Fully automated deep learning approach to dental development assessment in panoramic radiographs.

BACKGROUND: Dental development assessment is an important factor in dental age estimation and dental maturity evaluation. This study aimed to develop and evaluate the performance of an automated dental development staging system based on Demirjian's method using deep learning. METHODS: The study included 5133 anonymous panoramic radiographs obtained from the Department of Pediatric Dentistry database at Seoul National University Dental Hospital between 2020 and 2021. The proposed methodology involves a three-step procedure for dental staging: detection, segmentation, and classification. The panoramic data were randomly divided into training and validating sets (8:2), and YOLOv5, U-Net, and EfficientNet were trained and employed for each stage. The models' performance, along with the Grad-CAM analysis of EfficientNet, was evaluated. RESULTS: The mean average precision (mAP) was 0.995 for detection, and the segmentation achieved an accuracy of 0.978. The classification performance showed F1 scores of 69.23, 80.67, 84.97, and 90.81 for the Incisor, Canine, Premolar, and Molar models, respectively. In the Grad-CAM analysis, the classification model focused on the apical portion of the developing tooth, a crucial feature for staging according to Demirjian's method. CONCLUSIONS: These results indicate that the proposed deep learning approach for automated dental staging can serve as a supportive tool for dentists, facilitating rapid and objective dental age estimation and dental maturity evaluation.

Correlation between dental and skeletal maturity in Korean children based on dental maturity percentile: a retrospective study.

BACKGROUND: The correlation between dental maturity and skeletal maturity has been proposed, but its clinical application remains challenging. Moreover, the varying correlations observed in different studies indicate the necessity for research tailored to specific populations. AIM: To compare skeletal maturity in Korean children with advanced and delayed dental maturity using dental maturity percentile. DESIGN: Dental panoramic radiographs and cephalometric radiographs were obtained from 5133 and 395 healthy Korean children aged between 4 and 16 years old. Dental maturity was assessed with Demirjian's method, while skeletal maturity was assessed with the cervical vertebral maturation method. Standard percentile curves were developed through quantile regression. Advanced (93 boys and 110 girls) and delayed (92 boys and 100 girls) dental maturity groups were defined by the 50th percentile. RESULTS: The advanced group showed earlier skeletal maturity in multiple cervical stages (CS) in both boys (CS 1, 2, 3, 4, and 6) and girls (CS 1, 3, 4, 5, and 6). Significant differences, as determined by Mann-Whitney U tests, were observed in CS 1 for boys (p = 0.004) and in CS 4 for girls (p = 0.037). High Spearman correlation coefficients between dental maturity and cervical vertebral maturity exceeded 0.826 (p = 0.000) in all groups. CONCLUSION: A correlation between dental and skeletal maturity, as well as advanced skeletal maturity in the advanced dental maturity group, was observed. Using percentile curves to determine dental maturity may aid in assessing skeletal maturity, with potential applications in orthodontic diagnosis and treatment planning.

Criteria for early diagnosis of mandibular third molar agenesis based on the developmental stages of mandibular canine, first and second premolars, and second molar: a retrospective cohort study.

BACKGROUND: Permanent first molars with severe dental caries, developmental defects, or involved in oral pathologies are at risk of poor prognosis in children. Accordingly, using the third molar to replace the first molar can be a good treatment option when third molar agenesis is predicted early. Thus, this retrospective cohort study aimed to develop criteria for early detection of mandibular third molar (L8) agenesis based on the developmental stages of mandibular canine (L3), first premolar (L4), second premolar (L5), and second molar (L7). METHOD: Overall, 1,044 and 919 panoramic radiographs of 343 males and 317 females, respectively, taken between the ages of 6 and 12 years were included. All developmental stages of L3, L4, L5, L7, and L8 were analyzed based on the dental age, as suggested by Demirjian et al. The independent t-test was used to assess age differences between males and females. The rank correlation coefficients were examined using Kendall's tau with bootstrap analysis and Bonferroni's correction to confirm the teeth showing developmental stages most similar to those of L8s. Finally, a survival analysis was performed to determine the criteria for the early diagnosis of mandibular third molar agenesis. RESULTS: Some age differences were found in dental developmental stages between males and females. Correlation coefficients between all stages of L3, L4, L5, and L7 and L8 were high. In particular, the correlation coefficient between L7 and L8 was the highest, whereas that between L3 and L8 was the lowest. CONCLUSION: If at least two of the following criteria (F stage of L3, F stage of L4, F stage of L5, and E stage of L7) are met in the absence of L8 crypt, agenesis of L8 can be confirmed.

