The Global, Regional, and National Burden of Adult Lip, Oral, and Pharyngeal Cancer in 204 Countries and Territories: A Systematic Analysis for the Global Burden of Disease Study 2019.

Importance: Lip, oral, and pharyngeal cancers are important contributors to cancer burden worldwide, and a comprehensive evaluation of their burden globally, regionally, and nationally is crucial for effective policy planning. Objective: To analyze the total and risk-attributable burden of lip and oral cavity cancer (LOC) and other pharyngeal cancer (OPC) for 204 countries and territories and by Socio-demographic Index (SDI) using 2019 Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study estimates. Evidence Review: The incidence, mortality, and disability-adjusted life years (DALYs) due to LOC and OPC from 1990 to 2019 were estimated using GBD 2019 methods. The GBD 2019 comparative risk assessment framework was used to estimate the proportion of deaths and DALYs for LOC and OPC attributable to smoking, tobacco, and alcohol consumption in 2019. Findings: In 2019, 370 000 (95% uncertainty interval [UI], 338 000-401 000) cases and 199 000 (95% UI, 181 000-217 000) deaths for LOC and 167 000 (95% UI, 153 000-180 000) cases and 114 000 (95% UI, 103 000-126 000) deaths for OPC were estimated to occur globally, contributing 5.5 million (95% UI, 5.0-6.0 million) and 3.2 million (95% UI, 2.9-3.6 million) DALYs, respectively. From 1990 to 2019, low-middle and low SDI regions consistently showed the highest age-standardized mortality rates due to LOC and OPC, while the high SDI strata exhibited age-standardized incidence rates decreasing for LOC and increasing for OPC. Globally in 2019, smoking had the greatest contribution to risk-attributable OPC deaths for both sexes (55.8% [95% UI, 49.2%-62.0%] of all OPC deaths in male individuals and 17.4% [95% UI, 13.8%-21.2%] of all OPC deaths in female individuals). Smoking and alcohol both contributed to substantial LOC deaths globally among male individuals (42.3% [95% UI, 35.2%-48.6%] and 40.2% [95% UI, 33.3%-46.8%] of all risk-attributable cancer deaths, respectively), while chewing tobacco contributed to the greatest attributable LOC deaths among female individuals (27.6% [95% UI, 21.5%-33.8%]), driven by high risk-attributable burden in South and Southeast Asia. Conclusions and Relevance: In this systematic analysis, disparities in LOC and OPC burden existed across the SDI spectrum, and a considerable percentage of burden was attributable to tobacco and alcohol use. These estimates can contribute to an understanding of the distribution and disparities in LOC and OPC burden globally and support cancer control planning efforts.

Reliability of conditioned pain modulation in healthy individuals and chronic pain patients: a systematic review and meta-analysis.

OBJECTIVES: Conditioned pain modulation (CPM) is a psychophysical parameter that is used to reflect the efficacy of endogenous pain inhibition. CPM reliability is important for research and potential clinical applications. The aim of this systematic review and meta-analysis was to evaluate the reliability of CPM tests in healthy individuals and chronic pain patients. METHODS: We searched three databases for peer-reviewed studies published from inception to October 2020: EMBASE, Web of Science and NCBI. Risk of bias and the quality of the included studies were assessed. A meta-analysis with a random effects model was conducted to estimate intraclass correlation coefficients (ICCs). RESULTS: Meta-analysis was performed on 25 papers that examined healthy participants (k=21) or chronic pain patients (k=4). The highest CPM intra-session reliability was with pressure as test stimulus (TS) and ischemic pressure (IP) or cold pressor test (CPT) as conditioning stimulus (CS) in healthy individuals (ICC 0.64, 95% CI 0.45-0.77), and pressure as TS with CPT as CS in patients (ICC 0.77, 95% CI 0.70-0.82). The highest inter-session ICC was with IP as TS and IP or CPT as CS (ICC 0.51, 95% CI 0.42-0.59) in healthy subjects. The only data available in patients for inter-session reliability were with pressure as TS and CPT as CS (ICC 0.44, 95% CI 0.11-0.69). Quality ranged from very good to excellent using the QACMRR checklist. The majority of the studies (24 out of 25) scored inadequate in Kappa coefficient reporting item of the COSMIN-ROB checklist. CONCLUSIONS: Pressure and CPT were the TS and CS most consistently associated with good to excellent intra-session reliability in healthy volunteers and chronic pain patients. The inter-session reliability was fair or less for all modalities, both in healthy volunteers and chronic pain patients.

