Automated Detection and Classification of Oral Squamous Cell Carcinoma Using Deep Neural Networks.

This work aims to classify normal and carcinogenic cells in the oral cavity using two different approaches with an eye towards achieving high accuracy. The first approach extracts local binary patterns and metrics derived from a histogram from the dataset and is fed to several machine-learning models. The second approach uses a combination of neural networks as a backbone feature extractor and a random forest for classification. The results show that information can be learnt effectively from limited training images using these approaches. Some approaches use deep learning algorithms to generate a bounding box that can locate the suspected lesion. Other approaches use handcrafted textural feature extraction techniques and feed the resultant feature vectors to a classification model. The proposed method will extract the features pertaining to the images using pre-trained convolution neural networks (CNN) and train a classification model using the resulting feature vectors. By using the extracted features from a pre-trained CNN model to train a random forest, the problem of requiring a large amount of data to train deep learning models is bypassed. The study selected a dataset consisting of 1224 images, which were divided into two sets with varying resolutions.The performance of the model is calculated based on accuracy, specificity, sensitivity, and the area under curve (AUC). The proposed work is able to produce a highest test accuracy of 96.94% and an AUC of 0.976 using 696 images of 400× magnification and a highest test accuracy of 99.65% and an AUC of 0.9983 using only 528 images of 100× magnification images.

Measuring buccolingual inclination of mandibular canines and first molars using CBCT.

OBJECTIVES: To develop a reliable method to measure buccolingual inclination of mandibular canines and first molars, and to evaluate a possible correlation between buccolingual inclination with their respective interdental width. METHODS: The sample consisted of 37 boys and 41 girls untreated orthodontic patients averaging 13.2±0.96 years. A line tangent to the inferior border of the mandible and the long axis of the tooth measured buccolingual inclination. Intercanine and intermolar widths were measured on casts. RESULTS: Reliability (ICC) values were >0.94. The mean mandibular canine inclination was 98.0±4.1°, with mean width 26.0±2.2 mm. The mean mandibular molar inclination was 74.6±4.7° with mean width 40.9±2.7 mm. First molar inclination of Class II molar subjects (73.7±4.2°) was significantly less (p≤0.05) than of Class I subjects (75.6±4.9°). There were low correlations between interdental width and buccolingual inclination. CONCLUSIONS: A practical and reliable method to measure buccolingual inclination of mandibular canines and first molars is here described using Cone Beam Computed Tomography and a commercially available DICOM software.

The Yelandur study: a community-based approach to epilepsy in rural South India--epidemiological aspects.

Data on the epidemiology of epilepsy in a rural community in a developing country would be of value in planning a decentralized management of this malady in its early stages commensurate with available local resources. A detailed screening instrument covering various seizure types was used by trained paramedical workers in a door-to-door survey of a population of 64,963 in rural South India. The prevalence period was from 1 April 1990 to 31 March 1991. The crude prevalence rate per 1000 for active epilepsy was 4.38 for males, 3.40 for females and 3.91 for both. The minimum and maximum prevalence rates, the latter computed from a validation sample, were 3.91 and 4.63 for active epilepsy; 0.28 and 0.77 for inactive epilepsy and 4.19 and 5.41 for life-time prevalence. In addition, corresponding figures for hot-water epilepsy, a type of reflex epilepsy peculiar to this area, were 2.49 and 2.99 for active phase; 0.35 and 0.85 for inactive phase and 2.85 and 3.83 for life-time prevalence. The incidence rate for epilepsy was 49.3 per 100,000, the same as in developed countries. These data do not support the concept that the prevalence of epilepsy in developing countries is twice that in the developed world. However, the role of local/regional variations should be borne in mind before extrapolating the figures to an entire country.

Dental caries experience among school children in St. Vincent and The Grenadines: report of the first national oral health survey.

