Temporomandibular joint dysfunction and orthognathic surgery: a retrospective study

<p>Abstract</p> <p>Background</p> <p>Relations between maxillo-mandibular deformities and TMJ disorders have been the object of different studies in medical literature and there are various opinions concerning the alteration of TMJ dysfunction after orthognathic surgery. The purpose of the present study was to evaluate TMJ disorders changes before and after orthognathic surgery, and to assess the risk of creating new TMJ symptoms on asymptomatic patients.</p> <p>Methods</p> <p>A questionnaire was sent to 176 patients operated at the Maxillo-Facial Service of the Lille's 2 Universitary Hospital Center (Chairman Pr Joël Ferri) from 01.01.2006 to 01.01.2008. 57 patients (35 females and 22 males), age range from 16 to 65 years old, filled the questionnaire. The prevalence and the results on pain, sounds, clicking, joint locking, limited mouth opening, and tenseness were evaluated comparing different subgroups of patients.</p> <p>Results</p> <p>TMJ symptoms were significantly reduced after treatment for patients with pre-operative symptoms. The overall subjective treatment outcome was: improvement for 80.0% of patients, no change for 16.4% of patients, and an increase of symptoms for 3.6% of them. Thus, most patients were very satisfied with the results. However the appearance of new onset of TMJ symptoms is common. There was no statistical difference in the prevalence of preoperative TMJ symptoms and on postoperative results in class II compared to class III patients.</p> <p>Conclusions</p> <p>These observations demonstrate that: there is a high prevalence of TMJ disorders in dysgnathic patients; most of patients with preoperative TMJ signs and symptoms can improve TMJ dysfunction and pain levels can be reduced by orthognathic treatment; a percentage of dysgnathic patients who were preoperatively asymptomatic can develop TMJ disorders after surgery but this risk is low.</p

A saturated map of common genetic variants associated with human height

Common single-nucleotide polymorphisms (SNPs) are predicted to collectively explain 40-50% of phenotypic variation in human height, but identifying the specific variants and associated regions requires huge sample sizes(1). Here, using data from a genome-wide association study of 5.4 million individuals of diverse ancestries, we show that 12,111 independent SNPs that are significantly associated with height account for nearly all of the common SNP-based heritability. These SNPs are clustered within 7,209 non-overlapping genomic segments with a mean size of around 90 kb, covering about 21% of the genome. The density of independent associations varies across the genome and the regions of increased density are enriched for biologically relevant genes. In out-of-sample estimation and prediction, the 12,111 SNPs (or all SNPs in the HapMap 3 panel(2)) account for 40% (45%) of phenotypic variance in populations of European ancestry but only around 10-20% (14-24%) in populations of other ancestries. Effect sizes, associated regions and gene prioritization are similar across ancestries, indicating that reduced prediction accuracy is likely to be explained by linkage disequilibrium and differences in allele frequency within associated regions. Finally, we show that the relevant biological pathways are detectable with smaller sample sizes than are needed to implicate causal genes and variants. Overall, this study provides a comprehensive map of specific genomic regions that contain the vast majority of common height-associated variants. Although this map is saturated for populations of European ancestry, further research is needed to achieve equivalent saturation in other ancestries.A large genome-wide association study of more than 5 million individuals reveals that 12,111 single-nucleotide polymorphisms account for nearly all the heritability of height attributable to common genetic variants

Speech evaluation in children with temporomandibular disorders

OBJECTIVE: The aims of this study were to evaluate the influence of temporomandibular disorders (TMD) on speech in children, and to verify the influence of occlusal characteristics. MATERIAL AND METHODS: Speech and dental occlusal characteristics were assessed in 152 Brazilian children (78 boys and 74 girls), aged 8 to 12 (mean age 10.05 ± 1.39 years) with or without TMD signs and symptoms. The clinical signs were evaluated using the Research Diagnostic Criteria for TMD (RDC/TMD) (axis I) and the symptoms were evaluated using a questionnaire. The following groups were formed: Group TMD (n=40), TMD signs and symptoms (Group S and S, n=68), TMD signs or symptoms (Group S or S, n=33), and without signs and symptoms (Group N, n=11). Articulatory speech disorders were diagnosed during spontaneous speech and repetition of the words using the "Phonological Assessment of Child Speech" for the Portuguese language. It was also applied a list of 40 phonological balanced words, read by the speech pathologist and repeated by the children. Data were analyzed by descriptive statistics, Fisher's exact or Chi-square tests (&#945;=0.05). RESULTS: A slight prevalence of articulatory disturbances, such as substitutions, omissions and distortions of the sibilants /s/ and /z/, and no deviations in jaw lateral movements were observed. Reduction of vertical amplitude was found in 10 children, the prevalence being greater in TMD signs and symptoms children than in the normal children. The tongue protrusion in phonemes /t/, /d/, /n/, /l/ and frontal lips in phonemes /s/ and /z/ were the most prevalent visual alterations. There was a high percentage of dental occlusal alterations. CONCLUSIONS: There was no association between TMD and speech disorders. Occlusal alterations may be factors of influence, allowing distortions and frontal lisp in phonemes /s/ and /z/ and inadequate tongue position in phonemes /t/; /d/; /n/; /l/

Signs and symptoms of temporomandibular disorders in adolescents Sinais e sintomas de disfunção temporomandibular em adolescentes

The aim of this study was to verify the prevalence of signs and symptoms of temporomandibular disorders (TMD) in adolescents and its relationship to gender. The sample comprised 217 subjects, aged 12 to 18. The subjective symptoms and clinical signs of TMD were evaluated, using, respectively, a self-report questionnaire and the Craniomandibular Index, which has 2 subscales; the Dysfunction Index and the Palpation Index. The results of muscle tenderness showed great variability (0.9-32.25%). In relation to the temporomandibular joint, tenderness of the superior, dorsal and lateral condyle regions occurred in 10.6%, 10.6% and 7.83%, respectively, of the sample. Joint sound during opening was present in 19.8% of the sample and during closing in 14.7%. The most prevalent symptoms were joint sounds (26.72%) and headache (21.65%). There was no statistical difference between genders (p > 0.05), except for the tenderness of the lateral pterygoid muscles, which presented more prevalence in girls. In conclusion, clinical signs and symptoms of TMD can occur in adolescents; however, gender influence was not perceived.<br>O objetivo deste estudo foi verificar a prevalência de sinais e sintomas de disfunção temporomandibular (DTM) em adolescentes e sua relação com o gênero. A amostra foi constituída de 217 voluntários, com idade entre 12 e 18 anos. Os sintomas subjetivos e os sinais clínicos de DTM foram avaliados usando-se, respectivamente, um questionário e o "Craniomandibular Index", o qual possui 2 subescalas: "Dysfunction Index" e "Palpation Index". Os resultados para sensibilidade muscular mostraram grande variabilidade (0,9-32,25%). Com relação à articulação temporomandibular, a sensibilidade à palpação nas regiões superior, dorsal e lateral do côndilo ocorreu, respectivamente, em 10,6%, 10,6% e 7,83% da amostra. A prevalência do ruído articular no movimento de abertura foi de 19,8% e no fechamento, 14,7%. Os sintomas relatados mais prevalentes foram o ruído articular (26,72%) e dor de cabeça (21,65%). Nenhuma diferença estatística foi encontrada para a associação entre os gêneros (p > 0,05), exceto para a sensibilidade no músculo pterigóideo lateral, a qual se apresentou mais prevalente nas meninas. Os sinais clínicos e sintomas subjetivos de DTM foram observados em adolescentes, no entanto a influência do gênero não foi percebida nessa faixa etária