Five-year survival of class II restorations with and without base bulk-fill composite: a retrospective cohort study.

OBJECTIVE: This study aimed to determine the survival of class II composite restorations in premolars and molars with and without base bulk-fill composite in general dental practice. MATERIALS AND METHODS: We collected data from the electronic patient files of the Public Dental Services in the City of Oulu, Finland. The timespan of data collection was from August 15th, 2002, to August 9th, 2018. The data consisted of class II composite restorations both with and without base bulk-fill composite. We compared the survival of these restorations using Kaplan-Meier survival curves, the log-rank test, survival rates, and the Wilcoxon signed ranks test. RESULTS: We observed 297 restorations in 96 patients. The five-year survival rates for restorations with and without base bulk-fill composite were comparable in premolars (77.5% and 77.4%, respectively) but different in molars (69.9% and 57.8%, respectively, p = 0.069). In molars, the restorations with base bulk-fill composite exhibited a higher survival rate in 14 patients, whereas in 11 patients the restorations without base bulk-fill composites exhibited a higher survival rate. In 24 patients the survival rates were similar for restorations with and without the base bulk-fill composite (p = 0.246). CONCLUSIONS: The restorations with and without base bulk-fill composite had similar longevity. CLINICAL RELEVANCE: Base bulk-fill composites are safe to use in general practice due to their similar survival rates compared to conventional composites.

Family-related risk indicators and dental attendance in association with dental caries in preschool children.

BACKGROUND: Determining risk indicators behind dental caries is important for identifying children in need of enhanced dental care. The aim of this register-based study was to investigate the association of family-related risk indicators and dental attendance in the development of dental caries in preschool children. METHODS: The data for this study were collected from the medical records of 206 randomly chosen preschool children who lived in the city of Oulu, Finland, during 2014-2020. Data on challenges in family life, missing appointments and utilization of oral health care were collected. Sum functions were formed of risk indicators. Analyses were carried out for three age groups (1- to 2-, 3- to 4- and 5- to 6-year-olds) born between 2014 and 2018. RESULTS: There was a significant association between the number of family-related risk indicators and the prevalence of manifested caries lesions in the age group of 5- to 6-year-olds. All family-related risk indicators and information about health care utilization were associated with dental caries risk. Challenges in a child's family life were present among 20.3% of the 5- to 6-year-olds. In all age groups, the most common challenges in family life were parental exhaustion and problems in the parents' relationship or divorce. CONCLUSION: Family-related risk indicators and dental attendance should be considered when determining caries risk. The caries risk indicators investigated here are associated with each other.

Genome-wide association study identifies novel caries-associated loci showing sex-specificity-A study on the Northern Finland Birth Cohort 1966.

A genome-wide association study was performed in sex-stratified groups representing three different caries phenotypes among adults. The study sample consisted of 46-year-old participants of the Northern Finland Birth Cohort 1966 study (n = 1481). The phenotypes for analyses were the dentin caries phenotype (persons having at least one tooth with dentin caries lesion), and the enamel caries phenotype (those having teeth with more than 10 enamel caries lesions), while the control group had <10 enamel caries lesions and no teeth with dentin caries, respectively. A third phenotype dubbed the caries severity phenotype had a below-average number of teeth with initial lesions and at least one extensive dentin caries lesion; their controls had an above-average number of teeth with initial caries lesions and no teeth with extensive dentin caries lesions. All analyses were performed for the whole group and for sex-stratified subgroups. In females, loci in chromosomes 2, 5, and 15 showed a statistically significant association with caries severity. In males, there was a novel association between chromosome 5 and dentin caries. The results of this study may suggest a genetic background of caries among adults. In the future, the detection of genetic predisposing variants may allow the identification of patients at risk for caries, even in the absence of behavioral and environmental risk factors.

The association between dental caries and physical activity, physical fitness, and background factors among Finnish male conscripts.

