Kissing molars class III detected at a young age

Teruhide Hoshino,Yu Koyama,Akira Katakura 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background Kissing molars (KMs) is defined as a state in which the apex of two impacted molars face opposite directions and the occlusal surfaces touch each other and the crown is in one follicle. Class III KMs have been reported previously; however, reports on class III KMs in young people (< 18 years of age) are limited. Case presentation Here, we present the case of KMs class III confirmed at an early age, supported by a review of the literature. The patient was a 16-year-old female and experienced discomfort in the left molar of the lower jaw and visited in our department. We diagnosed KMs based on an impacted teeth on the buccal side, near the lower jaw wisdom teeth, and a cyst-like low-density area observed around the crown of both teeth, as revealed by computed tomography. We decide to extract the tooth and enucleate the cyst under local anesthesia as the patient experienced discomfort due to occlusion. Furthermore, the cyst-like structure removal and tooth extraction including tooth root were necessary as the patient had KM class III, possibly inducing complicated malocclusion. Although no previous reports recommended timing for KMs tooth extraction, we propose that extraction at an early stage is important regardless of age especially in class III cases. Conclusions We report a case of KM class III detected at an early age.

Mixed reality for extraction of maxillary mesiodens

Yu Koyama,Masahide Koyachi,Kotaro Tachizawa,Akira Iwasaki,Ichiro Wakita,Akihiro Nishiyama,Satoru Matsunaga,Akira Katakura,Keisuke Sugahara 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background Mesiodentes are the most common supernumerary teeth. The cause is not fully understood, although proliferations of genetic factors and the dental lamina have been implicated. Mesiodentes can cause delayed or ectopic eruption of permanent incisors, which can further alter occlusion and appearance. Careful attention should be paid to the position and direction of the mesiodentes because of possible damage to adjacent roots in the permanent dentition period, errant extraction in the deciduous and mixed dentition periods, and damage to the permanent tooth embryo. To avoid these complications, we applied mixed reality (MR) technology using the HoloLens® (Microsoft, California). In this study, we report on three cases of mesiodentes extraction under general anesthesia using MR technology. Results The patients ranged in age from 6 to 11 years, all three were boys, and the direction of eruption was inverted in all cases. The extraction approach was palatal in two cases and labial in one case. The average operative time was 32 min, and bleeding was minimal in all cases. No intraoperative or postoperative complications occurred. An image was shared preoperatively with all the surgeons using an actual situation model. Three surgeons used Microsoft Holo- Lens® during surgery, shared MR, and operated while superimposing the application image in the surgical field. Conclusions The procedure was performed safely; further development of MR surgery support systems in the future is suggested.

A clinico-statistical study of factors associated with intraoperative bleeding in orthognathic surgery

Keisuke Sugahara,Yu Koyama,Masahide Koyachi,Akira Watanabe,Kiyohiro Kasahara,Masayuki Takano,Akira Katakura 대한악안면성형재건외과학회 2022 Maxillofacial Plastic Reconstructive Surgery Vol.44 No.-

Background: Excessive bleeding is a major intraoperative risk associated with orthognathic surgery. This studyaimed to investigate the factors involved in massive bleeding during orthognathic surgeries so that safe surgeriescan be performed. Patients (n=213) diagnosed with jaw deformities and treated with bimaxillary orthognathicsurgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) in the Department of Oral andMaxillofacial Surgery at the Suidobashi Hospital, Tokyo Dental College between January 2014 and December 2016were included. Using the patients’ medical and operative records, the number of cases according to sex, age at thetime of surgery, body mass index (BMI), circulating blood volume, diagnosis of maxillary deformity, direction ofmaxillary movement, operative duration, incidence of bad split, injury of nasal mucosa, and blood type were analyzed. Results: The results revealed that BMI, circulating blood volume, nasal mucosal injury, and operative time wereassociated with the risk of intraoperative massive bleeding in orthognathic surgeries. Chi-square tests and binomiallogistic regression analyses showed significant differences in BMI, circulating blood volume, direction of maxillarymovement, operative duration, and injury to the nasal mucosa. Operative duration emerged as the most important riskfactor. Furthermore, a >4-mm upward migration of the posterior nasal spine predicted the risk of massive bleeding inorthognathic surgery. Conclusions: The upward movement of the maxilla should be recognized during the preoperative planning stage as arisk factor for intraoperative bleeding, and avoiding damage to the nasal mucosa should be considered a requirementfor surgeons to prevent massive bleeding during surgery

