Drs. Matthew McCabe and Donald J. Rinchuse uncover the latest trend in the use of lateral cepahlometric radiographs
Introduction: The purpose of this study was to survey orthodontists in North America to assess the routine use of lateral cephalometric radiographs in orthodontics.
Methods: A 20-item survey questionnaire was e-mailed to 2,215 randomly selected active members of the American Association of Orthodontists for 2013. The questionnaire assessed the percentage of patients on whom lateral cephalometric radiographs were taken and to what extent these records were being evaluated.
Results: Of the 2,215 orthodontists contacted, 232 completed the survey for a response rate of 10.47%.
•60.34% reported always taking “pre-treatment” lateral cephalometric radio-graphs, and 38.53% reported always performing a cephalometric “analysis” on pretreatment cephalograms.
•30.30% reported always taking “post-treatment” lateral cephalometric radiographs, and 6.49% reported always performing a cephalometric “analysis” on post-treatment cephalograms.
•75.11% reported using centric occlusion (maximum intercuspation), and 18.34% reported using centric relation for patient positioning in lateral cephalograms.
•37.95% reported at least inspecting the lateral cephalogram for diagnosis when a cephalometric “analysis” was not performed, and 81.94% reported using clinical findings over the lateral cephalometric analysis when a disparity existed between the two.
•68.47% reported using a digital-tracing software program, while 31.53% still utilize hand tracing.
•52.16% report having diagnosed pathology from a lateral cephalometric radiograph at some time in the past.
Conclusion: This study demonstrated the varying opinions of orthodontic practitioners on the routine use of lateral cephalometric radiographs in orthodontic diagnosis and treatment planning. There is a current trend toward the utilization of digital software and a decrease in the amount of practitioners routinely tracing lateral cephalometric radiographs.
Orthodontic diagnosis and treatment planning can be accomplished through the use of a multitude of orthodontic records. These records generally include a clinical exam, diagnostic study models, extraoral and intraoral photographs, a panoramic radiograph, and a lateral cephalometric radiograph.1 When considering all of the diagnostic information gained from these records, one may begin to wonder if all of this information is overlapping or does each piece individually lead us to a better and more thorough diagnosis of the patient.
The cephalometric radiograph has been around for nearly a century since it was introduced by Broadbent in 1931.2 Since then, multiple cephalometric analyses have been developed to evaluate patients’ skeletal and dental patterns. In practice, most orthodontists in the United States routinely obtain a lateral cephalometric radiograph with orthodontic records to use in diagnosis and treatment planning.
As with any medical radiograph, dental radiographs expose patients to ionizing radiation.3,4 Because of this, any unnecessary exposure should be avoided due to the cumulative effects of radiation exposure. The As Low As Reasonably Achievable (ALARA) principle is a concept that recommends reducing ionizing radiation exposure to levels as low as reasonably achievable for minimization of potential risks and adverse consequences.5,6,7 As healthcare providers, orthodontists have the ethical obligation to do no harm to patients under the Hippocratic Oath. With this in mind, orthodontists should always consider the amount of additional information that is gained by taking radiographs.
A major problem that orthodontists sometimes face is conflicting data obtained from the various analyses of orthodontic records. The soft tissue may present the clinician with one picture, the dental evaluation with yet another, and the skeletal evaluation with a third. Not only can there be potential for variability in findings from different sources, but there can also be errors with each source. For example, from one cephalometric analysis it may be concluded that the patient is of a certain dental or skeletal classification, whereas with another the exact opposite may be decided. This can cause confusion when trying to properly diagnose and treatment plan a case, particularly for a new orthodontist. So how does the clinician know how to prioritize information? If there is ambiguity, should the soft tissue dictate the treatment decisions? Should the cephalometric analysis? The answer is probably neither and both.
