”The heavenly court is full and the earthly pavilion is square”. It is a beauty instrument and a feature of blessed appearance. The earth pavilion is the chin. It is not only about the beauty of appearance, but also closely related to the breathing and biting functions. The growth center of the mandible is located in the condyle, which together with the articular fossa forms the temporomandibular joint. If the growth of the condyle is obstructed for various reasons, the jaw will be short in varying degrees. If the growth is obstructed on one side, there will be a deviation of the jaw and even the whole face. Mild micrognathia simply shows a cosmetic defect with a small chin and insufficient forward projection. There is no incongruity between the upper and lower teeth and it does not affect respiratory function. In this case, the treatment is the easiest, and the chin can be implanted through an intraoral incision. The most commonly used implant materials are the hard material called Medpor and the silicone material. Depending on the shape of each person’s chin, the surgeon will modify the molded material to create the chin that each person desires. In severe cases, the chin is short, receding, and inward in the lower third of the face, the ascending part of the jaw is too short, the upper and lower teeth have an abnormal occlusal relationship, and the upper and lower front teeth are tilted forward and protrude to show a serious cosmetic defect. A more serious problem is the impact on respiratory function, accompanied by snoring and sleep apnea syndrome, that is, when sleeping will hold the breath, lack of oxygen to the brain, although the sleep time is long, but always lack of energy, after middle age more and more aggravated, serious cases may lead to sudden death, a serious medical condition. The treatment of this condition must take into account the three main problems of short jaw, breathing function and the shape of the teeth and lips. It must not be simply a material implant and an augmentation. Unfortunately, this is a common practice, and there are even outrageous practices that use fat injections to fill in the jaw. In severe cases of small chins, even conventional chin osteotomies will not yield good results. Although conventional chinplasty may improve the appearance and respiratory function to some extent, the dental relationship does not improve and a deeper chin-labial furrow will appear. For severe degrees of micrognathia, the correct protocol is: in adults, an anterior sagittal osteotomy with rotational advancement of the mandible, additional ascending sagittal osteotomy advancement as needed, elevation of the mandibular angle, hyoid suspension, and anterior maxillary osteotomy. In children, it is best to use the distraction osteogenesis technique, which is both less damaging and more effective. A condition called Pirre Robin syndrome, which presents with a small lower jaw, posterior tongue drop, cleft palate, and often respiratory distress, can be treated with distraction osteogenesis in infants and children. Small jaws between mild and severe degrees are subject to the appropriate surgical approach depending on the situation. Unilateral short jaws, if in childhood, must not wait until adulthood to be treated (there are many doctors who give this wrong advice), but early treatment after the age of 6, preferably also with the traction osteogenesis technique, can effectively prevent the development of severe deformities. In adults, depending on the severity of the deformity, a simple skeletal reduction procedure to a combined upper and lower jaw osteotomy and lengthening can be performed.