We perform reconstruction using a fibular flap after mandibulectomy for surgical treatment of mandibular osteoradionecrosis in our department. However, pre-existing infection in the surgical field predisposes patients to postoperative infection. In this study, we investigated the incidence of surgical site infection （SSI） in the neck in patients with mandibular osteoradionecrosis who underwent reconstruction using a fibular flap. This retrospective study included 11 patients with mandibular osteoradionecrosis who underwent mandibulectomy and fibular flap reconstruction between January 2013 and December 2022 at our hospital. SSI occurred in eight patients (73%), Among the three patients without SSI, two underwent simultaneous transplantation of an anterolateral thigh flap and a pectoralis major flap, respectively. One patient developed a recurrent infection, followed by contralateral mandibular osteomyelitis, necessitating re-mandibulectomy and reconstruction using another fibular flap. Despite the high incidence of SSI （73%), infection control was achieved through irrigation and negative-pressure wound therapy. Patients with osteoradionecrosis have pre-existing infection around the mandible and low skin extensibility secondary to radiation therapy, which may lead to dead space formation and consequent SSI. Simultaneous transplantation of additional flaps along with a fibula flap may be beneficial to completely fill the dead space and minimize the risk of SSI in such cases.

　　Brooke-Spiegler syndrome（BSS）is a rare hereditary autosomal dominant disorder characterized by the development of multiple cylindromas, trichoepitheliomas, and, occasionally, spiradenomas. This report describes a 66-year-old woman presenting with multiple skin tumors, mainly involving the face and head, which progressively increased in size and number and resulted in significant esthetic deformity. Biopsy of the facial and head tumors led to histopathological diagnoses of cylindroma, trichoepithelioma, and spiradenoma. Mutations in the CYLD gene on chromosomes 16q12-q13 are known as the molecular basis of BSS. These CYLD gene mutations were detected in peripheral blood samples from both the patient and her son. A favorable esthetic outcome was achieved with surgical treatment. The surgical wound healed without hypertrophic scarring or keloid formation, and the scarring was inconspicuous. Moreover, no signs of recurrence were observed. This report suggests the usefulness of surgical treatment for this syndrome, for which no recommended treatment has been established.

　　Dermatofibrosarcoma protuberans（DFSP）is a rare, slow-growing fibro-cutaneous tumor of intermediate-grade malignancy that arises in the dermis of the trunk, proximal extremities, and, less commonly, in the head and neck area of adults. The high recurrence rate of DFSP, especially in the head, makes it particularly important to define tumor-encompassing margins for resection. However, due to the rarity of DFSP, clear guidelines for setting its resection margins are lacking, and for multiple DFSP involving the head, this is particularly challenging. Here, we describe a 22-year-old female presenting with multiple DFSP of the head. Due to a disparity between gross findings of the tumor and MRI data, the tumor was resected with a 20-mm margin from the Short T1 Inversion Recovery（STIR）high signal area on MRI, to minimize the risk of inadequate resection. Reconstruction was performed using a free latissimus dorsi flap. Postoperative pathology confirmed the negativity of the margins, and during the 8-month follow-up, there has been no evidence of recurrence or metastasis. This case report shows the potential utility of MRI STIR to determine safe excision margins in the presence of multiple DFSP, especially involving the head, where the risk of recurrence is high.

　　We report a case-series of secondary reconstructed auricular defects following wide resection of arteriovenous malformation in the auricular region. Our main method of auricular reconstruction involves the use of a tissue expander to expand the skin of a free flap prior to costal cartilage grafting, and this method results in a relatively functional auricule. One of five cases showed recurrence of the lesion, and one showed exposure of the costal cartilage. In cases of wide excision of arteriovenous malformation, reconstruction with a stable vascularized flap is preferable to prevent recurrence, and auricular reconstruction should be considered after confirming that symptoms are stable. Although relatively favorable results can be obtained by expanding the skin of a free flap, attention should always be paid to the risk of exposure of grafted cartilage due to thinning of the flap skin.

　　The standard strategy for treatment of a large cranial bone defect is to use an autogenous or artificial bone graft. A paste type of artificial bone is also useful to augment the volume of depressed cranial bone. However, as cranial bone defects can be diverse, material for reconstruction should be decided with sufficient consideration after consultation with the patient.
　　In this report, we describe the use of a custom-made artificial bone graft for the reconstruction of a cranial bone defect as well as augmentation of depressed cranial bone for cosmetic improvement in two patients. Custom-made artificial bones well-fitted the defective spaces, with no complications such as seroma infection.