Studies questioning the usefulness, or validity, of different orthodontic records are not a new topic by any means. It has been shown that variability exists on the intraexaminer8 (agreement among a single examiner) level and on the interexaminer9,10 (agreement among examiners) level when treatment planning. Proffit11 attributes the difference in treatment opinions to the lack of scientific data to support what works best under which conditions. It has also been suggested that the cephalometric radiograph is not essential for making treatment planning decisions.12 In a study by Han, et al.,8, it was found that in 55 percent of patients, study models alone provided adequate information for treatment planning, and the incremental addition of other diagnostic records made minimal difference. Nonetheless, orthodontic clinicians continue to routinely take cephalometric radiographs.
Orthodontists are taught to gather a plethora of information from the initial records. This is especially important for new orthodontists with less experience. Once this clinical experience is gained, the orthodontists’ judgment may be perceived to be as accurate as the cephalometric analyses.13 Therefore, rightfully or wrongly so, an experienced orthodontist may feel there is no need to collect all of the records or to trace lateral cephalometric radiographs.
According to the American Board of Orthodontics (ABO), a fundamental component of orthodontic records includes the lateral cephalometric radiograph and tracing.14 However, in a recent study published in the American Journal of Orthodontics and Dentofacial Orthopedics, it was suggested that the availability of a lateral cephalometric radiograph and its tracing did not make a significant difference in treatment-planning decisions.15 Due to the tremendous confusion concerning what records are “necessary” from a medical/legal standpoint verses a clinical one for diagnosis and treatment planning, a study is needed to determine what orthodontic practitioners are doing in practice. Therefore, the primary goal of this study was to survey a representative sample of orthodontists in North America regarding the routine use of lateral cephalometric radiographs in orthodontic diagnosis and treatment planning. The aim of the study was not to determine whether it is good or bad to use or not use cephalometric radiographs and tracings, but simply to determine what is being done in practice.
Materials and methods
The research protocol was approved by the Seton Hill University Institutional Review Board. Upon permission from the American Association of Orthodontists (AAO), a 20-item survey consisting of multiple-choice, Likert scale, and narrative questions was e-mailed to 2,215 randomly selected active members of the American Association of Orthodontists. The questionnaire was developed to assess in what percentage of patients’ lateral cephalometric radiographs are taken in practice and to what extent these records are being used for evaluation. In the survey, the first 14 items included questions regarding lateral cephalometric use in clinical practice. The remaining six questions consisted of demographic information, such as age, years in practice, board certification, gender, area of residency, and area of practice.
The survey was pretested with residents, full-time faculty, and part-time faculty at Seton Hill University Center for Orthodontics. Minor changes and corrections were then made, and the survey was finalized. The survey and supporting materials were then sent to a random sample of practicing orthodontists in North America.
The initial e-mail, containing a description and the actual survey, was sent out on February 26, 2013, and a reminder e-mail was sent approximately two weeks later on March 11, 2013. The survey was closed on April 10, 2013, and the responses were collected. SurveyMonkey® was used as the survey instrument and for data collection and analysis. Descriptive statistics were used to analyze the data.
Of the 2,215 who were sent the survey, 232 responded for a response rate of 10.47%. Table 1 summarizes the respondents’ demographic information, and important findings from the survey are listed in Table 2. The six demographic questions addressed gender, age, time in practice, ABO certification, region of orthodontic education, and region of practice.