Dexmedetomidine modulates transient receptor potential vanilloid subtype 1.

Dexmedetomidine, a highly selective alpha-2 adrenergic receptor agonist and novel sedative drug with minimal respiratory suppression, have shown anti-nociceptive activity in various pain models by poorly understood mechanisms. Because alpha-2 adrenergic receptor is co-localized with TRPV1 polymodal nociceptive receptor in dorsal root ganglion neurons and up-regulated in neuropathic pain animal models, the analgesic activity might be mediated through inhibition of TRPV1 in the peripheral nervous system. In an effort to elucidate whether modulatory effect of dexmedetomidine on TRPV1 activity could be the potential peripheral mechanism underlying the antinociceptive effect of dexmedetomidine, intracellular calcium concentration after capsaicin application was investigated in mice dorsal root ganglion (DRG) neurons, with and without pretreatment of dexmedetomidine. Dexmedetomidine (10 µM) reduced capsaicin-induced calcium responses by 29.7 ± 7.39% (n = 34, p < 0.0001), in dose-dependent manner. Higher level of inhibition was observed with increased dose of dexmedetomidine (50 µM, 45.1 ± 8.58%, n = 15, p = 0.0002), and lower inhibition by decreased dose (1 µM, 18.8 ± 1.48%, n = 148, p = 0.004). RT-PCR analysis revealed expression of TRPV1 and alpha-2A, alpha-2B and alpha-2C subtypes of adrenergic receptor in mice DRG neurons, and immunocytochemical analysis revealed co-expression of TRPV1 and alpha-2A receptors in primary cultured DRG neurons. In summary, these results suggested the inhibition of TRPV1 expressed in the primary sensory neurons as a potential mechanism that contributes to the anti-nociceptive action of dexmedetomidine.

Recessive Mutations in ACPT, Encoding Testicular Acid Phosphatase, Cause Hypoplastic Amelogenesis Imperfecta.

Amelogenesis imperfecta (AI) is a heterogeneous group of genetic disorders affecting tooth enamel. The affected enamel can be hypoplastic and/or hypomineralized. In this study, we identified ACPT (testicular acid phosphatase) biallelic mutations causing non-syndromic, generalized hypoplastic autosomal-recessive amelogenesis imperfecta (AI) in individuals from six apparently unrelated Turkish families. Families 1, 4, and 5 were affected by the homozygous ACPT mutation c.713C>T (p.Ser238Leu), family 2 by the homozygous ACPT mutation c.331C>T (p.Arg111Cys), family 3 by the homozygous ACPT mutation c.226C>T (p.Arg76Cys), and family 6 by the compound heterozygous ACPT mutations c.382G>C (p.Ala128Pro) and 397G>A (p.Glu133Lys). Analysis of the ACPT crystal structure suggests that these mutations damaged the activity of ACPT by altering the sizes and charges of key amino acid side chains, limiting accessibility of the catalytic core, and interfering with homodimerization. Immunohistochemical analysis confirmed localization of ACPT in secretory-stage ameloblasts. The study results provide evidence for the crucial function of ACPT during amelogenesis.

Candidate gene sequencing reveals mutations causing hypoplastic amelogenesis imperfecta.

OBJECTIVE: Amelogenesis imperfecta (AI) is a rare hereditary disorder affecting the quality and quantity of the tooth enamel. The purpose of this study was to identify the genetic etiology of hypoplastic AI families based on the candidate gene approach. MATERIALS AND METHODS: We recruited three Turkish families with hypoplastic AI and performed a candidate gene screening based on the characteristic clinical feature to find the pathogenic genetic etiology. RESULTS: The candidate gene sequencing of the LAMB3 gene for family 1 revealed a heterozygous nonsense mutation in the last exon [c.3431C > A, p.(Ser1144*)]. FAM20A gene sequencing for families 2 and 3 identified a homozygous deletion [c.34_35delCT, p.(Leu12Alafs*67)] and a homozygous deletion-insertion (c.1109 + 3_1109 + 7delinsTGGTC) mutation, respectively. CONCLUSION: The candidate gene approach can be successfully used to identify the genetic etiology of the AI in some cases with characteristic clinical features. CLINICAL RELEVANCE: Identification of the genetic etiology of the AI will help both the family members and dentist understand the nature of the disorder. Characteristic clinical feature can suggest possible genetic causes.