A safe, stable, and convenient three-dimensional device for high Le Fort I osteotomy

Sugahara, Keisuke,Koyachi, Masahide,Odaka, Kento,Matsunaga, Satoru,Katakura, Akira Korean Association of Maxillofacial Plastic and Re 2020 Maxillofacial Plastic Reconstructive Surgery Vol.42 No.-

Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions: This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

Re-epithelialization of the Buccal Mucosa after Alkaline Chemical Injury

Takaichi, Saneyuki,Muramatsu, Takashi,Lee, Jong-Min,Jung, Han-Sung,Shinozaki, Naoshi,Katakura, Akira,Yamane, Gen-yuki JAPAN SOCIETY OF HISTOCHEMISTRY AND CYTOCHEMISTRY 2014 Acta histochemica et cytochemica Vol.47 No.5

<P>Alkaline conditions in the oral cavity may be caused by a variety of stimuli, including tobacco products, antacids, alkaline drinking water and bicarbonate toothpaste. However, the effects of an alkaline pH on the oral mucosa had not been elucidated. The purpose of this study was to investigate how basal keratinocytes are actively involved in re-epithelialization after alkaline chemical injury. We generated epithelial defects in the oral mucosa of mice by applying an alkaline chemical, and the localization of cytokeratin 13, cytokeratin 14, PCNA and p63 was investigated during the re-epithelialization process. PCNA- and p63-positive staining was seen in basal cells covering the wound surface at 1 day after the chemical injury. Cytokeratin 14-positive and PCNA-negative basal keratinocytes were localized in a few layers of the wound epithelium during epithelial outgrowth. Cytokeratin 14-positive and PCNA-positive basal keratinocytes, indicating proliferation, were localized over the entire layer of the epithelium at the wound margin. These results imply that basal keratinocytes at the wound margin migrate to the wound surface, provoke differentiation and keratinization during epithelial outgrowth and that epithelial cells are supplied from the wound margin to the epithelial outgrowth after alkaline chemical injury.</P>

Ameloblastic carcinoma of the mandible: a case report

Satoru Ogane,Arisa Fujii,Taiki Suzuki,Kazuhiko Hashimoto,Sadamitsu Hashimoto,Masayuki Takano,Akira Katakura,Takeshi Nomura 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background Ameloblastic carcinoma is a malignant form of ameloblastoma and a very rare odontogenic tumor. We report a case of ameloblastic carcinoma that occurred after removal of a right-sided mandibular dental implant. Case presentation A 72-year-old female patient visited her family dentist with a complaint of pain around a lower right implant placed 37 years previously. Although the dental implant was removed with the diagnosis of periimplantitis, the patient experienced dullness of sensation in the lower lip and was followed up by her dentist, but after no improvement. She was referred to a highly specialized institution where she was diagnosed with osteomyelitis and treated the patient with medication; however, there was no improvement. In addition, granulation was observed in the same area leading to a suspicion of malignancy, and the patient was referred to our oral cancer center. The diagnosis of squamous cell carcinoma was made after a biopsy at our hospital. Under general anesthesia, the patient underwent mandibulectomy, right-sided neck dissection, free flap reconstruction with an anterolateral thigh flap, immediate reconstruction with a metal plate, and tracheostomy. Histological analysis of the resected specimen on hematoxylin and eosin staining showed structures reminiscent of enamel pulp and squamous epithelium in the center of the tumor. The tumor cells were highly atypical, with nuclear staining, hypertrophy, irregular nuclear size, and irregular nuclear shape, all of which were suggestive of cancer. Immunohistochemical analysis showed that Ki-67 was expressed in more than 80% of the targeted area, and the final diagnosis was primary ameloblastic carcinoma. Conclusion After reconstructive flap transplantation, occlusion was re-established using a maxillofacial prosthesis. The patient remained disease-free at the 1-year 3-month follow-up.