Reliability of the conditioned pain modulation paradigm across three anatomical sites.

Background and aims Conditioned Pain Modulation (CPM) is a measure of pain inhibition-facilitation in humans that may elucidate pain mechanisms and potentially serve as a diagnostic test. In laboratory settings, the difference between two pain measures [painful test stimulus (TS) without and with the conditioning stimulus (CS) application] reflects the CPM magnitude. Before the CPM test can be used as a diagnostic tool, its reliability on the same day (intra-session) and across multiple days (inter-session) needs to be known. Furthermore, it is important to determine the most reliable anatomical sites for both the TS and the CS. This study aimed to measure the intra-session and inter-session reliability of the CPM test paradigm in healthy subjects with the TS (pressure pain threshold-PPT) applied to three test sites: the face, hand, and dorsum of the foot, and the CS (cold pressor test-CPT) applied to the contralateral hand. Methods Sixty healthy participants aged 18-65 were tested by the same examiner on 3 separate days, with an interval of 2-7 days. On each day, testing was comprised of two identical experimental sessions in which the PPT test was performed on each of the three dominant anatomical sites in randomized order followed by the CPM test (repeating the PPT with CPT on the non-dominant hand). CPM magnitude was calculated as the percent change in PPT. The Intraclass Correlation Coefficient (ICC), Coefficient of Variation (CV), and Bland-Altman analyses were used to assess reliability. Results PPT relative reliability ranged from good to excellent at all three sites; the hand showed an intra-session ICC of 0.90 (0.84, 0.94) before CPT and ICC of 0.89 (0.83, 0.92) during CPT. The PPT absolute reliability was also high, showing a low bias and small variability when performed on all three sites; for example, CV of the hand intra-session was 8.0 before CPT and 8.1 during CPT. The relative reliability of the CPM test, although only fair, was most reliable when performed during the intra-session visits on the hand; ICC of 0.57 (0.37, 0.71) vs. 0.20 (0.03, 0.39) for the face, and 0.22 (0.01, 0.46) for the foot. The inter-session reliability was lower in all three anatomical sites, with the best reliability on the hand with an ICC of 0.40 (0.23, 0.55). The pattern of absolute reliability of CPM was similar to the relative reliability findings, with the reliability best on the hand, showing lower intra-session and inter-session variability (CV% = 43.5 and 51.5, vs. 70.1 and 73.1 for the face, and 75.9 and 78.9 for the foot). The CPM test was more reliable in women than in men, and in older vs. younger participants. Discussion The CPM test was most reliable when the TS was applied to the dominant hand and CS performed on the contralateral hand. These data indicate that using the CS and TS in the same but contralateral dermatome in CPM testing may create the most reliable results.

A case-control evaluation of fungiform papillae density in burning mouth syndrome.

HYPOTHESIS: It has been hypothesized that high fungiform papillae density may be a risk factor for developing the taste and pain alterations characteristic of burning mouth syndrome. OBJECTIVE: Evaluate whether fungiform papillae density, taste sensitivity, and mechanical pain sensitivity differ between burning mouth syndrome cases and controls. STUDY DESIGN: This case-control study compared cases diagnosed with primary burning mouth syndrome with pain-free controls. METHODS: Participants (17 female cases and 23 female controls) rated the intensity of sucrose, sodium chloride, citric acid, and quinine applied separately to each side of the anterior tongue and sampled whole mouth. Mechanical pain sensitivity was assessed separately for each side of the tongue using weighted pins. Digital photographs of participants' tongues were used to count fungiform papillae. RESULTS: Burning mouth syndrome cases had increased whole mouth taste intensity. Cases also had increased sensitivity to quinine on the anterior tongue, as well as increased mechanical pain sensitivity on the anterior tongue. Fungiform papillae density did not differ significantly between cases and controls. Fungiform papillae density on the left and right sides of the tongue were correlated in controls; however, there was no left/right side correlation in cases. CONCLUSION: Cases had increased pain and taste perception on the anterior tongue. The lack of correlation between left and right fungiform papillae density in cases may be an indication of asymmetrical lingual innervation in these patients. LEVEL OF EVIDENCE: 3b. Laryngoscope, 128:841-846, 2018.

Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for Clinical and Research Applications: recommendations of the International RDC/TMD Consortium Network* and Orofacial Pain Special Interest Group†.

AIMS: The original Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I diagnostic algorithms have been demonstrated to be reliable. However, the Validation Project determined that the RDC/TMD Axis I validity was below the target sensitivity of ≥ 0.70 and specificity of ≥ 0.95. Consequently, these empirical results supported the development of revised RDC/TMD Axis I diagnostic algorithms that were subsequently demonstrated to be valid for the most common pain-related TMD and for one temporomandibular joint (TMJ) intra-articular disorder. The original RDC/TMD Axis II instruments were shown to be both reliable and valid. Working from these findings and revisions, two international consensus workshops were convened, from which recommendations were obtained for the finalization of new Axis I diagnostic algorithms and new Axis II instruments. METHODS: Through a series of workshops and symposia, a panel of clinical and basic science pain experts modified the revised RDC/TMD Axis I algorithms by using comprehensive searches of published TMD diagnostic literature followed by review and consensus via a formal structured process. The panel's recommendations for further revision of the Axis I diagnostic algorithms were assessed for validity by using the Validation Project's data set, and for reliability by using newly collected data from the ongoing TMJ Impact Project-the follow-up study to the Validation Project. New Axis II instruments were identified through a comprehensive search of the literature providing valid instruments that, relative to the RDC/TMD, are shorter in length, are available in the public domain, and currently are being used in medical settings. RESULTS: The newly recommended Diagnostic Criteria for TMD (DC/TMD) Axis I protocol includes both a valid screener for detecting any pain-related TMD as well as valid diagnostic criteria for differentiating the most common pain-related TMD (sensitivity ≥ 0.86, specificity ≥ 0.98) and for one intra-articular disorder (sensitivity of 0.80 and specificity of 0.97). Diagnostic criteria for other common intra-articular disorders lack adequate validity for clinical diagnoses but can be used for screening purposes. Inter-examiner reliability for the clinical assessment associated with the validated DC/TMD criteria for pain-related TMD is excellent (kappa ≥ 0.85). Finally, a comprehensive classification system that includes both the common and less common TMD is also presented. The Axis II protocol retains selected original RDC/TMD screening instruments augmented with new instruments to assess jaw function as well as behavioral and additional psychosocial factors. The Axis II protocol is divided into screening and comprehensive self report instrument sets. The screening instruments' 41 questions assess pain intensity, pain-related disability, psychological distress, jaw functional limitations, and parafunctional behaviors, and a pain drawing is used to assess locations of pain. The comprehensive instruments, composed of 81 questions, assess in further detail jaw functional limitations and psychological distress as well as additional constructs of anxiety and presence of comorbid pain conditions. CONCLUSION: The recommended evidence-based new DC/TMD protocol is appropriate for use in both clinical and research settings. More comprehensive instruments augment short and simple screening instruments for Axis I and Axis II. These validated instruments allow for identification of patients with a range of simple to complex TMD presentations.

Recommendations for third molar removal: a practice-based cohort study.

OBJECTIVES: We investigated general dentists' reasons for recommending removal or retention of third molars and whether patients adhered to dentists' recommendations. METHODS: In a 2-year prospective cohort study (2009-2011) in the Pacific Northwest, we followed 801 patients aged 16 to 22 years from 50 general dental practices. Generalized estimating equations logistic regressions related patient and dentist characteristics to dentists' recommendations to remove third molars and to patient adherence. RESULTS: General dentists recommended removal of 1683 third molars from 469 (59%) participants, mainly to prevent future problems (79%) or because a third molar had an unfavorable orientation or was unlikely to erupt (57%). Dentists recommended retention and monitoring of 1244 third molars from 366 (46%) participants, because it was too early to decide (73%), eruption path was favorable (39%), or space for eruption was sufficient (26%). When dentists recommended removal, 55% of participants adhered to this recommendation during follow-up, and the main reason was availability of insurance (88%). CONCLUSIONS: General dentists frequently recommended removal of third molars for reasons not related to symptoms or pathology, but rather to prevent future problems.

