{'fraction_non_alphanumeric': 0.012218045112781954, 'fraction_numerical': 0.006578947368421052, 'mean_word_length': 5.4156626506024095, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Alveolar Reconstruction by Distraction Osteogenesis Under Unfavorable Conditions

We present a patient who underwent alveolar reconstruction using vertical mandibular lengthening by distraction osteogenesis under unfavorable conditions. Part of the alveolar bone in the center of the mandible was resected, together with a squamous cell carcinoma located on the oral floor. We used vertical mandibular lengthening from the region of the remaining mandible inferior to the bony defect to reconstruct the alveolus, combined with a free musculocutaneous flap as a cover. However, the transferred flap underwent complete necrosis and was replaced with another flap on the seventh postoperative day. Radiotherapy at a total dose of 50 Gy was administered from day 75 to day 109 after completion of the distraction, because of suspected residual tumor. Despite the severe conditions, most of the distraction gap became filled with new bone. This case indicates that distraction osteogenesis can be used even in irradiated or poorly vascularized areas, as in our patient.