or overestimated when performing linear measurements using CBCT images. In recent years, a digital imaging system called radiovisiography (RVG) has offered an alternative and instantaneous method for the measurement of intraoral radiography. It has been reported that the RVG system provided an approximately 80% reduction in radiation dosage in comparison to conventional X-ray film.
This present study aims at assessing the accuracy of panoramic reconstructed CBCT (test group) in determining the mesiodistal width of edentulous area and the length of the natural tooth adjacent to edentulous area and thereby comparing the respective measurements obtained from the postoperative RVG image as a control group.
| Subjects and Methods|| |
Study design: Retrospective in vivo study
- CBCT machine – Planmeca Promax Mid
- 3D Diagnostic software –Romexis software version 3.8.3R.
- Conventional X –Ray machine –Satellac
- Digital Radiography sensor - Gendex
- Software VIXWIN™ (PLATINUM) for Digital IOPA Measurements.
Inclusion criteria were the following: preoperative CBCT image of a tooth-bounded edentulous space in the posterior mandible, showing the area of interest for implant implantation; postoperative digital periapical radiography image of identical tooth-bound edentulous space in the posterior mandibular region, with the implant in situ; periapical radiographs employing the paralleling cone approach should have captured the crown and root apices of the neighboring teeth in the same patient, who must have an implant to determine magnification.
The exclusion criteria were the following: patients with Kennedy's class I and class II problems, periapical diseases, mal-aligned teeth, supra eruption of the opposite tooth, rotation, drifting, tilting of the neighboring tooth, etc.; inadequate CBCT pictures (e.g., the field of view did not cover the region of interest) and digital periapical radiography images (e.g., the field of view did not extend to the area of interest).
Source of data/sampling method: Simple random sampling
Seventy-seven samples were chosen from the CBCT image database generated at the Mangalore dental institution's department of oral medicine and radiology. CBCT images taken with a Planmeca-mid CBCT machine for implant placement and measurements were analyzed using Romexis software version 3.8.3 R. The 77 samples were chosen from the RVG image database archives at the institution's department of implantology. Software VIX WINTM was used to process Skanray RVG images for implant placement and measurements (PLATINUM).
| Methodology|| |
A retrospective study was done to assess the accuracy of CBCT and RVG measurements gathered at 77 probable implant sites during the last three years (2017 to 2020).
Sample size estimation
The sample size was estimated using G* Power software (Universitat Dusseldorf, Germany) with a statistical power of 90% and a significance level of 0.05. Therefore, it was determined to include 77 samples.
The study was approved by the Institutional Ethics Committee and was issued the protocol number (632/14.01.2021/YEC2). CBCT imaging parameters were 90 kV and 10 mA, with 40 × 50 mm FOVs and variable exposure periods. Romexis was used to investigate the mandibular first molar edentulous area (Planmeca ProMax 3D). The following measurements were taken using a digital ruler.
Measuring the implant's length and comparing it to the RVG measurements determined the accuracy of the periapical radiographs [Figure 1].
|Figure 1: Length of the implant measured from the neck of the implant to the apex of the implant. (The measurement was 10.3 mm but the implant length was 10 mm—a 0.3 mm difference that was compensated during later measurements.)|
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Based on the scanned area, RVG imaging parameters were 70 kV, 3 mA, and 0.13 seconds.
The Romexis software of the Planmeca ProMax 3D CBCT machine's measuring tool was used to measure the 75-micron-thick panoramic reconstructed CBCT at the probable implant location. The VIX WINTM (PLATINUM) software measuring scale was used to measure the digital radiography image.
