Complete Denture Preclinical Training Program and Digital Tools: A Pilot Study

PURPOSE

To determine whether digital training improves conceptual skills acquisition for custom tray fabrication and tooth arrangement in the preclinical curriculum for complete denture fabrication.

MATERIALS AND METHODS

A crossover design study compared third-year student grades after conventional (manual) and digital training. Half the students were trained with conventional techniques prior to digital, while the other half were trained with digital techniques prior to conventional. The first part of the study (DP1) focused on custom tray fabrication and involved 154 students. The second part (DP2) focused on tooth arrangement with 204 students. The effect of preliminary digital training on conceptual skills was assessed by comparing the results of the students using a Student's t-test. Results were also analyzed by ranking on the students' Perceptual Ability Test (PAT) score. Finally, students' satisfaction with the training was investigated.

RESULTS

Students who completed the initial digital session achieved better custom tray fabrication and tooth arrangement in the subsequent manual sessions. For manual laboratory work, the most dexterous students (PAT1 group) demonstrated the best performance. However, PAT2 students had the best performance during the digital sessions during DP1, and PAT1 and PAT2 students had the best performance during the digital sessions during DP2. Additionally, 40% of DP1 and 12% of DP2 students expressed satisfaction with digital sessions.

CONCLUSION

With complementary manual and digital teaching, digital tools may be useful for enhanced student learning. Digital training has contributed to improve results in manual sessions but did not affect student satisfaction and remained a limited tool to detect learning difficulties.

Use of digital tools for preclinical training in complete denture: A pilot study

INTRODUCTION

Advances in CAD-CAM complete dentures open up opportunities in preclinical laboratory education. A cross-over study was conducted to assess the benefit of digital training in custom tray fabrication. Hypotheses were that digital training improved conceptual skill acquisition and that assessment of digital work helps in the discrimination of students' difficulty.

MATERIALS AND METHODS

Third-year students were allocated either into group A and took the manual practical classes before the digital ones, or into group B (N = 154). Prior to the sessions, a motor skill test was conducted. The influence on the learning process was evaluated by comparing the groups' results to the manual lab work with a Student's t-test. The effectiveness of the assessment in discriminating manual aptitude and conceptual skill was studied through Spearman's rank coefficient between digital and manual scores in conceptual skill and with a subgroup analysis according to the results of the motor skill test. The level of significance was set up at .05. Students' satisfaction was also assessed with a questionnaire.

RESULTS

Students in group B achieved better scores. Spearman's rank coefficient test showed a weak correlation, R = .16. For manual lab work, the most manually skilled students did significantly better. In contrast, for the digital session, the medium manually skilled students did better. More than half of the students (55%) found the manual and digital sessions complementary, without identifying any difference depending on the learning sequence.

CONCLUSION

Digital training improved the students' results in the conventional practical exercise. Assessments of the digital and conventional custom trays were complementary in order to distinguish conceptual and motor skills.

Implementation of game-based training in oral rehabilitation of edentulous patients in an undergraduate dental course

BACKGROUND

Coronavirus disease-19 dramatically changed the learning conditions of dental students, with restricted access to training sessions and clinical practice. The "Playdent" project proposed the integration of serious games (SGs) in the third-year curriculum, based on tailor-made scenarios questioning the first dental visit of edentulous patients, and examined whether training with the games would advance students' learning outcomes.

MATERIALS AND METHODS

Test scores of 89 students, allocated either to a "test" group that accessed SGs during a 4-week test period in addition to conventional lectures or to a "control" group that benefited solely from conventional lectures, were measured before and immediately after the test period. The subsequent satisfaction of students was assessed in the "test" group.

RESULTS

Scores obtained after the 4-week period significantly increased within the "test" group (11.1% ± 24.9%, p = 0.04, degree of freedom [df] = 30) while they did not change within the "control" group (p = 0.21, df = 57). Qualitative feedback expressed by students who played SGs during the 4-week period demonstrated that 71% of them rated the SGs as satisfactory and 91% of them judged the consistency of SGs content with lectures to be satisfactory.

CONCLUSION

Game-based learning showed a positive impact on the learning outcomes of third-year students. Qualitative assessments provide insights into the pertinence of SGs offered in addition to traditional lectures of third-year complete denture courses. SGs may consolidate skills in oral rehabilitation acquired through traditional passive learning formats proposed in preclinical courses.

Elements of morphology: Standard terminology for the teeth and classifying genetic dental disorders

Dental anomalies occur frequently in a number of genetic disorders and act as major signs in diagnosing these disorders. We present definitions of the most common dental signs and propose a classification usable as a diagnostic tool by dentists, clinical geneticists, and other health care providers. The definitions are part of the series Elements of Morphology and have been established after careful discussions within an international group of experienced dentists and geneticists. The classification system was elaborated in the French collaborative network "TÊTECOU" and the affiliated O-Rares reference/competence centers. The classification includes isolated and syndromic disorders with oral and dental anomalies, to which causative genes and main extraoral signs and symptoms are added. A systematic literature analysis yielded 408 entities of which a causal gene has been identified in 79%. We classified dental disorders in eight groups: dental agenesis, supernumerary teeth, dental size and/or shape, enamel, dentin, dental eruption, periodontal and gingival, and tumor-like anomalies. We aim the classification to act as a shared reference for clinical and epidemiological studies. We welcome critical evaluations of the definitions and classification and will regularly update the classification for newly recognized conditions.

