ABSTRACT
UNLABELLED: The Hyoid Bone (HB) is a singular bone with no articulation, but is associated with some vital functions. The purpose of this study was to test the null hypotheses that there is no change in HB position in individuals with vertical jaw dysplasia. METHODS: Eleven factors were used to determine the position of the HB. In this paper the ANOVA (two way analysis of variance) method was used to analyze the variability of the mean of each HB position according the factors facial type and gender. Comparisons with these procedures define which measurements were associated with facial type, gender; and the interactive associations between them. RESULTS: The HB is related with vertical facial skeletal pattern being farther from mandible and a line joining it to the third cervical vertebra in deep bite, and from posterior nasal spine and sella turcica in open bite. There is sexual dimorphism in HB position. Men have a significant lower distance to the mandible and to the vertical pterigoidea; and higher values to the third cervical vertebra, to a line joining this vertebra to mandible, to the posterior nasal spine and to the sella turcica. Also, there is an association between HB position related group and gender. CONCLUSION: In this research there is a relation between the position of HB and vertical skeletal pattern. The position of the HB is more related with deep bite. There is a possibility of including the HB in the differential diagnosis of this dysplasia.
ABSTRACT
AIM: Anterior open bite (AOB) is an occlusal anomaly commonly associated with oral habits (OH). The aim of this study was to determine the prevalence of OH as a risk factor for the AOB. MATERIALS AND METHODS: A group of children aged between 3 and 12 years were observed. The statistical methodology included independent chi-square test, Fisher's exact test and binary logistic regression. RESULTS: The frequency of oral habits was of 43.5% in the deciduous dentition and 54.2% in the mixed dentition. There was a statistically significant association of pacifier sucking: 61.7 and 16.1 odd ratios (OR), and tongue thrust: 3.9 and 9.2 OR with AOB in both groups, respectively. Thumb sucking occurred only in the deciduous dentition with 5.6 OR. CONCLUSION: OH and AOB have a high frequency in children. They hinder the normal development of dental and skeletal structures. As OH are risk factors for AOB, the damaging habits most frequently associated are: pacifier sucking, thumb sucking, and tongue thrust. Due to the correlation between the prevalence of AOB and OH, prevention strategies incorporating psychological data related to children should be integrated into a national public health programme.
