[version 1; peer review: 2 not approved]
No competing interests were disclosed.
Mandibular third molar impaction impose a great dental problem especially to young adults. It is the most commonly impacted tooth in the entire dentition of humans. The cause of impaction may vary and may include lack of space, malposition and physical barrier on the path of eruption. This impaction can lead to different pathologies, from infection to development of cysts. Injury to the inferior alveolar nerve during extraction of mandibular third molar is also a possibility during treatment which can lead to numbness, tingling or burning sensation of the affected side. It can also have adverse effects on the adjacent second molar. Several studies have been done to determine the angulation, depth of impaction, space available between the second molar and ramus, proximity to inferior mandibular third, status of adjacent second molar using several criteria and classification using orthopantomography (OPG) and cone beam computed tomography (CBCT). But there is very little research done on the precision of both OPG and CBCT and comparisons of their diagnostic accuracy. In this study, adults above 21 years of age who have impacted mandibular third molar (IMTM) will be taken for OPG where OPG will provide two-dimensional radiography and CBCT will deliver three-dimensional radiography. Different criteria will be used to assess the status of the impaction and see the sensitivity and specificity in both OPG and CBCT. This study is important to help determine which radiographic diagnostic tool is preferable for assessing the status of impacted third molar and its relation to its surrounding structures and estimate the difficulty index for extraction of mandibular third molar impaction. It will also further help in preventing any injury or complication which can arise to the surrounding structures both during and after extraction and which will also help in achieving best possible outcome for patients.
Impaction is the failure of eruption of a tooth in human dentition within an estimated time period (
The impaction of mandibular third molar can cause a number of pathological conditions such as pericoronitis, bone loss, resorption of an adjacent root, periodontal diseases, odontogenic infections, odontogenic cysts and tumours and even jaw fractures.
The mandibular third molar is very much capable of causing pain, irritation and has the capacity to cause pathological conditions in its surrounding areas as mentioned above. Due to its decrease in function with mastication, it is commonly removed by surgical extraction
Orthopantomography (OPG) is a two-dimensional radiography technique, mainly used to see the mandibular third molar impaction status and its relation to the surrounding structures and estimate the complications that can arise due to injury of the inferior alveolar nerve.
Due to its three-dimensional imaging ability, cone beam computed tomography (CBCT) seems to be particularly beneficial, especially for third molars in the mandible that may be closely related to the mandibular alveolar nerve canal since it can provide a spatial resolution of the relationship between these two structures.
To assess accuracy of proximity of root apex of IMTM in OPG and compare it with CBCT To evaluate the accuracy of status of root resorption of adjacent 2
nd molar in OPG against CBCT
This will be a diagnostic study. This is a hospital-based study where the participants will receive consent in written form. They will be recruited from Oral Medicine and Radiology department of Sharad Pawar Dental college and Hospital, Sawangi (Meghe), Wardha. Approval has been received a from “INSTITUTIONAL ETHICS COMMITTEE (IEC)” of Datta Meghe Institute of Medical Science (Deemed to be University), Sawangi (Meghe), Wardha (Approval number DMIMS (DU)/IEC/2022/764 Dated 14/02/2022). This prospective study will be conducted in Oral Medicine and Radiology Department at Sharad Pawar Dental College and Hospital, Sawangi (Meghe), Wardha. Patients with third molar impaction who reported to the department of Oral Medicine and Radiology will be taken for radiography using OPG and after seven days a radiograph will be taken again using CBCT of the same patient. This is to ensure patient’s safety against overexposure to radiation.
All patients above 21 years of age with a unilateral or bilateral mandibular third molar impacted tooth that present to the hospital will be recruited. Consent will be taken from each patient for inclusion in this study.
Patients who presented with congenital or developmental abnormalities of jaw, with bony lesion of jaw (cyst, odontogenic tumor or fibro-osseous lesion), with adjacent impacted or missing 2 nd molar or if they have a history of trauma of jaw (confirmed clinically and radiographically) will be excluded.
After identifying patients who are 21 years of age and above who’s mandibular third molar on clinical examination are impacted or has not erupted yet in the oral cavity and from whom consent has been taken, the procedure will begin. Each patient will be taken for OPG (Planmeca proline cc) where radiographic film will be printed and will be kept for evaluation. After 7 days, the same patient will be recalled and this time, they will be taken for CBCT (Planmeca Promax). After exposing the patient to CBCT, an image will be obtained from Romexis viewer software and image will be printed. Comparison of OPG imaging with CBCT will be done under two parameters.