Studies on measured physical fitness and oral health are sparse. The aim of this study was to investigate the associations between self-reported physical activity and measured physical fitness and oral health of young men. The study population consisted of 13,564 Finnish male conscripts who had mandatory clinical oral examinations and physical fitness tests at the beginning of military service in 2011. Finally, around 10,800 conscripts had physical fitness test outcomes available and a total of 8552 conscripts answered a computer-based questionnaire on background factors. Decayed Tooth (DT) and Decayed, Missing, or Filled Tooth (DMFT) indices, outcomes of surveys and fitness tests were used in analyses by cross-tabulation and multivariable logistic regression model (odds ratios [OR] with 95% confidence interval [CI]) were calculated. Regularly exercising conscripts had a reduced need for dental restorative treatment than those reporting no physical activity (p < 0.0001). The proportion of participants with sound dentition (DT = 0) increased steadily with increasing physical activity (39.0-59.4%). Good measured physical fitness was a protective factor against increased dental restorative treatment need. A low prevalence of smoking and low use of alcohol and energy drinks were associated with frequent exercise, whereas consumption of sport drinks and snuff use were common among those who exercised frequently. Good measured physical fitness and self-reported physical activity are associated with reduced caries burden. There is a need for information about the harms of tobacco products and the benefits of a healthy diet, even for the increased energy needs of the physically active.

Prevalence of Erosive Tooth Wear and Associated Dietary Factors among a Group of Finnish Adolescents.

The aim of this study was to investigate the prevalence and severity of erosive tooth wear (ETW) among Finnish adolescents and to evaluate how frequency as well as amount of the use of erosive products is associated with ETW. The study population consisted of 328 voluntary, >15-year-old secondary school students (males 49.1%, females 50.9%) in three municipalities in Finland. Clinical examination to measure ETW (BEWE index) was carried out by trained and calibrated dentists. Piloted questionnaires included questions on consumption of drinks, fruits and berries, as well as tooth brushing frequency. Means and medians of frequencies and amounts of consumed erosive products were calculated and associations with ETW severity were analysed by logistic regression models. One-third (36.9%) of the participants were in need of at least preventive measures for ETW (BEWE sum score ≥3), but severe ETW (BEWE sum score >9) was rare (2.1%). Boys had severe ETW significantly more frequently than girls (p < 0.001). Habitual consumption of erosive drinks was common especially among boys compared to girls (p = 0.001). ETW was significantly associated with the amount of consumed erosive drinks, fruits, or berries. The prevalence of ETW among adolescences in Finland seems to be at the same level as in other Nordic and European countries. Consumption of erosive products is common and thus, the risk for tooth erosion is high, especially in boys. In addition to erosive drinks, also berries and fruits are associated with ETW and should be included in individual dietary counselling when early signs of ETW are clinically detected.

Mineralization of dental tissues and caries lesions detailed with Raman microspectroscopic imaging.

Dental caries is the most common oral disease that causes demineralization of the enamel and later of the dentin. Depth-wise assessment of the demineralization process could be used to help in treatment planning. In this study, we aimed to provide baseline information for the development of a Raman probe by characterizing the mineral composition of the dental tissues from large composition maps (6 × 3 mm2 with 15 µm step size) using Raman microspectroscopy. Ten human wisdom teeth with different stages of dental caries lesions were examined. All of the teeth were cut in half at representative locations of the caries lesions and then imaged with a Raman imaging microscope. The pre-processed spectral maps were combined into a single data matrix, and the spectra of the enamel, dentin, and caries were identified by K-means cluster analysis. Our results showed that unsupervised identification of dental caries is possible with the K-means clustering. The compositional analysis revealed that the carious lesions are less mineralized than the healthy enamel, and when the lesions extend into the dentin, they are even less mineralized. Furthermore, there were more carbonate imperfections in the mineral crystal lattice of the caries tissues than in healthy tissues. Interestingly, we observed gradients in the sound enamel showing higher mineralization and greater mineral crystal perfection towards the tooth surface. To conclude, our results provide a baseline for the methodological development aimed at clinical diagnostics for the early detection of active caries lesions.

Anticholinergic burden, oral hygiene practices, and oral hygiene status-cross-sectional findings from the Northern Finland Birth Cohort 1966.

