In those conditions where loss of tissue is responsible for the defect, as in the extirpation of neoplasms, ulcerative disease, etc., it is quite likely that cheiloplasty is required to rebuild the parts, but in many of these cases splendid results may be obtained by the judicious use of hydrocarbon protheses to overcome the usual post-operative oral distortion. It is understood that such injections should not be undertaken until the wounds are thoroughly healed and the cicatricial union fully contracted. This is true also in harelip operations undertaken later in life. The correction of labial defects coming under this method is not at all difficult, but artistic skill and judgment are as necessary as the surgical technic. The lips are plentifully supplied with blood vessels, and therefore greater care in injecting a foreign mass into their structure is necessary; furthermore, the lips cannot be placed at rest for any long period of time, so that the mass injected can never be expected to be kept in place if of a consistency hard enough to permit the contraction of the orbicularis muscle to move it about. From the very fact of this practically constant movement of a part it is self-evident such hard mass could not be retained or held in position for any length of time, unless the mass is small enough not to be affected by the movement, and under such condition the correction of a defect as desired by the patient would require perhaps months to accomplish, owing to the very fact that only droplike masses may be deposited under the skin in perhaps a half dozen places with the necessity of a long period of rest until the injections have been replaced by the new tissue before the next operation could be undertaken. It is absolutely absurd to think of injecting a lip with hard paraffin liquefied by heat and expect to obtain a satisfactory result. While it is true the mass is moldable immediately after its introduction, so that a desired shape may be obtained, it does not overcome the fact, however, that the mass must harden, as it will, and that, while a part of it is broken away, as it were, from the mass proper, there is a nuclear contraction as the hardening takes place, thus overcoming partly the molded form; furthermore, the movement of the parts here tends to displace the mass. Unequal muscular contraction breaks up not only the form but also the mass itself, during all of which time it is made to act as an irritant by virtue of the movement of the uneven edges of the paraffin upon the adjacent tissue. Furthermore, the presence of paraffin and the resultant mass of new and hard connective tissue, so well recognized by all experienced surgeons, is not desirable in the lip structure; it makes the lip appear bulky and hard and anything but natural.