A prospective study of clinical outcomes related to third molar removal or retention.

OBJECTIVES: We investigated outcomes of third molar removal or retention in adolescents and young adults. METHODS: We recruited patients aged 16 to 22 years from a dental practice-based research network in the Pacific Northwest from May 2009 through September 2010 who had at least 1 third molar present and had never undergone third molar removal. Data were acquired via questionnaire and clinical examination at baseline, periodic online questionnaires, and clinical examination at 24 months. RESULTS: A total of 801 patients participated. Among patients undergoing third molar removal, rates of paresthesia and jaw joint symptoms lasting more than 1 month were 6.3 and 34.3 per 100 person-years, respectively. Among patients not undergoing removal, corresponding rates were 0.7 and 8.8. Periodontal attachment loss at distal sites of second molars did not significantly differ by third molar removal status. Incident caries at the distal surfaces of second molars occurred in fewer than 1% of all sites. CONCLUSIONS: Rates of paresthesia and temporomandibular joint disorder were higher after third molar removal. Periodontal attachment loss and incident caries at the distal sites of second molars were not affected by extraction status.

A blueprint of pain curriculum across prelicensure health sciences programs: one NIH Pain Consortium Center of Excellence in Pain Education (CoEPE) experience.

UNLABELLED: To improve U.S. pain education and promote interinstitutional and interprofessional collaborations, the National Institutes of Health Pain Consortium has funded 12 sites to develop Centers of Excellence in Pain Education (CoEPEs). Each site was given the tasks of development, evaluation, integration, and promotion of pain management curriculum resources, including case studies that will be shared nationally. Collaborations among schools of medicine, dentistry, nursing, pharmacy, and others were encouraged. The John D. Loeser CoEPE is unique in that it represents extensive regionalization of health science education, in this case in the region covering the states of Washington, Wyoming, Alaska, Montana, and Idaho. This paper describes a blueprint of pain content and teaching methods across the University of Washington's 6 health sciences schools and provides recommendations for improvement in pain education at the prelicensure level. The Schools of Dentistry and Physician Assistant provide the highest percentage of total required curriculum hours devoted to pain compared with the Schools of Medicine, Nursing, Pharmacy, and Social Work. The findings confirm the paucity of pain content in health sciences curricula, missing International Association for the Study of Pain curriculum topics, and limited use of innovative teaching methods such as problem-based and team-based learning. PERSPECTIVE: Findings confirm the paucity of pain education across the health sciences curriculum in a CoEPE that serves a large region in the United States. The data provide a pain curriculum blueprint that can be used to recommend added pain content in health sciences programs across the country.

Intraoral somatosensory abnormalities in patients with atypical odontalgia--a controlled multicenter quantitative sensory testing study.

Intraoral somatosensory sensitivity in patients with atypical odontalgia (AO) has not been investigated systematically according to the most recent guidelines. The aims of this study were to examine intraoral somatosensory disturbances in AO patients using healthy subjects as reference, and to evaluate the percent agreement between intraoral quantitative sensory testing (QST) and qualitative sensory testing (QualST). Forty-seven AO patients and 69 healthy control subjects were included at Universities of Washington, Malmö, and Aarhus. In AO patients, intraoral somatosensory testing was performed on the painful site, the corresponding contralateral site, and at thenar. In healthy subjects, intraoral somatosensory testing was performed bilaterally on the upper premolar gingiva and at thenar. Thirteen QST and 3 QualST parameters were evaluated at each site, z-scores were computed for AO patients based on the healthy reference material, and LossGain scores were created. Compared with control subjects, 87.3% of AO patients had QST abnormalities. The most frequent somatosensory abnormalities in AO patients were somatosensory gain with regard to painful mechanical and cold stimuli and somatosensory loss with regard to cold detection and mechanical detection. The most frequent LossGain code was L0G2 (no somatosensory loss with gain of mechanical somatosensory function) (31.9% of AO patients). Percent agreement between corresponding QST and QualST measures of thermal and mechanical sensitivity ranged between 55.6% and 70.4% in AO patients and between 71.1% and 92.1% in control subjects. In conclusion, intraoral somatosensory abnormalities were commonly detected in AO patients, and agreement between quantitative and qualitative sensory testing was good to excellent.

