Systematic comparison of machine learning algorithms to develop and validate predictive models for periodontitis.

AIM: The aim of this study was to compare the validity of different machine learning algorithms to develop and validate predictive models for periodontitis. MATERIALS AND METHODS: Using national survey data from Taiwan (n = 3453) and the United States (n = 3685), predictors of periodontitis were extracted from the datasets and pre-processed, and then 10 machine learning algorithms were trained to develop predictive models. The models were validated both internally (bootstrap sampling) and externally (alternative country's dataset). The algorithms were compared across six performance metrics ([i] area under the curve for the receiver operating characteristic [AUC], [ii] accuracy, [iii] sensitivity, [iv] specificity, [v] positive predictive value, and [vi] negative predictive value) and two methods of data pre-processing ([i] machine-learning-based feature selection and [ii] dimensionality reduction into principal components). RESULTS: Many algorithms showed extremely strong performance during internal validation (AUC > 0.95, accuracy > 95%). However, this was not replicated in external validation, where predictive performance of all algorithms dropped off drastically. Furthermore, predictive performance differed according to data pre-processing methodology and the cohort on which they were trained. CONCLUSIONS: Larger sample sizes and more complex predictors of periodontitis are required before machine learning can be leveraged to its full potential.

Effectiveness of a 30-year periodontist's primary care for 1946 patients during five-year follow-up.

OBJECTIVE: To evaluate the effect of the periodontal primary care (PPC) on the improvement of periodontal probing depth based on a periodontist's 30-year practice. MATERIALS AND METHODS: We enrolled a total of 2,894 patients who underwent periodontal basic treatment between 1987 and 2017 with 84.5% retention rate. The study population was composed of 80% (n = 1,946) of retained patients with complete re-evaluation up to five-year follow-up. The outcome was measured by the improvement of probing depths (graded as 1:1-3 mm; 2:4-6 mm; 3: ≥7 mm) before and after PPC on both sextant and patient levels. Whether a better improvement was seen in the surgical group and the non-smoker group opposed to their comparators was assessed with various multi-variable regression models. RESULTS: On patient (sextant) level, 82% (38%) improved, 13% (59%) unchanged, and 5% (3%) deteriorated. Adjusted better improvement of probing depth was noted for the surgical group by 63% and non-smoker by 31% compared with their counterparts. The similar findings were found for the outcomes based on continuous probing depth scores. CONCLUSIONS: We demonstrate the improvement of probing depth scores with a periodontal primary care offered for the retained patients and larger effect for the surgical group and non-smoker patients.

Dental education changed by COVID-19: Student's perceptions and attitudes.

BACKGROUND: Dental students have encountered changes in the teaching format amid the SARS CoV-2 pandemic. This study aims to evaluate the attitudes of dental students of one medical university toward online courses and compare them with those of non-dental students amid the SARS CoV-2 pandemic. METHODS: A cross-sectional survey with a self-report online questionnaire was conducted at the medical university in May 2020 in Taipei. Students from the School of Dentistry, School of Dental Technology, and School of Oral Hygiene Study were enrolled in our survey. RESULTS: In total, 473 students responded to the survey, 318 (67.2%) of whom were dental students. Overall, 366 (77%) students agreed with the change to online learning. Only 10.4% of students thought that dental professional courses with a laboratory format could be changed to online courses. Dental students were significantly more worried than non-dental students about being infected with COVID-19 and about the COVID-19 pandemic continuing. CONCLUSIONS: In conclusion, changing to online learning seems to be perceived as feasible by students. However, more discussion about changing dental professional courses with a laboratory format to online courses considering the attitudes from students is needed.

The impact of COVID-19 on knowledge, attitude, and infection control behaviors among dentists.

BACKGROUND: This study seeks to elucidate the impact of COVID-19 on knowledge, attitude, and infection control behaviors among dentists. METHODS: Changes in knowledge, attitude, and infection control behaviors reported in 2020 (COVID-19 period) were compared to the historical control of the non-COVID-19 period in 2018. A proportional random sampling method was used to select the study samples from 400 dental institutions. The response rate was 69% in 2018 and 62.8% in 2020. A total of 276 dentists in 2018 and 251 dentists in 2020 responded to this questionnaire. Multiple logistic regression was used to assess the associations between factors and recommended infection control practices. RESULTS: High rates of correct COVID-19 knowledge (94.76%), fears of being infected with the virus (94%) and use of personal protective equipment (mask, glove and protection gown; 95%) were reported. We found that knowledge regarding environmental infection control, HIV transmission, and the window of HIV transmission were significantly higher in the post-COVID-19 period compared with the pre-COVID-19 period. High compliance rates of wearing mask, gloves and protection were reported. The number of dentists wearing a hair cap and a protective eye mask/face shield during the pandemic significantly increased compared with that noted before the COVID-19 pandemic. Factors associated with the use of a hair cap and an eye mask/face shield differed between the pre- and post-COVID-19 periods. The factors associated with compliance regarding environment infection control also differed between the pre- and post-COVID-19 periods. CONCLUSION: The significant impact of COVID-19 on the knowledge, attitude, and infection control behaviors among dental care workers was observed in the current study. In particular, the use of hair caps and protective eye mask or face shields as well as environmental disinfection protocols has significantly improved. Trial registration TMU-JIRB: N201804006.

