On the prevalence of various forms of malocclusion in patients seeking orthodontic care

Abstract

Distal occlusion is one of the most common forms of dento-maxillofacial abnormalities and is often accompanied by the development of pathology of the temporomandibular joint. However, there are no supporting statistics on the prevalence of malocclusion among the adult population. The aim of this study is to determine the prevalence of various malocclusion abnormalities among the adult population in order to identify possible concomitant pathologies of the TMJ.
Methods. Cephalometric analysis by Bojrk was performed for 147 images of lateral TRG in patients aged 18 to 45 years. The position of the upper and lower jaws in the sagittal plane was estimated by the parameters of the angles SNA and SNB, in the vertical plane the rotation of the upper jaw relative to the skull base PP/SN was estimated. The basic parameters for determining the type of malocclusion were the ANB angle value and the Wits. The vertical component in patients with detected distal occlusion was evaluated based on the definition of MP/SN.
Results. According to the study, the prevalence of distal occlusion based on the ANB and Wits parameters is 59,1% and 69,4%, the frequency of mesial occlusion is 12,2% and 22,5%, whereas the norm of the interbasic ratio varies between the ANB/Wits parameters – 28,6/8,2%, which is associated with rotations of the jaws to the skull base and rotations of the occlusal plane. Based on the vertical component of the distal occlusion, 25,5% of patients have a horizontal vector, 34,3% have a vertical vector, and 40,2% have a neutral vector. Of the entire examined group, distal occlusion with vertical growth type was observed in 23,8% of patients, which indicates possible TMJ disorders.