Journal of Oral & Facial Pain and Headache, 03/2015

Aims: To increase knowledge about how children diagnosed with juvenile idiopathic arthritis (JIA) perceive their oral health and dental care. Methods: Fifteen interviews with children diagnosed with JIA, aged 6 to 16 years, were analyzed according to classical grounded theory. Results: The children's main concern about their oral health was identified as creating a positive identity after being diagnosed with JIA and learning to live with oral health problems. While attempting to cope with this concern, the children often endured in silence, the core category in the analysis. A variety of aspects were found of this core coping strategy, which were categorized as differentiating from the disease, working on personal caretaking and positive attitude, fighting fears and sadness, control of professional aid, and building supportive relationships. The results emphasize the importance for caregivers to show empathy and interest in the child as a person, to ask precise questions when taking case histories so the child does not remain silent, to provide psychosocial support and suggest positive coping strategies, to describe and administer treatments, and to give hope for the future. Conclusion: Awareness of the social interaction between a child diagnosed with JIA and health professionals as well as awareness of how to approach a child with longstanding illness are crucial for disclosing and treating the child's orofacial symptoms. Keywords: children, idiopathic arthritis, oral health, pain, qualitative

Aims: To measure the oral health-related quality of life (OHRQoL) in patients with temporomandibular disorders (TMD) compared to controls and analyze its association with various demographic and clinical parameters. Methods: The survey included 187 TMD patients and 200 controls. OHRQoL was measured using the validated Hebrew version of the Oral Health Impact Profile-14 (OHIP-14). A self-report questionnaire assessed personal details, smoking habits, history of trauma and orthodontic treatment, comorbid headaches, oral habits, and pain. TMD patients were divided into diagnostic categories according to the newly recommended diagnostic criteria for TMD (DC/TMD) Axis I protocol. Differences between groups were examined with a Pearson chi-square test for categorical variables and analysis of variance (ANOVA) for continuous variables. Results: Among TMD patients, the diagnostic categories included: (1) masticatory muscle disorders (MMD; n = 38; 20.32%), (2) isolated disorders of the temporomandibular joint (TMJ; n = 46; 24.59%), (3) patients with both MMD and TMJ (TMP; n = 103; 55.08%). Compared to controls, TMD patients exhibited worse global OHIP-14 scores (12.50 ± 8.14 vs 9.58 ± 10.00; P = .002) and worse scores in the following domains: physical pain (P .001), psychological discomfort (P = .005), physical disability (P = .004), and psychological disability (P = .013). Among TMD patients, those categorized as TMP exhibited the highest scores in the physical pain (P = .02) domain. Previous orthodontic treatment, comorbid headache and body pain, limitations in mouth opening and lateral movement, pain, and muscle tenderness scores were found to be strongly related to the OHIP-14. Conclusion: TMD patients suffered from impaired OHRQoL considerably more than controls. OHRQoL in TMD patients is a multidimensional phenomenon influenced by previous orthodontic treatment, comorbid symptoms, pain, functional limitations, and muscle tenderness scores. Keywords: oral health-related quality of life (OHRQoL), pain, temporomandibular disorders (TMD)

Aims: To carry out an epidemiologic characterization of the most common subtypes of temporomandibular disorders (TMD) and to identify associated factors in a Brazilian sample of young adolescents. Methods: From a population of public schoolchildren (12 to 14 years of age), 3,117 students were randomly invited to participate in this study. TMD was assessed according to the Research Diagnostic Criteria for TMD (RDC/TMD) Axis I, in addition to some questions of the Axis II history questionnaire. The associated factors, ie, difficulty with concentration/attention, anger, sadness, anxiety, headache complaints, oral parafunctions, diurnal jaw clenching, tooth grinding at night, and parents not living together, were assessed based on the responses of the adolescents and their parents to structured questions. For the statistical analyses, descriptive statistics, chi-square tests, odds ratio, and logistic regression models were used, adopting a 95% confidence interval and 5% level of significance. Results: The sample consisted of 1,307 individuals (response rate of 41.9%), 56.8% (n = 742) girls. Overall, 397 (30.4%) adolescents presented with TMD, of whom 330 (25.2%) had painful TMD diagnoses. The majority of these had painful TMD of muscular origin (13.1%) and comprised chronic cases (14.9%). Girls presented higher frequencies of TMD overall, painful TMD, painful combined TMD, and chronic painful TMD diagnoses The final multivariate logistic regression model revealed that headache complaints (odds ratio 2.87; confidence intervals 2.21-3.72), oral parafunctions (2.08; 1.26-3.44), tooth grinding at night (2.05; 1.56-2.70), diurnal jaw clenching (1.96; 1.50-2.55), and parents not living together (1.38; 1.07-1.80) were the factors significantly associated with a TMD (overall) diagnosis. Conclusion: About 25% of the adolescents evaluated presented painful TMD, and the majority of these comprised muscular and chronic cases. Some factors, such as reports of headache complaints, oral parafunctions, tooth grinding at night, and parents not living together, were associated with this condition among young Brazilian adolescents. Special attention should be given to these factors among adolescents with TMD. Keywords: adolescents, epidemiology, prevalence, temporomandibular joint disorders