Clinical investigation of patients with jaw deformity with comorbidities

Kiyohiro Kasahara,Teruhide Hoshino,Kei Sugiura,Yuki Tanimoto,Masahide Koyachi,Masae Yamamoto,Keisuke Sugahara,Masayuki Takano,Akira Katakura 대한악안면성형재건외과학회 2022 Maxillofacial Plastic Reconstructive Surgery Vol.44 No.-

Background: With improvements in the safety and stability of surgeries, the number of orthognathic surgeries isincreasing. Most patients who undergo orthognathic surgeries are younger, and the number of orthognathic surgeriesfor patients with comorbidities is also increasing. We report a survey and clinical investigation of patients withcomorbidities who underwent orthognathic surgeries at our department to improve the safety of orthognathicsurgery. Results: The participants included 296 men and 712 women, with a mean age of 28 years (13?19 years, n=144;20?29 years, n=483; 30?39 years, n=236; 40?49 years, n=102; 50?59 years, n=39; ≥60 years, n=4). In total, 347patients underwent one-stage Le Fort type I osteotomy and sagittal split ramus osteotomy (SSRO), 243 underwentSSRO, 287 underwent plate removal, 126 underwent genioplasty and plate removal, and five underwent othersurgeries. In total, 529 patients had comorbidities (52%), including allergic diseases (n=220, 33%), respiratory diseases(n=107, 16%), neurologic and psychiatric diseases (n=69, 10%), gynecologic diseases (n=28, 4%), hematologicdiseases (n=27, 4%), cardiovascular diseases (n=24, 4%), digestive diseases (n=22, 3%), metabolic and endocrinediseases (n=18, 3%), spinal diseases (n=11, 2%), ophthalmologic diseases (n=11, 2%), renal and urological diseases(n=9, 1%), and other diseases (n=117, 18%). Among the patients with comorbidities, 11 with hemorrhagic diatheses(hemophilia and von Willebrand disease), arrhythmia (atrioventricular block), psychiatric disease (adjustment disorder),and metabolic disease (diabetes) required cautious perioperative management. The patient with hemophilia wasmanaged with regular low-dose recombinant factor VIII replacement therapy, and the patient with type I diabetesmellitus was administered continuous insulin infusion and sliding-scale insulin therapy; both patients had an uneventfulcourse. Conclusions: The study findings suggest that with the increase in orthognathic surgeries, oral and maxillofacialsurgeons should adequately manage cases requiring cautious perioperative control and highlight the importance ofpreoperative screening. Despite the well-established safety and postoperative stability of orthognathic surgeries, oralsurgeons should adopt appropriate additional preventive measures for patients with comorbidities.

설편평상피암에 있어서의 고밀도 SNP Genotyping 어레이를 이용한 전게놈북제수와 헤테로접합성 소실의 분석

黑岩 司(Kuroiwa Tsukasa),山本信治(Yamamoto Nobuharu),恩田健志(Onda Takeshi),別所央城(Bessyo Hiroki),藥師寺 孝( Yakushiji Takashi),片倉 朗(Katakura Akira),野伸夫(Takano Nobuo),柴原孝彦(Shibahara Takahiko) 대한구강악안면외과학회 2011 대한구강악안면외과학회지 Vol.37 No.6