Effects of dental treatment and systemic disease on oral health-related quality of life in Korean pediatric patients.

BACKGROUND: The findings that not only dental caries but also systemic disease can exert a negative effect on oral health-related quality of life (OHRQoL), and that dental treatment can improve OHRQoL have been confirmed in multiple studies. The purpose of this study is to investigate the impact of dental treatment on OHRQoL of Korean pediatric patients and the differences in OHRQoL between patients with and without systemic disease. METHODS: All the primary caregivers of pediatric patients who underwent dental treatments under either general anesthesia or intravenous deep sedation at Seoul National University Dental Hospital completed abbreviated versions of the Child Oral Health Impact Profile (COHIP-14) and Family Impact Scale (FIS-12) surveys on OHRQOL pre- and post-treatment (average: 2.4 ± 1.7 months after dental treatment). This is a case control study with patients divided into two groups according to the presence or absence of systemic disease. RESULTS: Data from 93 pediatric patients (46 male and 47 female, average patient age: 5.0 ± 3.4 years) were analyzed to compare OHRQoL before and after treatment with the Wilcoxon signed-rank test and to calculate the effect size using Cohen's d. All of the patients exhibited an improvement in OHRQoL (COHIP-14: p <  0.001, effect size = 1.0; FIS-12: p <  0.001, effect size = 0.7). Patients with systemic diseases demonstrated lower OHRQoL in both pre- and post-treatment surveys than patients without systemic diseases (Wilcoxon Rank-sum test, both COHIP-14 and FIS-12: p <  0.05). The COHIP-14 appears to have a greater impact on the FIS-12 in patients with systemic disease than those without (explanatory power of 65.3 and 44.6%, respectively). CONCLUSIONS: Based on the primary caregivers' perceptions, dental treatment can improve the OHRQoL in Korean pediatric patients. Systemic disease results in a reduced OHRQoL, and the awareness of patients' oral health appeared to have a greater impact on OHRQoL for family members of patients with a systemic disease. TRIAL REGISTRATION: KCT0002473 (Clinical Research Information Service, Republic of Korea) and 22 Sep 2017, retrospectively registered.

Evaluation of Stress Response During Mesiodens Extraction Under General Anesthesia Using Heart Rate Variability.

PURPOSE: Stress related to dental treatment can be associated with negative outcomes. Heart rate variability (HRV) is an objective measurement of autonomic nervous system activity. Therefore, HRV was used to identify autonomic nervous system reactions during mesiodens extraction under general anesthesia in children. MATERIALS AND METHODS: Electrocardiography was performed with customized software during treatment. HRV parameters were analyzed according to time and frequency domains during each dental procedure (local anesthesia, incision, flap, bone removal, extraction of mesiodens, and suturing). The relations of HRV parameters to age also were determined. RESULTS: Total autonomic nervous system activity decreased markedly after local anesthesia injection. Depending on the responses of sympathetic nerve activity, patients were categorized in a stress group and a nonstress group. The ratio of low-frequency power (LF) to high-frequency power (HF), an indication of sympathetic and parasympathetic balance, increased in the stress group after incision and flap formation. Conversely, the LF/HF ratio decreased during treatment in the nonstress group. However, HR, widely used to evaluate stress responses, did not change statistically during mesiodens extraction in either group. HRV parameters did not differ statistically according to age. CONCLUSIONS: The internal stress related to mesiodens extraction can be evaluated more objectively with HRV parameters than with conventional methods. Sympathetic nerve activity in the stress group differed from that in the nonstress group during the treatment procedures.

Novel FGF10 mutation in autosomal dominant aplasia of lacrimal and salivary glands.

