Facial Anthropometric Measurements according to diagnosis of breathing mode and gender in adults

Purpose: to compare the facial anthropometric measures in adults according to the breathing mode and genre. Methods: the study sample comprised 82 adult subjects, aged 18 to 35 years old, 59 females and 23 males. From the speech pathology and otorhinolaryngologic assessments, 46 nasal breathers and 36 mouth breathers were diagnosed. The facial measures were achieved with a caliper and compared according to the subject’s breathing mode diagnosis and genre, through the Student’s t-test and Pearson’s Correlation, with a significance level of 5%. Results: the vertical anthropometric measures (middle third, lower third, facial height, upper lip and lower lip) were found to be significantly greater in mouth breathers and displayed positive correlation with the breathing mode. All facial measurements performed were found to be higher in males and showed positive correlation with the variable genre. Conclusion: the facial anthropometric measures of vertical plane were found to be greater in mouth breathers, suggesting a more elongated facial pattern of growth in these subjects. All the facial anthropometric measures obtained in the vertical, horizontal and transverse planes were found to be higher in male subjects.

having experience in orofacial motricity.A Western® digital caliper, resolution 0.01mm and precision ± 0.02mm, was the instrument used to obtain the measures.In order to obtain the measure of facial width, 8.25cm metal extensions were adapted to the instrument nozzles for external measurement 6 .
During the assessment, the subject remained in front of the examiner, in sitting position, the feet flat on the ground, natural head position, lips enclosed and the teeth in centric occlusion without pressure 5,7,8 .
Subsequently, to identify the precise localization, the craniofacial spots were palpated and marked in the skin with dermographic pencil.The anthropometric measurements were performed without pressing the caliper ends against the skin surface, because that could alter the results.All the measurements were performed twice for greater reliability.The result on each measurement was achieved through the average of two collections in milimeters 5,7,8 .
The anthropometric measurements were collected as follows: • middle third of the face: distance from the glabella to the subnasal (g-sn); • lower third of the face: distance from the subnasal to the gnathion (sn-gn); • facial height: distance from the glabella to the gnathion (g-gn); • facial width: distance between the prominence of the zygomatic arches (zy-zy); • right side: distance from the outside corner of the right eye to the right labial commissure (ex-ch); • left side: distance from the outside corner of the left eye to the left labial commissure (ex-ch); • upper lip height: distance from the subnasal to the lowest point of the upper lip (sn-sto); • lower lip height: distance from the highest point of the lower lip to the gnathion (sto-gn).
For data analysis, the Kolmogov-Smirnov test was used to verify the normality of the facial anthropometric measures distribution.Aiming to compare the anthropometric measures according to the breathing mode and gender, the Student's t-test was used.To assess the association of the variables 'breathing mode and gender' with the facial anthropometric measurements, the Pearson's Correlation test was used.The statistical analyses were performed by the SPSS (Statistical Package for Social Science, version 20) software, considering the significance level of 5%.
assessment, and constitutes one of the evaluation items for the protocols in the orofacial myology and motricity area 3,4 .It is widely used as it is a simple, low-cost, non-invasive method, and easy to interpret 5 .
Based on the above, the purpose of this study was to compare the facial anthropometric measurements in adults according to the breathing mode and gender.

METHODS
This analytic cross-sectional study was approved by the research ethics committee of the Federal University of Santa Maria under the protocol number 04039912.7.0000.5346.All the participants had the Free and Informed Consent Term signed.
The sample comprised subjects from orthodontic, otorhinolaryngology, speech-language pathology and physiotherapy clinics, and the wider community, with previous divulgation in newspapers, radio stations, social networks and posters affixed in health service facilities, characterizing a non-probability convenience sample.
Subjects aged 18 to 35, leukodermas, both sexes, were included in the study.Subjects with craniofacial syndrome and/or malformation, presenting with a history of orthodontic and/or speech-language pathology and/or physiotherapy treatment were excluded.
In order to form groups according to the breathing mode, the subjects underwent speech-language and othorhinolaryngologic assessment.The speechlanguage was performed based on the MBGR protocol (clinical history and orofacial myofunctional assessment) 3,4 .Based on this assessment, it was verified the morphological and functional characterization of the stomatognathic system, which contributed to the breathing mode diagnosis and served as a basis to verify the conformity with the criteria for the formation of the nasal and mouth breathers groups.
The otorhinolaryngologic assessment comprised the anamnesis, oroscopy, anterior rhinoscopy, otoscopy and nasofibropharyngoscopy.The endoscopic examination was performed with nasofibroscope Pentax FNL -10 RP3, 3.7mm diameter, inserted into the nasal cavity to the region of the rhinopharynx, where the presence of pharyngeal tonsils (adenoids) was assessed.
The orofacial anthropometric assessment was performed by a single speech-language pathologist On the other hand, no correlation or differences were found in the averages of cross-sectional (sides of the face) e horizontal (facial width) measures between the nasal and mouth breathers (Tables 1  and 3).
In gender comparison, it became evident that all averages of facial anthropometric measures were significantly higher in males (Table 2).Additionally, all facial anthropometric measures displayed positive correlation with the variable 'gender', with a weak correlation with facial width and a moderate correlation with other measures (Table 3).

