The impact of COVID-19 pandemic on student performance and self-evaluation in preclinical operative dentistry.

INTRODUCTION: During the COVID-19 pandemic, dental schools were required to reformat their curricula to accommodate regulations mandated to protect the health of students and faculty. For students enrolled in the Operative Dentistry preclinical courses at the Harvard School of Dental Medicine (HSDM), this modified curriculum included frontloading the course with lectures delivered remotely, followed by in-person laboratory exercises of learned concepts. The aim of this article was to determine the impact that the modifications had on student performance and student self-evaluation capabilities. MATERIALS AND METHODS: Thirty-eight students were introduced to this restructured course. Their performance in a final multiple-choice (MC) examination, four preclinical laboratory competency assessments (class II amalgam preparation and restoration, class III composite preparation and restoration) and their self-assessment of these preclinical competency assessments were then compared with the pre-COVID pandemic (P-CP) classes from years 2014 to 2019 (n = 216 students). Linear regressions were performed to determine differences in mean faculty scores, self-assessment scores, student-faculty score gaps (S-F gaps) and absolute S-F gaps seen between the class impacted by the pandemic and the P-CP classes. RESULTS: The results demonstrated that students during the COVID-19 pandemic (D-CP) had a higher average faculty score in all four preclinical laboratory competency assessments and in the final MC examination. In addition, the S-F gap was smaller in this cohort as compared with the P-CP classes. CONCLUSION: Despite the challenges of restructuring the preclinical curricula, D-CP students performed better than their P-CP predecessors in multiple facets of this Operative Dentistry course including self-assessment accuracy.

3D Digital technology as an alternative educational tool in preclinical dentistry.

INTRODUCTION: The advancement of 3D digital scanners has allowed educators to uphold the quality of education whilst implementing novel methods of assessment. OBJECTIVE: The purpose of this study was to compare two evaluation methods, conventional and digital scanned assessments, on student cavity preparations and students and faculty's perceptions of these assessment methods. METHODS: Predoctoral students performed Class II amalgam and Class III resin composite preparations on simulated teeth for their preclinical competency examinations. Two calibrated faculty evaluated the students' preparations using dental instruments for conventional assessments and 3D scanned images for digital assessments. Faculty scores from both assessment methods were compared and statistically analysed (p < .05). Students also self-assessed their performance using the digital scanned images and filled out a perception survey. RESULTS: There was no statistically significant difference between the conventional (Class II; 73.3 ± 12.2 and Class III; 82.5 ± 8.9) and the digital assessment with scanned images (Class II; 71.3 ± 11.0 and Class III; 82.2 ± 8.2). Faculty scores from both methods have shown a trend of comparability. Most students agreed that digital ideal preparation models were useful (84.2%) and almost all students agreed that digital technology helped them learn operative dentistry (91.1%). In contrast, most students agreed that conventional assessment should be the main self-evaluation system (82.2%) and disagreed that digital assessment is more effective than conventional self-assessment (68.3%). CONCLUSION: Our study demonstrated that 3D digital technology could be an alternative and/or supplementary educational tool to aid in upholding the quality of dental education.

Can an interactive case-based activity help bridge the theory-practice gap in operative dentistry?

INTRODUCTION: A theory-practice gap in pre-doctoral dental education is a common source of stress for dental students. An interactive, small-group, case-based activity was designed to bridge the gap between pre-clinical and clinical experiences. The aim of our study was to assess the effectiveness of the case-based activity by evaluating students' comfort level in operative procedures. MATERIALS AND METHODS: Over 5 years, a total of 172 second-year students from the classes of 2017 through 2021 participated in the case-based activity delivered after the completion of the core operative dentistry course. The exercise included a pre-activity online quiz, an in-class case-based session and a laboratory exercise. Students' self-reported comfort levels in performing operative procedures were collected by surveys at three different times. They included the post-course survey distributed after the completion of the core operative dentistry course, the post-activity survey distributed after the completion of the case-based activity, and the follow-up survey distributed after students completed their first operative procedures in clinic. RESULTS: There was a 93% response rate. The average rating of all eight statements revealed statistically significant increase in students' comfort level after completing the case-based activity and after performing their first operative procedures in the teaching practice. CONCLUSION: This observation suggests that the case-based activity was effective in raising students' comfort levels. The activity may serve as an important tool in bridging the theory-practice gap between pre-clinical and clinical operative experiences.