OBJECTIVE: Aplasia of lacrimal and salivary glands (ALSG) is a rare autosomal dominant inherited disease, characterized by aplasia, atresia, or hypoplasia of the lacrimal and salivary systems with variable expressivity. The purpose of this study was to identify genetic etiology of an ALSG family. MATERIALS AND METHODS: We recruited a Turkish family with ALSG and performed a mutational analysis, based on the candidate gene approach, to clarify the molecular genetic etiology. RESULTS: The candidate gene sequencing of the FGF10 gene identified a novel heterozygous nonsense mutation (c.237G > A, p.Trp79*) in the exon 1. CONCLUSION: The identified novel mutation would result in a haploinsufficiency of the FGF10, because of nonsense-mediated mRNA decay caused by a premature stop codon. This report further confirms that ALSG is caused by the haploinsufficiency of functional FGF10. CLINICAL RELEVANCE: Identification of the genetic etiology of the ALSG will help both the family members and dentist understand the nature of the disorder. Therefore, it will positively motivate oral health care to avoid further destruction of the tooth due to the lack of salivary production.

Colorimetric distribution of human attached gingiva and alveolar mucosa.

STATEMENT OF PROBLEM: Few studies have investigated the colorimetric distribution of gingival color, including the posterior area and alveolar mucosa. PURPOSE: The purpose of this in vivo study was to investigate the distribution of colorimetric values in different areas of gingiva and to determine its relationship to colorimetric findings of the tooth and skin in a young Korean population. MATERIAL AND METHODS: Participants included 40 periodontally healthy adults (22 men and 18 women) 25 to 36 years of age. Commission Internationale de l'Eclairage values (CIELab: L* lightness, a* green-red, and b* blue-yellow) were measured using a colorimeter at a total of 23 sites for each participant, including attached gingiva (AG) and alveolar mucosa (AM) in the maxillary and mandibular and incisor and molar regions, maxillary central incisor, and skin points of the glabella, cheek, and inner upper arm. RESULTS: AG showed higher L* and lower a* values than AM. AG demonstrated higher L* and lower a* values in the maxillary region than in the mandibular region and higher b* values in the incisor region than in the molar region. AM revealed higher L* and lower a* and b* values in the incisor region than in the molar region. Positive significant correlations were found for L* between the skin area and AM and for b* between the skin area and AG. CONCLUSIONS: The colorimetric values of AG and AM differ according to the area, possibly as a result of differences in anatomic and histologic distribution that influence optical properties.

Development of a Web-Based Nationwide Korean Pediatric Dental Sedation Registry.

OBJECTIVE: Finding a balance between sedation efficacy and safety remains an ongoing challenge. In children, the risk of sedation-related complications is relatively high. It is of utmost importance to determine the factors related to improved overall sedation outcomes. However, most previous reports have been based on small samples at single institutions. The Korean Academy of Pediatric Dentistry (KAPD) developed a Korean Pediatric Dental Sedation Registry using a web-based platform. STUDY DESIGN: Specialists in pediatric dental sedation selected the itemized list included within the registry through an extensive literature review. The web-based registry was built into the KAPD homepage to facilitate easy access to the sedation data. All teaching and university hospitals agreed to participate in the Korean Pediatric Dental Sedation Registry. CONCLUSION: This is the first attempt to collect sedation data on a nationwide scale in the field of pediatric dentistry. The sedation database established with the registry may facilitate standardizing and improving pediatric dental sedation clinical practices.

Oxygen saturation and perfusion index from pulse oximetry in adult volunteers with viable incisors.

