title: Correlation between Visible Length of the Iris and the Length of the Maxillary Central Incisor Using Digital Image Analysis- A Pilot Study.
abstract: BACKGROUND
  Complete denture therapy is one such modality where science and art goes hand in hand. Selection of artificial teeth for completely edentulous patients is not easy in the absence of pre extraction records, because till date concrete guidelines do not exist.
  
  
  OBJECTIVE
  The purpose of this study was to determine if a correlation existed between the visible length of the iris and the length of the maxillary central incisor to potentially provide a guide for teeth selection.
  
  
  METHODS
  A total of 20 Indian dental students consented to participate in the pilot study. Standardized digital images of the face revealing the eyes and component of teeth on smiling was captured using a digital camera. The digital measurements of the visible iris length (medial aperture height, tangential to iris) and the length of the maxillary central incisor from the zenith to the incisal edge were analysed using Adobe Photoshop creative cloud software. The data was statistically evaluated and results were tabulated. Karl Pearson's Coefficient of Correlation was utilized to detect if any association existed between the two variables.
  
  
  RESULTS
  The mean value of length of central incisor was 10.39 mm and the mean value of the visible length of iris was found to be 12.9 mm. A Pearson correlation analysis revealed an r-value <0.3 indicating minimal association between the two variables with a p-value >0.01 (.322).
  
  
  CONCLUSIONS
  On inference, the correlation between the visible iris length and that of maxillary central incisor were unable to produce a strong positive statistical association. However, an association factor between the two has been obtained. Deduction of 2.5 mm from the dimension of visible iris length will help in attaining the length of artificial maxillary central incisor tooth.
authors.affiliation: Postgraduate student, Department of Prosthodontics, SRM Dental College , Ramapuram, Chennai, Tamil Nadu, India .
authors.lastname: Rohini
authors.affiliation: Postgraduate student, Department of Prosthodontics, SRM Dental College , Ramapuram, Chennai, Tamil Nadu, India .
authors.lastname: Hemalatha
authors.affiliation: Professor, Department of Prosthodontics, SRM Dental College , Ramapuram, Chennai, Tamil Nadu, India .
authors.forename: Gopi Naveen
authors.initials: GN
authors.lastname: Chander
authors.affiliation: Reader, Department of Prosthodontics, SRM Dental College , Ramapuram, Chennai, Tamil Nadu, India .
authors.forename: Kuttae Viswanathan
authors.initials: KV
authors.lastname: Anitha
keywords: Aesthetics; Artificial tooth; Complete denture; Human eye