Taste deficits related to dental deafferentation: an electrogustometric study in humans

Dental treatments, the prevalence of which increases with age, can cause orofacial somatosensory deficits. In order to examine whether they may also affect taste sensitivity, electrogustometric thresholds were measured at 9 loci on the tongue surface in 391 healthy non-smoking, non-medicated subjects. Results showed that the greater the number of deafferented teeth, the higher the thresholds. Irrespective of age, subjects with more than 7 deafferented teeth exhibited significantly higher thresholds than subjects with fewer than 7 deafferented teeth. Conversely, across age groups, no statistical difference was observed among subjects with no, or few, deafferented teeth. Hence, a taste deficit, which was not correlated to aging, was observed. An association was noticed between the location of taste deficits and the location of deafferented teeth. Higher thresholds at anterior sites, with no possible traumatic injury relationship, suggested that neurophysiological convergence between dental somatosensory and taste pathways - possibly in the nucleus tractus solitarius - could be responsible for these relative decreases of taste sensitivity when dental afferences were lacking. Among trigeminal contributions, lingual nerve and inferior alveolar nerve may synergize taste.

Decreased taste sensitivity in cancer patients under chemotherapy

GOALS OF WORK

The aim of the study was to measure taste thresholds among cancer patients under chemotherapy compared to controls.

PATIENTS AND METHODS

The study was performed with 110 cancer patients and 170 healthy subjects of similar age distribution were included in the study. The electrogustometric detection threshold was evaluated as the lowest current intensity perceived by the subject in three tongue sites independently with a constant current generator.

MAIN RESULTS

Taste thresholds for all cancer patients demonstrated significantly higher values compared to controls.

CONCLUSIONS

Cancer patients treated by chemotherapy demonstrated a temporary taste sensitivity deficit. Associated with the illness due to the treatment, this deficit explains the patients complaining of "abnormal or bad tastes", which results in food aversion and has a negative impact on nutritional status and quality of life. In order to prevent the risk of anorexia and the enhanced morbidity related to this deficit, treatment should include relevant information to the subject for anticipating objective taste modifications and a psychological follow-up during the actual change of taste quality perceptions in everyday life.

Histologic changes associated with experimental partial anterior disc displacement in the rabbit temporomandibular joint

AIMS

To correlate histologic changes with the stress developed by various disc interferences via a model of partial anterior disc displacement in the rabbit temporomandibular joint (TMJ).

METHODS

Eighteen male New Zealand rabbits were operated on to expose the temporomandibular disc without severing its attachments. A suture was passed around the lateral part of the disc over the condylar attachments and the 2 strands were fixed in the orbital cavity. In 9 rabbits, a resorbable suture was used to secure the disc displacement. In the other 9, a nonresorbable suture was fixed with a nickel-titanium spring to displace and maintain tension on the disc. Three non-operated animals served as controls. The animals were sacrificed at 12 and 24 weeks after surgery, and the TMJs were prepared for undecalcified histology.

RESULTS

In the first group, the disc remained in a normal position, but its morphology was modified and small histologic changes were observed in the cartilage. In the second group, the disc was displaced in various positions corresponding to the strength delivered by the spring.

CONCLUSION

Adaptive changes were observed in joints with a slightly displaced disc, while degenerative changes were associated with larger disc displacements. In each experimental joint, histologic changes increased from the medial to lateral parts. This phenomenon was related to the stress gradient induced by axial disc rotation over the condyle. Any disc displacement always resulted in changes in the cartilage.

Histomorphometric parameters and susceptibility to neutrophil elastase degradation of skin elastic fibres from healthy individuals and patients with Marfan syndrome, Ehlers-Danlos type IV, and pseudoxanthoma elasticum

The morphometric parameters of mid-dermal elastic fibres from the skin of four patients with Marfan syndrome, four patients with Ehlers-Danlos syndrome type IV (EDS IV), and two patients with pseudoxanthoma elasticum (PXE) were determined, and compared with those of healthy individuals of a similar age range. The volume fraction occupied by elastic fibres was significantly reduced in Marfan patients compared with normal controls, and this was independent of age. In contrast, it was significantly increased in PXE patients, whereas the volume fraction occupied by skin elastic fibres varied within the EDS IV group. Dermal elastic fibres from patients with Marfan syndrome, EDS IV and PXE are hydrolysed by human neutrophil elastase in a qualitatively and quantitatively different fashion from those from healthy individuals. Marfan syndrome and EDS IV dermal elastic fibres were found to be more resistant to hydrolysis by human neutrophil elastase, but PXE elastic fibres were hydrolysed at a rate similar to elastic fibres from control skin.

Abnormal incisor-tooth differentiation in transgenic mice expressing the muscle-specific desmin gene

Immunocytochemistry and electron microscopic observations on the incisor-tooth organ of transgenic mice expressing the muscle-specific desmin gene under the direction of the vimentin promoter, reveal that the expression of the hybrid transgene occurs both in mesenchymal cells and differentiating odontoblasts. The muscle-specific desmin, as estimated by fluorescence intensity, is more expressed in immature mesenchymal cells than in postmitotic differentiated odontoblasts. The expression of the transgene generates alteration of the odontoblast-intermediate filament network and interferes with the secretory activity of both odontoblasts and ameloblasts. Our results are consistent with the hypothesis that odontoblasts have inductive properties on the differentiation of ameloblasts and that intermediate filaments among other factors play the role of cell and tissue organizer.