OBJECTIVE: Evaluation of pulp vitality is an important diagnostic procedure in dentistry. Conventional techniques for measurement of pulp vitality, including thermal stimulation, electrical stimulation, or direct dentin stimulation, are frequently associated with false positive or false negative results. Recently, oxygen saturation from pulse oximetry has been utilized in the evaluation of pulp vitality. Perfusion index (PI) data calculated from photoplethysmography have been widely used to evaluate peripheral perfusion. The combination of oxygen saturation and PI may aid in the accurate measurement of pulp vitality. We aimed to investigate the baseline values of oxygen saturation and PI using pulse oximetry in adult volunteers. MATERIAL AND METHODS: Fifteen adult volunteers with viable incisors were tested. To measure PI, a fabricated oxygen sensor was applied to an incisor without a pulp lesion while oxygen saturation was simultaneously measured in the finger. Oxygen saturation and PI were continuously measured with customized software. The normal reference values of oxygen saturation and PI were obtained by analyzing the recorded data. RESULTS: Pulse oximetry showed relatively stable, objective, and accurate oxygen saturation results. The tooth oxygen saturation ranged from 97% to 100%. The PI ranged from 0.3% to 0.5%, and PI and oxygen saturation showed relatively consistent values across subjects. CONCLUSIONS: Although there are some limitations to our study, these results may prove useful for detecting teeth with impaired vitality and non-invasively differentiating between necrotic and vital pulp.

The post-traumatic colour change of primary incisors: a colourimetric and longitudinal study.

BACKGROUND: Tooth colour change after trauma has been described subjectively as ranging from yellow/pink to grey/black. AIM: To investigate the longitudinal colourimetric change of post-traumatic discoloured primary incisor using an intraoral colourimeter. DESIGN: A total of 34 primary incisors from 15 boys and eight girls were studied. The mean post-injury day during clinic visits (SD) and number of visit was 205.4 (194.8) and 3.9 (2.0). CIE L* (lightness), a* (green-red) and b* (blue-yellow) of the maxillary primary incisors were measured at every visit. The colour difference (ΔE*ab ) was calculated between the traumatized tooth and the control. Scatter graphs were made depicting the colour change of discoloured teeth and the ΔE*ab over time. RESULTS: Mean CIE L*, a* and b* of the unaffected control were 80.8 (2.29), 0.9 (0.77) and 13.1 (2.67), respectively. L* gradually decreased to 70.7 (on day 71), then slowly recovered. a* increased to 3.7 (day 29) and decreased slowly. b* only demonstrated a small change that was within the control range during the follow-up. ΔE*ab increased to 9.58 (day 56) and decreased slowly. CONCLUSION: The earlier recovery of a* was followed by the recovery of L*. During the post-traumatic period, ΔE*ab failed to reach the clinically acceptable threshold.

Usefulness of permutation entropy as an anesthetic depth indicator in children.

Permutation entropy (PE) as a complexity measure has been introduced to monitor anesthetic depth for adult. However, PE has not yet been evaluated for its clinical applicability as an indicator of anesthetic depth in children. Therefore, in order to investigate the validity of PE, we compared PE with BIS using pharmacodynamic (PD) modeling in children. Electroencephalogram (EEG) was obtained from BIS monitor during sevoflurane deepening and lightening protocol. End-tidal sevoflurane concentration (Etsevo) and BIS were measured simultaneously. PE was calculated from the processed EEG with the scale ranging from 0 to 100. NONMEM software was used to investigate the PD relationship between Etsevo with BIS and PE. Adjusted PE (APE) values were decreased as anesthesia deepened. APE and BIS showed significant linear correlation (P < 0.001), indicating that PE also reflects anesthesia depth. PD parameters for APE and BIS were estimated with a sigmoid Emax model which describes the relationship between Etsevo and APE/BIS (E o : 78, E max : 17.6, C e50 : 2.5 vol%; γ: 13.1, k eo : 0.47 min(-1) for APE; E o : 89.4; E max : 15.7; C e50 : 2.2 vol%; γ: 6.6, keo: 0.52 min(-1) for BIS). PE seems to be a useful indicator of anesthetic depth, which is comparable to BIS in children.

Clinical Usefulness of Proseal Laryngeal Mask Airway for Anesthesia during Dental Procedures in Children.

AIM: Although the Proseal laryngeal mask airway (PLMA) has been widely used in anesthesia, little is known about its clinical effectiveness during dental procedures. We describe the clinical feasibility of the PLMA for managing airways in the field of pediatric dentistry. . STUDY DESIGN: We reviewed the medical records of children who underwent airway management with the use of the PLMA from January 2011 to December 2012 at an outpatient facility at Seoul National Dental University Hospital. RESULTS: During the study period, the airways of 19 children were managed with the PLMA for dental procedures. During its placement, blood pressure and heart rate were stably maintained. There were no interruptions of the dental procedures. None of the children experienced oxygen desaturation or ventilation difficulty. In one patient, the PLMA was dislodged for a short time, but the problem was easily solved with repositioning. After transferring to the post-anesthetic care unit, there were no incidences of oxygen desaturation or vomiting. All of the children were discharged from the hospital without complications. CONCLUSION: The PLMA can be successfully used in airway management during dental treatment in children.

