The Proportions functionality provides insights into the spatial relationships between different facial features. You can calculate common reference proportions used in facial analysis. This functionality can be very useful as a pre-assessment tool to plan your treatment or as a post-op comparison to show to your patients their realistic outcomes. 

The Both, Before or After buttons are meant for:

• Both: see the proportions on both the before and the after.
• Before: see the proportions on the before 3D image.
• After: see the proportions on the after 3D image.
   

The available face proportions are:

• 1/3 rule: divides the face horizontally into three segments -the forehead, the middle of the face (brose to nose), and the lower face (nose to chin)- and provides an additional reference line in the lower third segment.
  When enabled it presents the percentage of each segment as part of a whole. This is a very visual way of analyzing proportions and symmetry.
  Crisalix automatically calculates the ⅓ rule proportions of the 3D image and also allows to adjust each segment. For that, select the blue dot at the right of each segment and drag it up or down according to your needs.
   
• 1/5 rule: divides the face horizontally into five equal segments, each the width of an eye. The nasal alar base width should be equal to the intercanthal distance. Also, width of the mouth is equal to the distance between the medial iris margins. Crisalix automatically calculates the 1/5 rule and you can use it to evaluate facial harmony based on proportions. 
   
• Golden ratio: select to overlay an X-Y axis onto the face 3D. The value of the X-axis remains fixed (= 1) while the Y-axis dynamically adjusts proportionally based on the golden ratio (approximately 1.618). This visual representation will help you assess your patient's facial proportions according to the principles of the golden ratio.
   
• Bony base-intercanthus ratio: Evaluates the proportional relationship between the bony base width and the intercanthal distance. This measurement helps in assessing skeletal balance and facial harmony, particularly in cases involving skeletal asymmetry or reconstructive planning.
   
• Ala-to-tip ratio: Measures the proportion between the nasal ala (outer nostril width) and the nasal tip width. This ratio is crucial in rhinoplasty planning, ensuring nasal proportions remain aesthetically balanced and harmonious within the overall facial structure.