OBJECTIVE: To determine the prevalence and severity of dental caries among school children of St. Vincent and The Grenadines. Also, to establish baseline data on dental caries and determine the extent to which the present oral health care system is meeting dental needs. BASIC RESEARCH DESIGN: National cross-sectional survey utilising the World Health Organization's pathfinder methods. Dental examinations were conducted from October to November 1991 by three trained examiners. PARTICIPANTS: A total of 1648 students, 21% of school children in St. Vincent and The Grenadines, were sampled through multistage systematic sampling. OUTCOME MEASURES: Dental caries was diagnosed clinically according to the World Health Organization's diagnostic criteria. RESULTS: Caries prevalence in the permanent dentition was 69.4%, ranging from 68 to 73% according to gender and geographic location. In the primary dentition caries prevalence was 76.6%. Mean DMFT for the survey population was 2.69, dmft was 3.25, while the DMFT scores for gender and location types varied from 2.39 to 3.25. DMFT at 12 years was 3.25. No difference in caries prevalence was observed between gender in the permanent dentition but prevalence was significantly different in the primary dentition being higher among boys. Prevalence was significantly higher in the urban population relative to the rural population. The decayed component constituted 92% of DMFT and 91% of dmft. CONCLUSION: Moderate caries severity and high levels of untreated decay were found in both primary and permanent teeth. The results emphasise the need for continuous surveillance and for appropriate intervention and prevention programmes.

Oral health status, knowledge, and practices in an Amish population.

This study was conducted in the summer of 1985 to assess the oral health status, knowledge, and practices of an Amish population in southwest Michigan. Dental caries experience, periodontal health, and oral hygiene status were recorded using decayed, missing, and filled surfaces (DMFS), periodontal index (PI), and simplified oral hygiene index (OHI-S). Data on oral health knowledge and practices were collected by interviews using a structured questionnaire. Results showed significantly lower levels of disease among Amish. DMFS scores for 5-17-year-old Amish children were almost half that of the US general population (NIDR 1979-80). PI score of all ages combined was 2.0, which was 3.6 times lower than a national sample (1971-74). Lower levels of disease in Amish could be related to their way of life and dietary patterns. A relatively higher level of unmet need for prosthodontic care, inadequate oral health knowledge, and barriers to dental care in the study population emphasize the need for dental public health and health education programs.

Training status and interest in certification of nondiplomate faculty teaching predoctoral dental public health.

OBJECTIVES: A survey was conducted to better understand the training needs of faculty members without dental public health (DPH) specialty board certification who teach DPH to dental students. METHODS: An 11-item questionnaire was sent to 193 non-DPH diplomate faculty members at US dental schools who were dentists and at least one of the following: a member of the American Association of Dental Schools Community and Preventive Dentistry Section, a referral from an academic American Board of Dental Public Health diplomate, a DPH faculty listed on the school's Web pages, a DPH contact from the AADS Institutional Directory, or the school's dean if no other contact. RESULTS: A 70 percent response rate was obtained. Seventy-nine percent of the respondents taught at least one national board-related DPH topic. Among these faculty members, 67 percent have or are in training for the master of public health, 26 percent have completed or are in a DPH residency, and 63 percent desire training in one or more of the DPH topics. The majority (64%) does not plan to take the specialty exam, while 28 percent plan to take the exam within five years. About half reported no personal incentives to take the exam and 39 percent perceived no institutional incentives. CONCLUSIONS: These nondiplomate teachers of predoctoral DPH desire training, but appear to have barriers and perceive few benefits to achieving DPH board certification.

Academic dental public health diplomates: their distribution and recommendations concerning the predoctoral dental public health faculty.

OBJECTIVE: The purpose of this study was to assess the representation of academically based diplomates of the American Board of Dental Public Health (ABDPH) and to identify their perceptions on the training of dental public health predoctoral faculty. METHODS: Data were collected by a mailed, self-administered, 13-item questionnaire. The population was the 48 diplomates of the ABDPH as of March 1997 associated with academic institutions. RESULTS: Twenty of the 55 US dental schools had a diplomate of the ABDPH with a mean of 1.8 diplomates per school with a diplomate. An average of 4.5 full-time faculty members per school were associated with teaching dental public health. A master's degree in public health (MPH) was the most frequently suggested educational requirement for dental public health faculty. Continuing education courses were training needs perceived for dental public health faculty. The lack of time, money, and incentives, along with perceived rigidity of requirements for board certification, were reported as major barriers for faculty becoming dental public health board certified. CONCLUSIONS: Numerous challenges confront the development of a strong dental public health presence in US dental schools. These challenges include, among others, insufficient numbers of academic dental public health specialists and insufficient motivations to encourage promising candidates to pursue specialty status.

Oral diseases and socio-economic status (SES).