Both control and test groups were measured
Following measurements were made:
The mesiodistal width (MD) of the edentulous area at the crest of the mandibular ridge in the first molar region [Figure 2], MD of the edentulous area at the highest point of the contour of the adjacent teeth in the mandibular first molar region [Figure 3], and measuring the length of the natural teeth in the mandibular first molar region from the highest cusp to root apex [Figure 4]. The same measurements were made on the CBCT [Figure 5].
|Figure 2: Measurement of the mesiodistal width of the edentulous area at the crest of the mandibular ridge at the first molar region in RVG|
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|Figure 3: Measurement of the mesiodistal width of the edentulous area at the highest point of the contour of the adjacent teeth in the mandibular first molar region in RVG|
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|Figure 4: Measurement of the length of the natural teeth from the highest cusp to the apex adjacent to the edentulous area in the mandibular first molar region in RVG|
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Accuracy of linear measurements made by CBCT and RVG were compared to each other using the Statistical Package for the Social Sciences (SPSS) software version 24 (IBM, New York, USA), and the results were compared using an independent t-test.
| Results|| |
A retrospective study assessed the accuracy of CBCT and RVG readings at 77 probable implant sites, notably in mandibular posterior edentulous regions. Two examiners obtained two values and aggregated them to evaluate interobserver variability. The mean data was derived using the independent t-test. [Table 1] reveals the arithmetic mean and standard deviation between CBCT and RVG for three different groups.
|Table 1: Arithmetic mean and standard deviation between CBCT and RVG for three different groups|
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[Table 2] reveals that the mean difference between CBCT and RVG values at the crest and highest contour was − 0.21039 and 0.02961, respectively. The mean difference between CBCT and RVG readings along the tooth was 0.80481, which was statistically significant (P = 0.018). RVG outperformed CBCT (SD = 1.7) in estimating tooth length. [Graph 1] compares three test groups. RVG provided statistically significant data for group 3 (tooth length) compared to CBCT (SD = 1.7), which was underestimated.
|Table 2: Mean difference between the two groups namely CBCT and RVG at three different implant sites|
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| Discussion|| |
Dental implant treatment requires careful planning and diagnostic-quality X-rays. Anatomical features (such as the mandibular canal, maxillary sinus floor, and mental foramen) and bone quantity and quality must frequently be examined in three dimensions before surgery to enhance implant insertion success and to assist bone grafting treatments. Implantology diagnostics are progressively using CBCT panoramic reconstructed imaging. CBCT delivers cross-sectional and 3D pictures with less radiation and expense than multi-slice computed tomography (MSCT). Most clinicians assume CBCT scans are reliable and distortion-free when assessing anatomical features before implantation. They are ignorant of possible flaws or differences. Previous research on linear measurement of the edentulous area using CBCT could not identify the accuracy of measurements at probable implantation sites since most studies were ex vivo with minimal in vivo examinations.
For this investigation, we compared preoperative CBCT images with postoperative RVG images to determine the most probable implantation sites for 77 patients. The postoperative RVG was utilized to estimate post-implant magnification based on implant size to determine magnification error. RVG was employed as a control group because of its improved picture quality, instantaneous image production, and decreased radiation exposure.
No statistically significant changes were seen between the two groups when mesiodistal measures were obtained at the ridge crest and adjacent tooth contour.
The neighboring tooth's length was underestimated by CBCT (P = 0.018). Twelve of the 77 samples were underestimated. Linear assessments of neighboring tooth length showed a statistically significant mean difference of 0.080 to a P value of 0.018. CBCT bone measurements may be reliable if errors are less than 1 mm, according to research.
Although repeated measurements were precise for both procedures, CBCT panoramic reconstruction measured 1.7 mm less tooth length than RVG. This suggests the observed tooth length disparity was due to radiography foreshortening or poor resolution of tiny root apices relative to the surrounding bone. Both traditional RVG and CBCT reconstructed panoramic images cannot account for changes in tooth angulation between serial images without additional imaging or clinical observation.
When a tooth turns during treatment and is solely projected in the buccolingual dimension, root morphological changes may be misinterpreted as resorption. Volumetric imaging should analyze 3D information, not diminish picture potential during reconstructions. This research and debate could help practitioners better appreciate the disadvantages of reconstructed pictures.
Differences in these measurements were likely owing to buccolingual tooth angulation and difficulties in landmark recognition of cusp and root tips due to tooth rotation, location, and morphology.