OBJECTIVES: To study the association between anticholinergic burden and oral hygiene practices and oral hygiene status among 46-year-old people. MATERIALS AND METHODS: The study included 1945 participants from the Northern Finland Birth Cohort 1966 (NFBC1966), who had a complete dental status. The participants underwent clinical medical and dental examinations, and their medication data were gathered by combining self-reported drug use with information from the National Prescription Register. Anticholinergic burden was measured using nine previously published anticholinergic scales. Oral hygiene practices were assessed with toothbrushing frequency and oral hygiene status with the presence of visible dental plaque. Poisson regression with robust variance estimation and negative binomial regression models were used to estimate relative risks (RR). RESULTS: Thirty percent of the participants reported brushing their teeth twice a day and about 25% of their teeth had dental plaque on them. Fifteen percent of the participants used at least one anticholinergic drug or had an anticholinergic burden according to the nine anticholinergic scales. After adjustments for confounding factors, the RRs of anticholinergic burden varied between 0.95 and 1.11 for toothbrushing frequency. Anticholinergic burden (according to Anticholinergic Activity Scale, Anticholinergic Cognitive Burden, Chew's scale) was associated statistically significantly with the number of teeth with dental plaque. For the three scales, RRs varied from 1.24 to 1.50. CONCLUSIONS: Anticholinergic burden associated with poor oral hygiene. CLINICAL RELEVANCE: The findings stress the importance of providing oral hygiene instructions and prophylactic measures to patients taking anticholinergic drugs.

Multicenter study to develop and validate a risk assessment tool as part of composite scoring system for erosive tooth wear.

OBJECTIVES: (i) To develop, validate, and apply in practice a new risk assessment tool for erosive tooth wear (ETW) including a risk factors questionnaire and a saliva secretion evaluation, which combined with a clinical index, can be part of an ETW composite scoring system; (ii) to assess ETW lesions and current and past erosive challenges in younger age groups. METHODS: The Tooth Surface Loss/Erosion Working Group of the European Association of Dental Public Health consisted of an international panel of experts designed the survey component of the new tool (Erosive Wear Assessment of Risk-EWAR) and confirmed its construct and content validity. After receiving ethical approvals and informed consents, the EWAR tool (questionnaire + saliva secretion evaluation) was applied in a multicenter cross-sectional study with 207 participants aged 15-21 years old from four countries (Finland, Greece, Romania, the USA). BEWE score was used for the clinical assessment of ETW. RESULTS: A total of 58.5% of participants had ETW. 10.9% and 20.3% of participants had low secretion of stimulated (< 1 ml/min) and unstimulated saliva (< 0.25 ml/min), respectively. The following factors were bivariately significantly associated with ETW: energy drink consumption, low secretion of stimulated saliva, juices consumption, erosive drink consumption for quenching thirst between meals, erosive drink kept in the mouth, feeling pain/icing after consuming something acidic or cold, and co-existence of other type of tooth wear. In regression analysis, only energy drink consumption (OR = 3.5, 95% CI: 1.39, 8.9), low secretion of stimulated saliva (OR = 36.3, 95% CI: 4.71, 78.94), and feeling pain/icing (OR = 8.8, 95% CI: 1.92, 40.04) remained significant. CONCLUSIONS: The examiners of the study reported that the EWAR tool appeared to be an affordable and easy-to-use instrument. Some challenges occurred during the saliva collection process. Inferential analysis revealed that the risk factors/indicators of low stimulated salivary flow, energy drink consumption, and pain/icing with ETW were considered the most important in ETW occurrence. CLINICAL RELEVANCE: EWAR tool combined with the BEWE clinical index can be used for ETW risk assessment for epidemiological studies and chairside use.

Can health kiosks be used to identify oral health care needs? A pilot study.