Aims: To investigate the association in adolescents between toothache and sense of coherence (SOC), a psychosocial construct defined as a global orientation to life. Methods: A school-based cross-sectional study was carried out in 36 municipalities comprising up to 50,000 residents in southern Brazil. The target population was adolescents from 15 to 19 years of age. The sample consisted of 1,150 adolescents chosen by systematic sampling; the final adjusted analysis by Poisson regression included 1,065 individuals. Data were collected using a questionnaire, SOC scale, and the Decayed Missing Filled Teeth (DMFT) index. Results: Of the adolescents in the sample, 29.8% reported experiencing toothache in the previous 6 months. The prevalence of dental caries was 31.0%, and the DMFT index was 3.22. SOC was a significant protective factor for toothache; the prevalence ratio was 0.65 (95% confidence interval [CI] = 0.55-0.75). Girls presented 39% more toothaches than boys (95% CI = 1.15-1.68). Individuals who saw the dentist for reasons other than reviews or check-ups had a toothache prevalence that was 85% higher than their counterparts (95% CI = 1.47-2.34). Adolescents with tooth decay reported up to two times more toothache than those without tooth decay. Conclusion: The results of this study showed that a strong SOC protected against toothache. A health-promotion approach may lead to better patterns of oral health. Keywords: cross-sectional study, health of the adolescent, pain, sense of coherence, toothache

Aims: To assess the spatial and temporal sensory effects of the topical application of capsaicin and menthol on the gingiva of healthy volunteers. Methods: Capsaicin, menthol, and saline (control) were applied topically on the gingiva in the maxillary premolar area of healthy volunteers for 15 minutes. Pain intensity was rated on a 0 to 10 visual analog scale (VAS). Before, immediately after, and 30 minutes after application, three mechanical stimuli were applied at 15 gingival sites: fixed-intensity stimuli were applied by 32 mN and 512 mN von Frey filaments, and stimuli of increasing intensity were applied by an electronic von Frey (EVF, 10 g/s). The EVF was used to test the pinprick pain threshold (PiPT). The perceived pain from filament stimulation was rated on a 0-50-100 numeric rating scale (NRS). Analysis of variance for repeated measures was used to analyze the NRS scores, PiPT values, the number of hypersensitive or hyposensitive test sites, and the coordinates of the center of gravity (COG) of somatosensory sensitivity. Results: The mean ± SEM VAS score of pain intensity produced by the application of capsaicin (4.6 ± 0.5) was significantly higher than that produced by menthol (0.3 ± 0.2) and saline (0.1 ± 0.1) (P .001). Capsaicin induced local desensitization to all stimuli (P .047) , and at the application site, capsaicin induced significant desensitization to 512 mN stimuli (P = .003). Menthol did not induce significant somatosensory changes (P > .147), and saline induced slight desensitization in two sites surrounding the application site (P .023). The COG coordinates did not shift significantly over time during any condition (P > .125). Conclusion: Capsaicin but not menthol induced mechanical desensitization in the application area but not in the surrounding areas. Keywords: capsaicin, intraoral somatosensory testing, menthol, psychophysics, spatial, temporal

Aims: To validate the Chinese version of Migraine Screener (ID-Migraine) in medical students in mainland China and to estimate the diagnostic accuracy of ID-Migraine by means of a systematic review with meta-analysis. Methods: A total of 555 medical university students participated in the clinical study. Of these, 190 volunteered to take part in a face-to-face consultation and 365 in a telephone interview to diagnose the presence of migraine according to the criteria of the International Classification of Headache Disorders. The correctness of the diagnosis made clinically and by telephone was assessed by Cohen's kappa statistics. Twenty-two studies were included in the meta-analysis. Sensitivity and specificity were calculated for the clinical study and the meta-analysis. Results: The overall sensitivity and specificity of the Chinese version of ID-Migraine was 84.0% (95% confidence intervals [CI]: 75.0%-90.0%) and 64.0% (95% CI: 59.0%-68.0%), respectively. The Cohen's kappa value of the diagnosis obtained by the face-to-face consultation and the telephone interview was 0.85 (95% CI: 0.69-1.00). A total of 8,682 participants from the 22 studies were included in the meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio were 81.0% (95% CI: 80.0%-82.0%), 68.0% (95% CI: 66.0%-69.0%) and 17.03 (95% CI: 9.94-29.18), respectively. Conclusions: The accurate recognition of migraine by the medical students suggests that the Chinese ID-Migraine version is a valid screening tool. In addition the meta-analysis confirmed the high diagnostic accuracy of this screening tool. Keywords: ID-Migraine, meta-analysis, migraine, screening, validation

