Photographic Assessment of Cephalometric Measurements in Skeletal Class II Cases: A Comparative Study

Abstract

Introduction: Cephalometry has many limitations of which radiation exposure is most important. Hence, there is a need to resort to other safer methods which could give equal if not better results.

Aim: The purpose of this study was to compare and correlate the craniofacial measurements obtained from cephalometric radiographs and analogous measurements from standardized facial profile photographs in skeletal class II cases.

Materials and methods: A total of 30 lateral cephalograms and profile photographs of patients exhibiting skeletal class II malocclusion, in the age group of 19-25 years of age, were examined in this study using Dolphin software (version 11.8). A standardized protocol was followed for all the lateral cephalograms and photographs. A total of 15 parameters were studied in this study out of which seven were angular and eight were linear parameters. Angular parameters included Frankfort Mandibular Plane Angle (FMA), Mandibular Plane-Occlusal Plane (MP-OP) angle, Occlusal Plane (OP) angle, gonial angle, ANB angle, facial angle and convexity whereas linear parameters included Anterior Facial Height (AFH), Ramal height, Posterior Facial Height: Anterior Facial Height (PFH/ AFH), convexity (in mm), Nasion perpendicular- Point A, Nasion perpendicular- Pogonion, Witts and Mandibular body length. All these parameters were digitised on both the cephalogram and photographs and were compared using one sample-2 tailed t-test, Pearson correlation coefficient. Bland-Altman Plot was considered to find comparison between the measurements from photographs and cephalograms in skeletal class II patients.

Results: On comparing the angular cephalometric and photographic variables for the skeletal class II subjects we found the cephalometric parameters like FMA, MP-OP angle, OP, gonial angle, convexity (in degrees) to have an insignificant difference compared to the analogous photographic measurements. On comparing the linear cephalometric and photographic variables, it was found that all the cephalometric parameters like AFH, ramal height, PFH/AFH, N perp-Point A, N perp-Poghad a good relationship with the analogous photographic measurements.

Conclusion: The photographic method can be considered as a repeatable and reproducible method if a homogeneous protocol is followed. Thus, photographic measurements may reflect to be a rational and practical diagnostic substitute to measurements obtained from cephalograms in Class II malocclusion subjects.

Keywords: Angular parameters; Diagnosis; Dolphin software; Linear parameters; Natural head position.

[Table/Fig-1]:

Photographic setup.

[Table/Fig-2]:

Standardized photograph with adhesive dots placed at the palpable landmarks.

[Table/Fig-3]:

Standardized photograph with patient biting on the FOX Plane.

[Table/Fig-4]:

Grids used to confirm parallelism of the FH plane (Images left to right)

[Table/Fig-6]:

Digitizing the lateral cephalogram using Dolphin Software.

[Table/Fig-7]:

Measurements of all the parameters on the lateral cephalogram using Dolphin Software. (Images left to right)

[Table/Fig-8]:

Digitizing the photograph using Dolphin.

[Table/Fig-9]:

Measurements of all the parameters on the photograph using Dolphin Software. (Images left to right)

[Table/Fig-12]:

Comparison of cephalometric and photographic methods in assessments of linear variables in skeletal class II subjects (all the points between -1 and +1 meant that the cephalometric and photographic values were similar).

[Table/Fig-13]:

Comparison of cephalometric and photographic methods in assessments of linear variables in skeletal class II subjects (all the points between -1 and +1 meant that the cephalometric and photographic values were similar). In this case all the points are within the range, which means that all the linear variables in cephalograms and photographs were similar.