OBJECTIVE: The aim of this study was to investigate the reliability of digital imaging for detecting restorative treatment need among individuals in their 20s by comparing the outcome of digital imaging with clinical caries findings at the patient level. MATERIAL AND METHODS: Five intraoral clinical daylight and digital fluorescence images were taken extraorally of 21 patients. A clinical examination was then performed by a trained and calibrated dentist. Additionally, the patients answered a multiple-choice questionnaire about their health habits. The images were analysed and caries findings were recorded. For statistical analysis, sensitivity and specificity were calculated. Results were shown as ROC curves and AUC values. All analyses were done using SPSS (version 24.0, Chicago, IL). RESULTS: Caries lesions were most often detected in molars and least often in canines. When using the clinical status as gold standard, digital imaging gave an AUC value of 0.617, whereas the outcome by questionnaire gave an AUC value of 0.719. When using the combined outcome of digital imaging and the questionnaire, the AUC value was 0.694 with clinical validation. CONCLUSIONS: It can be concluded that health kiosks may help to reduce the number of patients waiting for dental treatment; more specifically, the questionnaire with individual feedback may provide a new instrument for providing instructions for homecare online. However, the camera system must be developed further, and dentists and dental hygienists require training to analyse the images.

Knowledge on and treatment practices of erosive tooth wear among Finnish dentists.

OBJECTIVES: To investigate Finnish dentists' knowledge on and means of recording, detecting and diagnosing erosive tooth wear (ETW). Treatment options and possible differences in treatment decisions between general and specialized dentists were also evaluated. MATERIALS AND METHODS: An electronic questionnaire was sent by e-mail to 3664 Finnish dentists. Respondents' gender, age, work experience, field of specialty, and practice location were requested. The questionnaire also included a patient case where the dentists were asked about their choice of treatment. Statistical analyses were performed using means, proportions, and cross tabulations. RESULTS: Response rate was 24% (n = 866). Almost all respondents (98.0%) recorded ETW in patient files, but only 4.1% used a detailed scoring system. Of the respondents, 64.4% usually found the cause of ETW. Use of carbonated beverages (84.3%), energy drinks (57.0%), and reflux disease (53.1%) were reported to be probable causes. The majority of the respondents (80.9%) usually assessed patient's dietary history while 1.9% evaluated saliva secretion rate. When asked about treatment decisions of ETW patients, the differences between general dentists and specialized dentists were not as obvious as hypothesized. CONCLUSIONS: This study suggests that the Finnish dentists who participated in this survey are able to detect and/or diagnose erosive tooth wear, but there is variation in recording it. The differences in treatment decisions between general dentists and specialized dentists seem to be moderate. The treatment practices for ETW are not established and further research to create clinical guidelines seems to be needed.

Dental fear among adolescents with cleft.

BACKGROUND: Dental fear is a prevalent phenomenon among children and adolescents globally. AIM: To investigate dental fear among 18-year-olds with cleft lip and/or palate (CLP) at their final follow-up cleft clinic visit, and to evaluate the association between dental fear and OHRQoL. DESIGN: This cross-sectional study included the cohort of children with CLP treated at the Oulu University Hospital Cleft Lip and Palate Center, in northern Finland since 1995. A total of 62 of 64 individuals participated in this study. The validated Finnish version of the Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. Dental fear was studied using the validated Modified Dental Anxiety Scale (MDAS) and cognitive vulnerability model (CVM). RESULTS: Almost two fifths of the participants reported moderate dental fear. Participants with cleft including lip and participants reporting impact on OHRQoL reported higher mean MDAS scores. In an unadjusted model, adolescents with cleft including lip had risk for higher dental MDAS scores compared with the ones with cleft including only palate. CONCLUSIONS: Dental fear is common among adolescents with CLP, specifically among those with clefts involving the lip. OHRQoL and dental fear seem to be associated.

10-year follow-up study on attendance pattern after dental treatment in primary oral health care clinic for fearful patients.