Seven-year follow-up of patients diagnosed with atypical odontalgia: a prospective study.

AIMS: To examine the long-term prognosis of 46 previously examined atypical odontalgia (AO) patients. METHODS: In 2002 and 2009, AO patients completed validated instruments measuring pain characteristics (pain frequency and intensity), physical functioning (Graded Chronic Pain Severity, GCPS) and emotional functioning (Symptoms Checklist, SCL-90R). The main outcome was global improvement. Baseline data on quantitative somatosensory testing and responsiveness to lidocaine injection were available for a subgroup of patients. Paired tests compared baseline and follow-up data, and logistic regression explored the possible prognostic value of baseline data. RESULTS: Data from 37 patients (80%) were obtained. Thirteen patients (35%; 95% confidence intervals [CI] 20.2%-52.5%) rated their overall pain status as significantly improved, 22 (60%; 95% CI 42.1%-75.3%) as a little improved or unchanged, and two patients (5%; 95% CI 0.7%-18.2%) as worse. Five patients (14%; 95% CI 4.5%-28.8%) were pain-free, indicated by a characteristic pain intensity score of 0. Average pain intensity decreased (from 5.7 ± 2.0 to 3.5 ± 2.4; P < .001). Pain frequency (P < .001) and GCPS (P < .001) also decreased, whereas SCL-90R scores remained unchanged and 26 of the 37 patients reported ongoing treatment. Low baseline pain intensity was the only factor predictive of favorable outcome. CONCLUSION: A third of the AO patients improved considerably over time, but for many of the patients, AO was a persistent and treatment-resistant condition.

Chairside intraoral qualitative somatosensory testing: reliability and comparison between patients with atypical odontalgia and healthy controls.

AIMS: To assess intraoral inter- and intraexaminer reliability of three qualitative measures of intraoral somatosensory function and to compare these measures between patients with atypical odontalgia (AO) and healthy controls. METHODS: Thirty-one AO patients and 47 healthy controls participated. Inter- and intraexaminer reliability was tested on a subgroup of 46 subjects (25 AO; 21 healthy). Sensitivity to touch, cold, and pinprick stimuli was evaluated on the painful gingival site and the corresponding contralateral site in AO patients, and bilaterally on the gingiva of the first maxillary premolars in controls. Patients were asked to report hypersensitivity, hyposensitivity, or normal sensitivity to stimuli on the painful site compared with the nonpainful site. Kappa values were calculated, and chi-square and Fisher's exact tests were used to compare frequencies between groups. RESULTS: Kappa values ranged between 0.63 and 0.75. The frequency of hypersensitivity to either modality was significantly higher in patients (29% to 61%) than in controls (9% to 17%) (P < .015), whereas reports of hyposensitivity were similar between groups (2% to 16%) (P > .057). Only 3.2% of the AO patients had no reports of abnormal sensitivity on any of the tests, compared with 59.6% of the healthy subjects (P < .001). CONCLUSION: Intraoral qualitative somatosensory testing can detect intraoral sensory disturbances in AO patients, and the reliability is sufficient for initial screening of orofacial somatosensory function.

Trajectories of pain in adolescents: a prospective cohort study.