The first parameter which will be included is the proximity of root apex of IMTM to Mandibular canal in OPG and compare the findings with CBCT where CBCT will be used as gold standard (as CBCT is considered to be accurate enough as it provides 3D imaging). If root apex of IMTM appears to contact or not contact Mandibular canal in OPG image, this will be compared with CBCT image to see if it gives the same result or different interpretation. This will provide the sensitivity and specificity of OPG for this particular finding as given in
| True positive | True negative | False positive | False negative | Sensitivity % | Specificity % | |
|---|---|---|---|---|---|---|
| Contact or Not contact |
| Grade A | No evidence of any root resorption |
| Grade B | Irregular defect noted on root surface and exceeding 2 mm depth |
| Grade C | Obvious irregularities noted exceeding 2 mm with involvement of the root is maintained |
| Grade D | Resorption involving the pulp with loss of root shape |
| Grade E | Total root resorption |
| True positive | True negative | False positive | False negative | Sensitivity % | Specificity % | |
|---|---|---|---|---|---|---|
| Root resorption present or absent |
All assessment and interpretations will be done by 1 Post graduate student and will be re-evaluated by 2 professors. If different opinion in interpretation occurs amongst them, further evaluation will be done until all evaluators unanimously agreed with one interpretation. All findings will be recorded in excel sheet and will be send for statistical evaluation.
This study will begin recruiting patients in 1 st September of 2023 and will begin taking patients for OPG and CBCT and at the same time interpretation for the two parameters mentioned in the methodology will be done. This process will be done till 31 st of December 2023. In the month of January 2024 statistical analysis along with result evaluation will be done.
Minimum sample size required on the basis of sensitivity estimation
Where n = sample size, Z = 95% Confidence interval, d = desired error of margin, Sens = Sensitivity, Prev = Prevalence
Estimated Sensitivity of OPG the diagnostic accuracy of panoramic radiograph (while keeping CBCT findings as gold standard) in predicting close relation between the impacted third molar root and inferior alveolar nerve canal = 0.9855. (from the reference article
Prevalence of relation between the impacted third molar root and inferior alveolar nerve canal to correctly identify the state of impaction, with mandibular canal considering the estimated probability value of 50% = 0.5.
Estimation Error (d) 5% = 0.05
Z (1-α/2) = 1.96 at 5% Error
n = 44
Total sample size required is 44
SPSS, 207.0 version of software will be used for statistical analysis (PSPP is a proprietary free alternative that can be utilized). Chi square test will be used to find the association with demographic variables. Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) will be calculated for OPG using CBCT as gold standard and evaluation will be based on confirmation of whether apex of IMTM has contact Mandibular canal and whether root resorption is present on adjacent 2 nd molar. The percentage of agreement (positive agreement, negative agreement, overall agreement) will be evaluated based on agreement analysis (on primary and secondary endpoints) in comparison between the two procedures. The Kappa coefficient will be used to find out the value of agreement statistics tested with a significant p-value < 0.05 and at 95% confidence interval.
Preliminary preparations are in process. Patients have been recruited and will shortly be taken for radiograph using OPG and after 7 days CBCT.
Evaluating the status of mandibular third molar with its surrounding dento-alveolar structures is highly applicable in the approach for its management and to avoid any serious complications that can occur post operatively and prevent any detrimental effect it can have on its adjacent second molar (especially with distal caries). OPG is a very useful and easily accessible radiograph. As it provides a two dimensional imaging, proximity of apex of IMTM to mandibular canal can be assessed and if the accuracy is close to that of CBCT which gives 3 dimensional imaging, OPG alone will be sufficient enough to alert the surgeons whether apex of root of IMTM is contacting Mandibular canal or not and help prevent any major post-surgical complication.
A study was conducted by Zahra Haddad
Priya Prabhakar
P Vani Priya
Aya Ohshima
Approval was obtained from Institutional Ethics committee of Datta Meghe Institute of Medical Science. No. DMIMS (DU)/IEC/2022/764. Written informed consent will be taken from all patients that meet our criteria for recruitment.
Zenodo: Comparative evaluation for the accuracy of mandibular third molar impaction status with respect to surrounding dentoalveolar structures using orthopantomogram (OPG) as against cone beam computed tomography (CBCT),
This project contains the following extended data:
CERTIFICATE OF CONSENT THESIS.docx
Data are available under the terms of the
I want to sincerely thank Dr Manoj Patil sir and Laxmikant Umate Sir for helping me with the framework of this protocol.
The title adequately conveys the main focus of the study, which is to compare the accuracy of assessing mandibular third molar impaction status concerning surrounding dentoalveolar structures using orthopantomogram (OPG) and cone beam computed tomography (CBCT). It effectively highlights the comparative nature of the study and specifies the radiographic techniques being compared. Additionally, the title is succinct and informative, making it suitable for academic and clinical audiences interested in dental radiography and mandibular third molar impaction. To enhance clarity and specificity, minor adjustments can be made to the title: Consider adding "Accuracy" or "Diagnostic Accuracy" to explicitly mention the aspect being compared. Specify "Diagnostic Imaging" or "Radiographic Assessment" to clarify the nature of the comparison.
