Analysis of the prevalence of the open bite in the medical records of preventive orthodontics at the Faculdade de Ilhéus

Objective: To verify the prevalence of open bite in the medical records of preventive orthodontics at the Faculdade de Ilhéus, associating it with the individual's psychological behavior and functional analysis. Material and methods: A cross-sectional study was carried out with 145 medical records of preventive orthodontics of the Faculdade de Ilhéus in the years 2018 and 2019. Result: The prevalence of open bite identified in the medical records of preventive orthodontics of the Faculdade de Ilhéus was 15.8%. The female gender was the majority with 55%, with 61% of cases of malocclusion. Regarding the dentition that the patient was in, 73.91% were in mixed dentition, 21.74% in primary dentition and only 4.35% in permanent dentition. In the functional analysis observed in the dental document, 40.54% were oral-nasal breathers, followed by 35.14% with interposed tongue and abnormal speech was 24.22%. Patients who had an open bite in the psychological behavior item 68.75% used pacifiers and 31.25% had the habit of digital sucking. Conclusion: The data collected in this study reinforce the significant prevalence of open bite and the close association with harmful habits and the individual's respiratory, swallowing and phonation physiology. Explanatory measures are necessary for those responsible for the prevention of harmful habits that can cause open bite in children, if the open bite is already present, it should be interfered as soon as possible, as this way the less invasive treatment can be adopted by the orthodontist, enabling a satisfactory regression to the patient.


Introduction
Over time, the incidence of malocclusion has become a worldwide oral health problem, surpassed only by dental caries and periodontal diseases, and is an alarming problem, especially for orthodontists. (Dias & Gleiser, 2008). Epidemiological surveys help to understand the prevalence or incidence of a particular disease affecting the population. They are scientific evidence that contributes and encourages the research field to discuss, clarify, and search for less invasive and accessible public health solutions to improve people's quality of life. (Miotto et al., 2016).
The open bite is the negative overbite between the upper and lower teeth. This malocclusion can occur both anteriorly and posteriorly and rarely affects the entire dental arch. Among the existing malocclusions, there is a relevant esthetic and functional involvement with skeletal and dental alterations. Several etiologic factors for the occurrence of an open bite have been discussed in the literature, including dental ankylosis, tooth eruption imbalance, hypertrophic tonsils, oral breathing, and finger sucking or pacifying habits. All of these causes have the potential to interfere with normal development of the face and stomatognathic system. (Henriques et al., 2000).
The anterior open bite is a difficult malocclusion to treat because several etiologic factors may be involved in the changes caused by this condition, in addition to genetic and environmental factors. This malocclusion can cause esthetic and functional disturbances for the patient. (Salehi et al., 2015). Considering this, the aim of the study is to review the prevalence of the open bite in the medical records of preventive orthodontics at the Faculdade de Ilhéus, considering the psychological behavior and functional analysis of the individual.

Methodology
145 records of preventive orthodontics were selected in 2018 and 2019. The age of the patients ranged from 4 to 13 years, and both genders were included in the present study. Patients'dentition (mixed primary dentition or permanent dentition) was observed. The information on the functional analysis item was examined to determine whether the patient had normal or abnormal speech and swallowing; bucconasal, nasal, or oral breathing; and normal, inserted, or trapped tongue.
The psychological behavior item was analyzed in the preventive orthodontics records to determine if the patient had a habit of sucking a pacifier and sucking fingers (non-nutritive harmful habits).
Medical records that did not contain information on whether the patient had an open bite, in addition to the functional analysis and psychological behavior items, were excluded from the analysis.

Discussion
The results of this study show that the prevalence of open bite was 15.86% and had a significant expression. Moreover, there was a direct and relevant association between malocclusion and patients' psychological behavior and functional analysis. open bite in the mixed dentition and found that only 6.7% had malocclusion in this dentition, which is in contrast to this study. Tibolla et al (2012) analyzed the prevalence of open bite, finding 34.2% occurred in the primary dentition, 24.4% in the mixed dentition, and 15% in the permanent dentition, which does not agree with the present study. It goes without saying that an early diagnosis favors a less invasive treatment for the patient, since self-correction of the open bite in the primary dentition is still possible up to the first four years of life after the elimination of the harmful habits.
In cases where the patient has an open bite in the mixed dentition, interceptive and corrective orthodontics should be used, which is a less conservative procedure. There are few cases in the literature in which an open bite occurs in the permanent dentition because children often abandon harmful habits before entering this dentition. In the study conducted by Maciel et al. (2005), only 20% of open bite cases showed oral nasal breathing, which differs from the present study because of the different static parameters. The change in breathing pattern may result from hypertrophy of structures such as adenoids and tonsils, leading to nasal obstruction. Maciel et al (2005) found that 59% of patients had tongue interposition. In many cases where the patient has an open bite, the change in tongue position represents a morphologic adaptation to the oral environment and may exacerbate malocclusion. An open bite can cause atypical phonation because the tongue protrudes outward or to the side at the time of phonemic articulation.
Multifactorial involvement of other fields such as speech-language pathology and otolaryngology are essential for effective correction of the open bite.
In the study by Pizzol et al (2012), 11% of preschool children in the city of Araraquara-SP had the habit of digital sucking. On the other hand, Miotto et al. (2014) found a prevalence of the habit of digital sucking of 39.3% and 36.3% of children used a pacifier in cases of open bite. In another study, also conducted by Miotto et al. (2016), the habit of digital sucking was only 3.9% and 29.4% used a pacifier, which is not consistent with the present study. Colombi et al. (2017) analyzed open biting and harmful habits in children from 9 schools in the city of Nova Venécia-ES, where they found 45.8% with pacifier use and 14.8% with finger sucking habits, making this study the closest to the present study. In the present study, most of the patients with open bite had some non-nutritive sucking habit, and this factor may be directly related to the etiology of malocclusion. It is well known that these habits produce a feeling of emotional satisfaction in infants and children, which is often not only achieved through breast milk and is also used as an artifice to soothe and comfort children. Open biting occurs early and is common in children who have the habit of using pacifiers or sucking their fingers. However, it is important to observe the growth pattern of the patient's face and evaluate the intensity, duration, and frequency of the habit (Graber's triad) to provide a guide to the severity of malocclusion. This study was performed with a small sample of medical records, since some documents did not contain records of the patient with or without open bite, functional analysis, and psychological behavior.

Conclusion
The current study highlights that open bite has epidemiological relevance and shows the relationship between harmful habits and functional analysis and dental malocclusion. Therefore, preventive measures should be implemented in schools, day care centers, and oral health events for those responsible for educating about harmful habits that can cause open bite. In cases where the open bite already exists, the orthodontist must consider the patient's facial growth pattern and heredity, perform interceptive and corrective orthodontics, investigate the causes, and determine if problems with breathing, phonation, or swallowing may be involved in the malocclusion, and recommend multidisciplinary treatment to achieve successful treatment with little chance of recurrence.