Correlation of Craniofacial Measurements between Cephalometric Radiographs and Facial Photographs

Abstract

Objective: The aim of this study was to correlate the linear and angular measurements between lateral cephalogram and lateral photographs.

Method: An observational cross-sectional study was carried out at the department of orthodontics, Karachi Medi- cal and Dental College, Karachi, Pakistan. The study was conducted for six months from 30th  October  2016  to  30th April 2017. Inclusion criteria included no previous orthodontic or surgical treatment, having all six maxillary anterior teeth present, no craniofacial trauma and no neurologic disturbances. Exclusion criteria includes those patients in whom radiation exposure cannot be given. A sample of 179 patients was selected which included 49 males and 139 females and they were examined by  the  researcher. A lateral  cephalogram  and  a  digital single lens reflex (DSLR) camera was used to obtain the linear and angular craniofacial measurements.  A  standard lateral cephalogram and standardized lateral photograph of each patient was taken respectively and    then their measurements were taken with respect to  different  variables.  Cephalogram  measurements  taken  were as follows: (1) SNA (sella-nasion to A point); (2) SNB (sella-nasion to B point); (3) SNMP (sella-nasion to mandibular plane); (4) total facial height; (5) lower facial height; and (6) mandibular  length.  Whereas photo- graphic measurements taken were as follows: (1) TN'A' (angle between tragion-soft tissue nasion line and soft tissue nasion-soft tissue A-point line); (2) TN'B' (angle between tragion-soft tissue nasion line and soft tissue nasion-soft tissue B-point line); (3) FH'MP' (angle between soft tissue Frankfort plane and soft tissue mandibular plane); (4) CP'MP' (angle between cranial plane and soft tissue mandibular plane); (5) lower facial height; (6) total facial height; (7) mandibular length; and (8) chin projection. The lateral cephalogram and lateral photo- graphs measurements of patients were compared respectively and the Pearson correlation between them was calculated using SPSS 20.

Results: The results obtained showed that there was a moderate correlation between SNA and TN'A', SNB and SN'B', SNMP and FH'MP' whereas the correlation between facial heights and lower facial heights was very weak and CP and CP'MP' holds no correlation between them. All the correlations found between were statistically sig- nificant and had linear, positive co-relation between them.

Conclusion: Photographs can be used in place of lateral cephalogram X-rays for diagnostics and treatment planning.