## 3 Discussion  
This case report aims to report, analyze and introduce the role of personalized alloplastic total TMJ replacement in the sequential management of TMJ ankylosis in early childhood, in this case caused by perinatal Staphylococcus Aureus sepsis. Pediatric TMJ ankylosis should be best viewed as a separate entity due to the lack of consensus on its surgical treatment, the importance of postoperative physiotherapy, and the growth potential of the jaw. Few other features must lead us to think about differences in the management of TMJ ankylosis in children and adults [24]. First of all, as mentioned before, pediatric patients, unlike adults, are growing individuals, which also represents a further element of difficulty in treatment [25; 26]. Second, ankylosis and subsequent dentofacial deformities are usually less severe in adults, making their contextual correction easier than in pediatric patients. Third, the appearance of the face and the limitations of opening the mouth could affect the psychological state and the ability to establish social relationships of children. The timing of the surgery represents an essential topic, taking also in account the necessity of postoperative cooperation of the patient. [PERSON] et al. suggested that children of 3 years of age or older represent suitable candidates for ankylosis removal, while [PERSON] recommended a minimum surgery eligibility age of 7 years old, considering the injury risks and the compliance of the patient [26]. In our department, pediatric patients affected by TMJ ankylosis are always advised to undergo surgery as soon as possible, usually at 5-7 years old, depending on the compliance of patient and of the family. There is no reason to wait until the end of the growth process to plan the surgery. Delayed treatment may simply worsen psychosocial and physical problems deriving from a moderate to severe facial deformity, and a consequential decrease of life quality. CCG is generally considered as the first choice for the treatment of this disease in the pediatrics, as it was for our patient [18]. This is because of the ease of harvesting and adapting the graft, the low morbidity of the donor site, the biological and anatomical similarity with the mandibular condyle and its growth potential. Thanks to this development capacity, the CCG theoretically should permit the unaffected side to maintain the same growth pattern, maintaining therefore mandibular symmetry throughout the whole patient's growth process [27; 28; 29]. However, the graft growth process could be uncontrolled and unpredictable, ultimately ending in facial asymmetry causing lifelong functional and aesthetic defects. Long-term reports of mandibular growth in children with reconstructed TMJs using CCG shows excessive growth on the treated side occurring in 54% of the 72 cases evaluated, and only 38% of the cases presented uniform growth on both sides, and a relapse of the ankylosis on the recipient site is far from rare [30]. Figure 9: MMO of 25 mm 6 months after TMJ prosthetic replacement. Graft resorption is another complication that could occur post-operatively, due to poor vascularization of the recipient site secondary to the fibrotic process causing the disease, which may increase the risk of fracture or displacement of the graft itself. Donor site morbidity risks are minimum, but include pneumothorax, infection and chest deformity [31]. Early mobilization and aggressive physiotherapy should be initiated in the immediate post-operative period for patients undergoing GCC surgery, immediately after the release of the intermaximillary fixation (IMF) [32]. In the case of our patient, although proper healing was expected, clinical and radiographic evidences of an ankylions relapse on the recipient site were highlighted 6 months postoperatively, probably caused by a lack of compliance on proper physiotherapy. At this point the surgical treatment options were few, and the possibility of performing an alloplastic custom-made total joint replacement began to be more consistent.