The abstract provides a brief overview of the study's background, objectives, methods, and potential implications. However, it lacks specificity regarding the study design, inclusion/exclusion criteria, and statistical analysis plan. The abstract effectively communicates the significance of mandibular third molar impaction and the need for accurate radiographic assessment. However, it could benefit from more precise language and a clearer delineation of the study's objectives and methodology. Moreover, the abstract does not explicitly state the research setting or the specific criteria used to assess impaction status, which may limit its suitability for certain audiences. While the abstract covers key aspects of the study, such as the use of OPG and CBCT for assessing mandibular third molar impaction, it lacks details on the specific parameters or criteria used for evaluation. Additionally, it does not mention the duration of the study or the expected timeline for results, which could provide readers with a better understanding of the study's scope and timeline. Adequacy of Keywords:
The keywords "OPG," "CBCT," "impacted," and "third molar" effectively capture the main focus of the study. However, including additional keywords related to study design (e.g., "diagnostic accuracy," "comparison study") and outcomes (e.g., "sensitivity," "specificity," "complications") could enhance the searchability and visibility of the abstract in academic databases.
The manuscript provides an overview of mandibular third molar impaction, its clinical significance, and the importance of accurate radiographic assessment. It adequately sets the context for the study by highlighting the prevalence of mandibular third molar impaction and its associated complications. However, the introduction lacks depth in discussing the existing literature on the accuracy of radiographic techniques in assessing mandibular third molar impaction. While the manuscript briefly references relevant studies on mandibular third molar impaction, the literature review lacks depth and critical analysis. There is a need for a comprehensive review of existing literature, including studies comparing different radiographic techniques for assessing mandibular third molar impaction. Moreover, the manuscript fails to provide a clear rationale for conducting the proposed study and identifying research gaps. The manuscript describes a prospective diagnostic study with clear inclusion and exclusion criteria, study design, and protocol methods. Ethical considerations and approval from the Institutional Ethics Committee are appropriately addressed. However, the manuscript lacks clarity on the blinding procedures and potential biases in the interpretation of radiographic images. Additionally, there is no mention of the criteria for patient selection, which could impact the generalizability of the findings. The methodology section outlines the study design, inclusion/exclusion criteria, experimental methods, sample size calculation, and statistical analysis plan. However, there are several limitations and ambiguities in the methodology. For instance, the manuscript does not specify the radiographic parameters used for assessing root resorption of the adjacent second molar. Furthermore, the rationale for the chosen sample size calculation method is not adequately justified. The sample size calculation is based solely on the estimated sensitivity of orthopantomography (OPG) without considering other factors such as specificity or prevalence of the condition. This may lead to an inadequate sample size and compromise the statistical power of the study. Additionally, while the statistical analysis plan is outlined, there is no mention of the specific statistical tests to be used for comparing OPG and cone beam computed tomography (CBCT) findings. The manuscript provides a detailed description of the interpretation process, including the involvement of multiple evaluators and consensus agreements. However, the interpretation of radiographic images may be subject to interobserver variability, which is not adequately addressed. The conclusion is largely descriptive and fails to provide a critical synthesis of the study findings in relation to existing literature. The language used in the manuscript is clear and concise, with minimal grammatical errors. However, there is a lack of coherence in the organization of ideas, particularly in the discussion section. The references cited are relevant to the topic but appear to be outdated, indicating a need for inclusion of more recent studies.
Although the study tackles a clinically relevant question, significant enhancements are required in study design, methodology, literature review, and interpretation of findings to align with the rigorous standards of scientific inquiry.
Is the study design appropriate for the research question?
No
Is the rationale for, and objectives of, the study clearly described?
Yes
Are sufficient details of the methods provided to allow replication by others?
Partly
Are the datasets clearly presented in a useable and accessible format?
Not applicable
Reviewer Expertise:
Oral cancer, Oral Precancer, Facial Trauma, Oral Epithelial Dysplasia, Dental Education, Medically compromised patients
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.
The Research protocol need further revisions.
It is suggested that the sample size calculation section follows:
This will be a diagnostic study. – replace “diagnostic ‘ with “observational” “This prospective study will be conducted…” – is the study prospective or retrospective? “Sample size calculation” section should be placed before the “Experimental methods” Table 1 is not explained how sensitivity % and specificity l%” be calculate? Table 2 reference nr4 is not correctly cited in the “Reference “ section Table 3, similarly to table 1, explain how sensitivity % and specificity% will be obtained The paragraph on the experimental methods starting with ‘All assessments and interpretations…should be rephrased. E.g. … All… will be done by the primary investigator (place the initials of the PG student) . Inter-examiner reliability will be conducted by two senior/or supervisors. Calibrations will be conducted between the PI and the supervisors on the interpretations and evaluations until agreements are reached at 0.8 Kappa etc. The Discussion section should be discussing the results and engaging the findings comparing with existing literature. Because this is still a protocol, the discussion section is just similar to literature review
Is the study design appropriate for the research question?
Yes
Is the rationale for, and objectives of, the study clearly described?
Yes
Are sufficient details of the methods provided to allow replication by others?
Partly
Are the datasets clearly presented in a useable and accessible format?
No
Reviewer Expertise:
Cephalometry and dental radiography, Cleft lip and palate, malocclusion assessment, orthognathics surgery,
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.