Secular changes in dental development of Korean children aged 4 to 16 years over a 10-year period.

This study evaluated 10-year secular changes in dental maturity and dental development among Korean children. A retrospective analysis of panoramic radiograph samples from Korean children (4-16 years old) taken in 2010 and 2020 was conducted. The 2010 group consisted of 3491 radiographs (1970 boys and 1521 girls), and the 2020 group included 5133 radiographs (2825 boys and 2308 girls). Using Demirjian's method, dental maturity scores and dental developmental stages were assessed. For intra-observer reliability, Weighted Cohen's kappa was used, and Mann-Whitney U tests were performed to compare the 2020 and 2010 groups. A slight acceleration in dental maturity was observed in both boys and girls, with the difference being more noticeable in boys at an earlier age. Statistically significant differences were noted at ages 4, 5 and 7 for boys, and at age 6 for girls. Despite these differences, the individual dental development stages of 2020 and 2010 showed inconsistent trends with limited differences. Generally, girls demonstrate more advanced dental maturity than boys. A slight acceleration in Korean children's dental maturity was observed over a 10-year period when comparing the 2020 groups to the 2010 groups.

Image segmentation of impacted mesiodens using deep learning.

This study aimed to evaluate the performance of deep learning algorithms for the classification and segmentation of impacted mesiodens in pediatric panoramic radiographs. A total of 850 panoramic radiographs of pediatric patients (aged 3-9 years) was included in this study. The U-Net semantic segmentation algorithm was applied for the detection and segmentation of mesiodens in the upper anterior region. For enhancement of the algorithm, pre-trained ResNet models were applied to the encoding path. The segmentation performance of the algorithm was tested using the Jaccard index and Dice coefficient. The diagnostic accuracy, precision, recall, F1-score and time to diagnosis of the algorithms were compared with those of human expert groups using the test dataset. Cohen's kappa statistics were compared between the model and human groups. The segmentation model exhibited a high Jaccard index and Dice coefficient (>90%). In mesiodens diagnosis, the trained model achieved 91-92% accuracy and a 94-95% F1-score, which were comparable with human expert group results (96%). The diagnostic duration of the deep learning model was 7.5 seconds, which was significantly faster in mesiodens detection compared to human groups. The agreement between the deep learning model and human experts is moderate (Cohen's kappa = 0.767). The proposed deep learning algorithm showed good segmentation performance and approached the performance of human experts in the diagnosis of mesiodens, with a significantly faster diagnosis time.

Deep sedation with sevoflurane insufflated via a nasal cannula in uncooperative child undergoing the repair of dental injury.

Sevoflurane, a potent volatile anesthetic, has been attempted to be used for procedural sedation. Because of lack of a commercially available sedation apparatus for sevoflurane administration, anesthetic gas delivery apparatus should be connected to general anesthetic machine for delivering sevoflurane gas. In this case, deep sedation was maintained during treatment of dental injuries involving the upper lip and incisor by sevoflurane insufflations via a nasal cannula. Especially, this may be advantageous in treating dental injuries involving upper lip and maxillary anterior teeth because the treatment is not disturbed during sevoflurane insufflations via a nasal cannula.

Deep sedation with sevoflurane inhalation via a nasal hood for brief dental procedures in pediatric patients.

Nitrous oxide is widely used for dental sedation. However, weak potency of nitrous oxide requires additional sedatives for maintaining a deeper level of sedation. Sevoflurane, a mainstay in pediatric anesthesia, is a potent anesthetic agent. Some attempts have been made to use sevoflurane for conscious sedation. In this case, we successfully treat pediatric patients under deep sedation by sevoflurane inhalation without other sedatives. Sevoflurane may be useful for sedation in pediatric dental outpatient setting.