The Role of Maxillofacial Structure and Malocclusion on Condylar Displacement in Maximum Intercuspation and Centric Relation in Patients Seeking Orthodontic Treatment-A Scoping Review

BACKGROUND

Available knowledge about malocclusion and cephalometric variables and their connection with an increased risk of condylar displacement (CD) is scarce. This article aims to present current information on the relationship between centric relation-maximum intercuspal position discrepancies and maxillofacial morphology and malocclusion in patients seeking orthodontic treatment as well as to identify those who require expanded diagnostic evaluation for this disorder.

METHODS

This review analyzed the PubMed, Cochrane Library, Web of Science, and Scopus electronic databases up to February 2022. Keywords and additional manual searches were performed. Literature selection was based the PRISMA-ScR checklist. The JBI Critical Appraisal Tool assessed the methodological quality of included studies.

RESULTS

The databases search provided 2321 studies. A total of 10 studies were included in this review after eligibility criteria and JBI assessment. This review was separated into five parts that evaluated CD correlations depending on the following: maxillofacial structure in different vertical and sagittal skeletal patterns, vertical, horizontal, and transverse malocclusions.

CONCLUSIONS

A hyperdivergent facial skeletal structure is a risk factor for increased CD, particularly in the vertical dimension. The condylar processes are usually displaced in a posteroinferior direction. Further studies are warranted to elucidate the relationship among remaining skeletal and dental malocclusions and the occurrence of CD.

The relationship between mandibular arch length and widths in a sample of Yemeni subjects with normal dento-Skeletal relationship

Objective:

To assess the relationship between mandibular arch length and widths in a sample of Yemeni subjects aged (18-25) years.

Materials and Methods:

The investigation involved clinical examination of (765) adults; only 214 (101 females, 113 males) out of the total sample were selected to fulfill the criteria for the study sample (normal dento-skeletal relationship). Study models were constructed and evaluated to measure mandibular arch dimensions. The Spearman's correlation coefficient (r) was calculated between the measurements of arch widths and lengths.

Results:

Overall, the male group demonstrated greater transverse and sagittal mandibular dimensions; However, this was only statistically significant for measurements of inter-first and second molar distances and anterior arch length (P < 0.05). Relatively stronger linear relationships were observed between the inter-canine distance and mandibular arch lengths (P < 0.05, Spearman's r ranged between 0.17 to 0.50).

Conclusion:

Among studied mandibular dimensions in subjects with normal dento-skeletal relationship, only the inter-canine distance demonstrated a week to moderate linear relationship with the mandibular arch lengths.

Dental arch asymmetry

Objective:

This study was conducted to assess the dental arch asymmetry in a Yemeni sample aged (18-25) years.

Materials and Methods:

The investigation involved clinical examination of 1479 adults; only 253 (129 females, 124 males) out of the total sample were selected to fulfill the criteria for the study sample. Study models were constructed and evaluated to measure mandibular arch dimensions. Three linear distances were utilized on each side on the dental arch: Incisal-canine distance, canine-molar distance and incisal-molar distance, which represent the dental arch segmental measurements.

Results:

When applying “t-test” at P < 0.05, no significant differences were found between the right and left canine-molar, incisal-canine and incisal-molar distances in both dental arches for both sexes. The greater variation (0.30 mm) was observed between right and left canine-molar distance in the maxillary dental arch in male and the smaller (0.04 mm) in the mandibular dental arch between the right and left canine-molar distance in females.

Conclusion:

The findings of the present study revealed a symmetrical pattern of dental arches, since the right and left sides showed no statistically significant difference. In general, it can be observed that the measurements related to the central incisors and canines have the widest range of reading and give the impression that the location of central incisor and canines to each other and to other teeth is the strongest factor in determining the dental arch asymmetry.