Evaluating dental student self-assessment across preclinical anatomy waxing and operative exercises.

PURPOSE/OBJECTIVE: A career in healthcare is built on the foundations of continuous self-reflection and self-assessment. Previous studies have solely compared student self-assessment to faculty grades in a single discipline. The objective of this study was to investigate whether associations of a student's self-assessment skills exist across multiple disciplines in the predoctoral setting. METHODS: Sixty-five students from two class years at the Harvard School of Dental Medicine completed preclinical competency exams in dental anatomy waxing and operative dentistry. The difference between the student's self-assessment score and average faculty grade for each exercise was calculated as the student‒faculty (S-F) gap, which served as a proxy to determine how students evaluate their work. Regression analysis was performed to assess associations between wax-up and preclinical operative S-F gaps. RESULTS: Mean S-F gaps for waxing and preclinical operative procedures were positive (5.7 ± 6.1 and 7.6 ± 6.7, respectively). Additionally, students in the lower quartile tended to overestimate performance to a greater degree than their peers in the upper quartile. Furthermore, the waxing S-F gaps were positively associated with S-F gaps of each operative procedure, particularly with the combined operative exercise S-F gaps, where a statistically significant association was seen (coefficient = 0.28; p = 0.04). CONCLUSION(S): Previously, we identified a negative correlation between students' self-assessment skills (S-F gaps) and their preclinical performance. In this study, we further demonstrated an association of S-F gaps in two fundamental exercises: wax-up and operative dentistry. This underscores the roles of S-F gaps as possible indicators of students' preclinical and clinical performance, and it holds potential to become a widely standardized and applicable calculation that may help evaluate the effectiveness of the dental curricula and optimize student learning.

Association of student performance between dental anatomy waxing and preclinical operative dentistry.

Spatial perception and psychomotor skills are critical components to clinical dentistry. However, measures within the dental school curricula have not been sufficiently studied and evaluated for their effectiveness in predicting preclinical performance. The objective of this study was to examine whether students' waxing skills are associated with preclinical operative performance. This study included 65 students from two class years at the Harvard School of Dental Medicine. Regression analysis was utilized to assess associations between waxing scores and operative exam scores. Waxing scores were found to be positively correlated with all operative practical exam scores and significantly associated with the class III resin composite restoration (coefficient, 0.42; P = 0.02) and the combined operative exam scores (coefficient, 0.33; P = 0.04). Wax-up assessments could serve as a predictor for preclinical performance and identify students who would benefit from additional assistance to help foster a more inclusive learning environment.

Dental Student Perceptions of Distance Education over Time: A Mixed-Methods Study.

OBJECTIVES: Amid the COVID-19 pandemic, the transition to distance learning raised pertinent questions regarding advantages and challenges compared to traditional in-person learning. This study aimed to investigate dental students' perceptions of distance learning throughout the pandemic, examining its impact on their education. METHODS: This study employed a convergent mixed-methods design. Three online surveys were conducted in 2020, 2021, and 2022 to collect quantitative data. Additionally, qualitative semi-structured interviews were carried out in 2022. Interviews were recorded and transcribed; then, thematic analysis was performed following an inductive approach. RESULTS: As perceived by the participants, distance learning entails advantages and challenges. Initially, they felt uncertainty and negativity about the new environment with distance learning. However, their perceptions shifted positively as they adapted, even after returning to hybrid and in-person modules. Furthermore, most participants felt that distance learning is better suited for didactic content. It was suggested that didactic courses contain approximately 25-50% of online methods. CONCLUSIONS: Distance learning has provided valuable opportunities to reinforce curricula and improve learning efficacy during the pandemic. Our findings suggest that a hybrid learning model that combines traditional and distance modules appears to be an effective approach for future dental education.