BACKGROUND: Dental fear may lead to avoidance of regular dental treatment. The scope of this long-term practe-based study was to monitor the dental attendance of patients who received chair-side dental and fear treatment. METHODS: In 2000-2006, patients in the City of Oulu, Finland, received treatment for dental fear in the Clinic for Fearful Dental Patients (CFDP) from primary health care dentists trained on this subject. Of the originally treated patients (n = 163), 152 (93%) with sufficient information in dental records made up the study population. Information on their age and sex was available. The number of dental examinations, emergency visits and missed appointments was collected covering the follow-up period of 10 years 2006-2016. For analyses, data were dichotomized according to age at baseline and preliminary outcome baseline condition of dental fear treatment evaluated in 2006. To investigate association further, Poisson regression as well as binary logistic regression models were conducted. As register keeper, the City of Oulu gave permission for this retrospective data-based study. RESULTS: Patients receiving dental fear treatment at younger age (2-10 y) had significantly more dental examinations than those treated at > 10 years. Preliminary success was associated with the number of examinations, but not with emergency visits and missed appointments. Sex was not a significant factor in later dental attendance. There was an association between few dental examinations and dental emergency care need with unsuccessful baseline outcome of dental fear treatment. CONCLUSIONS: Successful dental fear treatment especially at an early age is beneficial for future dental attendance measured by the number of examinations and consequently, less need for emergency care than in the opposite case. Successful fear treatment has positive impact on later dental care and regular dental attendance.

Dental caries among Finnish teenagers participating in physical activity and diet intervention: association with anthropometrics and behavioural factors.

BACKGROUND: An association between childhood anthropometric measurements and dental caries is conflicting. The prevalence and severity of dental caries and its association with anthropometric and behavioural factors, were investigated among Finnish teenagers. METHODS: The study sample comprised 202 15-17-year-old participants in the Physical Activity and Nutrition in Children (PANIC) Study. Dental caries findings were recorded using International Caries Detection and Assessment System (ICDAS) criteria, including activity estimation; numbers of decayed teeth (DT) and decayed, missing and filled teeth (DMFT) were recorded. Body weight, height and waist circumference were measured and respective body mass index (BMI) was calculated. Body fat percentage was assessed by dual-energy X-ray absorptiometry. Health-related behaviours and consumption of food and drinks were assessed using questionnaires, and intake of nutrients using a 4-day food record. RESULTS: Mean DMFT for all the participants was 2.4 (SD = 2.9), DT 0.6 (SD = 1.3), and 36% had DMFT = 0. No difference between genders was observed. In bivariate analyses, use of sugar-sweetened beverages (SSB) three times or less per week and not having used snuff associated significantly, whereas higher carbohydrate intake (E%), toothbrushing less often than twice a day and higher caries experience at baseline almost significantly with DT > 0. In adjusted regression analyses, frequent use of SSB and higher carbohydrate intake increased the odds for DT > 0. Additionally, higher carbohydrate intake (E%) and infrequent tooth brushing significantly associated with a higher number of DT. CONCLUSION: Caries prevalence is still low and similar in Finnish teenage girls and boys. Behavioural factors are, but anthropometric factors are not associated with dental caries.

Consumption of snacks and dental caries among Finnish young men: a cross-sectional epidemiological study.

The aim of this study was to investigate the frequency of consumption of snack products, as well as the association between snacking and restorative treatment need, and associated factors among a healthy Finnish male population. Approximately 8500 conscripts answered a computer-based questionnaire covering their snacking habits and other health behaviours. Restorative treatment need and history (DT, DMFT) were examined by trained and calibrated dentists. Cross-tabulations were used to investigate the associations between snacking habits and the other researched variables, and logistic regression analyses (odds ratio and 95% confidence interval) were used to investigate the variables influencing the restorative treatment need. In the present study, almost one-third of the study group consumed snack products daily, most often fizzy and energy drinks. Only 10% had received a diet counselling. The most common situations involving snacking were at the cinema and while playing computer games. According to Pearson's Chi square test, snacking was associated with smoking and snuffing and infrequent tooth brushing (p < 0.001). According to the regression analyses, daily snacking, smoking, and doing exercise daily increased the odds for restorative treatment need whereas higher education level and tooth brushing twice or more often per day decreased the odds for restorative treatment need. It can be concluded that daily snacking is common among Finnish young men and is associated with restorative treatment need. Snacking is also associated with other harmful oral and general health habits. Individual dietary counselling should be routinely offered to everybody in dental clinics.

Chemical imaging of human teeth by a time-resolved Raman spectrometer based on a CMOS single-photon avalanche diode line sensor.