OBJECTIVE: To determine the association between social, economic and behavioural risk factors and national prevalences of: oral cancer, dental caries (12-year-olds) and destructive periodontal disease (35-44-year-olds). DATA SOURCES: Sources for the social and economic parameters were the UN Development Program; the behavioural risk factors' source was the World Health Organization, the UN Food and Agricultural Organization and the World Atlas of History. Oral diseases data came from UICC Globocan and the World Health Organization databases. DATA EXTRACTION: Data were extracted by hand from official publications. DATA SYNTHESIS: Data were synthesized and analyzed in sequence using SPSS, Pearson's correlation coefficient and multiple regression analyses. CONCLUSIONS: There is a discernable association between the three oral diseases and the variables selected, which varies in strength, being strongest for chronic destructive periodontitis and weakest for oral cancer. Dental caries lies in between. The degree to which variables account for differences in the three oral diseases between the countries studied is striking, being insignificant for oral cancer incidence, modest for oral cancer mortality, stronger for dental caries and strongest for destructive periodontal disease. Removing variables with strong co-linearity with the Human Development Index has little effect on the regression coefficients.

Dental caries in children under age three attending a university clinic.

PURPOSE: The aim of study was to determine the rates of dental caries and assess the restorative needs of children under three years of age attending an urban university clinic from 1993-1997. METHODS: In this retrospective study, data were abstracted from patient records and included demographic information, caries experience, and restorative needs. RESULTS: Gender distribution of the sample included 55% males and 45% females. The study population was predominantly African-American (51%) and Hispanic (34%), with a mean age of 20 months. A majority of the population had dental benefits through Medicaid (92%). Nearly one-third of the study population and as many as 56% of the children between 24 and 36 months had dental caries. Among those off the bottle (50%), children with severe dental caries had been weaned off the bottle at a significantly older age compared to those without any caries (16.9 vs. 10 months, P = 0.000). CONCLUSIONS: This study provides further validity to the early oral health exam and early dental treatment, not only for preventive measures but also for restorative needs. The relatively high prevalence of early childhood caries could have been prevented by appropriate primary preventive strategies.

Oral health knowledge, attitudes and preventive practices of third grade school children.

PURPOSE: The aim of study was to investigate the oral health knowledge, attitudes and preventive practices of third grade school children in Harris County. METHODS: In this cross-sectional study, oral health knowledge, attitudes, and preventive practices of the children were investigated by means of a self-administered, bilingual questionnaire. Three calibrated examiners collected data on dental caries, periodontitis, and fluorosis of 1,031 school children. RESULTS: Most children reported "fairly adequate" oral hygiene habits (58%) and oral health knowledge (48%), and "adequate" dietary patterns (59%). Children with inadequate oral health knowledge were twice as likely to have caries than children with adequate knowledge (OR = 2.05, 95% CI = 1.29, 3.28). The mean combined DMFT/dft scores of children with inadequate knowledge were significantly higher than the mean for children with adequate knowledge (t = 2.6, P = 0.009). CONCLUSIONS: Results indicate a need to improve oral health knowledge and preventive practices among the study population. Because of the cross-sectional nature of the study, it is not possible to illustrate a cause-effect relationship between oral health education and prevalence of caries.

Comparison of changes in autonomic and respiratory parameters of girls after yoga and games at a community home.

The heart rate, breathing rate, and skin resistance were recorded for 20 community home girls (Home group) and for 20 age-matched girls from a regular school (School group). The former group had a significantly higher rate of breathing and a more irregular breath pattern known to correlate with high fear and anxiety, than the School group. Skin resistance was significantly lower in the School group, which may suggest greater arousal, 28 girls of the Home group formed 14 pairs, matched for age and duration of stay in the home. Subjects of a pair were randomly assigned to either yoga or games groups. For the former emphasis was on relaxation and awareness, whereas for the latter increasing physical activity was emphasized. At the end of an hour daily for six months both groups showed a significant decrease in the resting heart rate relative to initial values (Wilcoxon paired-sample rest), and the yoga group showed a significant decrease in breath rate, which appeared more regular but no significant increase in the skin resistance. These results suggest that a yoga program which includes relaxation, awareness, and graded physical activity is a useful addition to the routine of community home children.

Periodontal health status of school children in St. Vincent and the Grenadines.