Predoctoral Student Performance in a Restorative Dentistry Course During the COVID-19 Pandemic.

PURPOSE: To compare predoctoral student performance in restorative dentistry related to curricular changes implemented in response to the COVID-19 pandemic and to evaluate the impact of remote education on performance in didactic and preclinical examinations and objective structured clinical examinations (OSCEs). MATERIALS AND METHODS: The study population consisted of 172 students, all members of the DMD graduating classes from 2017 to 2021. Scores in the Final Restorative Treatment (FRTx) course, subdivided into didactic and preclinical lab work, and the OSCEs were assessed and compared between pre-pandemic students and during-pandemic students. RESULTS: Performance in the preclinical lab exercises was statistically significantly higher in the during-pandemic cohort than in the pre-pandemic cohort after adjusting for students' gender and admission scores. Performance in restorative dentistry as measured by the OSCE was not statistically different among during-pandemic students compared to the pre-pandemic students. It was observed that students were more efficient and engaged during the more limited lab sessions with the increased student-to-faculty ratio that allowed for more feedback. CONCLUSION: Although virtual education cannot replace in-person experiences, this model served students satisfactorily during the COVID-19 pandemic, with added support structures such as flexible scheduling, interactive sessions, and additional small-group discussions to maintain academic performance in predoctoral education.

Association of admissions factors with student performance in preclinical operative dentistry.

PURPOSE/OBJECTIVE: Admission to dental school is based on various factors including academic achievements in undergraduate coursework and the Dental Admission Test (DAT) scores. Students' success in an operative course requires fundamental knowledge, hand skills, spatial awareness, and self-assessment ability. The goal of this study is to evaluate how admissions factors, such as Grade Point Average (GPA) and DAT, including the Perceptual Ability Test (PAT), relate to students' academic and preclinical performance and self-assessment skills in preclinical operative dentistry. METHODS: A total of 239 students were included from seven class years (2016-2022). Third-year dental students participated in a preclinical operative dentistry course. At the end of the course, they took the final multiple-choice exam and performed four competency examination procedures: Class II amalgam preparation and restoration and Class III resin-composite preparation and restoration. Calibrated faculty graded students' work independently and students also self-assessed their performance using the same rubrics as faculty. Linear regressions were performed to estimate the association between the admission factors with the mean faculty scores (measuring preclinical performance), student-faculty (S-F) gap scores (evaluating self-assessment skills), and their final didactic exam scores. RESULTS: Overall, students' self-assessment was higher compared to faculty score. Linear regression analysis demonstrated positive correlations between the PAT and students' preclinical performance as well as between the DAT and their didactic exam scores. In general, S-F gap score decreased as PAT score increased, and it was statistically significant lower for the Class III preparation, indicating a better self-assessment skill. No correlations were observed between student performance and GPA scores. CONCLUSION: The findings from the association between student performance and admission factors may play an important role in the dental school admissions process and assist students who may benefit from early faculty intervention and support.

Comparing dental student preclinical self-assessment in the United States and Japan.

PURPOSE/OBJECTIVES: Self-assessment is an essential skill for dental professionals. Understanding global trends in self-assessment can highlight the learning needs of students across a diversity of cultural backgrounds. The aim of this study is to compare the self-assessment ability of dental students in the United States and Japan, where cultural backgrounds may differ. METHODS: Students in the United States (n = 176) completed a typodont premolar and anterior Class II and Class III preparation and restoration. Students in Japan (n = 175) completed a typodont premolar crown preparation. Students and faculty then evaluated the student performance using rubrics for each respective procedure. The difference between the student's self-assessment score and the average faculty score (S-F gap) was calculated and the data were analyzed. RESULTS: The mean S-F gap was 2.8% in Japan and 7.6% in the United States. This indicates that Japanese students tended to assess themselves closer to their faculty graders than students in the United States. On average, students in both countries scored themselves higher than their faculty graders. Students in the United States more frequently overestimated their performance and students in Japan more frequently underestimated their performance. For students in the lower quartile, the mean S-F gap was 5.1% in Japan and 14.6% in the United States, indicating a large cultural discrepancy in the lower quartile groups. CONCLUSIONS: Although different preclinical procedures were compared, our findings demonstrated that Japanese students may score themselves more closely to their faculty assessors than students in the United States. Further investigation with more students completing the same preclinical activity will be needed.