Raman spectroscopy is a powerful analytical tool to be used in many biomedical applications and could be potentially translated into clinical work. The challenge of Raman spectroscopy in biomedical applications is the high inherent fluorescence of biological samples. One promising method to suppress the fluorescence background is to use pulsed lasers and time-gated detectors but the complexity of time-gated systems has hindered their widespread usage. We present here chemical imaging of human teeth by means of a new kind of compact and practical fluorescence-suppressed Raman spectrometer based on a time-resolved 16 × 256 CMOS single-photon avalanche diode (SPAD) line sensor with an integrated 256-channel 3-bit on-chip time-to-digital converter. The chemical images were constructed by utilizing a simple unsupervised machine learning algorithm (k-means clustering). The high quality of Raman spectra measured with the time-resolved CMOS SPAD-based Raman spectrometer was verified by comparing the spectra to those collected with a commercial conventional continuous wave (CW) Raman spectrometer. The spectra measured by using the time-resolved CMOS SPAD-based Raman spectrometer had 4.4-8.8 times higher signal to peak-to-peak noise ratio values than the spectra from the CW Raman spectrometer when the same radiant exposure (∼300 J mm-2) was used with both spectrometers. This paper shows in practice the potential of time-resolved CMOS SPAD-based Raman spectroscopy in the field of biomedicine and we expect that the presented technology could pave the way for the development of new kind of compact and practical fluorescence-suppressed Raman spectrometers to be used both in biomedical research and clinical settings.

Association of dietary habits with restorative dental treatment need and BMI among Finnish conscripts: a cross-sectional epidemiological study.

OBJECTIVE: Processed foods and fatty, sugary snacking products, such as fizzy drinks and desserts, have become more popular, causing a desire to replace meals with snacks worldwide. High-sugar and fat-rich food components have been reported to be associated with increased level of dental caries as well as underweight and overweight. The aim of the present cross-sectional population-based study was to analyse the eating behaviours of young, healthy Finnish males in association with oral health and BMI, considering self-reported and residential background factors. DESIGN: Cross-sectional study. SETTING: Finnish Defence Forces, Finland. PARTICIPANTS: The used clinical data were gathered from 13 564 Finnish conscripts born in the beginning of the 1990s through clinical check-ups. In addition, about 8700 of the conscripts answered a computer-assisted questionnaire ('Oral Health of the Conscripts 2011' data) about their background information and health habits. RESULTS: There was distinct variation in dietary patterns. Eating breakfast, regular physical exercise and daily tooth brushing all decreased the odds for restorative dental treatment need (decayed teeth), whereas smoking and drinking fizzy drinks for quenching thirst increased it. Eating breakfast and dinner were each associated with lower BMI, but smoking increased the odds for higher BMI (≥25 kg/m2). CONCLUSIONS: Regular, proper meals and especially eating breakfast decreased the odds for both dental caries and high BMI (≥25 kg/m2).

Association of Enamel Caries Lesions with Oral Hygiene and DMFT among Adults.

The aim of this study was to evaluate the prevalence of enamel caries lesions and their association with tooth brushing frequency, tooth brushing quality, and past caries experience among Finnish adults. The study population comprised 46-year-old members of the Northern Finland Birth Cohort 1966 (n = 1,961). Caries lesions were examined and recorded at surface level using the International Caries Detection and Assessment System (ICDAS). The cut-off point for enamel caries was set to ICDAS score 3. The cut-off point for brushing frequency was twice daily. Visible plaque on buccal tooth surfaces represented brushing quality. Using enamel caries lesions (ICDAS1-3) as a dependent variable, an adjusted logistic regression model was conducted to investigate the association with gender, brushing frequency, visible plaque, dentin caries lesions (ICDAS4-6), teeth with restorations, extractions and fractures. Almost all participants (99%) had enamel and 40% had dentin caries lesions; the mean number of teeth with enamel caries lesions was 13.8 (SD 4.6). According to the adjusted logistic regression model, the high prevalence of ICDAS1-3 lesions was associated with having visible plaque on more than 20% of teeth and having more than 13 restored teeth. In conclusion, the prevalence of enamel caries lesions is high among the Finnish adult population. The results of this study suggest that in addition to tooth brushing frequency, the presence of visible plaque seems to be critical when evaluating the association between tooth brushing and enamel caries.