A national oral health survey of school children was conducted in October through November 1991. The objective was to determine the periodontal status of school children in St. Vincent and The Grenadines (SVG), the pattern and severity of periodontal disease, estimate treatment needs and provide information for health planners. The study had a cross-sectional design, and 1646 schoolchildren representing all school districts were selected via multistage, systematic sampling. Examinations were conducted by three examiners using CPITN probe. Periodontal indicators and treatment needs were determined using the CPITN index. Calculus was the most prevalent condition with values ranging from 26 to 83 percent, bleeding was the least prevalent condition, while children with healthy indicator were intermediate in prevalence. Subjects with healthy indicators ranged from a low of 12 percent among 15-19 year olds, to a high of 51 percent among seven-year-olds. The mean number of healthy sextants varied from three to five, and mean number of sextants with bleeding or calculus varied from one to three. Oral hygiene instruction (OHI) was the most common treatment need, ranging from 49 to 88 percent. The need for prophylaxis was associated with increase in age, with the highest prophylaxis treatment needs of 83 percent, among 15-19 year olds. No significant differences were observed in periodontal status between gender, and also between urban and rural children. A high prevalence of calculus and bleeding was observed among SVG school children. Study recommends initiation of primary prevention programs in form of health promotion and health education.

Opinions about oral cancer prevention and early detection among dentists practising along the Texas-Mexico border.

OBJECTIVES: The purpose of this study was to assess dentists' opinions about oral cancer (OC) prevention and early detection. METHODS: Data were collected by a self-administered mail questionnaire sent to all 398 registered dentists practising along the Texas-Mexico border. RESULTS: The effective response rate to the survey was 40%. While 90% of respondents agreed that oral cancer examinations (OCE) should be provided annually for patients 40 years of age and older, only 59% of respondents believed their OC knowledge was current. While 99% agreed that dentists were qualified to perform OCE, only 54 and 68% respectively, agreed that dental hygienists and physicians were similarly qualified. Dentists who rated their undergraduate OC training favorably (OR = 2.68, 1.23-5.81, P = 0.011), had attended their last oral cancer continuing education (OCCE) course within the past 5 years (OR = 2.46, 1.25-4.86, P = 0.009), and those who performed OCE on all patients 40 years and older (OR = 2.64, 1.32-5.26, P = 0.005), were more likely to agree their OC knowledge was current. CONCLUSIONS: Respondents expressed diverse opinions about OC prevention and early detection. Positive opinion on currency of OC knowledge was associated with performance of OCE. Results indicate a need for OCCE targeting the study population as well as increased emphasis on OC curriculum in dental schools.

Relationship of dental caries and fluorosis to fluoride supplement history in a non-fluoridated sample of schoolchildren.

A random sample of 206 Michigan children, aged from 9 to 13, were examined for fluorosis from a larger group of 2038 children participating in a dental project. Clinical examinations included caries data (DMFS) and assessment of fluorosis by use of the Tooth Surface Index of Fluorosis (TSIF). Separate examiners were used for each index. The response rate of a questionnaire mailed to parents to gather information on residence histories, use of fluoride supplements, and antibiotics was 78%. The prevalence of fluorosis was about 20% among the respondents. Of the 4868 tooth surfaces examined, 9.2% were affected by fluorosis. In all cases, dental fluorosis was judged as mild, with most occurrences on the posterior teeth. No instances of moderate or severe fluorosis were found. The caries experience of respondents was 1.69 +/- 2.73 DMFS. Caries experience does not appear to be significantly related to income, education, or fluoride supplement use. Approximately 52% of respondents were reported to have taken fluoride supplements with various degrees of consistency. Parents' education was positively related to both prevalence of fluorosis (odds ratio = 2.2) and use of fluoride supplements (odds ratio = 2.7). No significant relation was revealed with evidence of fluorosis and use of supplements. This study shows a relatively mild level of dental fluorosis in a sample of children from a non-fluoridated area. Dental fluorosis in this group does not appear to be related to use of fluoride supplements or differences in caries experience.

Prevalence of fractured incisal teeth among children in Harris County, Texas.

Trauma to the teeth is a common reason for emergency room visits among children, with the maxillary anterior teeth being mostly affected. The consequences of dental trauma include disfigurement, speech defects and psychological effects. This is a cross-sectional study comprising 1039 students, with 47% being males and 53% females. Teeth were examined for physical evidence of trauma. The prevalence of incisal fracture was 2.4% with no significant gender difference (2.9% and 2.0% among males and females, respectively). The male to female prevalence ratio was 1.45 to 1.0. The maxillary incisors accounted for 96% of fractured teeth. Among children with traumatized incisors, 86% had one tooth affected, while 14% had two traumatized teeth. The prevalence of incisal trauma was significantly higher among children of low socioeconomic status (chi2=5.86, P=0.02, df=1). Though African American and Hispanic children had higher prevalence than White children, the differences were not statistically significant. The study reports a low prevalence of incisal trauma among Harris County children and a socioeconomic difference. This study recommends further investigation of incisal trauma in this region as well as educational programs to prevent dental trauma.