Chromosomal loss of heterozygosity (LOH) is a common mechanism for the inactivation of tumor suppressor genes in human epithelial cancers. LOH patterns can be generated through allelotyping using polymorphic microsatellite markers; however, owing to the limited number of available microsatellite markers and the requirement for large amounts of DNA, only a modest number of microsatellite markers can be screened. Hybridization to single nucleotide polymorphism (SNP) arrays using Affymetarix GeneChip Mapping 10 K 2.0 Array is an efficient method to detect genome-wide cancer LOH. We determined the presence of LOH in oral SCCs using these arrays. DNA was extracted from tissue samples obtained from 10 patients with tongue SCCs who presented at the Hospital of Tokyo Dental College. We examined the presence of LOH in 3 of the 10 patients using these arrays. At the locus that had LOH, we examined the presence of LOH using microsatellite markers. LOH analysis using Affymetarix GeneChip Mapping 10K Array showed LOH in all patients at the 1q31.1. The LOH regions were detected and demarcated by the copy number 1 with the series of three SNP probes. LOH analysis of 1q31.1 using microsatellite markers (D1S1189, D1S2151, D1S2595) showed LOH in all 10 patients (100). Our data may suggest that a putative tumor suppressor gene is located at the 1q31.1 region. Inactivation of such a gene may play a role in tongue tumorigenesis.

Maxillary reconstruction using tunneling flap technique with 3D custom-made titanium mesh plate and particulate cancellous bone and marrow graft: a case report

Takano, Masayuki,Sugahara, Keisuke,Koyachi, Masahide,Odaka, Kento,Matsunaga, Satoru,Homma, Shinya,Abe, Shinichi,Katakura, Akira,Shibahara, Takahiko Korean Association of Maxillofacial Plastic and Re 2019 Maxillofacial Plastic Reconstructive Surgery Vol.41 No.-

Background: Reconstructive surgery is often required for tumors of the oral and maxillofacial region, irrespective of whether they are benign or malignant, the area involved, and the tumor size. Recently, three-dimensional (3D) models are increasingly used in reconstructive surgery. However, these models have rarely been adapted for the fabrication of custom-made reconstruction materials. In this report, we present a case of maxillary reconstruction using a laboratory-engineered, custom-made mesh plate from a 3D model. Case presentation: The patient was a 56-year-old female, who had undergone maxillary resection in 2011 for intraoral squamous cell carcinoma that presented as a swelling of the anterior maxillary gingiva. Five years later, there was no recurrence of the malignant tumor and a maxillary reconstruction was planned. Computed tomography (CT) revealed a large bony defect in the dental-alveolar area of the anterior maxilla. Using the CT data, a 3D model of the maxilla was prepared, and the site of reconstruction determined. A custom-made mesh plate was fabricated using the 3D model (Okada Medical Supply, Tokyo, Japan). We performed the reconstruction using the custom-made titanium mesh plate and the particulate cancellous bone and marrow graft from her iliac bone. We employed the tunneling flap technique without alveolar crest incision, to prevent surgical wound dehiscence, mesh exposure, and alveolar bone loss. Ten months later, three dental implants were inserted in the graft. Before the final crown setting, we performed a gingivoplasty with palate mucosal graft. The patient has expressed total satisfaction with both the functional and esthetic outcomes of the procedure. Conclusion: We have successfully performed a maxillary and dental reconstruction using a custom-made, pre-bent titanium mesh plate.

Prognostic factors for maxillary sinus mucosal thickening following Le Fort I osteotomy: a retrospective analysis

Iwamoto, Masashi,Watanabe, Miki,Yamamoto, Masae,Narita, Masato,Kamio, Takashi,Takaki, Takashi,Shibahara, Takahiko,Katakura, Akira Korean Association of Maxillofacial Plastic and Re 2019 Maxillofacial Plastic Reconstructive Surgery Vol.41 No.-

Background: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. Methods: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. Results: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. Conclusions: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.