Identification Of Reliable Extraoral Anatomical Landmarks In Relation To Maxillary Canines In Dentulous Subjects: An In Vivo Study

Abstract

Context: Position of canine in edentulous patients plays an important role in denture esthetics. Various Extraoral landmarks are used in dental literature to obtain canine position.

Aims: This study aims to correlate various Extraoral landmarks i.e., Intercommisural distance (ICD), Interalar distance (IAD), Innercanthal distance (InCD), Interpupillary distance (IPD), Outercanthal distance (OCD), Bizygomatic distance (BZD), Distance between left and right projection of the line drawn from inner canthus of the eyes to the ala of the nose (DPIcA) with Inter canine tip width (ICTW) and width of distal canine distance (WDC) in dentate patients to determine position of maxillary canines in edentulous patients.

Study Design: Observational cross sectional study

Material and Methods: This study was conducted in 150 individuals with age range of 20-30 years. Customised instrument was fabricated for stabilisation of head and extraoral landmarks and accurate location of landmarks. Landmarks were located in resting position (i.e., ICD, IAD, InCD, IPD, OCD, BZD and DPIcA) using customised instrument and distance was measured using digital vernier caliper. Markings were made on autoclaved bite fork to measure ICTW. WDC were measured using dental floss. Data summarisation and statistical analysis were done.

Statistical analysis: Chi square test and Anova test.

Results: A Significant correlation was found between all the extraoral and intraoral landmarks (ICTW and WDC) except for BZD. No Correlation was found between BZD and WDC. Highest correlation was found for ICD (r = .370) for ICTW and IAD (r =.351) for WDC. Regression analysis was applied and equations were derived to obtain ICTW and WDC.

Conclusions: For the studied population, significant correlation was found between extraoral landmarks and canine position. Thus, they can serve as a reliable guide for location of canine position. Calculated values obtained by using derived equation were accurate and  within range of +-0.5mm from obtained mean values.