Risk for a second primary hypopharyngeal and esophageal cancer after an initial primary oral cancer.

OBJECTIVE: To investigate the risk for second primary cancer in the hypopharynx and esophagus (SPC-HE) among individuals with an initial oral/oropharyngeal cancer. MATERIALS AND METHODS: Mass screening data from Taiwan (2004-2009) included individuals who were ≥18 years old and smoked cigarettes and/or chewed betel quid. Occurrence of SPC-HE was monitored until December 31, 2014. Results were expressed as adjusted relative risk (aRR) and 95% confidence interval (CI). RESULTS: One hundred and fifty-eight out of 4,494 subjects with oral cancer developed SPC-HE (incidence rate: 6.47 per 1,000 person-years). Relative to patients with primary cancers in the lip, the risk of an SPC-HE was higher in patients with primary cancers in oropharynx (aRR: 19.98, 95% CI: 4.72-84.55), floor of mouth (aRR: 12.13, 95% CI: 2.67-55.15), and hard palate (aRR: 7.31, 95% CI: 1.65-32.37), but not in patients with cancers in tongue (aRR: 3.67, 95% CI: 0.89-15.17) or gum (aRR: 3.99, 95% CI: 0.92-17.35). Regression analyses also showed the risk of an SPC-HE was greater in alcohol drinkers than those who did not (aRR: 1.65, 95% CI: 1.10-2.48). CONCLUSIONS: Compared with the initial cancer in the lip, patients with a cancer in the oropharynx, floor of mouth, and hard palate had a higher risk for the SPC-HE.

A population-based study on the association between the intake of soft drinks and periodontal disease in Taiwanese adults aged 35-44 years (KCIS no. 33).

OBJECTIVE: To elucidate the association between the intake of soft drinks and periodontal disease (PD) among Taiwanese middle-aged adults. DESIGN: The cross-sectional design was employed to assess a dose-response relationship between the intake of soft drinks and PD after controlling for relevant confounding factors, with adjusted odds ratios obtained from a multivariate logistic regression model. SETTING: Keelung Community-based Integrated Screening (KCIS) programme, Keelung, Taiwan. SUBJECTS: Participants (n 10 213) aged 35-44 years who had undergone oral checks for PD between 2005 and 2009. RESULTS: A dose-response relationship between the intake of soft drinks and elevated risk for PD defined by community periodontal index ≥3 (the current status of PD) was noted (P=0·02 by trend test). Compared with infrequent intake of soft drinks (≤2 times/week), the adjusted OR increased from 1·05 (95 % CI 0·92, 1·20) for the frequency of 3-4 times/week to 1·17 (95 % CI 1·03, 1·34) for the frequency of ≥5 times/week. A similar trend (P<0·01) was also observed for PD defined by loss of attachment ≥1 (representing the long-term cumulative gum damage due to PD). CONCLUSIONS: A dose-response relationship between the intake frequency of soft drinks and PD was observed in Taiwanese middle-aged adults. Such evidence could be used in health promotion to support reductions in soft drink intake.

The performance of the two-year postgraduate year dentist training program in Taiwan.

