Comparative analysis between mandibular positions in centric relation and maximum intercuspation by cone beam computed tomography (CONE-BEAM)

Abstract

This research consisted of a quantitative assessment, and aimed to measure the possible discrepancies between the maxillomandibular positions for centric relation (CR) and maximum intercuspation (MI), using computed tomography volumetric cone beam (cone beam method). The sample of the study consisted of 10 asymptomatic young adult patients divided into two types of standard occlusion: normal occlusion and Angle Class I occlusion. In order to obtain the centric relation, a JIG device and mandible manipulation were used to deprogram the habitual conditions of the jaw. The evaluations were conducted in both frontal and lateral tomographic images, showing the condyle/articular fossa relation. The images were processed in the software included in the NewTom 3G device (QR NNT software version 2.00), and 8 tomographic images were obtained per patient, four laterally and four frontally exhibiting the TMA’s (in CR and MI, on both sides, right and left). By means of tools included in another software, linear and angular measurements were performed and statistically analyzed by student t test. According to the methodology and the analysis performed in asymptomatic patients, it was not possible to detect statistically significant differences between the positions of centric relation and maximum intercuspation. However, the resources of cone beam tomography are of extreme relevance to the completion of further studies that use heterogeneous groups of samples in order to compare the results.

Differences between centric relation and maximum intercuspation as possible cause for development of temporomandibular disorder analyzed with T-scan III

“…It is not clear how occlusal changes (natural dentition development, occlusal treatments, or restoration procedures) affect the function of the TMJ. [ 21 58 ] However, in our study comparing results between groups it is clear that occlussal changes affect TMJ and also fixed dentures if they are not well articulated also can affect TMJ in future.…”

“…The position of MIC is defined as the position of the occlusal relationship in which the teeth of both arches are mostly interposed independent of condylar position. [ 20 21 22 23 24 ] MIC also known as Centric Occlusion: this position is dictated by the teeth themselves, determined when the patient habitually self-closes into complete tooth intercuspation. [ 6 20 21 24 25 26 ]…”

Evaluation of condylar position by CBCT after static and dynamic registration in edentulous patients

“…CR seems to be a correct position that ensures space for the articular disc and avoids temporomandibular disorders. 1,19,25,27 Comparing static with dynamic registration, the first one is dependent upon a number of factors, for example: muscle tone, tissue resiliency, guidance of the mandible and pressure applied. 4,9,28 It requires stabilized bases and tissue resiliency or advanced alveolar ridge resorption could affect their stability.…”

“…The capture of the area of interest with rapid scan time (10-70 s) minimizes the exposure of adjacent structures, while exposing the patient to low radiation doses. [19][20][21][22][23] The aim of this study was to compare the condylar position, using frontal and lateral CBCT images, after static and dynamic registration, to understand which of the two methods contributes to the best radiographic CR position. The secondary objectives were to: analyze symmetry between right and left condyles and examine the relationship between articular eminence and condylar position.…”

CBCT imaging – A boon to orthodontics

“…By providing concurrent visualization of TMJs and maxillomandibular spatial relationships and occlusion, CBCT images provide clinicians with the opportunity to visualize and measure the local and regional effects associated with TMJ abnormalities. Similarly, cases involving centric occlusion versus centric relation (CO/CR) discrepancies, unilateral Class II malocclusions, or a retrognathic mandible may involve displacement of the TMJ in CO versus CR, and additional diagnostic information derived from CBCT scans would be beneficial in these cases (Ferreira et al, 2009).…”