 Let's discuss about genioplasty on how it's done and what are its various types. Chin is one of a prominent facial features and the society tends to describe one's personality characteristics based on the chin features. Genioplasty is a surgical procedure which is used to re-control or reposition the chin. Like any other ortho-nathic or osteotomy procedures, genioplasty has also undergone evolution in its technique over the time. It was Hoffer in 1942 who introduced horizontal osteotomy in the same crisis region through an extraoral incision. Later in 1957, froner and obvidesa performed horizontal osteotomy following deed-loving of the anterior mandible using an intraoral incision. As you can see in this figure, the osteotomized segment of the chin or the anterior mandible can be repositioned in all three planes of space, that is the vertical, anterior posterior and transverse planes. Let's now move on to the surgical procedure. The incision is usually performed under general anesthesia. Once the patient is positioned, local anesthetic solution is infiltrated into the lower labial vestibule. Incision is then placed on the lower labial mucosa approximately half way between the depth of the vestibule and the wet dry line of the lip. The incision extends to premolar region on both the sides. Once the mucosa incision is completed, the mentalis muscle is then divided and the incision is deepened till the periosteum. Periosteum is incised and a full thickness flap is raised to expose the inferior border of the mandible. So, first you perform an incision on the labial mucosa, then the mentalis muscle is divided and the incision deepened to cut the periosteum. After periosteum is incised, as the periosteum dissection is carried out to expose the inferior border of the mandible. After you have raised the flap, mental nerve is visualized on both the sides and is preserved throughout the procedure. Therefore, from the anterior mandible, you strip off all the soft tissues, that is the mucosa, the submucosal layer, the muscles and the periosteum. So, this is like removing gloves from your hands and hence this is called deed loving of the anterior mandible. The next step is the osteotomy which is performed using a reciprocating saw or an oscillating saw. Prior to performing the osteotomy, it is always preferable to inscribe the proposed line of osteotomy using a thin burr. This is the proposed line of osteotomy. The osteotomy cut is made at least 4.5 millimeters below the apices of the anterior teeth. Approximately here you have the anterior teeth roots at least 4.5 millimeters below the apices you make the osteotomy cut. And this osteotomy is at least 10 to 15 millimeters above the inferior border. The distance from the osteotomy cut to the inferior border should at least be 10 to 15 millimeters. Also the posterior ends of the osteotomy, the posterior ends means it is these two ends should be positioned below and behind the mental phyramid on both the sides. On either side the posterior end of the osteotomy should be below and behind the mental phyramid and make sure the cut is symmetric through the buccal and lingual cortices throughout. There shouldn't be any incomplete osteotomy. The cut should be symmetric and complete through both the cortices. Now the osteotomy is complete and next the segmented portion needs to be freed from the rest of the mandible. This is the segmented inferior portion which needs to be freed from the rest of the mandible. But here remember to keep the segment critical to the digastric and genio-hyoid muscles. How are the digastric and genio-hyoid muscles related to anterior mandible? The anterior belly of the digastric muscle originates from the digastric fossa at the inferior border of anterior mandible and genio-hyoid muscle originates from the inferior genio-tubical which is present on the medial aspect of the anterior mandible. Why should you keep the segment critical? If you make the segment a free graft that means if this segment doesn't have any periosteal or periosteal attachment it becomes a free graft and there will be intense inflammatory reaction and avascular necrosis. So for this reason make sure the inferior segment is critical. Now that the osteotomy is complete let's see how all can the osteotomized segment be repositioned. This is an example of augmentation genioplasty wherein the cut segment, the cut inferior segment is moved anteriorly and fixed using wires or semi-rigid plates. So in this case the chin is advanced. You may also perform a retro positioning of the chin, you can push the chin behind. An important factor to consider here is the good adaptation of the soft tissue following the chin repositioning. But in the reduction of chin the soft tissue adaptation following the posterior repositioning is not 100% age. For this reason a concavity may be carved into the anterior mandible that is you contour the anterior portion of the mandible so that the soft tissue of the chin can maintain their natural contour. Moving on for major advancement of the chin you can perform a stepwise augmentation that is the osteotomized inferior segment is again cut and sliced more than once. So there are there is more than one horizontal segment and both the segments can be moved forward. But this is now a less commonly used technique due to the advent of rigid internal fixation. However far the inferior segment is moved it can now be fixed. Therefore this technique is not commonly used these days. Genioplasty can also be performed to correct facial asymmetry. For example if the chin midline doesn't coincide with the facial midline you perform a modified osteotomy and the bone graft is removed for example from the left side. You then move the osteotomized segment towards the left and fit this bone graft back into the right side. This is an osteotomy plan for mild facial asymmetry pertaining to the chin. This is an example of an extended genioplasty which is used in case of major facial asymmetries. Here again you follow a degloving incision to expose the mental nerve and the body of the mandible. Genioplasty is extended to the antagonial angle that is anterior to the mandibular angle you extend the osteotomy. This is followed by laterally sliding the lower border of mandible thus correcting the facial asymmetry. You move the segmentalized inferior border towards the side of deficiency thus correcting the asymmetry. This procedure is advocated in patients undergoing correction of facial asymmetry due to hemifacial microsomia or unilateral ankylosis of temporal mandibular joint. We have now had a look at the various applications and techniques of genioplasty. Following osteotomy the occlusion is checked and confirmed using occlusion splint. The segmentalized inferior border may be stabilized and fixed using figure of 8 wiring or bone plate. Few of the complications associated with genioplasty are edema, sensory loss due to damage to mental nerve, wound hyacinths, avascular necrosis of segments and chintosis due to mishandling of mentalis muscle. That's all about genioplasty. Thank you.