Background/purpose: The postgraduate year dentist training program (PGYD) officially implemented in 2010. This study aimed to assess PGYD trainees' subjective satisfaction perception and objective competence performance according to different training institutions (either dental clinics or hospitals). Materials and methods: A nationwide cross-sectional survey was conducted in 2018. Subjective satisfaction questionnaires from 222 PGYD trainees and 166 PGYD trainees' scores of objective structured clinical examinations (OSCEs) were collected for analysis. The t-test and logistic regression were used to compare differences between two groups. Results: In subjective satisfaction, PGYD trainees in hospitals revealed less positive perceptions on teachers (odds ratios [ORs] range: 0.33-0.7) and on training plans and auxiliary facilities (ORs range: 0.23-0.69), but they had more opportunities to attend and present at professional meetings than those in clinics. In PGYD trainees' opinion, the optimal training period allocation was 25% in hospitals and 75% in clinics. Overall, trainees in hospitals had better OSCE scores than those in clinics (OR [95% confidence interval, CI]: 3.12 [1.68-5.79]), except for the item of "the relation between physical condition and dental treatment outcome" (0.3 [0.1-0.97]). Conclusion: PGYD trainees in dental clinics have more positive perceptions on teachers and on training plans and auxiliary facilities, but PGYD trainees in hospitals have better OSCE scores. PGYD trainees prefer to be trained in clinics for a better connection with future careers, while hospitals can offer better training for PGYD trainees to become independent dentists because they have better training environment and more educational resources.

A comparative study of propofol alone and propofol combined with midazolam for dental treatments in special needs patients.

ABSTRACT: Although dental treatment with sedation is performed increasingly in special needs patients, data on adding midazolam to intravenous propofol sedation are very limited for this group. The purpose of this study was to identify the factors and procedure time associated with the use of intravenous sedation with propofol alone or propofol combined with midazolam in dental patients with special needs.This was a retrospective data analysis. The sedation medications and relevant covariates, including demographic parameters, disability levels, oral health conditions, dental procedures, treatment time, and side effects, of 718 patients with special needs were collected between April 2013 and September 2014. The unfavorable side effects by sedation types were reported. Factors associated with procedure time and the sedation medications were assessed with multiple logistic regression analyses.Of 718 patients, 8 patients experienced unfavorable side effects (vomiting, sleepiness, or emotional disturbance) after the dental procedures; the rate was 0.6% in the 509 patients who received propofol only. In 209 patients who received propofol and midazolam, 2.4% experienced the side effects. Sedation time was associated with body mass index (BMI) < 25 (adjusted odds ratio [aOR] = 1.45, 95% confidence interval [CI]: 1.04-2.04) and the performance of multiple dental procedures (aOR = 1.44, 95% CI: 1.06-1.97) but not associated with the sedation types. A significant odds ratio for the combined use of propofol and midazolam was shown for adolescents (aOR = 2.22, 95% CI: 1.28-3.86), men (aOR = 2.05, 95% CI: 1.41-2.98), patients with cognitive impairment (aOR = 1.99, 95% CI: 1.21-3.29), and patients undergoing scaling procedures (aOR = 1.64, 95% CI: 1.13-2.39).With the acceptable side effects of the use of propofol alone and propofol combined with midazolam, multiple dental procedures increase the sedation time and the factors associated with the combined use of propofol and midazolam are younger age, male sex, recognition problems, and the type dental procedure in the dental treatment of patients with special needs.

The Association between Bone Mineral Density and Periodontal Disease in Middle-Aged Adults.

The association between osteoporosis and periodontal disease (PD) has been revealed by previous studies, but there have been few studies on the association in younger adults. We enrolled a total of 7298 adults aged 40 to 44 who underwent PD screening between 2003 and 2008. Data on quantitative ultrasound for the measurement of bone mineral density (BMD) were collected for the diagnostic criteria of osteopenia and osteoporosis. The Community Periodontal Index (CPI) was measured for defining PD. A multiple logistic regression model was used to assess the effect of low bone mass on the risk of PD. Of 7298 enrollees, 31% had periodontal pockets >3 mm, 36.2% had osteopenia, and 2.1% had osteoporosis. The 39.8% of PD prevalence was high in adults with osteoporosis, followed by 33.3% in osteopenia. A negative association was found between BMD and CPI value (p < 0.0001). Low bone mass was associated with the risk of PD (adjusted OR: 1.13; 95% CI:1.02-1.26) after adjusting the confounding factors, including age, gender, education level, overweight, smoking status, past history of osteoporosis, and diabetes mellitus. An association between BMD and PD among young adults was found. An intervention program for the prevention of PD and osteoporosis could be considered starting in young adults.

Clinical Orodental Anomalies in Taiwanese Children under Age Six: a Study Based on the 1995-1997 National Dental Survey.