The results indicated the majority of practitioners almost always took pretreatment lateral cephalometric radiographs. 60.34% reported always doing so, and 34.05% reported doing so in 66%–99% of patients. The amount of clinicians who traced pretreatment lateral cephalometric radiographs varied. 38.53% reported always tracing them, 19.05% did so in 66%–99% of patients, and 25.97% reported doing so in 1%–32% of patients. The amount of clinicians who took post-treatment lateral cephalometric radiographs also varied. 30.30% reported always doing so, 24.68% did so in 66%-99% of patients, 23.38% did so in 1%-32% of patients, and 14.29% never took post-treatment lateral cephalometric radiographs. The majority of clinicians did not trace post-treatment lateral cephalometric radiographs, as 29.87% never did and 48.48% only did so in 1%-32% of patients. The number of clinicians who used a cephalometric radiograph for diagnosis when no cephalometric analysis was performed varied greatly. 37.95% reported always doing so, 16.07% did in 66%–99% of patients, 17.41% did in 1%–32% of patients, and 20.09% never did. Very few practitioners reported utilizing cone beam computed technology (CBCT) to make lateral cephalometric radiographs. 71.55% never did and 22.84% did in only 1%–32% of patients. The majority of respondents selected all of the available choices when asked about reasons for taking lateral cephalometric radiographs. 90.09% selected for better diagnostics, 81.90% selected to monitor growth, and 75.86% selected for legal reasons (multiple answers were allowed here). The majority (75.11%) of practitioners reported using centric occlusion (maximum intercuspation) for patient positioning in lateral cephalometric radiographs. Most (81.94%) reported going with clinical findings over the lateral cephalometric findings when a disparity existed between the two. More clinicians (68.47%) reported utilizing digital tracing software programs over hand tracing. In most offices (76.13%), the orthodontist completes the tracing instead of the staff. Multiple reasons were selected for using a particular analysis. 54.87% selected they use the analysis that works best based on their practice, 47.79% selected they use the analysis they learned in residency, and 18.14% selected they use the analysis the literature states is the most valid or reliable (multiple answers were allowed here). 52.16% reported diagnosing pathology on a lateral cephalometric radiograph at some time in their career. Lastly, the majority of clinicians strongly agree (32.03%) or somewhat agree (36.80%) that cephalometric tracing is important in making treatment decisions.
Cephalometric radiography and analyses have long since been considered a part of the “gold standard” for orthodontic diagnosis at the start of orthodontic treatment.12,16,17 Additionally, the American Association of Orthodontists Clinical Practice Guidelines14 includes pretreatment and post-treatment lateral cephalometric radiographs as a standard of care for orthodontic treatment. Keeping this information in mind, orthodontic practitioners have the obligation to ensure the patient is given the correct diagnosis and best treatment options available. However, it was not the intention of the present study to offer an opinion on the benefit or validity of cephalometric use.
The results of this study demonstrate that the majority of orthodontic practitioners are routinely taking “pretreatment” lateral cephalometric radiographs. A total of 60.34% of respondents reported taking them on all patients, and 34.05% reported taking them on at least 66%-99% of patients. This finding was in line with what was expected. It was also found that 38.53% of the respondents routinely performed a cephalometric analysis on all pretreatment lateral cephalometric radiographs; 19.05% on 66%-99% of patients; 8.66% on 33%-65% of patients; 25.97% on 1%-32% of patients; and 7.79% on none at all. According to a similar study performed by the Journal of Clinical Orthodontics (JCO) in 200818, 74.2% reported routinely performing a cephalometric analysis on pretreatment cephalometric radiographs. This was down from 82.2% in 2002 and 89.9% in 1996. These findings demonstrate that although clinicians are still routinely taking pretreatment lateral cephalometric radiographs, they are selectively choosing on which patients to perform a pretreatment cephalometric analysis.
According to Silling, et al.,13, the priority given to cephalometric analysis in treatment planning seems to vary considerably. Some practitioners feel that it is indispensable in every case. Others are of the opinion that it is useful to them only in specific instances or in particular types of malocclusion. Obviously, many factors influence the extent to which an orthodontist relies on cephalometric analysis in arriving at a treatment plan. The most important of these are probably educational background and degree of experience.
In today’s age of technology, digital radiographic systems and digital tracing software programs are rapidly replacing traditional hand tracing of lateral cephalometric radiographs. These digital images offer several advantages over conventional film-based radiography: faster data processing; elimination of chemicals and associated environmental hazards; and the ability to alter and improve the image and correct for exposure errors, thus virtually eliminating the need for a second exposure.19,20,21 Digital radiographic images are easy to store and facilitate communication between healthcare providers. Additionally, depending on the system used, they can require lower levels of radiation.22
The findings of this study illustrate the trend away from hand tracing of lateral cephalometric radiographs. Of those who traced, 68.47% reported doing so utilizing a digital software tracing program, and only 31.53% reported still hand tracing. These findings illustrate the increased use of digital technology in practice today and are in agreement with the results obtained in the 2008 JCO study.18 They found the percentage of orthodontists still hand tracing cephalograms to be 28.7%, which was down from 48.0% in 2002 and 61.2% in 1996.