As the patient group was in their early to mid-teens, root growth likely occurred between CBCT and RVG imaging.
This investigation identified various measuring inaccuracies. Repeated sample measurements were employed to resolve landmark identification, voxel size resolution constraints, standardize digital and software-generated calipers for CBCT panoramic reconstructions. Patient location changes, focal trough compatibility with patient anatomy, and image artifacts and ghosting were avoided by thorough volume placement and focal trough modification. The present investigation was a retrospective study that reduced the reliability or accuracy of CBCT estimates.
More prospective clinical investigations are needed to assess the linear distance in both the axial and panoramic views, and it should be compared and contrasted with the use of radiographic markers.
| Conclusion|| |
The findings of the current study can be used to draw the following conclusion:
Conventional RVG radiographic measurements were relatively comparable to the actual tooth length, while CBCT panoramic reconstructions underestimated the lengths by 15% but were under clinically acceptable range.
CBCT showed linear underestimation, although the range was clinically acceptable.
The clinician should know CBCT fundamentals and how to compare clinical and radiological investigations.
Paraclinical tests are supplementary instruments with no clinical use. If acquisition requirements are met strictly, they will be more dependable. Artifacts affect CBCT. Inaccuracy varies by geography.
The kind of slice (oblique or vertical), view (axial or panoramic), and buccolingual and occlusogingival orientations affect the information CBCT provides to the doctor.
CBCT error rate for MD width was lower than for coronoapical length.
Although the CBCT equipment was accurate, clinical usage required operator training with CBCT software. It is critical to pay close attention to the calibration of data obtained from clinical and CBCT examinations.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Pjetursson BE, Heimisdottir K. Dental implants-are they better than natural teeth? Eur J Oral Sci 2018;126:81-7.
Pauwels R. History of dental radiography: Evolution of 2D and 3D imaging modalities. Med Phys Int 2020;8:235-77.
Jacobs R, Salmon B, Codari M, Hassan B, Bornstein MM. Cone beam computed tomography in implant dentistry: Recommendations for clinical use. BMC Oral Health 2018;18:1-6.
Verdugo F, Simonian K, McDonald RS, Nowzari H. Quantitation of mandibular ramus volume as a source of bone grafting. Clin Implant Dent Relat Res 2009;11:32-7.
Freire-Maia B, Machado VD, Valerio CS, Custódio AL, Manzi FR, Junqueira JL, et al
. Evaluation of the accuracy of linear measurements on multi-slice and cone beam computed tomography scans to detect the mandibular canal during bilateral sagittal split osteotomy of the mandible. Int J Oral Maxillofac Surg 2017;46:296-302.
Molly, L. Bone density and primary stability in implant therapy. Clin Oral Implants Res 2006;17:124-35.
Scarfe WC, Farman AG, Sukovic P. Clinical applications of cone -beam computed tomography in dental practice. J Can Dent Assoc 2006;72:75-80.
Fokas G, Vaughn VM, Scarfe WC, Bornstein MM. Accuracy of linear measurements on CBCT images related to presurgical implant treatment planning: A systematic review. Clin Oral Implants Res 2018;29:393-415.
Kobayashi K, Shimoda S, Nakagawa Y, Yamamoto A. Accuracy in measurement of distance using limited cone-beam computerized tomography. Int J Oral Maxillofac Implants 2004;19:228-31.
Flores-Mir C, Rosenblatt MR, Major PW, Carey JP, Heo G. Measurement accuracy and reliability of tooth length on conventional and CBCT reconstructed panoramic radiographs. Dental Press J Orthod 2014;19:45-53.
Kaley J, Phillips C. Factors related to root resorption in edgewise practice. Angle Orthod 1991;61:125-32.
Garcia-Figueroa MA, Raboud DW, Lam EW, Heo G, Major PW. Effect of buccolingual root angulation on the mesiodistal angulation shown on panoramic radiographs. Am J Orthod Dentofacial Orthop 2008;134:93-9.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2]