| Abstract|| |
Aim: Despite the rising popularity of cone-beam computed tomography (CBCT) imaging in the field of dentistry, very few studies have addressed the questions of which dental specialties most frequently request CBCT images and which CBCT indications are most popular. This study attempts to answer both of these questions. Methods and Materials: CBCT request forms spanning a 1-year period were analyzed for data. Collected data included the specialty of the referring dentist and the referral reason. Results: A total of 660 referral forms were analyzed. Oral and maxillofacial surgeons were the discipline to most commonly request CBCT examinations. Pretreatment evaluation of potential dental implant sites was the most common indication for requesting CBCT scans. Conclusions: All dental specialties refer patients for CBCT examinations but at different frequencies and for various reasons that pertain to their respective disciplines. Clinical significance: These findings should be the basis for customizing the availability and scope of imaging services and in developing and modifying educational programmes for dentists and dental specialists.
Keywords: Cone-beam computed tomography, cone-beam CT, referral
|How to cite this article:|
Jadu FM, Jan AM. Referral pattern to a university-based oral and maxillofacial cone beam CT service. Indian J Dent Res 2019;30:544-7
|How to cite this URL:|
Jadu FM, Jan AM. Referral pattern to a university-based oral and maxillofacial cone beam CT service. Indian J Dent Res [serial online] 2019 [cited 2021 May 13];30:544-7. Available from: https://www.ijdr.in/text.asp?2019/30/4/544/271054
| Introduction|| |
Diagnostic images play an integral part in the diagnostic process, especially for dental practitioners. As such, the industry is moving at a swift rate in an effort to produce technologies that provide more diagnostic information to the healthcare provider while minimizing radiation risks to the patient. Cone-beam computed tomography (CBCT) is a prime example of one such technology. Since its introduction to dentistry in 1998, this relatively new imaging technique has revolutionized the practice of dentistry. Many dentists and dental specialists alike rely heavily on the information provided by CBCT images to diagnose patients and finalize treatment plans.
However, the additional information provided by CBCT images is deemed useless if not recognized by the individual interpreting the images, which brings to question the role of oral and maxillofacial radiologists (OMFR) in interpreting diagnostic images generally and CBCT images specifically. At this point in time, this is a fundamental question because dental schools are not yet implementing the teaching practices or training of their future dentists to interpret CBCT images. This practice will probably change over the next few years as the use of CBCT images in the practice of dentistry increases.
Few studies in the literature have addressed the questions of which dental specialties were more likely to request CBCT imaging for their patients and for what purposes., Warhekar et al. published one such study in February of 2015 and Hol et al. published another later in the same year., The Warhekar et al. study, conducted in India, investigated the reason for CBCT referral. Furthermore, the study compared the CBCT referral pattern between a private and institutional dental practice. They found few differences between the two sectors and they found that planning dental implant placement was the most common reason for CBCT referrals. The Hol et al. study was a Norwegian nationwide study that investigated the referrals and the reasons for CBCT examinations. They found that dental specialists referred more than general dentists and they also found that treatment planning was the most common CBCT indication.
The aim of this study was to analyze the referral patterns to a university-based CBCT service in an attempt to answer the above-mentioned questions. We predict that different dental specialists will refer a patient for CBCT at different rates and for different reasons. We are hopeful that the results of this study will help bridge the understanding between the different dental disciplines and assist dental schools in creating appropriate curricula and education courses for CBCT imaging.
| Materials and Methods|| |
Using a retrospective study design and after approval was obtained from the research ethics board (project 011-16), the referral forms to a university-based CBCT service were reviewed for relevant data. Sample size calculations were made using a precision of 5% and a 95% confidence interval (CI), and it was estimated that a sample of at least 350 referral forms would be needed for the study. Accordingly, the referral forms included in this study spanned a 1-year period (September 1, 2016 to August 31, 2017) and data collection took place at the same university at which the CBCT service was based. Collected data included several parameters: the age and gender of the patient; the specialty of the referring dentist; and the reason for referring the patient for CBCT imaging. In addition, the field of view (FOV) and voxel (VOX) size settings that were chosen for the scan were also recorded.
