Comparative assessment of cephalometric with its analogous photographic variables

Abstract

Objective: The purpose of this study was to evaluate the accuracy of photographic measurements and compare it with its analogous cephalometric variables.

Materials and methods: Lateral cephalograms and standardized facial profile photographs were obtained from a sample of 120 subjects (92 females, 28 males; age 12-22 years with mean age of 17.5 years). A total of 4 linear and 7 angular measurements along with 3 ratios analogous to one another were measured on both. Descriptive statistics for all measurements were computed. Pearson's correlation coefficients were computed between analogous measurements, and regression analysis was done for each variable measured on the photograph to accurately predict the cephalometric variable.

Results: The reliability of the standardized photographic technique was satisfactory. Most photographic measurements showed highly significant correlations (P < 0.001) with cephalometric variables. Among all measurements used, the A'N'B' angle was the most effective in explaining the variability of its analogous cephalometric (r²= 0.35). The Frankfort-mandibular plane angle' angle showed best results for vertical assessment (r²= 0.81) along with anterior face height (AFH) and lower anterior facial height (r²= 0.859) and ratio lower posterior facial height/AFH (r²= 0.702).

Conclusions: Although we cannot rule out lateral cephalogram as the primary record in orthodontics, photographic assessment can always be used through proper standardization, as an alternative diagnostic aid, and also for large-scale epidemiological purposes and places with unavailability of cephalostat.

Keywords: Diagnostic aid; lateral cephalograms; standardized facial profile photographs.

Figure 1

Natural head position by modified protractor on the tip of the nose and the soft-tissue pogonion

Figure 2

Marking the occlusal plane by plaster of Paris using fox plane as a reference

Figure 3

Patient seated for right profile photograph

Figure 4

Landmarks used in profile photograph and lateral cephalograms (1) N' (soft-tissue nasion) (2) Or' (soft-tissue orbitale) (3) T (tragion) (4) Sn Point (subnasale) (5) A' (soft-tissue Point A) (6) B' (soft-tissue Point B) (7) Goæ (soft-tissue gonion) (8) Pog' (soft-tissue pogonion) (9) Me' (soft-Tissue menton) landmarks used in lateral cephalogram (1) N (nasion) (2) Or (orbitale) (3) Po (porion) (4) Ar (articulare) 5. Anterior nasal spine) (6) A (subspinale) (7) Go (gonion) (constructed) (8) B (supramentale) (9) Pog (pogonion) 10. Me (menton)

Figure 5

Sagittal measurements in profile photograph and lateral cephalogram (1) Wits' appraisal l2. A' N' B' 3. family nurse practitioners' (Soft-tissue facial angles) (4) N'.Sn.Pog' (5) N'Me'/A'B' (soft-tissue A-B plane angle) Lateral cephalogram: (1) Wits apprasial (2) ANB angle (3) family nurse practitioners (facial angle) (4) N.ANS.Pog angle (5) NMe/AB (AB plane angle)

Figure 6

Vertical measurements in profile photograph and lateral cephalogram (1) Anterior facial height' (2) Lower anterior facial height' (3) Posterior facial height' (4) Tr.Go'.Me' (Soft-tissue gonial angle) (5) Frankfort-mandibular plane angle' (Soft-tissue Frankfort to mandibular plane angle) (6) Occlusal plane angle' (soft-tissue Frankfort to occlusal plane angle) Lateral cephalogram: (1) Anterior facial height (2) Lower anterior facial height (3) Lower Posterior facial height (4) Ar.Go.Me (Gonial angle) 5. Frankfort-mandibular plane angle (6) Occlusal plane angle

Figure 7

Scatter plot illustrating linear regression plot between cephalometric and photographic measurement ANB versus A'N'B'

Figure 8

Scatter plot illustrating linear regression plot between cephalometric and photographic measurement anterior face height versus anterior face height'

Figure 9

Scatter plot illustrating linear regression plot between cephalometric and photographic measurement lower anterior facial height versus lower anterior facial height'

Figure 10

Scatter plot illustrating linear regression plot between cephalometric and photographic measurement Frankfort-mandibular plane angle versus Frankfort-mandibular plane angle