The increased use of digital radiography and digital software tracing programs has elicited some clinicians to critically examine the reliability of this new technology. For example, Santoro, et al.,21 assessed the accuracy of digital and analog cephalometric measurements. Although digital imaging introduces new errors, such as resolution, pixel size, shades of gray, and so forth, the differences noted between cephalometric measures identified on digital images compared to manual tracing of conventional films were clinically insignificant. It was concluded that both methods could be safely regarded as reliable.
It seems logical that if radiographic records are taken, we are examining them at a minimum. A total of 52.16% of the respondents in this study reported diagnosing pathology from a lateral cephalometric radiograph at some point in their career. This value was higher than originally expected but illustrates one of the additional values of the lateral cephalometric radiograph. In addition, potential legal implications may be involved in the event of missing a diagnosis that was present on records taken but not examined. Nijkamp, et al.,12 goes as far to suggest that cephalometric radiography is only justified if it directly influences information on non-radiographic records used for orthodontic treatment planning. With the multiple treatment records available for orthodontic evaluation, it is important to ensure that orthodontists are using all of the records they have decided to take in diagnosis and treatment planning. Also, we are in a time when more attention is given to ionizing radiation than ever before, so orthodontists should be judicious in their use of cephalometric radiographs and ensure they benefit treatment decisions. If these records are being taken but not evaluated, orthodontists must decide the worth of putting patients through the additional radiation exposure created when taking lateral cephalometric radiographs. If these records are being evaluated and used in diagnosis and treatment planning, the justification for their routine use is warranted.
As 51.52% of the respondents reported being board certified or in the process of becoming certified, lateral cephalometrics will continue to be an important piece of the “gold standard” for orthodontic records, as per the AAO Clinical Guidelines.14 As a requirement for case submission for board certification with the American Board of Orthodontics, pretreatment and post-treatment lateral cephalograms will most likely continue to be routinely taken.
There were several limitations of this survey. The data from this study are based on the assumption that answers were an accurate and honest representation of what is currently occurring in practice. As noted earlier, the survey results are based on the responses of 232 orthodontists of the 2,215 surveyed. Although lower than ideal, this rate of 10.47% was within the expected range of 10%-12% that the American Association of Orthodontists considered a typical response rate based on the sample size.
Future studies related to this topic may include devising a system to help determine which types of patients would benefit from having a lateral cephalometric analysis performed. A second future study could possibly evaluate treatment-planning decisions when only four of the five traditional records (clinical exam, diagnostic study models, extraoral and intraoral photographs, panoramic radiographs, and lateral cephalometric radiographs) are available. This potential study could be designed where the four available records vary from case to case to help determine which records are most valuable to the clinician.
There are a number of conclusions that can be drawn from this survey investigation of lateral cephalometric use in practice. As previously mentioned, there is a current trend toward the utilization of digital software and away from traditional hand tracing, which is in agreement with results obtained from other studies. Also, the current number of orthodontic practitioners routinely tracing lateral cephalometric radiographs appears to be decreasing consistently since the surveys completed in 1986, 1990, 1996, 2002, and 2008 by the JCO.18 However, cephalometric records are still considered by the AAO and the ABO to be a part of the “gold standard” for orthodontic records and are recommended as the standard of care in orthodontics. Other salient findings from this study follow:
•60.34% reported always taking “pretreatment” lateral cephalometric radiographs, and 38.53% reported always performing a cephalometric “analysis” on pretreatment cephalograms.
•30.30% reported always taking “post-treatment” lateral cephalometric radiographs, and 6.49% reported always performing a cephalometric “analysis” on post-treatment cephalograms.
•75.11% reported using centric occlusion (maximum intercuspation), 18.34% reported using centric relation, and 6.55% reported other for patient positioning in lateral cephalograms.
•81.94% reported valuing the finding of a clinical exam over that of a lateral cephalometric analysis.
•52.16% reported having diagnosed pathology from a lateral cephalometric radiograph at some time in the past.
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