There are few published studies that report the prevalence of intraoral anomalies for young children. The purpose of this study was to investigate the prevalence and distribution of several congenital oral and paraoral anomalies in Taiwanese children under age six. Twenty-five cities and townships were randomly sampled in different areas of Taiwan using the stratified method. These cities and townships represent cross-sectional samples of geographic locations and socioeconomic levels. A total of 981 Taiwanese children under age six were examined with dental mirrors and explorers as part of the national dental survey. The results of this survey indicated an 11.31% prevalence of geographic tongue. This number is higher than that reported in studies previously performed in different countries. The occurrence of double teeth in primary dentition was found to be 2.14%. Ankyloglossia had a frequency of 1.22%, and primary talon cusp a frequency of 0.61%. Seven (0.71%) children exhibited fissured tongues. Thirteen (1.33%) cases of hypodontia were found. These values were different from those reported in several other countries, which may be attributed to differences in the ethnic and racial composition of the population studied.

Hand hygiene compliance and accuracy in a university dental teaching hospital.

OBJECTIVE: This study aimed to evaluate compliance with guidelines on hand hygiene by examining five handwashing categories in postgraduate year (PGY) dentists at a university teaching hospital and to evaluate the accuracy rates of handwashing. METHODS: Through direct observation, trained PGY dentists were monitored throughout their daily care routine of before contact with patients, before using an instrument, after contact with patients, upon direct exposure to patients' fluids, and while touching the patients' surrounding area. Hand hygiene opportunities were considered complete in each category. A total of 16,597 hand hygiene opportunities across 37 individuals were observed from July to October 2012 and from September to October 2013. RESULTS: The overall handwashing compliance rate was 34.7%. The handwashing compliance rate was higher during work in oral surgery services (92.8%) than during work in general clinical practice (34.2%). The accuracy rate of handwashing was also higher during work in oral surgery services (87.5%) than during work in general clinical practice (51.0%). Similar results were obtained across all five handwashing categories. CONCLUSIONS: Handwashing compliance and accuracy rates are low in PGY dentists. More education and continuous monitoring are suggested to improve handwashing compliance, as well as the correct handwashing procedures for dentists.

Impact of varying anatomic sites on advanced stage and survival of oral cancer: 9-year prospective cohort of 27 717 cases.

BACKGROUND: To elucidate the impact of varying anatomic sites on advanced stage of and death from oral cancer. METHODS: A total of 27 717 oral cancers mainly from a population-based visual inspection program in Taiwan from 2004 to 2009 was followed until the end of 2012. RESULTS: Using lip cancer as reference, the odds ratios (95% confidence interval [CI]) of advanced stage of cancer were 2.20 (1.92-2.51) for tongue, 2.60 (2.28-2.97) for buccal, 2.68 (2.20-3.28) for floor of mouth, 2.96 (2.52-3.47) for hard palate, 6.04 (5.17-7.05) for gingiva, and 10.83 (9.20-12.74) for oropharynx. The estimated hazard ratios (95% CI) for oral cancer death increased from 1.48 (1.31-1.67) in buccal, 1.61 (1.43-1.82) in tongue, 1.68 (1.41-1.99) in floor of mouth, 1.79 (1.57-2.05) in gingiva, 1.97 (1.71-2.26) in hard palate, and 2.15 (1.89-2.45) in oropharynx. CONCLUSION: Different anatomic sites had variations in advanced stage of and death from oral cancer and need vigilant surveillance.

Receiver Operating Characteristic Curve-Based Prediction Model for Periodontal Disease Updated With the Calibrated Community Periodontal Index.

BACKGROUND: The accuracy of a prediction model for periodontal disease using the community periodontal index (CPI) has been undertaken by using an area under a receiver operating characteristics (AUROC) curve. How the uncalibrated CPI, as measured by general dentists trained by periodontists in a large epidemiologic study, and affects the performance in a prediction model, has not been researched yet. METHODS: A two-stage design was conducted by first proposing a validation study to calibrate CPI between a senior periodontal specialist and trained general dentists who measured CPIs in the main study of a nationwide survey. A Bayesian hierarchical logistic regression model was applied to estimate the non-updated and updated clinical weights used for building up risk scores. How the calibrated CPI affected performance of the updated prediction model was quantified by comparing AUROC curves between the original and updated models. RESULTS: Estimates regarding calibration of CPI obtained from the validation study were 66% and 85% for sensitivity and specificity, respectively. After updating, clinical weights of each predictor were inflated, and the risk score for the highest risk category was elevated from 434 to 630. Such an update improved the AUROC performance of the two corresponding prediction models from 62.6% (95% confidence interval [CI]: 61.7% to 63.6%) for the non-updated model to 68.9% (95% CI: 68.0% to 69.6%) for the updated one, reaching a statistically significant difference (P <0.05). CONCLUSION: An improvement in the updated prediction model was demonstrated for periodontal disease as measured by the calibrated CPI derived from a large epidemiologic survey.