Accuracy of radiographic and protrusive occlusal record methods in determining condylar guidance angles: a systematic review and meta-analysis

Background: The objective of this systematic review was to compare the accuracy of radiographic and protrusive occlusal record (POR) methods in determining horizontal condylar guidance (HCG) angles in dentate and edentulous patients. Methods: : Studies assessing condylar guiding angles in dentulous/partially edentulous and totally edentulous patients free of temporomandibular disorders using both radiographic and protrusive occlusal record methods were included. A comprehensive search with PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, Google Scholar and Open Grey databases was done. Two reviewers extracted the data after eligibility assessment. Study quality was examined using the NIH quality assessment tool and graded based on tooth selection, number of root canals assessed, study environment, number of observers, test reliability report, validation approach, validation criteria, and validity reliability. A meta-analysis of pooled data, subgroups and sensitivity analysis was performed using RevMan (P<0.05). Results: : The qualitative synthesis contained 33 papers, 32 of which were included in the meta-analysis. The standardised mean difference between the radiographic and protrusive occlusal record methods for right and left HCG angle in dentate patients was 0.68 [0.37, 0.98] and 0.63 [0.32, 0.95], respectively, and for right and left HCG angle in edentulous patients was 0.80 [0.36, 1.24] and 0.66 [0.18, 1.15], indicating a statistically significant difference (p<0.05). Conclusions: : Clinical variability among the selected studies could not be completely avoided and the sample sizes were limited, resulting in a lack of statistical power. To rule out potential causes of heterogeneity, subgroup and sensitivity analyses were done separately for dentate and edentulous individuals for the right and left HCG angle. The present systematic review and meta-analysis concluded that for the dentate and edentulous patients, the right and left HCG angle values determined by radiographic method showed statistically significant difference as compared to the protrusive occlusal records. PROSPERO registration: CRD42020206599 (28/09/2020)