Importance of bitewing radiographs for the early detection of interproximal carious lesions and the impact on healthcare expenditure in Japan.

BACKGROUND: Globally, the direct cost of dental caries is approximately $298B yearly, consuming 5-10% of national healthcare budgets. Bitewing radiographs (BWR) are the standard method of diagnosing interproximal dental caries. In Japan, bitewing radiographs are rarely used. This retrospective observational study was conducted to measure the potential economic impact of carious lesions left undiagnosed and untreated due to this omission of bitewing radiographs. METHODS: The total number of existing carious lesions, the number of undiagnosed lesions, and costs of treating these lesions were calculated from the national database of Ministry of Health, Labor and Wellness in Japan between June 2013 and 2017. The number of affected teeth was estimated using prevalence data and undiagnosed lesions were estimated. The expense associated with treating progressed lesions was calculated using the standard Japanese fee structure. BWR trends were assessed, and analyses were performed to understand the differences between states and populations over time. RESULTS: The average number of BWR taken monthly per office was 48.3±1.1 (average ± SD). It was calculated that an average of 6,429,155 lesions went undiagnosed per month, 93.5 teeth per practice, and 1.6 teeth per patient. The cost of treating lesions that went undiagnosed and then progressed into more invasive restorations was estimated to be between $57M-$218M more (difference between NaF varnish and class II restorations), and $150M-$443M more (difference between Class II restoration and crown or crown with RCT). CONCLUSIONS: BWRs are crucial in diagnosing a significant number of carious lesions. There is considerable impact on health and cost to the national health system due to undiagnosed lesions. Practitioners need to be educated on reading and understanding BWR, and policy should be changed to cover BWR.

Effect of an experimental chitosan/casein gel on demineralized enamel under a cariogenic challenge.

BACKGROUND: Dental caries is considered one of the most common oral health diseases. OBJECTIVES: The aim of the study was to evaluate the effects of an experimental chitosan/casein gel on enamel demineralization/remineralization in an environment with a high cariogenic challenge. MATERIAL AND METHODS: Thirty-six specimens of bovine enamel (4 mm × 3 mm × 2 mm) were ground flat and polished. Then, the specimens were immersed in acetate buffer for 43 h with half of the surface protected (serving as control) and the other half exposed. All demineralized surfaces were randomly assigned into 3 groups (n = 12 per group) according to the type of treatment (G1 - control, G2 - 1.5% chitosan gel with 1.5% casein, and G3 - 1.5% chitosan gel without casein), and the corresponding treatment was applied once a week for 3 weeks. The specimens were also subjected to pH cycles of demineralization/ remineralization and the treatments were performed 3 times at 7-day intervals for a total of 21 days. Surface images were obtained for the analysis of initial roughness and, after the cariogenic challenge, new images were obtained to evaluate the final roughness, volume loss and wear profile using laser confocal microscopy. After the analyses, the specimens were cut and the depth of demineralization was measured. The data were analyzed using the Kruskal-Wallis analysis of variance (ANOVA) and the Tukey's test. RESULTS: While the chitosan gel with casein showed a similar loss to the control group (p > 0.05), both gels resulted in similar volume loss (p > 0.05). There were no statistical differences regarding the wear profile, surface roughness and depth of demineralization between the groups (p > 0.05). CONCLUSIONS: The chitosan gel reduced volume loss of the demineralized enamel without significantly impacting the surface smoothness.

Decision tree protocol for demineralized gingival margin extension in class II composite cavity preparations.