There are 9 different clinical disciplines at the university at which the CBCT practice is based and from which all the referrals came; they are oral and maxillofacial surgery (OMFS), periodontics, implant dentistry fellows, orthodontics, general dentistry, endodontics, prosthodontics (prostho), oral and maxillofacial pathology (OMFP), and pediatric dentistry. Within each clinical discipline, there are different levels of specialization including clinical board trainees, masters of science (MSc) students, doctorate of philosophy (PhD) students, specialists, and consultants.
The CBCT unit from which the data were collected was the iCAT classic (Imaging Sciences International, LLC, Hatfield, PA). Before any scan is performed, 2 parameters need to be chosen by the operator, the FOV, which is the size of the area to be scanned, and the VOX size, which determines the resolution of the image. Both of these parameters are related to the radiation dose received by the patient. For the particular iCAT unit used in this study, the available FOV settings were 4, 6, 8, 10, 13, and 17 cm I height (h) × 16 cm in diameter (d) and 8 cm (h) × 8 cm (d). The VOX size settings included 0.4, 0.3, and 0.2 mm. Both of these parameters are chosen based on preset protocols put forth by the OMFR faculty at the university for the different CBCT indications.
Statistical analysis was done using the statistical package for social sciences (SPSS) version 22 (SPSS Inc, Chicago, IL, USA). Simple descriptive statistics were used to define the study variable characteristics through a form of counts and percentages for the categorical and nominal variables, whereas continuous variables were presented by the mean and standard deviation. To establish a relationship between categorical variables, this study used the χ2 test and a conventional P value of <0.05 to reject the null hypothesis.
| Results|| |
Six hundred and sixty (660) referral forms were included in this retrospective study. These were for patients that ranged in age between 7 and 89 years with a mean age of 34.7 years. There were slightly more female patients (58.8%) than males (41.2%). However, 48 referral forms failed to provide the gender of the referred patient.
Most cases (25%) referred for CBCT imaging were scanned using a 10 cm (h) × 16 cm (d) FOV closely followed by the 6 cm (h) × 16 cm (d) FOV at 21%. Only 13 cases (2%) were scanned using the largest available FOV 17 cm (h) × 16 cm (d), and no cases were scanned using the smallest FOV setting of 4 cm (h) × 16 cm (d). With regards to VOX, most cases (79%) were done using the lowest resolution setting of 0.4 mm followed by 15% at 0.3 mm and only 5% at the highest resolution setting of 0.2 mm.
Most referral forms were from OMFS (24.0%) followed by periodontists (21.9%). Implant dentistry fellows also contributed to a significant number of referrals (18.3%). The remaining referral forms (22.7%) came from various dental specialties, including orthodontists, general dentists, endodontists, prosthodontists, and OMFP. Fortunately, pediatric dentists requested the least number of CBCT examinations (0.3%). These results are summarized in [Table 1].
Pretreatment dental implant assessment was by far the most common indication for which patients were referred for CBCT imaging (72.3%). The second most common indication was graft treatment planning (15.7%). Evaluation of impacted and endodontically treated teeth both contributed an equal number of cases (8.9% each). These results are summarized in [Table 2].
[Table 3] demonstrates the distribution of each reason for referral by specialty and demonstrates the statistically significant results. The evaluation of dental implant sites was more commonly requested by periodontists and implant dentistry fellows, and this was significantly different from all other specialties (P < 0.001). Similarly, assessment of graft sites was more commonly requested by the same 2 specialties, and this result was statistically significant as well (P < 0.001). Orthodontists and OMFS were the 2 most common specialties to request CBCT examinations for evaluation of impacted teeth (P < 0.001) and the temporomandibular joints (P < 0.001). This result was significantly different for these 2 disciplines. Not surprisingly, evaluation of root canal treated teeth (P < 0.001) and impacted third molars (P < 0.001) was more likely to be requested by endodontists and OMFS, respectively.
|Table 3: Distribution of referral forms by reason for referral and specialty|
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| Discussion|| |
The age and gender findings of this study were similar to those of Warhekar et al. The mean age was 37.2 years, and the gender distribution was 56.7% male and 43.4% female. Warhekar et al. also found that CBCT referral was least preferred for older patients, whereas in this study, it was found that children were less likely to be referred for CBCT imaging as evidenced by the fact that pediatric dentists were the least likely to request CBCT examinations for their patients.
