Agenesis of 5 or more permanent teeth is infrequent, and orthodontic treatment for asymmetric or multiple consecutive missing teeth is challenging. Collaboration among dental specialists to develop individualized treatment plans is critical to achieving optimal outcomes and ensuring patient satisfaction. A 15-year-old non-syndromic girl presented with skeletal Class I malocclusion. She had agenesis of 5 asymmetric permanent teeth, comprising 3 consecutive teeth (the maxillary left canine and first and second premolars), the maxillary right second premolar, and the mandibular right first premolar, and 5 persistent deciduous teeth. Miniscrews were placed distal to the mandibular right first deciduous molar and first molar. The mandibular right molars were uprighted and the space left by first premolar agenesis closed by miniscrew-assisted mesial movement of the molars. The bilateral maxillary deciduous second premolars were preserved. After extracting the maxillary left deciduous canine and the first deciduous molar, 2 miniscrew-supported pontics were placed perpendicular to the alveolus to control the adjacent teeth and maintain space. Active treatment lasted 36 months. Prosthetic treatment for the maxillary left canine and first premolar was completed 3 years after dental implant placement. Occlusion remained stable, even after 5 years of retention. This report highlights the finding that excellent occlusion and esthetics can be achieved by collaborative management involving orthodontists, oral surgeons, and prosthodontists in cases of hypodontia.
Understanding occlusal balance in complete dentures requires conceptualizing mandibular movement and denture dynamics, which many dental students find difficult. This study introduced and evaluated an instructional digital model designed to facilitate accurate 3-dimensional and dynamic representation of these phenomena. This model allowed 360° visualization of mandibular movement and denture dynamics. Its effectiveness was evaluated when used in conjunction with small-group discussions (SGDs) for teaching occlusal balance to undergraduate dental students. Fifth-year students (n=128) at Tokyo Dental College completed both an SGD session and a digital-model learning session, with the order randomized at the small-group level (SGD-first group, n=67; digital model-first group, n=61). Comprehension was assessed using a pre-test and two posttests administered after each session (post-test 1 and post-test 2), each scored on a 10-point scale. Inter- and intra-group comparisons were performed using the Mann-Whitney U and Wilcoxon signed-rank tests, respectively. There were no significant differences between the SGD-first and digital model-first groups in pre-test (4.01±1.90 vs. 4.20±2.00) or post-test 1 scores (5.12±1.91 vs. 4.54±2.20). After completing both sessions, post-test 2 scores were higher in students who completed SGD followed by digital model learning (6.12±2.09) than in those who completed digital model learning followed by SGD (5.59±2.10), with a statistically significant difference between instructional sequences (p=0.046). Intra-group analyses also showed a statistically significant difference between post-test 1 and post-test 2 in both groups, with higher scores at post-test 2 (p<0.05). These results suggest that combining SGDs with the digital model enhances student comprehension of occlusal schemes and balance as it allows these phenomena to be confirmed visually.
As a population ages, the need for complete dentures and other large, removable prostheses remains high in edentulous adults. Appropriate denture fabrication requires comprehension of the anatomical structures of the edentulous mucosa and submucosa. This study aimed to clarify the educational challenges of teaching these structures. Dental student level of comprehension and instructor perception of teaching difficulty when using edentulous models were evaluated. Participants comprised 137 third-year dental students at Tokyo Dental College. Before a lecture on anatomical landmarks and the structure of the edentulous mucosa and submucosa, they were required to complete a pre-test to assess identification of 10 mucosal and 10 submucosal structures in the maxillary and mandibular edentulous ridges. Following the lecture, they participated in a practical session using a commercially available soft-tissue edentulous model under guidance from 19 instructors. A post-test followed this practical session. Correct answer rates were determined and total mucosal and submucosal scores compared. Instructors also completed a questionnaire regarding the difficulty of teaching each structure. The mean mucosal score increased from 60.7% (pre) to 83.8% (post), and the submucosal score increased from 39.3% to 72.3%. Both changes were statistically significant (p<0.0001). However, pre-test scores for submucosal structures were markedly lower than those for mucosal structures. Seven of the 10 mucosal structures were reported by 10% or fewer of the instructors as difficult to teach, whereas 9 of the 10 submucosal structures were reported by over 50% of the instructors as difficult to teach. Despite lectures and currently available models, comprehension of submucosal structures remains challenging for students. Moreover, these structures are perceived to be difficult to teach. Improved educational tools that reproduce the 3-dimensional relationships between mucosa and underlying bone are needed to enhance education regarding complete denture fabrication.
2q37 deletion syndrome is an extremely rare chromosomal disorder, with approximately 150 cases reported worldwide. Affected individuals are known to have multisystem involvement, though dental findings associated with this syndrome remain poorly documented. This report describes the long-term dental management and oral characteristics of a pediatric patient with 2q37 deletion syndrome. The patient was an 11-year 2-monthold boy who presented with the chief complaints of dental caries and maxillary anterior crowding. Similarly to in previous reports regarding this syndrome, a clinical examination revealed short stature (120 cm, approximately 3 standard deviations below the mean), intellectual disability, tetralogy of Fallot, and habitual vomiting. Intraoral findings included 6 carious teeth, a high-arched palate, a constricted maxillary arch, and severe anterior crowding. Mild dental erosion associated with habitual vomiting was also noted. The initial dental treatment addressed the caries in the maxillary first molars and anterior teeth. Due to limited cooperation from the patient, orthodontic treatment was deferred, though regular follow-up examinations were conducted over a period of 7 years. Caregiver motivation remained high and patient cooperation improved, and sectional orthodontic treatment was initiated when he reached the age of 18 years 2 months. Throughout the approximately 10-year period of dental care, the mother of the patient, serving as caregiver, has remained consistently engaged, allowing for routine dental management to be maintained. No new carious lesions have developed during this period and notable improvement in anterior alignment has been achieved. Long-term follow-up will be continued.
When teeth or odontogenic structures are present in excess of the normal number in the dental arch they are referred to as supernumerary. This paper describes a rare case of a maxillary right distomolar and left paramolar in an otherwise non-syndromic individual. The patient was a 23-year-old Japanese man who presented at our clinic seeking periodontal treatment. Intraoral examination revealed supernumerary teeth in the maxilla, and an extraction plan including the wisdom teeth was developed.