Identification of different patterns of change in pain over time - trajectories - has the potential to provide new information on the course of pain. Describing trajectories among adolescents would improve understanding of how pain conditions can develop. This prospective cohort study identified distinct trajectories of pain among adolescents (11-14 years) in the general population (n=1336). Latent class growth analysis was carried out on the self-reported frequency of back pain, headache, stomach pain and facial pain, which was collected every 3 months for 3 years. Forty four percent of adolescents had a 'painful' trajectory for at least one pain site, and 12% reported persistent pain at one or more pain site. Headache was the most common; 25% of subjects were in a 'painful' trajectory and 5% reported persistent pain. Back pain and stomach pain were also common, with 22% and 21% of subjects in painful trajectories, respectively. Facial pain was the least common, with only 10% in a painful trajectory, and 1% reporting persistent pain. Trajectory characteristics were similar at baseline across pain sites, with the more painful trajectories having significantly higher levels of depression and somatization, lower life satisfaction and more females. Trajectories did not differ significantly at baseline in physical activity levels or BMI. Agreement of trajectory membership among pain sites was moderate. In summary, reporting a painful trajectory was common among adolescents, but persistent pain was reported by a small minority, and was usually experienced at a single pain site.

Gender differences in pain modulation by diffuse noxious inhibitory controls: a systematic review.

Over the last decade, extensive research has demonstrated sex differences in pain perception and modulation. Several factors have been proposed to account for the differences observed between men and women, including pain modulation through diffuse noxious inhibitory controls (DNIC). Studies investigating sex differences in DNIC have shown mixed results, with some reporting decreased DNIC effect in women compared with men, while others found no difference in DNIC between the sexes. Additional studies have investigated DNIC in both sexes without focusing on sex differences. This systematic review aimed to answer the following question: "In humans of reproductive age without chronic pain, are women more likely than men to have decreased Diffuse Noxious Inhibitory Controls?" Relevant studies were identified by computerized searches of Pubmed/Medline, Embase, Biosis, Web of Science, PsycInfo and Cochrane (from January 1980 through February 2009). The search was limited to human studies with no language restriction. The initial search identified 718 titles and abstracts. Seventeen studies were included in the final stage and data regarding age and gender of participants, methodology and outcome measurements were extracted and analyzed. The majority of studies using pain report as the outcome found significantly more efficient DNIC in males than females (mean female/male ratio=0.54). Studies evaluating pain thresholds and nociceptive flexion reflex indicated the opposite when simply averaged across studies; however, weighted analyses of threshold found more efficient DNIC in males. Gender differences in DNIC effect depend on both the experimental methodology and the modes of measurement of the effect.

Reliability of intraoral quantitative sensory testing (QST).

The German Research Network on Neuropathic Pain (DFNS) has recommended a protocol with 13 quantitative sensory testing (QST) measures for detecting somatosensory abnormalities. Reliability is an important scientific property and has been adequately tested for cutaneous QST. This study evaluates intraoral sites for which no reliability trials have yet been published. Inter- and intra-examiner reliability of 13 QST measures at intra- and extraoral trigeminal sites were investigated. Twenty-one healthy volunteers from Malmö University, Malmö, Sweden (13 women and 8 men, mean age 40.4 years, range 24-71) participated. Two independent examiners previously trained in the DFNS QST protocol examined the participants using the entire protocol. Each participant was examined twice on the same day, once by each examiner (inter-examiner reliability). After 1-3 weeks, one examiner re-examined all participants (intra-examiner reliability). The measurements were made on the skin of the right cheek, the tip of the tongue, and bilaterally on the gingival mucosa of the upper premolar region. The intraclass correlation coefficient (ICC) or kappa was used to calculate variations. Most tests had acceptable to excellent inter-examiner (ICC 0.41-0.89) and intra-examiner (ICC 0.43-0.87) reliability. For each test, inter- and intra-examiner reliabilities at intra- and extraoral sites were similar. No significant differences between right and left sides were found intraorally. We conclude that inter- and intra-examiner reliabilities of most QST measures are acceptable for assessing somatosensory function in the orofacial region.

Impact of temporomandibular disorder pain in adolescents: differences by age and gender.

