Facial skeletal alterations in mouth breathing paediatric patients: Cephalometric evaluations

The morphogenesis of the dento-maxillofacial district is related to epigenetic factors and intrinsic genetic factors, and to local and general environmental factors, which interfere with the neuromuscular balance. Among the several local environmental factors that can interfere with a harmonious and balanced craniofacial growth, there are spoiled habits, such as mouth breathing. Mouth breathing represents the most serious condition, since not only plays a fundamental role in the development of the entire dento-maxillofacial apparatus, but also lead to negative consequences at the systemic level as far as pulmonary, circulatory, nervous, endocrine and digestive functions. The orthodontist plays an important role in the diagnosis, since the most significant symptoms are of orthodontic nature such as, for example, the alteration of the shape of the dental arches, of occlusion, and growth vectors of the maxillary. The aim of this study is to determine whether the tendency to develop a condition of skeletal hyper-divergence with high vertical anterior dimensions of the middle and lower facial third, are related to the degree of patency in the nasopharyngeal canal. Cephalometric data from 50 mouth-breathing subjects and 30 prevalent nasal-breathing subjects were analyzed, looking for a correlation between the degree of skeletal divergence of the jaw (the FMA angle in particular) and the degree of patency of the nasopharyngeal canal (AD-PTV). Data confirmed the correlation between facial morphology and the reduction of the nasopharyngeal space in mouth breathing subjects. The correlation between skeletal class II malocclusion and the reduction of the sagittal diameters of the rhino-pharyngeal canal wasn’t relevant. Finally, although the table of percentages shows an increase in the diameters of the upper airways in older subjects, demonstrating the physiological atrophy during the growth, this correlation is not statistically significant. This study demonstrated a significant correlation between small nasopharyngeal canal size and facial skeletal hyper-divergence was also demonstrated.