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Prepare for your Consult: Math, Geometry and Engineering Term Alert!

Leave the art for oil paint and canvas at collectives in San Francisco. Go with an engineering and science based approach for your breasts at Feldman Plastic Surgery.

Dr. Feldman's dimensional planning uses a data driven, analytical approach to select implants based your chest and breast measurements with adjustments for your anatomical asymmetry that therefore will always be proportionate to your frame.

Hope is not a surgical technique nor sizing method.

To better understand what is going on in Dr. Feldman's mind during your exam and implant sizing, let's review some basic engineering, geometry and math terminology he frequently discusses during your consult (and most have forgotten from high school).

In geometry, a hypotenuse is the longest side of a right-angled triangle, the side opposite of the right angle. The length of the hypotenuse of a right triangle can be found using the Pythagorean theorem, which states that the square of the length of the hypotenuse equals the sum of the squares of the lengths of the other two sides.

Dr. Feldman may discuss how your rib angle or anatomy will require a different width implant due to prominent breastbone, as the implant will sit on the hypotenuse rather than shorter base width.

Equilateral triangle
In geometry, an equilateral triangle is a triangle in which all three sides are equal. In the familiar Euclidean geometry, equilateral triangles are also equiangular; that is, all three internal angles are also congruent to each other and are each 60°.
The ideal breast aesthetic is an equilateral triangle when measuring the distance from sternal notch to each nipple, as well as the distance between your nipples.

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length of a diameter is also called the diameter. In this sense one speaks of the diameter rather than a diameter (which refers to the line itself), because all diameters of a circle or sphere have the same length, this being twice the radius r.

Dr. Feldman uses round implants almost exclusively, and the implant diameter must match your adjusted chest/breast base width measurement. This is how implants are selected, and it has nothing to do with cc’s or cup sizes.

In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line. Slope is calculated by finding the ratio of the "vertical change" to the "horizontal change" between (any) two distinct points on a line.

The less slope an implant has (another way to think of this is width to projection ratio) the more natural a shape it will have from the side profile. The more slope (and therefore projection) an implant has the less natural the breast will be. The slope will be determined by the implant profile. Slope will increase from low to moderate, moderate to full, and full to extra full.

Moment arm (torque)
The magnitude of torque depends on three quantities: the force applied, the length of the lever arm connecting the axis to the point of force application, and the angle between the force vector and the lever arm

The more force, and further from the axis that force occurs, the higher the torque or moment arm. As force due to  implant size/weight increase so does the torque. This is why a result with larger implants will not last as long as more conservative implants all other variables the same. The moment arm or torque on your neck, upper back and shoulders of large perky breasts is much less than those of the same large breasts when they’re droopy, as the droppy breasts have a longer lever arm length. Think about holding a cup of coffee against your chest. You could do it all day long. Now hold that same cup of coffee with arm outstretched. You will only last a few minutes! That’s a moment (lever) arm.

The word concave means curving in or hollowed inward, as opposed to convex. Pectus Excavatum is a rib deformity with a concave chest shape.

Convex, meaning "curving out" or "extending outward. Pectus Carinatum is a rib deformity with convex rib shape.

Diverging Lines
Two or more lines that get further and further apart towards the end. Nipples that are laterally malpositioned, or ribs that are angled outwards (pectus carinatum) create diverging breast and nipple lines that may be exaggerated by augmentation as the implant adds projection.

Converging Lines
Two or more lines that get closer and closer towards the end. Nipples that are medially malpositioned, or ribs that are angled inwards create converging lines that may be exaggerated by augmentation.