Chin Augmentation

Introduction
Chin augmentation, according to Dr. Sam Rizk, a board certified new york facial plastic surgeon and director of Manhattan Facial Plastic Surgery, is an extremely rewarding surgery, especially when combined with rhinoplasty or facelift surgery. Most commonly, Dr. Sam Rizk performs a chin implant, but sometimes he will recommend a sliding genioplasty or jaw movement forward. The chin implant surgery carries less risk and complications and is the most common approach but in rare cases, the sliding genioplasty is the better option, despite its increased risk of complications and recovery. The chin implant surgery has a much more rapid recovery than the sliding genioplasty.

Patient Selection
Appropriate patient selection is the first step in avoiding complications. This begins with a good medical history and physical examination focusing on the patient’s dental occlusion. In other words is there a significant occlusion abnormality and does the patient have dental abnormalities. In rare cases, a chin advancement can be combined with a chin augmentation if both a dental occlusion problem and a small chin are present. Sometimes a chin implant is also placed not just to provide a stronger chin but also to change the shape of the chin to a more rounded or a more square chin. There are many shapes and sizes of chin implants which Dr. Sam Rizk also customizes during the surgery by sculpting each implant to the patient’s chin and anatomy.

Once the patient is established as a a good medical candidate, it is important to assess the patient’s motivations and expectations for the surgery. A new chin cannot alter the social environment of the patient or help patient attain a better job or significant other. If these are the patient’s motivations, then a successful surgery will be viewed as a failure for the inability of the surgery to attain the patient’s social goals.

Complication counseling preoperatively and complication management postoperatively
Although complication rates are low with chin augmentation or chin advancement surgery, the patient needs to be thoroughly counseled. Complications can be categorized into soft tissue, nerve, muscle, bone or tooth. Smoking increases risk of complications with any surgery and patients are advised to stop smoking at least 3 weeks preoperatively and 3 weeks postoperatively. Anticoagulant medications should be discontinued 2 weeks before and after surgery to decrease the risk of bleeding and hematoma. Medicines that fall in this category include aspirin, motrin, and vitamin E as well as fish oil and other herbal medicines and nonsteroidal anti-inflammatory medications. Soft tissue complications may include hematoma, scarring, wound infection or cellulitis, fistula, skin bunching or dimpling, skin necrosis, or abscess. If a hematoma occurs, it is rare but is easily treated with needle aspiration of the bloody fluid. Scar formation is rare as incisions are usually well hidden in submental crease and if a hypertrophic scar occurs, this can be injected with various medicines to shrink it and silicone sheets can also decrease scar visibility. Dr. Sam Rizk prefers the external submental approach to chin augmentation as this has a lower rate of infection than the intraoral approach. The rate of infection of chin implants is about 5%. If an infection occurs, it is first treated with antibiotics. If the antibiotics do not improve the infection, then Dr. Sam Rizk feels the implant sometimes has to be removed but this is very rare and occurs in less than 1% of Dr. Rizk’s patients. If the infection does not contain fluid , there is a high likelihood that the oral antibiotics will treat the infection successfully. In late cases of infection detection, it may cause the implant to extrude or move, if the infection is not treated early. Capsular contraction is another complication which may occur more with silastic chin implants than medpor type implants. Capsular contracture around an implant can lead to a very unnatural, poorly-contoured appearance to the chin. However, the medpor implants are more difficult to remove due to their integration. Capsular contracture can cause the skin to bunch or dimple. If this occurs, a capsulectomy may need to be performed and a larger implant may need to be placed. Sometimes also fat grafting can be performed and may correct the abnormalities of capsular contracture. Nerve damage is more common with a sliding genioplasty chin advancement than with chin implants. A sliding genioplasty jaw advancement involves bone osteotomies (or cuts) and screws. Avoiding the tooth roots is especially important when cutting the bone, particularly in adolescents since mandibular growth is not complete until the late teens. Lower lip numbness can also occur with implant placement due to stretching of the nerve, compression, or severing the mental nerve. If the nerve is stretched, the problem usually resolves spontaneously but usually takes several months. Some Lower lip and neck numbness is normal from swelling after the surgery and may persist for up to 6 months. Chin ptosis or mentalis muscle dysfunction may occur but is very rare. To avoid this complication, the mentalis muscle, which elevates and compresses the chin against the anterior mandible needs to be re-approximated during the surgery. Sometimes muscle hyperactivity or irritability of the mentalis muscle can occur in less than 5% of patients and manifests as dimpling with talking or animation. This complication can be treated with Botox. Bone complications are unusual but may occur as well. Mandible fracture and bony nonunion have been reported after osteotomies or bone cuts with the sliding genioplasty chin advancement procedure but not with the chin implant surgery. However, chin bony resorption has been reported and may occur with chin implants but is rare and not usually manifested or visualized as the change is so small to be recognized aesthetically. Bony resorption has been suspected to be associated with pressure from large implants. Implant malposition occurs if the implant is too low on the chin or if it moves too far superior on the anterior mandible. These problems of superior migration occur more with intraoral placement of the chin implant rather than the submental external approach. Also if the implant is secured with sutures to the mandible, this is less likely to occur. Asymmetry may also occur if one flange of the implant is not in proper contact with the mandible. This problem can be seen during the surgery and corrected intraoperatively ideally. Suturing the implant to the mandible also avoids another problem which occurs if the chin implant springs forward and creates a dead space of non-contact behind it with the mandible.

Summary
Overall, chin augmentation procedures are safe and effective. Complications are rare and can often be avoided with proper patient selection and proper implant placement and suturing to avoid movement. Most importantly, appropriate implant size selection is necessary by studying the patient’s face and proportions. Potential problems need to be discussed with patients preoperatively so that such problems are understood as risks rather than viewed as unanticipated complications.