Brazilian dental students' knowledge and attitudes towards HIV infection.

The purpose of this study was to investigate a group of Brazilian dental students' knowledge about HIV infection, the infection control measures utilized by the dental students, and students' attitudes towards treating HIV/AIDS patients. The study population consisted of 250 dental students from Universidade Federal da Bahia, Brazil, who were treating patients in clinics of the university and extra-mural rotations at the time of the study. The survey instrument was a self-administered questionnaire which consisted of 32 pre-coded questions and two open-ended questions. The overall response rate to the questionnaire was 54%. More than 80% of respondents (N = 135) considered every dental patient a potential HIV carrier. A majority of the students were aware of the association between HIV and Kaposi's sarcoma (92.5%), oral candidiasis (90.3%) and oral hairy leukoplakia (52.7%). A gender difference was observed in students' knowledge of oral manifestations and infection control measures, with females having better knowledge than males (p < 0.05). Because of certain inadequacies in knowledge and infection control practices among respondents, a curriculum focusing on the management of HIV/AIDS, including infection control and legal issues is recommended.

Effects of posterior teeth replacement on temporomandibular joint sounds: a preliminary report.

Previous reports have shown the prevalence of jaw clicking to be significantly higher in a population with missing posterior teeth compared with an dentulous population. This study presents a 2- to 5-year assessment of the effects of posterior teeth replacement on the amplitude of jaw clicking in subjects who were asymptomatic in all respects except jaw clicking. Patients requiring removable partial dentures (RPDs) were clinically and anamnestically examined and temporomandibular joint (TMJ) sounds were recorded using a modified stethoscope attached to an adjustable headgear. Amplified signals were displayed on a strip chart recorder. The amplitude of TMJ sounds at preinsertion of RPDs were 27.5 +/- 17.7 dB at opening, and 11.1 +/- 12.7 dB at closing. Similar values after prosthesis insertion were 15.8 +/- 17.0 dB and 7.4 +/- 7.5 dB, respectively. Paired t test analyses showed significant differences in the amplitude of sound for opening and closing before inserting the prosthesis (p = 0.003) and for opening before and after treatment (p = 0.014). Following replacement of posterior teeth, the clicking amplitude decreased in 68% of recordings, remained unchanged in 11%, and increased in 21%.

Oral health survey of 5-12-year-old children of National Guard employees in Riyadh, Saudi Arabia.

OBJECTIVES: To assess the oral health status, preventive practices and mutans streptococci (MS) levels among the children of National Guard personnel living in Riyadh, Saudi Arabia. DESIGN: Cross-sectional study of schoolchildren. SETTING: Dental Clinic of the National Guard Hospital in Riyadh, Saudi Arabia. SAMPLE AND METHODS: A sample of 272 5-12-year-old children, 154 males and 118 females (95% Bedouin), were selected from approximately 35 National Guard schools in the Riyadh area. An examination was performed in the dental clinic in the National Guard hospital. Oral hygiene was assessed using the Simplified Debris Index (DI-S); Gingival Index (GI) was used to measure gingival health; dental fluorosis was recorded according to the criteria of Dean. Dental caries (dmft, dmfs, DMFT and DMFS) was recorded according to the recommendations of Haugejorden. Concentration of MS in saline rinse samples was assessed by routine laboratory methods and expressed as colony forming units (CFU) per ml (log10). RESULTS: There was a high level of dental caries (mean dmft = 3.8 +/- 3.2; mean dmfs = 21.5 +/- 15.7; mean DMFT = 2.0 +/- 1.9; mean DMFS = 3.1 +/- 3.7). Only 0.7% of the children had no caries experience (dmft + DMFT). MS levels ranged from 0 to 7.5 x 10(5) CFU per ml (mean MS = 4.10 +/- 0.90 log10 CFU per ml). A significant relationship between MS and caries experience was observed (P = 0.003). Mild fluorosis was observed in 14% of the children. Oral hygiene scores indicated that most of the examined tooth surfaces had detectable plaque (mean DI-S = 1.78). Gingivitis was present in 100% of the children and was considered moderate to severe in 14% (mean GI = 1.18). CONCLUSIONS: The study revealed a high level of oral diseases and poor oral hygiene in the study population and a need for therapeutic and preventive measures.