This study proposed the development of a protocol for class-II preparations with demineralized gingival margins for the improvement of the longevity of restorations. Evidence sources such as location/color/surface hardness/width of demineralized gingival margin with enamel/demineralized enamel (DE)/dentin/cementum were reviewed based on methodological studies and systematic reviews. A decision tree protocol was developed with criteria (i) lesion location: demineralized gingival margins in enamel must be removed, but if close to cementoenamel-junction, color should be evaluated. (ii) Color: yellow/brown lesions must be removed, but if white/opaque, then the surface hardness should be evaluated. (iii) Surface hardness: soft/demineralized gingival margin must be removed, but if adequately hard, width should be evaluated. (iv) Width: lesions less than half-enamel thickness and impenetrable by an explorer, remineralization is possible and the lesion does not need to be removed. A decision tree protocol was set up with the current available literature. Further continued investigations will be needed for the appropriate protocol updates.

The effect of gender on student self-assessment skills in operative preclinical dentistry.

PURPOSE/OBJECTIVE: Self-assessment is a fundamental skill for dentists and other health care providers. It enables these professionals' ability to critically evaluate the quality of their clinical work and improve through self-directed learning. Researchers have investigated how gender affects self-assessment skills and have shown that male students tend to overestimate their performance while female students tend to underestimate theirs as compared to peer or faculty assessment. The goal of this study was to evaluate how the self-assessment skills of dental students differ by gender in operative preclinical dentistry. METHODS: Third-year dental students (N = 208, Class of 2016-2021) self-assessed their work using the same rubrics as faculty on four operative dentistry competency examination procedures: Class II amalgam preparation and restoration and Class III resin-composite preparation and restoration. Two calibrated full-time faculty graded all procedures independently. The Student self-assessment-Faculty grade (S-F) gap scores were calculated and statistically analyzed. RESULTS: Overall, both genders overestimated their self-assessment for all four procedures as compared to actual scores given by faculty. Males overestimated more significantly than females for Class II Amalgam preparation, but not for the other three procedures. However, when the S-F gap for all procedures was combined and analyzed together, male students significantly overestimated their self-assessments compared to female students. When female and male students grading scores were stratified into quartiles, there were significantly larger differences between males and females in the lower quartiles, which suggest that difference in self-assessment abilities was more prominent among the lower performing students. CONCLUSION: The results of this study demonstrate that gender may affect the accuracy of self-assessment in operative preclinical dentistry.

Clinical anatomy of the inferior labial gland: a narrative review.

OBJECTIVE: In this article we review the literature on the inferior labial gland from a clinical and anatomical perspective. BACKGROUND: Regardless of its importance in clinical practice, there are no medical literature that comprehensively reviewed the inferior labial gland. METHODS: A database search using PubMed and Google Scholar was conducted. The following keywords were used in the search: "lower labial salivary gland", "lower labial gland", "inferior labial salivary gland", AND "inferior labial gland". CONCLUSIONS: The human labial glands are types of minor salivary gland that continuously secrete small amounts of mucous and serous substances to maintain oral health. The inferior labial glands are innervated by the inferior labial branch of the mental nerve, and the inferior labial branch of the facial artery is the main arterial supply to the lower lip. Although they only have an auxiliary role in saliva production compared to the major salivary glands, minor salivary glands provide a certain amount of lubrication in the oral cavity by the continuous outflow of saliva. The inferior labial gland not only promotes moisturization in the oral cavity but also secretes substances with antibacterial effects, which is important for the function of the oral cavity. A recent study showed that the rate of salivary secretion from the inferior labial glands does not change with age, and in some cases the inferior labial glands are used for diagnosing intractable diseases such as Sjogren's syndrome and cystic fibrosis. In addition, since the inferior labial glands themselves can be the site of cyst and/or neoplasia development, we should be careful to distinguish them from other diseases. Elucidation of the anatomy, physiology, and pathology of the inferior labial glands, is important for understanding human health and diseases.

Comprehensive review of the incisive branch of the inferior alveolar nerve.

The incisive branch of the inferior alveolar nerve is a vital anatomical structure within the anterior mandible that has not been thoroughly defined and outlined in reports in the literature until recent years. Advances in radiological imaging, particularly the widespread use of cone-beam computed tomography has allowed for accurate visualization of the mandibular incisive canal (MIC) and its associated incisive branch of the inferior alveolar nerve. Surgical damage to the MIC, which could result in hemorrhage and sensory disturbance, may occur in commonly practiced oral and maxillofacial procedures, such as chin bone harvesting, implant placement, fracture repair and removal of pathologic entities of the anterior mandible. Knowledge of both the presence, dimensions and location of the incisive branch is a vital component to pre and peri-operative planning of oral and maxillofacial surgeries performed within the mandible, particularly within the interforaminal zone. In this article, the terminology, anatomy, imaging, surgical consideration, and pathology of the incisive branch will be discussed.

