The Bulletin of Tokyo Dental College
Print ISSN : 0040-8891
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Original Articles
  • Norio Kasahara, Satoru Matsunaga, Masashi Yamada, Yasutaka Nakamura, M ...
    2020 Volume 61 Issue 2 Pages 73-82
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 10, 2020
    JOURNALS FREE ACCESS

    The purpose of this study was to elucidate the characteristics of dental malpractice trials undertaken by medical malpractice divisions and ordinary divisions in district courts. Dentistry disputes in a total of 84 trials held between 1977 and 2014 were investigated. A total of 45 were conducted by medical malpractice divisions, resulting in 18 approvals and 27 dismissals, while 39 were undertaken by ordinary divisions, leading to 24 approvals and 15 dismissals. The parameters analyzed comprised category of dental treatment, judgment, amount claimed, and amount accepted. The results revealed that the mean amount claimed in trials held by medical malpractice divisions (¥12,563,324) was lower than that sought in trials conducted by ordinary divisions. The amount accepted was also found to exceed 50% of the amount claimed in 6 trials held by ordinary divisions (maximum 75.2%), but in only 2 trials conducted by medical malpractice divisions (maximum 54.8%); the mean amount accepted in trials held by medical malpractice divisions was 24.2%. These results indicate that judgments in trials conducted by medical malpractice divisions place a stronger emphasis on resolution of dental malpractice dispute than on pursuing truth or carrying out proper legal procedures.

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  • Yasutaka Nakamura, Michinaga Samejima, Kiyoshi Minaguchi, Phrabhakaran ...
    2020 Volume 61 Issue 2 Pages 83-94
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 10, 2020
    JOURNALS FREE ACCESS

    Population flow between Southeast Asian countries and Japan continues to gather pace. Accordingly, the number of foreigners involved in incidents in Japan has markedly increased, which means that forensic dentistry is now increasingly being faced with the need to analyze DNA from persons of non-Japanese extraction. The DNA test currently used for personal identification mainly utilizes short tandem repeats (STRs) on autosomal chromosomes and the Y-chromosome. This test was developed for use in personal identification, not for distinguishing among races; nonetheless, the standard method for personal identification is often used because the procedure has been established. To determine the degree to which racial differences can be distinguished by standard DNA analysis, 23 STRs located on the Y chromosome were investigated in 218 Malay and 426 Japanese males. The frequencies of each STR were calculated in the two populations. The difference in the power of discrimination between the Malay and Japanese populations ranged from a minimum of 0.01 to a maximum of 0.27; the difference in polymorphic information content ranged from 0.01 (minimum) to 0.23 (maximum). No major differences were noted in the polymorphisms in these two Mongoloid populations, but the distributions of the 17 STRs differed significantly. Short tandem repeat types demonstrating a likelihood of racial differences were identified in 14 of the STRs. Race-specific STR types were identified in 10 STRs. These results suggest that the likelihood of Malay or Japanese genetic background can be judged based on Y-chromosome STR test results.

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  • Mayuko Uchino, Hidehito Arima, Hiroshi Kobayashi, Junya Nagata, Toshih ...
    2020 Volume 61 Issue 2 Pages 95-102
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 10, 2020
    JOURNALS FREE ACCESS

    The aim of this study was to investigate the condition of the maxillary lateral incisors and evaluate the methods used for cleft closure in patients with cleft lip and palate, including the treatment of the maxillary lateral incisors. A total of 214 patients (260 clefts) with alveolar clefts who had started Phase II treatment and entered the maintenance period at the Department of Orthodontics at Tokyo Dental College, Chiba Hospital, between 1975 and 2014 were included. Panoramic, intraoral, and occlusal radiographs, as well as intraoral photographs and medical records, were used to investigate cleft classification, the presence or absence and location of maxillary lateral incisors, and frequency and treatment method for peg lateral incisors in the cleft region. There were more unilateral cleft cases (78.5%) than bilateral cleft cases. The prevalence of congenital absence of the maxillary lateral incisors was similar between unilateral (53.0%) and bilateral cases (53.3%). Peg laterals occurred frequently, with 89.9% occurring in unilateral cases. The maxillary lateral incisors were more commonly found in the secondary than in the primary palate. The number of non-extraction cases was larger than that of extraction cases, regardless of cleft type or the location of the peg laterals. In many cases, the peg laterals were treated with non-extraction and space closure or crown modification. These results suggest that, depending on their condition, the peg laterals should be preserved as much as possible in devising a treatment plan.

