Mouth breathing induces condylar remodelling and chondrocyte apoptosis via both the extrinsic and mitochondrial pathways in male adolescent rats

Do symptoms and signs of temporomandibular disorders have an association with breathing pattern: a cross-sectional study on Turkish children and adolescents

BACKGROUND

This paper aimed to explore the prevalence of temporomandibular disorders (TMDs) signs/symptoms, and to investigate the possible link between signs/symptoms of TMDs and mouth breathing (MB) by evaluating along with other risk factors, in a Turkish subpopulation of children and adolescence.

METHODS

This study was conducted with the archival data of the patients who applied with orthodontic complaints. Data on demographic characteristics, family-related factors, systemic status, occlusion, breathing patterns, oral habits, and bruxism were retrieved from the archival records.

RESULTS

Nine hundred forty-five children and adolescents with a mean age of 14.82 ± 2.06 years were included in the study. Of the participants, 66% were girls, 60.4% were delivered by C-section, 8.4% of the participants had at least one systemic disease, 9.2% of the participants had allergy, and 4.3% of the participants' parents were divorced, 18.7% have an oral habit, 6.6% have bruxism, 29.8% have malocclusion and 14.1% have MB. Eight-point-five percent of participants have signs/symptoms of TMD. Among them 2.9% have pain, 3.7% have joint sounds, 1.4% have deflection, and 3.9% have deviation. Evaluation of the risk factors revealed a significant relation between the signs/symptoms of TMD and bruxism (OR 8.07 95% CI 4.36-14.92), gender (OR 2.01 95% CI 1.13-3.59), marital status of parents (OR 2.62 95% CI 1.07-6.42), and MB (OR 3.26 95% CI 1.86-5.71).

CONCLUSIONS

According to the study's findings, girls and those with bruxism, divorced parents, and MB behavior are more likely to have signs/symptoms of TMD. Age found to have significant effect on the occurrence of the signs/symptoms of TMD alone, but together with other factors the effect of the age is disappeared. Early screening and intervention of MB as well as the signs/symptoms of TMD can help to limit detrimental effects of these conditions on growth, and quality of life of children and adolescents.

Craniofacial and olfactory sensory changes after long-term unilateral nasal obstruction-an animal study using MMP-3-LUC transgenic rats

Nasal obstruction exerts considerable physiological effects on the respiratory system and craniofacial morphology during the developmental stage. This study used MMP-3-LUC transgenic rats for in vivo tracking of long-term expression in the rat nasal region after unilateral nasal obstruction. Skeletal changes of the craniofacial, nasal, and sinus regions were measured through micro-computed tomography examination and analysis with 3D image processing and calculation. Matrix metalloproteinase-3 and olfactory marker protein expression were also investigated through immunohistochemistry (IHC). Unilateral nasal obstruction significantly reduced the MMP-3 signal in the nasal region of MMP-3-LUC transgenic rats, which was mainly expressed in the respiratory epithelium. Long-term obstruction also caused morphological changes of the craniofacial hard tissue, such as nasal septal deviation, longer inter-jaw distance, and increased maxillary molar dental height. It also caused compensatory growth in olfactory nerve bundles and the olfactory epithelium, as confirmed by IHC. In our study, long-term unilateral nasal obstruction caused nasal septal deviation toward the unobstructed side, hyper divergent facial development including longer molar dental height, and reduced MMP-3 production. However, further investigation is necessary to explore the mechanism in depth.