the term “ hyaluronic acid ” ( ha ) as used in the present application refers to hyaluronic acid or salts of hyaluronic acid , such as the sodium , potassium , magnesium and calcium salts , among others . the term “ hyaluronic acid ” is also intended to include not only elemental hyaluronic acid , but hyaluronic acid with other trace of elements or in various compositions with other elements , as long as the chemical and physical properties of hyaluronic acid remain unchanged . in addition , the term “ hyaluronic acid ” as used in the present application is intended to include natural formulas , synthetic formulas or combination of these natural and synthetic formulas . embodiments of this invention are directed to a technique where a relatively large amount of hyaluronic acid , for example an entire syringe , is emptied into one area creating a deep nodule of the hyaluronic acid material in the deep tissue that does not break down readily , perhaps by limiting access to the hyaluronidase . the deep nodule or bolus lifts up the skin . the methods of the invention may be beneficially used to correct tissue prolapse and / or tissue atrophy ( or loss ) in any area , and are particularly useful when applied in the area of the upper middle face and cheek . the methods of the invention involve administering injections into the deep part of the skin ( i . e ., deep fat or just above the bone ) using large injections of a hyaluronic acid composition that has been formulated for injection into the superficial part of the skin . by defining certain important injection sites , the present inventor has been able to develop a technique which allows the cheek to be sculpted and also raises the groove under the eye giving a more youthful appearance . embodiments of this invention include raising the cheek and lifting the groove under the eye to a higher location , as is typically seen in a younger face . one unique feature of the tri - site bolus ™ technique of the present invention is the creation of the bolus , that is , creating a small nodule in the deep tissue that can obliterate the groove and also raise the cheeks and also have a longer durability . the nodule can be , for example , approximately the size of a grape . however , modification of the shape and size of the nodule to suit the particular application is envisioned in accordance with the present invention . in another embodiment of this invention , an injection can be made the same way into the chin to create the effect of a chin implant . such implants can also be created in other locations where a raised contour is desired , such as the cheekbones . creating the non - visible nodule in the deeper tissue may have applications for other areas . for example , the nodule may be formed in the fatty tissue of the cheek , in order to counter the hollow - cheeked appearance that commonly occurs as a result of aging . in another embodiment of this invention , the same bolus technique is utilized to repair what is referred to as malar bags , which are sacks of loose skin seen under the eyes . typically , surgery cutting out the excess skin was the only option . fig1 - 4 are photos that show the correction of a prominent malar bag under the left eye of a patient using the methods of the present invention . thus , the bolus technique can be effectively utilized for correction of malar bags using injections of hyaluronic acid . the injections used in the methods of the present invention can be made , for example , at a depth of 0 . 3 - 1 . 5 cm below the surface of the skin . however , one of skill in the art will appreciate that the depth at with the injection is made will vary depending on the specific injection site . further , the injections can be administered without requiring large bore needles or surgical incisions , as the methods of the present invention utilize small bore needles . preferably , the hyaluronic acid bolus is injected into the skin using a needle having a gauge of from 24 ( 0 . 559 mm ) to 30 ( 0 . 305 mm ), where the bolus is more preferably injected using a needle having a gauge of from 26 ( 0 . 457 mm ) to 28 ( 0 . 356 mm ), and is most preferably injected using a 27 gauge needle ( 0 . 406 mm ). a hyaluronic acid product having a thickness of 30 viscosity is presently preferred . examples of products that can be used include juvederm ® ( a highly - crosslinked hyaluronic acid product sold by allergan , inc .) and restylane ® perlane ® ( a non - animal stabilized hyaluronic acid product used to fill deep folds , sold by q - med ab ). for example , the product juvederme ® 30 can be effectively used in the embodiments of this invention . however , use of any medically - acceptable hyaluronic acid product is envisioned in accordance with the present invention . in some embodiments of this invention , about 1 . 5 to 6 , preferably about 3 to 4 , full syringes ( for example 0 . 7 cc or 0 . 8 cc syringes ) can be injected on each side of the subject &# 39 ; s face to fill wrinkles or folds in the skin . it is preferred that at least 1 cc , more preferably at least 2 cc , even more preferably about 2 to 3 cc , are injected on each side . one of skill in the art will appreciate that the amount of hyaluronic acid to be injected will also vary depending on the specific injection site . although the methods of the present invention primarily address the use of hyaluronic acid , use of other injectables is also envisioned . additional uses for the methods of the present invention , beyond use in the cheeks , under the eyes , and in the chin , are also envisioned . for example , and without limitation , the methods of the present invention may also be useful for filling scars or other surface deformities in the skin . it will , of course , be appreciated that the above description has been given by way of example only and that modifications in detail may be made within the scope of the present invention . the invention is capable of modification , alteration , and equivalents in form and function , as will occur to those ordinarily skilled in the pertinent arts having the benefit of this disclosure . while the present invention has been described for what are presently considered the preferred embodiments , the invention is not so limited . to the contrary , the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the detailed description provided above .
the present invention relates , generally , to methods of providing long - term minimization of wrinkles or folds in the skin by injecting a bolus of hyaluronic acid deep into the skin . the methods of the present invention are particularly beneficial for improving the contours of the cheeks , filling folds under the eyes , and providing the visual effect of a chin implant , without requiring the use of surgical procedures .