Genome-Wide Association Study of Erosive Tooth Wear in a Finnish Cohort.

Erosive tooth wear is defined as irreversible loss of dental tissues due to intrinsic or extrinsic acids, exacerbated by mechanical forces. Recent studies have suggested a higher prevalence of erosive tooth wear in males, as well as a genetic contribution to susceptibility to erosive tooth wear. Our aim was to examine erosive tooth wear by performing a genome-wide association study (GWAS) in a sample of the Northern Finland Birth Cohort 1966 (n = 1,962). Erosive tooth wear was assessed clinically using the basic erosive wear examination. A GWAS was performed for the whole sample as well as separately for males and females. We identified one genome-wide significant signal (rs11681214) in the GWAS of the whole sample near the genes PXDN and MYT1L. When the sample was stratified by sex, the strongest genome-wide significant signals were observed in or near the genes FGFR1, C8orf86, CDH4, SCD5, F2R, and ING1. Additionally, multiple suggestive association signals were detected in all GWASs performed. Many of the signals were in or near the genes putatively related to oral environment or tooth development, and some were near the regions considered to be associated with dental caries, such as 2p24, 4q21, and 13q33. Replications of these associations in other samples, as well as experimental studies to determine the biological functions of associated genetic variants, are needed.

Familial oligodontia and regional odontodysplasia associated with a PAX9 initiation codon mutation.

OBJECTIVE: Tooth agenesis is one of the most common craniofacial developmental anomalies. In hypodontia, one to five teeth are missing, whereas oligodontia refers to the absence of at least six teeth, excluding the third molars. Mutations in several genes including MSX1, PAX9, AXIN2, and WNT10A have been shown to cause non-syndromic tooth agenesis. Regional odontodysplasia (RO), also known as "ghost teeth," is a rare developmental anomaly of tooth formation affecting both dentitions. Some possible causes of RO have been suggested, yet the etiology remains unknown. Because the phenotypes of both oligodontia and RO co-occur in one Finnish family, the aim here was to investigate the genetic etiology of the two conditions. MATERIALS AND METHODS: A mutation screening of the genes MSX1, PAX9, AXIN2, and WNT10A was performed for the family members of a RO patient and family history of oligodontia. RESULTS: An initiation codon mutation of the PAX9 gene was found in the proband and segregating with oligodontia in the family. CONCLUSIONS: The etiology of regional odontodysplasia (RO) may be genetic and the same genes can be involved both in RO and tooth agenesis. CLINICAL RELEVANCE: Our results give new insights into the etiology of regional odontodysplasia, yet further results are needed.

Prevalence of temporomandibular disorders (TMD) among Finnish prisoners: cross-sectional clinical study.

OBJECTIVE: The aim of the present study was to evaluate the prevalence of self-reported temporomandibular disorders (TMD) symptoms and clinically diagnosed TMD among Finnish prisoners. MATERIAL AND METHODS: Altogether 100 prisoners from the Pelso Prison, Vaala, Finland, underwent dental and TMD clinical examinations performed by a calibrated and well-trained dentist. Symptom Questionnaire and clinical examination according to a Finnish pre-final version of the DC/TMD (Diagnostic Criteria for Temporomandibular Disorders) Axis I protocol were used to evaluate the prevalence of TMD sub-diagnoses. RESULTS: The most common TMD symptoms were facial pain (54.0%), temporomandibular joint noises (43.0%) and headache (37.0%). The prevalence of joint-related TMD diagnoses was four and a half times higher than diagnoses attributed with pain (76.0% vs. 17.0%). The most common TMD diagnoses were degenerative joint disease (33.0%) and disc displacement with reduction (33.0%). CONCLUSIONS: The prevalence of self-reported TMD symptoms and clinical assessed TMD, especially join-related TMD diagnoses, is high among Finnish prisoners. Examination and treatment of TMD should become a common practice also in prison dental care.