Effects of healthcare policy and education on reading accuracy of bitewing radiographs for interproximal caries.

OBJECTIVES: The aim of this study is to assess the accuracy of bitewing radiograph interpretation of predoctoral students, residents and general dentists who work under different core curriculum of dental education and healthcare policy. METHODS: A total of 118 examiners including predoctoral dental students, residents and general dentists from USA and Japan were tasked with evaluating a series of bitewing radiographs and diagnosing interproximal carious lesions. This study was approved by the Harvard Medical School Institutional Review Board (IRB). Participants graded interproximal aspects of those images and categorized the following criteria; "intact", "enamel caries <1/2 width", "enamel caries >1/2 width" or "caries into dentin". The gold-standard was determined by the consensus of two HSDM full-time faculty. RESULTS: There was significant difference in the sensitivity for all three caries levels between the two groups but there was no significant difference on specificity. The positive-predictive and negative-predictive values of the USA group for the enamel caries (<1/2 of enamel) were significantly higher than the Japanese group. The average of AUC (ROC) was significantly higher in the USA group (0.885 ± 0.04) than the Japanese group (0.785 ± 0.08, p<0.01). CONCLUSION: Teaching and adopting BW radiographs for diagnosis of interproximal caries is integral for dental providers to accurately and efficiently use them in their practices. It is critical that all dental educators approach policymakers to explain the importance of BW radiographs and promote their efficacy for prevention and early diagnosis of interproximal caries.

A rare case of trifid mandibular canal with bilateral retromolar foramina.

There are many reported anatomical variations of the mandibular canal. Consequently, there is great variation in the retromolar area, such as the quantity, size, and location of the retromolar foramen (RMF), the bony entrance of the retromolar canal (RMC). These variations allow for different accessory innervations to the mandibular molars and their adjacent buccal tissue because the RMC contains neurovascular bundles. Consideration of these anatomical variations is crucial for avoiding complications in anesthesia, implant placement, and surgery. However, the rarer canal types are often only imaged by computed tomography (CT) or cone beam computed tomography (CBCT). We present a rare case with bilateral RMF and a unilateral trifid mandibular canal in a cadaver.

A comparison of diagnosis of early stage interproximal caries with bitewing radiographs and periapical images using consensus reference.

OBJECTIVES:: The purpose of this study was to assess the diagnostic property of intraoral bitewing radiographs (BTW) for early stage interproximal caries, and to compare them with periapical radiographs (PA) at different levels of caries progression. METHODS:: A total of 241 interproximal surfaces of BTW and corresponding PAs were used. Seven teaching faculty consisting of three oral and maxillofacial radiologists, two operative faculty, and two prosthodontists evaluated the images. The observers graded images as either "intact", "enamel caries <1/2 width", "enamel caries >1/2 width", or "caries into dentin". The gold-standard was established by consensus of two experienced faculty with 35 years and 27 years of experience. Specificity, sensitivity, positive-predictive value, and negative-predictive value were calculated for the different level of caries progression. Furthermore, receiver operating curves) of BTW and PAs of each evaluator were made and the area under the curve of BTW and PAs were compared. RESULTS:: There was no significant difference in the specificity of BTW and PAs. BTW showed significantly higher sensitivity than PAs in all levels of caries progression (p<0.01). Positive-predictive value and negative-predictive value of BTWs were also significantly higher than PAs. One-way ANOVA and Tukey HSD test showed a significant difference in sensitivity with different levels of caries progression. The average area under the curve was significantly higher for BTWs than PAs (p<0.01). CONCLUSIONS:: BTWs offer a significant advantage over PAs in the diagnoses of early stages of interproximal carious lesions.