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  • Issei Takahashi, Teruo Sakamoto, Takenobu Ishii, Kenji Sueishi
    2020 Volume 61 Issue 2 Pages 103-120
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 10, 2020
    JOURNALS FREE ACCESS

    Narrowing of the maxillary dental arch is a major cause of occlusal abnormalities in cleft lip and palate patients. Although the dental arch may be expanded in such cases, relapse will often occur during the subsequent retention period. In this study, the stability of expansion of the maxillary arch was investigated by examining 3-dimensional change in the maxillary arch during the treatment and post-retention periods. Three-dimensional measurements was performed on maxillary plaster models obtained from 8 unilateral cleft lip and palate patients (mean age, 12.5 years) who had undergone maxillary arch expansion using an edgewise appliance and quad helix (CLP group). The controls consisted of 8 unilateral cleft lip and alveolus patients (mean age, 12.9 years). Measurements were made during the pretreatment, post-treatment, and post-retention periods. In the CLP group, horizontal relapse was observed in the alveolar and dental arches between the second premolars, together with vertical relapse on the cleft side of the central incisor, lateral incisor, and canine. The sites where relapse occurred demonstrated decreased growth before orthodontic treatment. A correlation was observed between the extents of expansion and relapse. These findings suggest that excessive horizontal or vertical tooth movement in areas showing developmental failure should be avoided in order to increase stability after orthodontic treatment.

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Case Reports
  • Toshiyuki Handa, Tatsuya Ichinohe
    2020 Volume 61 Issue 2 Pages 121-126
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 05, 2020
    JOURNALS FREE ACCESS

    Here, we report a case in which acupuncture combined with trigger point injection was effective in a patient with chronic myofascial pain with referred pain in the masticatory muscles. The patient was a 46-year-old woman with the chief complaint of chronic persistent pain in the region of the left mandibular first molar, which had been extracted 5 months earlier. Stellate ganglion block was performed and amitriptyline administered at another hospital, but were ineffective. At her initial visit to our hospital, her primary complaint was chronic persistent pain in the region of the bilateral mandibular first molars. Several tender points were found on the masseter, temporalis, and sternocleidomastoid muscles, with bilateral referred pain. The pain score according to the visual analogue scale was 85. No significant psychological factors were found, however. Based on these findings, the diagnosis was chronic myofascial pain with referred pain in the masticatory muscles. Therefore, stretching of masticatory muscle and trigger point injection were performed. Two months later, the patient requested trigger point injections to be performed at all tender points, as the previous injections had been effective. The total volume of local anesthetic that this would require was considered to be excessive as there was a large number of tender points, however, and it was feared that a toxic reaction might occur. Therefore, acupuncture in combination with trigger point injection was selected instead. The symptoms disappeared within 9 months after commencement of this therapy, and treatment was completed within 1 year. The present results suggest that acupuncture therapy is effective when used in combination with trigger point injection.

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  • Rie Fujii, Kazuki Morinaga, Tomohiro Asai, Natsuko Aida, Masashi Yamad ...
    2020 Volume 61 Issue 2 Pages 127-133
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 05, 2020
    JOURNALS FREE ACCESS

