A cephalometric study of the tongue position in class III patients

Aims: The objective of this study was to evaluate the tongue position during deglutition with respect to the occlusal plane in class III patients with teeth in centric occlusion. Methods: 24 lateral cephalometric radiographs of a group of 30 class III patients were randomly selected and divided into two Groups: The fi rst group for class III patients with open bite and the second group for class III patients with inverted overbite. The angles formed by the plane of the tongue and the occlusal plane obtained in all the samples were compared between the two studied groups. The T-test was used to evaluate the differences among studied angles. Results: The average of the anterior angles in patients with inverted overbite was lower than the average of the anterior-lower angles in class III patients with open bite. Anterior-lower angles with values between 24.17 and 34.08 were observed for class III with inverted overbite. T test of equality of means 6.661 signifi cance, the angles were signifi cantly different (p< .001) in both studied cases. Conclusion: Tongue posture is signifi cantly different during deglutition in class III with open bite and inverted overbite. Research Article A cephalometric study of the tongue position in class III patients Wilfredo Molina Wills1* and Vanessa Rodriguez2 1Ex-Researcher of the Physiology Department of Medicine School in The University of The Andes Venezuela, Professor of the Dentist College in Mérida Venezuela, Venezuela 2Private Practice, Venezuela Received: 07 June, 2019 Accepted: 19 July, 2019 Published: 20 July, 2019 *Corresponding author: Dr. Wilfredo Molina Wills, ExResearcher of the Physiology Department of Medicine School in The University of The Andes Venezuela, Professor of the Dentist College in Mérida Venezuela, Venezuela, E-mail:


Introduction
Tongue is the largest organ of the oral cavity [1]. The posture, size and shape of the tongue are of signifi cance for dent alveolar structures [2]. It has been showed that form; position and function of the tongue have some direct relationship with some types of oro-dental morphopathologics [3].
The tongue have probably infl uence by modifi cations in oro-dental environment, especially of the mandible [4]. It appears that a range of physiologic, pathologic, and mechanism factors can infl uence growth [5]. Although it has been that a close form and function relationship exists.
In previous studies have been reported the infl uence or not of the tongue size on the perimeter of the mandible dental arch in class III patients [6]. In the same way, it has been mentioned in class III patients with open bite has concave profi le, a long lower facial height and mandible protrusion [7].
The purpose of this study was to evaluate the position of the tongue in relationship with the occlusal plane during swallowing with teeth in centric occlusion in class III patients.

Material and Methods
Lateral cephalometric radiographs with the x-ray beam perpendicular to the patient ' s sagittal plane in natural head position to standardize orientation of the head that is reproducible for each individual were taken. This head position is a common method of orientation for cephalometric radiography [8,9]. Twenty-four lateral cephalometric radiographs of a group of 30 class III patients were randomly selected. These cephalogram were realized during deglutition with teeth at centric occlusion with the same operator. The selected cephalometric radiographs were divided into two groups: The fi rst group for class III patients with open bite and the second group for class III patients with inverted overbite.
The angles formed by the plane of the tongue and the occlusal plane obtained in all the samples of the fi rst group were compared with the same angles of the twelve samples of Group 2.

Clinical characteristics
Patients selected for this study had a growth pattern related to a dentofacial deformity with mandibular prognathism in relation to the maxilla. The selected cases had serious maxillomandibular discrepancies and typical class III profi le. To carry out this study, the patients approved all the procedures.

Ethical contents
This study was approved by ethics committee of the school of dentists of Merida state in Venezuela.
All the issues of the Helsinki Declaration related to research in human subjects were observed.

Results
Twelve cephalograms were classifi ed as class III with open bite for 50 % of the studied cases and twelve cephalograms for 50 % of the cases with class III and inverted overbite table 1. Table 1-f= (frequency). The major percentage of the 24 studied cases, the tip of the tongue was located at the level of the fi rst premolar during deglutition (13 cases for a 54.36% of all studied patients) fi gure 3.

Statistical results
Anterior-lower angles showed a 24.17 STD deviation 3.639 for class III with inverted overbite, and a 34.08 STD deviation        Due to the fi ndings of this study, it is possible to suggest that the position and thrust of the tongue in class III patients may be related to the bite type. But more studies are needed to clarify this issue.

Conclusion
The present study has shown that: