THE BILATERAL FORM

The bilateral form is the most common of the subtle variations of the Golden Proportion, seen in nature and art.

We see in the figure above that A:B = B:C = 1.000 : 0.618

If we now align the mid-points of B and C as in figure above and place them one just above the other, we then find that there is now a "larger-to-whole" relationship and that on either side of the midline we have the "larger to the smaller" simple relationship.

Patterns of this bilateral form are frequently found in the beauty of nature and works of art. The two examples of the photograph frame shows the midline marked and a smaller to larger relationship either side.

The same patern is seen in the examples of tarton cloth as well as the Spanish Royal Palace and the headlights of the motor car. Click images below to enlarge

Dental

We have already seen that the incisors are in the Golden Proportion to each other and this photograph of teeth shows the bilateral variation, whilst the gauge and grid indicate the bilateral neutral space.
	The Golden Mean gauge shows a strong indication of the correct position of the Canine/Premolar dominant corner of the arch. This latter corner thereby influences the antero posterior position of the front teeth. (Related to the width of smile and eye measurement).

It is interesting to visualize the anterior aesthetic segment featured against the backcloth of this neutral space framed by the lips. Notice the way the car headlights are in the same proportion to the distance between them as the neutral space is to the width of the arch that shows in the smile.