The Warhekar et al. study conducted in 2015 is a similar study that investigated the reason for referral to CBCT at a private service and an institutional center. Their findings were consistent with this study in that OMFS (21.9%) was the specialty to utilize CBCT services the most. They also found that OMFR (14.2%) was a group that utilized the service heavily following by prosthodontists (9.3%) and orthodontists (7.8%), whereas in this study periodontists (21.2%) were the second most common group of specialists to utilize CBCT services. This finding was in agreement with the finding that predental implant treatment planning was the most common indication for referral to CBCT as both OMFS and periodontists are the two disciplines most likely to place dental implants. As for OMFR, they do not have specialty clinics at our academic institution and therefore, were rarely presented with an opportunity to request CBCT examinations.
A nationwide survey conducted in Norway by Hol et al. demonstrated results that were consistent with this study. The survey found that periodontists (16%) and OMFS (12%) were the two dental disciplines most likely to utilize the services of a CBCT. They also found that localization of impacted teeth (43%) and dental implant treatment planning (34%) were the two most common CBCT indications. The Norway survey also found that dental specialists were more likely to utilize the services of CBCT imaging compared with general dentists. This latter finding was slightly different from our findings in this study as general dentists were more likely to request CBCT than endodontists, prosthodontists, and pediatric dentists. This may be a reflection of the differences in the scopes of practice of general dentists in the two different countries. General dentists in our study requested CBCT examinations mostly for dental implant treatment planning purposes, and a significant number of those general dentists were actually advanced general dentists with additional postgraduate training.
Not surprising was the finding that periodontists and implant dentistry fellows were the two most common disciplines to request CBCT examinations for assessment of dental implant sites and evaluation of graft sites as this directly pertains to their specialty., Similarly, it was anticipated that most CBCT requests from endodontists were done to evaluate root canal-treated teeth, and most requests for evaluation of impacted third molars were from OMFS., Orthodontists and OMFS were the two most common disciplines to request CBCT scans for evaluation of impacted teeth, evaluation of temporomandibular joints, and pathological investigation. This result was consistent with other studies' findings that demonstrate the high frequency at which orthodontists encounter these problems.,, Investigation of these problems often requires the use of 3D imaging, and CBCT has become the imaging modality of choice because of the many advantages it offers such as the relatively low radiation doses delivered to the patient and the submillimeter image resolution. OMFS is often confronted with these problems and are expected not only to manage but also to investigate them, which again requires the use of CBCT imaging. These findings reflect the extensive variety of practice protocols and management options, all of which were acceptable and aligned with the results observed in this study regarding CBCT referral patterns.
The authors are currently in the process of reviewing the radiographic reports that were produced for the referral forms included in this study to evaluate the information provided by the OMFR and to record the type and significance of incidental findings. A follow-up to that study could be to evaluate treatment outcomes and whether the radiographic reports had any bearing on the treatment planning and management of the patient.
| Conclusion|| |
All dental specialties refer patients for CBCT examinations but at different frequencies and for various reasons related to their respective disciplines. This is most likely a reflection of the amount of knowledge and training provided with regards to CBCT as an imaging modality and the availability and convenience of CBCT as a service.
The authors wish to thank Mr. Yousef Jan for his assistance with the data collection and entry and Mr. Kalvin Balucanag for his assistance with the statistical analysis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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Dr. Fatima M Jadu
Department of Oral Diagnostic Sciences, Division of Oral and Maxillofacial Radiology, King Abdulaziz University, Faculty of Dentistry, P.O. Box 80200, Jeddah - 21589
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2], [Table 3]