    The recent use of cone beam computed tomography (CBCT) in the field of dentistry to obtain 3-dimensional (3D) images has enabled more effective examination and diagnosis in endodontic treatment. Such information has also been reported to be of benefit in surgical endodontic treatment such as intentional replantation. Here, we report a case of intentional replantation with the assistance of CBCT in which a good therapeutic outcome was achieved. The patient was a 30-year-old woman who visited our hospital with the chief complaint of spontaneous pain in the right maxillary first molar. Dental radiographs revealed a radiolucent area in the apical portion of the distal root, and a radiopaque area thought to be a broken shard from a small surgical instrument measuring approximately 1.5 mm in length. The shard was located outside the distal apical foramen. Based on these findings, the diagnosis was acute suppurative apical periodontitis of the right maxillary first molar. Infected root canal therapy was subsequently commenced. The patient’s symptoms showed no improvement, however, and the pain persisted. Therefore, dental CBCT was performed to obtain 3D images, which confirmed a radiopaque area thought to be a broken shard from a small surgical instrument located outside the apical foramen of the distal root and facing in a direction that made it impossible to remove from the root canal. Because the patient’s symptoms had shown no improvement and a foreign body was observed outside the apical foramen, intentional replantation combined with root resection was performed with informed consent. At a 1-year follow-up visit, progress was good, and there were no reported symptoms or signs. When reaching a diagnosis is difficult based on clinical findings and dental radiographs alone, the 3D images provided by CBCT offer a means of securing a more reliable diagnosis, allowing planning of treatment to be more effective.

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  • Yoshiaki Shimoo, Takashi Uesugi, Masaru Hiruta, Yuichi Ishiura, Kazuhi ...
    2020 Volume 61 Issue 2 Pages 135-143
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 05, 2020
    JOURNALS FREE ACCESS

    Here, we describe the provision of an implant-supported prosthesis in a patient with impacted teeth in the maxilla, which complicated implant placement and necessitated utilization of the extraction sockets of previously impacted teeth and residual submerged roots. The patient was a 63-year-old man who visited our clinic with the chief complaint of difficulty in mastication. Numerous residual roots were observed in the maxilla, and radiographic imaging revealed that the residual roots of teeth #13 and #16 were fully impacted. The patient complained of a strong sensation of a foreign body in the area of a denture support overlying these residual roots. Therefore, the impacted teeth were extracted, 5 implants placed, and a temporary prosthesis provided. Given the necessity of placing the implant through the extraction socket of the impacted canine (#13), favorable initial stability was achieved using a long (>20 mm) implant. Moreover, autogenous bone obtained by osteotomy was grafted onto the extracted impacted tooth socket. The clinical condition was stable at approximately 1 year after implant placement and so the final prosthesis was delivered, with periodic check-ups being performed every 3 months thereafter. After 4 years, the patient has reported no symptoms. Clinically, there are no signs of inflammation, and the postoperative condition is deemed to be very favorable.

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  • Mamoru Yotsuya, Masahiro Nakano, Kazuhiro Umehara, Takao Nomura, Toru ...
    2020 Volume 61 Issue 2 Pages 145-150
    Published: 2020
    Released: July 04, 2020
    [Advance publication] Released: June 05, 2020
    JOURNALS FREE ACCESS

    Occlusal reconstruction comprising orthodontic treatment, autotransplantation, and implant treatment was performed in a 30-year-old woman with missing maxillary anterior teeth. An initial examination revealed marked root resorption of the maxillary anterior teeth. Both the maxillary canines were missing, causing constriction of the dental arch. Conserving the right maxillary central and lateral incisors, which were dislocated due to trauma, was considered to be too difficult, and a bridge was not selected as there was insufficient load bearing capacity in the adjacent abutment teeth, making the prognosis uncertain. Partial dentures were rejected due to the patient’s age and esthetic demands. First, the right mandibular lateral incisor was extracted to relieve crowding in the mandibular anterior teeth, leaving the patient with 3 mandibular incisors. Orthodontic treatment was then performed to harmonize the occlusal relationship between the mandibular and maxillary anterior teeth. Next, the right mandibular lateral incisor was transplanted to the extraction site of the right maxillary lateral incisor. After fixation of the autotransplanted tooth, the shape of the bone around the implant site improved. The final prosthesis for the right maxillary central incisor was provided via implant treatment. As seen in a follow-up 16 years later, the interproximal dental papilla was intact, and the patient’s esthetic demands were fulfilled. Utilizing the functions of the periodontal ligament of the natural teeth was a useful part of orthodontic treatment and autotransplantation.

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