Mandibular midline osteotomy for correction of bimaxillary transverse discrepancy: a technical note.

Bimaxillary transverse width discrepancies are commonly encountered among patients with dentofacial deformities. Skeletal discrepancies should be diagnosed and managed appropriately with possible surgical corrections. Transverse width deficiencies can present in varieties of combinations involving the maxilla and mandible. We observed that in a significant proportion of cases, the maxilla is normal, and the mandible showed deficiency in the transverse dimension after pre-surgical orthodontics. We designed novel osteotomy techniques to enhance mandibular transverse width correction, as well as simultaneous genioplasty. Chin repositioning along any plane is applicable concomitant with mandibular midline arch widening. When there is a requirement for larger widening, gonial angle reduction may be necessary. This technical note focuses on key points in management of patients with transversely deficient mandible and the factors affecting the outcome and stability. Further research on the maximum amount of stable widening will be conducted. We believe that developing evidence-based additional modifications to existing conventional surgical procedures can aid precise correction of complex dentofacial deformities.

[Oral Function Restoration via Two-Stage Reconstructive Treatment of an Extensive Maxillary Defect Following Maxillectomy].

Recently, the number of survivors that had oral cancer has increased, but deterioration in the quality of life of patients concerning oral function and cosmetic appearance has become problematic. Prosthodontic dentures usefully treat jaw defects after maxillary resection for cancer, but advances in microsurgery have rendered the possibility to reconstruct maxillary defect and oral cavity using a microvascular flap. Here, we describe 2-stage treatment after 35 years postoperatively. We restored the maxillofacial function using microvascular flaps and partial denture. The patient was a 59-year-old woman who underwent left lateral maxillectomy 35 years previously to treat an advanced left maxilla gingival carcinoma. A maxillary prosthesis was applied, requiring repeated adjustments and refabrications. The patient visited to obtain improvements for oral and maxillofacial functions and long-term quality of life. The left maxillary bone defect was 45×50 mm in area. Collaborating with the Department of Plastic and Reconstructive Surgery, the patient underwent reconstructive treatment using a microvascular forearm flap and partial denture. The patient's progress was excellent; eating, swallowing, and articulation improved. For 1 year postoperatively, the patient was satisfied with the results.

[A Case of Tongue Carcinoma with Malignant Transformation Caused by the Pandemic].

In April 2020, a state of emergency was declared because of the pandemic, and the public was instructed to refrain from leaving their homes. Consequently, this stirred up anxiety about visiting medical institutions. Here, we describe a case of tongue carcinoma that developed from an oral precancerous lesion into a malignant transformation owing to the effects of refraining from medical examinations caused by the pandemic. The patient was a 62-year-old woman. In March 2020, the patient became aware of a mass at the tongue's margin and was referred to our department. An excisional biopsy was performed, and a diagnosis of inflammatory change was made. The following month, a white ulcerative lesion was found, and another excisional biopsy was performed; therefore, a diagnosis of left tongue leukoplakia without epithelial dysplasia was made. The patient was scheduled for surgery; however, refused treatment and consultation because of the pandemic. In September 2021, the patient revisited our department on her own volition because an ulcerative lesion with indistinct borders and induration was found at the left lingual margin. Upon close examination, a diagnosis of left tongue squamous cell carcinoma(cT2N2bM0, Stage ⅣA)was made. In October 2021, radical tumor resection and reconstruction were performed. After 8 months postoperatively, the patient is currently well.

[A Case of Lower Gingival Carcinoma Treated Surgically Using Computer-Assisted Patient-Specific Cutting Guide and Mandibular Reconstruction Plate].

We report a case of advanced lower gingival carcinoma treated with a computer-assisted custom-made surgical guide and reconstruction plate system(TruMatch®)in combination with a pectoralis major myocutaneous flap. In a 74-year-old male patient, a neoplastic lesion with a 30×30 mm periapical induration was observed around an extraction socket of left mandibular third molar. After various examinations, we diagnosed lower gingival carcinoma(cT4aN2bM0, Stage ⅣA). The patient was a paraplegic with a spinal cord injury, and reconstruction of mandible with free flap was not indicated, requiring minimally invasive surgery. Therefore, a surgical guide and reconstruction plate were prepared preoperatively using the Tru- Match® system. Under general anesthesia, the patient underwent tracheostomy, left modified radical neck dissection, segmental mandibulectomy, and reconstruction of the mandible using this system in combination with a pectoralis major myocutaneous flap. Postoperatively, the patient had minimal dysfunction. Currently, at 18 months follow up postoperatively, good prognosis was observed. In conclusion, this is a useful surgical system with accurate and less invasive surgery for segmental mandibulectomy of advanced lower gingival carcinoma.