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.

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.

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.

Relationship of pain and symptoms to pubertal development in adolescents.

Temporomandibular disorder (TMD) pain, abdominal pain, migraine and tension-type headache are more prevalent in women than in men. This study assessed the relationship of back pain, headache, abdominal pain, TMD pain, and the presence of multiple pain conditions to gender and pubertal development in a cross-sectional, population-based survey of adolescents. We also examined the association between pubertal development and depressive and somatic symptoms, factors often associated with pain in adults. We hypothesized that prevalence of all pain conditions, as well as rates of other symptoms, would increase as puberty progresses in females, but not males. Subjects (3,101 boys and girls, 11-17 years old, selected from an HMO population) reported on the presence of each pain condition in the prior 3 months and completed scales assessing pubertal development, and depressive and somatic symptoms. Data were analyzed using descriptive statistics and multivariate logistic regression. Prevalence rates were weighted for factors affecting response. Prevalence of back pain, headache and TMD pain increased significantly (odds ratios, OR=1.4-2.0, P<0.001) and stomach pain increased marginally with increasing pubertal development in girls. Rates of somatization, depression and probability of experiencing multiple pains also increased with pubertal development in girls (P<0.0001). For boys, prevalence of back (OR=1.9, P<0.0001) and facial pain (OR=1.5, P<0.01) increased, stomach pain decreased somewhat and headache prevalence was virtually unchanged with increasing maturity. For both sexes, pubertal development was a better predictor of pain than was age. Thus it appears that pain, other somatic symptoms and depression increase systematically with pubertal development in girls.

Relationship between overbite/overjet and clicking or crepitus of the temporomandibular joint.

AIMS: Since occlusal variables such as overbite and overjet have been thought to be associated with temporomandibular disorders (TMD), and joint sounds are some of the most prevalent signs of TMD, the aim of this study was to determine whether overbite and overjet are risk factors for temporomandibular joint (TMJ) sounds. METHODS: A population-based cross-sectional study of 3,033 subjects (age range, 10 to 75 years; 53% female) was conducted in Germany. Overbite/overjet, reproducible reciprocal clicking (RRC) during open-close jaw movements that did not occur in the protrusive jaw position, and joint crepitus were assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). RESULTS: When age and gender were controlled for, high or low values of overbite and overjet were not associated with a greater risk of RRC and crepitus as compared to a reference category of a normal overbite and overjet of 2 to 3 mm (multiple logistic regression; odds ratios 0.7 to 1.3; P > .05 for all). CONCLUSION: This study showed that higher or lower overbite or overjet jaw relationships, even extreme values, are not risk factors for TMJ sounds as assessed by clinical examination.