Aims: To investigate the potential role of polymorphisms in matrix metalloproteinase-9 (MMP-9), glutathione S-transferase M1 (GSTM1) and T1 (GSTT1), and methylenetetrahydrofolate reductase (MTHFR) genes as risk factors for development of temporomandibular disorders (TMD) in a Serbian population. Methods: This case-control study included 282 subjects: 100 with TMD and 182 healthy controls. Genotyping was done by means of polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) for single nucleotide polymorphisms (SNPs) analysis (C-1562T MMP-9 and C677T MTHFR) or multiplex PCR and real-time PCR methods for deletion analysis (GSTM1, GSTT1) of DNA obtained from buccal swabs. The association of gene variants with TMD risk was determined by calculating odds ratios (OR) and their 95% confidence intervals (CI). Results: A statistically significant difference in genotype and allele frequencies was found between the TMD group and controls for the MMP-9 SNP. Heterozygotes (CT) were significantly more frequent in the TMD group than in the control group and carriers of the T allele had an approximately twofold increase of TMD risk (OR = 2.13, 95% CI = 1.24-3.67, P = .005). The null GSTT1 genotype as well as the combined non-null GSTM1/ null GSTT1 were associated with lower risk of TMD (OR = 0.28, CI = 0.10-0.74, P = .004 and OR = 0.16, CI = 0.03-0.58, P .001, respectively). GSTM1 alone and MTHFR polymorphisms did not show an association with TMD. Conclusion: The C-1562T SNP in the promoter region of the MMP-9 gene, the GSTT1 null, as well as the combined GSTM1 non-null and GSTT1 null genotypes are modulators of TMD risk in a Serbian population. Keywords: genetic polymorphisms, GSTs, MMP, MTHFR, temporomandibular disorders

Aims: To study the effects of a novel matrix metalloproteinase-2 (MMP-2) and MMP-9 inhibitor, AQU-118, on mechanical allodynia in the spinal nerve ligation (SNL) model of neuropathic pain and the chronic constriction injury of the infraorbital nerve (CCI-IoN) model of neuropathic orofacial pain. Methods: Five groups of SNL rats were given daily oral doses of AQU-118 (5, 10, 20 mg/kg), gabapentin (100 mg/kg), or vehicle (0.5% methylcellulose) and then paw withdrawal threshold was measured with von Frey filaments (VF). Three groups of CCI-IoN rats were given daily oral doses of either AQU-118 (40 mg/kg), gabapentin (100 mg/kg), or vehicle (0.5% methylcellulose) and then mechanical allodynia was measured with facial VF and non-reflex-based orofacial stimulation test (OFST) assay. Naïve rats were also tested for the effect of AQU-118 (40 mg/kg) on basal sensitivity to mechanical stimulation/locomotive activity. Results: Mechanical allodynia in SNL rats was attenuated by gabapentin (100 mg/kg) and AQU-118 (in a dose-dependent manner). Mechanical allodynia in CCI-IoN rats was also attenuated (in an equipotent manner) by both AQU-118 (40 mg/ kg) and gabapentin (100 mg/kg) as measured by both facial VF and OFST assay. Upon cessation of either AQU-118 or gabapentin, VF-related responses in both models and OFST assay times reverted to levels observed in vehicle-treated rats. No statistically significant change was observed in locomotive activity/paw withdrawal threshold by AQU-118 (40 mg/kg) in naïve rats. Conclusion: The results demonstrated that oral AQU-118 attenuates mechanical allodynia in both neuropathic pain models and with efficacies that mirror gabapentin at the 40 mg/kg dose used in the CCI-IoN model but without effect on basal sensitivity to mechanical stimulation/locomotive activity. These findings support a possible role for MMP-2/-9 in the etiology of neuropathic pain and also suggest that inhibition strategies represent a viable treatment option. Keywords: allodynia, inhibitor, matrix metalloproteinase, MMP-2, MMP-9, operant, orofacial pain

Aims: To clarify the effect of estrogen and food hardness on condylar cartilage and the cartilage-bone interface. Methods: A total of 56 rats were divided into four groups: (1) ovariectomized rats fed a normal (pressed pellet) food, (2) ovariectomized rats fed a soft (powder) food, (3) control rats fed a normal (pressed pellet) food, and (4) control rats fed a soft (powder) food. Some rats (n = 29) were sacrificed at the age of 67 days and others (n = 27) at the age of 87 days, and then 5-μm-thick sagittal paraffin sections were prepared from each temporomandibular joint (TMJ). Toluidine blue staining, in situ hybridization with type X collagen, terminal deoxynucleotidyl transferase and deoxyuridine triphosphate nick end labeling (TUNEL-assay), and tartrate-resistant acid phosphatase (TRAP) histochemistry were performed. Immunohistochemical analyses included cathepsin K, adiponectin, proliferating cell nuclear antigen (PCNA), and type X collagen staining. Analysis of variance and appropriate post-hoc tests were used in all analyses. Results: Ovariectomy and normal food consistency increased the thickness of condylar cartilage (P .001), PCNA expression (P .001) and type X collagen expression (P .001). Ovariectomy decreased the number (P .05) and size of osteoclasts (P .01). Soft food increased the number of cartilage cells stained positively against adiponectin (P .01). Conclusion: Decreased estrogen level and normal food hardness increase the thickness of condylar cartilage by various mechanisms. Keywords: adiponectin, estrogen, food hardness, loading, mandibular condylar cartilage, osteoclast, PCNA, proliferation, TRAP, type X collagen