RESULTS
Through the results analysis, it was verified that all the averages of the vertical anthropometric measures (middle third, lower third, facial height, upper lip and lower lip) were significantly higher in mouth-breathing subjects than in nasal breathers (Table 1).It was also possible to observe a moderate positive correlation between the breathing mode and the measures of the lower third, facial height and lower lip, as well as a weak positive correlation between the breathing mode and the measures of the middle third and upper lip (Table 3).  in the averages of the middle third in none of the age groups studied.On the other hand, it became evident that the measures of the sides of the face and facial height correlate only with gender (Table 3), the averages being higher in males (Table 2), with no association with the breathing mode verified.
Regarding the averages obtained, it can be observed that the middle third and lower third of the face are close to the values suggested by the literature on adult patients (55 to 65 mm) 20 .An aspect that draws attention are the higher values of the middle thirds than those in the lower thirds, which is in accordance with only one study selected, that have found the middle third significantly higher in adult nipo-brazilian women when compared with black and white women, whose lower third was higher 12 .These results differ from other studies that verified that the middle third was lower than the lower third 8,11,21,22 .Despite the fact that only leukoderma subjects have been included, the ample racial miscegenation in Brazil, found especially in the state of Rio Grande do Sul, have probably influenced this outcome, since most of the studies with other samples of Brazilians showed that the middle third is lower than the lower third.
Another interesting finding refers to the average value of the upper lip measure, which was significantly higher in mouth-breathing subjects than in nasal breathers.Although some studies mention the shortened upper lip as one of the clinical characteristics of the mouth breather 23,24 , as well as in other research carried out with children 8,19 , this characteristic was not found in the anthropometric assessment.This probably occurs due to the solicitation of labial closure during the assessment, which may generate a muscular effort that is able to compensate the aspect of the shortened upper lip 8 .In other study, a statistically significant difference

DISCUSSION
The present study aimed to assess the impact of breathing mode on craniofacial morphology in adult subjects, based on the comparison of anthropometric measurements in nasal and mouth breathers.No studies were found regarding anthropometric assessment in adult mouth breathers, which justifies the comparison of some findings with studies carried out with children.Facial anthropometric measurements were also compared between genders, since several studies have demonstrated differences in facial anthropometric measures between males and females [9][10][11][12][13] .
Through the comparison of facial measures between breathing modes, it was verified that all vertical measures (middle third, lower third, facial height, upper lip and lower lip) were significantly higher in mouth breathers, with a positive, weak to moderate correlation between these variables.
The literature reports that mouth-breathing patients frequently exhibit the habitual tongue position on the floor of the mouth 14,15 , open or half-open lips 15,16 , which favors the posteroinferior rotation of the mandible 17 , an increase in the mandibular plane 17 and the antigonic incisura 18 , characterizing a predominantly vertical craniofacial growth, dolichofacial type.This can explain the findings of the present study, confirming the influence of breathing mode on the increase of all measurements performed in the vertical plane.
The findings in this study partially support results of other authors 19 , who compared the facial anthropometric measures among children with no speechlanguage complaints, and mouth-breathing children aged seven to 11.The authors verified a statistically significant difference in the measures of the upper lip, lower lip, lower third and the right and left side of the face, and no significant differences were evident anthropometric measures, as demonstrated in previous studies.Accordingly, it is recommended further research that applies a similar analysis model, taking into account other variables that may impact the facial anthropometric measures.
In this study, it was possible to detect that mouthbreathing subjects showed a predominantly vertical pattern of growth, confirming therefore the influence of the breathing mode alteration on craniofacial morphology.For this reason, it must be stressed the need of multidisciplinary follow-up and treatment of mouth breathing mode during childhood, to minimize the negative effects before the period of craniofacial growth spurt.

CONCLUSION
The facial anthropometric measures of the vertical plane were higher in mouth breathers, suggesting a more elongated facial pattern of growth in these subjects.
Sexual dimorphism was observed in all the measures obtained (vertical, horizontal and crosssectional plane), with all the measures being higher in males.
was verified in the measure of the upper lip by analyzing the variable 'habitual resting position' with and without labial closure, which was higher in the first situation 25 .
In the analysis of facial measurements according to the variable 'gender', it was verified that all the anthropometric measures performed were significantly higher in males than in females (Table 2), which is in accordance with the literature 10,11,13 .This study confirmed the hypothesis that there is a sexual dysmorphism in facial measurements in adults, since all the anthropometric measurements showed an association with the variable 'gender' in Pearson's Correlation test (Table 3).This finding confirms the need to take into account this variable when designing studies involving facial anthropometric measurements.