Chin augmentation or augmentation mentoplasty with synthetic implants was first introduced in the 1950s and has become an increasingly popular cosmetic procedure for chin retrusion or microgenia [2
]. This procedure involves the placement of an implant in the subperiosteal pocket with the aim of improving chin projection and/or augmenting the chin [1
Complications of chin augmentation include infection, malposition of the implant (leading to patient dissatisfaction), and extrusion of the implant intraorally [1
]. A case series of 324 chin implants by Godin et al. found an infection rate of 0.62%, while another case series of 125 consecutive patients by Aynehchi et al. reported no infections [1
]. There were no cases of chin implant migration in both case series.
Chin augmentation with synthetic implants is a less complicated procedure than genioplasty which requires an osteotomy and replating and consequently is associated with less surgical morbidity [6
]. Mental nerve injury and neuralgia is reported as high as 10% when an osteotomy is performed as anatomical variations of the inferior alveolar canal and mental foramen confer risk to the nerve [7
]. Synthetic chin implant augmentation mitigates this risk as the mental nerve can be identified and protected during the surgical procedure.
Both transoral and external approaches have been described for the insertion of chin implants. A preference for the transoral approach is evident in the literature as it avoids an external scar, which had been reported to cause scar alopecia in males [1
]. The complication rates for both approaches are comparable, although some authors state a lower infection and malposition rate with the external approach [4
The surgical technique involves the creation of an optimally sized subperiosteal pocket in which the chin implant is placed, minimising the risk of implant migration [1
]. Although additional fixation techniques with sutures or screws can be used, this introduces a greater risk of damage to the mental nerve and mentalis muscle and is not necessary as a primary procedure [1
Traumatic dislodgement and migration of chin implants is an unexpected complication and not normally reported in long-term morbidity studies. Our case highlights an unusual migration and as previously noted in the literature, an external submental approach to resite and/or secure the chin implant is recommended [6
There have been no prior reported cases of mental nerve compression secondary to traumatic chin implant migration in the recent literature. This case highlights a potential complication to discuss with patients who participate in high risk activities for facial trauma such as contact sports. Mental nerve compression causes distressing symptoms for the patient and should be discussed when considering elective chin augmentation.