AIMS: To evaluate the impact of temporomandibular disorder (TMD) pain by age and gender in adolescents, with assessments of this impact specifically on school absence, medication consumption, perceived need for treatment, jaw function limitation, depressive symptoms scores and somatic complaints, and graded chronic pain scale. METHODS: In a population-based sample, a mailed questionnaire was sent to 350 patients with self-reported TMD pain (group 1) and 350 healthy age- and sex-matched individuals (group 2) aged 12 to 19 years 2 to 4 weeks after their annual dental examination. The groups were divided into younger (age 12 to 15) and older (age 16 to 19) groups. Descriptive statistics and 95% confidence intervals were used, and chi-square and t-tests were calculated for analyzing group differences. Odds ratios were estimated using logistic regression. RESULTS: As expected, groups 1 and 2 differed significantly in most variables related to psychosocial and behavioral factors. For adolescents reporting TMD pain once a week or more, no gender or age differences in pain intensity were seen. Jaw function limitation, depressive symptoms scores, somatic complaints, graded chronic pain, and perceived need for TMD treatment were all significantly higher in girls than in boys. Older girls reported higher analgesic consumption and school absences than older boys. CONCLUSION: Girls reporting TMD pain had significantly greater impact on behavioral and psychosocial factors than boys. Almost one third of older girls, compared to one out of 10 older boys, reported school absences and analgesic consumption because of their TMD pain.

Incidence and temporal patterns of temporomandibular disorder pain among Swedish adolescents.

AIMS: To estimate the incidence of temporomandibular disorder (TMD) pain among Swedish adolescents by age and gender and to describe the temporal patterns of TMD pain. METHODS: This 3-year longitudinal study was carried out at all Public Dental Service clinics in a Swedish county from 2000 to 2003. All individuals aged 12 to 19 years in the county who visited the clinics for annual examinations were eligible for the study. RESULTS: Overall, the incidence of TMD pain among all adolescents was 2.9% annually among 2,255 participating adolescents. Incidence among girls was significantly higher than in boys, 4.5% versus 1.3%, respectively. Incidence increased with age in girls and boys, although less so in boys (3.0% to 6.9% versus 1.7% to 2.6%). These adolescents were re-examined annually for 3 years, and a fluctuating pattern of TMD pain was common. Overall, 11.4% of all subjects reported TMD pain on at least 1 occasion; 88.6% of the cohort remained pain-free. Of those reporting TMD pain, 4.7% could be defined as intermittent cases, 3.1% were single-incident cases, 0.9% were recurrent cases, and 0.9% had continuing pain for 1 or 2 years. CONCLUSION: The incidence of self-reported TMD pain among Swedish adolescents aged 12 to 19 years increased with age, particularly among girls. The pattern of pain in most adolescents fluctuated over time. Less than 1% of the cohort had continued pain over each year, and the majority of these subjects were girls.

Predictors of onset of facial pain and temporomandibular disorders in early adolescence.

There are few prospective studies assessing risk factors for onset of temporomandibular (TMD) pain disorders in any age group. The aim of this prospective cohort study was to identify risk factors for onset of clinically significant TMD pain (i.e., pain meeting research diagnostic criteria for myofascial pain and/or arthralgia) during early adolescence. Subjects were 1,996 boys and girls, initially 11 years old, randomly selected from a large nonprofit health care system. Subjects completed a baseline telephone interview and were followed up with mailed questionnaires every 3 months for 3 years. At baseline and all follow ups, subjects were asked to report the presence of facial pain in the past 3 months. Subjects reporting a first onset of facial pain received a standardized clinical examination. In multivariate analyses, baseline predictors of clinically significant pain included female gender [Odds Ratio (OR)=2.0, 95% Confidence Interval (CI)=1.2-3.3] and negative somatic and psychological symptoms including somatization (OR=1.8, CI=1.1-2.8), number of other pain complaints (OR=3.2, CI=1.7-6.1) and life dissatisfaction (OR=4.1, CI=1.9-9.0). Many of the risk factors for onset of clinically significant TMD pain in adolescents are similar to risk factors for onset of TMD and other pain problems in adults, as well as risk factors for onset of other pain conditions in adolescents. These findings suggest that the development of TMD pain in adolescence may reflect an underlying vulnerability to musculoskeletal pain that is not unique to the orofacial region.