[in Japanese]

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One of the patients with difficulty, there is a case to complain of discomfort or abnormal sense of occlusion, the dentist is able to encounter patients with objective findings that can not be confirmed. Usually, although confirmation is using articulating paper, wax, and silicone materials, no abnormalities found in the state especially occlusal contact. In addition, for the insistent demand of the patient to the discomfort occlusion, the dentist may easily gone the occlusal adjustment. As a result, not only does not improve the patient’s complaint, its symptoms may even also be worse in reverse. And the relationship of trust between the patient and the dentist will break. And it may even be caught in a direction unfavorable unexpected. For discomfort related to occlusion, in clinical practice guidelines committee in Japan Prostjodontic Siciety, creating clinical practice guidelines related to occlusal dysesthesia were studied.
In the development of clinical practice guidelines, we have attempted to formulate guidelines created by a panel of the Commission, there are few high-quality paper sufficiently related to occlusal dysesthesia, did not lead to the creation of clinical practice guidelines. Therefore, a consensus meeting held on occlusal discomfort as Japan Prosthodontic Society, examined the appropriate designation of this disease. From the results of the pre-survey, this disease has to be called and “occlusal discomfort syndrome”.
For the purpose of indicating the direction of research activities and creating clinical practice guidelines in the future, the position paper of this time, a multi-center was carried out on the current situation and the course of dental treatment up to this syndrome patients uncomfortable occlusion literature and one of the few in the past was created from the findings of a patient with.

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This position paper proposes a definition and naming standard for removable partial dentures (RPDs) using thermoplastic resin, and presents a guideline for clinical application. A panel of 14 experts having broad experience with clinical application of RPDs using thermoplastic resin was selected from members of the Japan Prosthodontic Society. At a meeting of the panel, “non-metal clasp denture” was defined as the generic name of RPDs with retentive elements (resin clasps) made of thermoplastic resin. The panel classified non-metal clasp dentures into two types: one with a flexible structure that lacks a metal framework and the other having a rigid structure that includes a metal framework. According to current prosthetic principles, flexible non-metal clasp dentures are not recommended as definitive dentures, except for limited cases such as patients with a metal allergy. Rigid non-metal clasp dentures are recommended in cases where patients will not accept metal clasps for esthetic reasons. Non-metal clasp dentures should follow the same design principles as conventional RPDs using metal clasps. Since the physical properties of thermoplastic-resin products vary greatly, clinicians should utilize them with careful consideration of the specific properties of each product. In general, thermoplastic resin has lower color-stability and higher risk of fracture than polymethylmethacrylate. Additionally, the surface of thermoplastic resin becomes roughened more easily than polymethylmethacrylate. Studies on the physical properties of thermoplastic resin, treatment efficacy and follow-up are insufficient to reach a definitive conclusion at this time. Therefore, this position paper should be revised based on future studies and a clinical guideline should be developed.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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Patient: The patient was a 71-year-old female who visited our hospital with chief complaints being esthetic impairment and masticatory disturbance due to a defect of the upper right first premolar. The 90-degree twisted prosthetic morphology of the upper right second premolar was modified, and the occlusal pattern led by the canine was conserved using an implant. For the defect of the upper right first premolar, a bridge was selected in consideration of the adjacent tooth condition to establish a stable oral cavity environment.
Discussion: The prosthetic restoration method was selected by accurately identifying the risk of occlusion of the residual teeth and periodontal condition.
Conclusion: The residual tooth conditions were accurately identified, prosthetic treatment with implants and bridges was applied to defects of the bilateral teeth, and stable therapeutic results were achieved on both sides.

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Patient: A 76-year-old man visited our clinic with the chief complaint of difficulty in mastication due to a poor-fitting denture. Since a flap from segmental mandibulectomy was observed, upper and lower dentures were fabricated considering the morphology and artesian displacement of a denture in the same area.
Discussion: A favorable result was obtained since marked movement disorder and invasion to the soft tissue were not observed after oral cancer surgery, the shape of the denture in the flap area was carefully designed, and a higher QOL was achieved. The patient needs to be carefully monitored to lower the risk.
Conclusion: Functional recovery and improved QOL were achieved by flap-conscious denture design.

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Patient: A 57-year-old female patient visited our department after undergoing a right half glossectomy, pharynx and mandibular segmentectomy due to carcinoma and leukoplakia. At the first examination, she complained of articulation disorder of /k/ pronunciation. Palatograms with /ta/, /ki/, /ka/ were used to design a palatal augmentation prosthesis for this patient.
Discussion: Application of the palatal augmentation prosthesis that was based on the /ki/ and /ka/ consonant palatograms satisfactorily restored the articulation function of the patient with glossectomy and mandibulectomy.
Conclusion: In this glossectomy patient with difficulty in recovering articulation, the use of a palatal augmentation prosthesis fabricated utilizing palatograms improved both articulation and swallowing function, and showed a favorable prognosis.

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Patient: A 52-year-old man presented to our clinic with the chief complaint of tooth mobility and pain on occlusion. Full-mouth third-degree alveolar bone loss was found and the diagnosis was aggressive periodontitis. Extraction of all severely damaged teeth and prosthodontic replacement were indicated. With a history of discontinuation of dental treatment due to dental fear, immediate dentures were initially constructed. The remaining teeth were treated later and then the final dentures were fitted.
Discussion: Marked improvement in chewing third- and higher-category food items was observed after fitting the dentures. With improvement of the intraoral environment, the patient was able to eat and speak properly and became highly motivated.
Conclusion: When prosthodontic treatment using immediate dentures was performed in this patient with severe periodontal disease associated with psychological factors, both esthetic and functional improvements were achieved and the patient’s quality of life improved.

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Patient: The patient was a 54-year-old female who visited for implant treatment for a free-ended maxillary edentulous space on the left side. Since a fixed partial denture in the right mandibular molar region was found to be broken at the initial oral examination, restoration using implants was performed in both edentulous spaces.
Discussion: Following sufficient informed consent, the patient wished to undergo prosthetic treatment using implants. In this patient, no inflammation or abnormal bone resorption was observed around the implants 3 years after the implant treatment, and a functionally and esthetically satisfactory oral environment is considered to have been maintained.
Conclusion: In this patient, a favorable outcome was achieved by restoring both the maxillary and mandibular dentitions using implants.

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Patient: A 62-year-old male complained of pain and gingival enlargement in the right lower molar area and masticatory dysfunction. After removing dental implants in the upper-left and lower-right molar areas, the crown height and the occlusal support of the molar regions were recovered, and the centric occlusion, occlusal plane and vertical dimension were restored using provisional restorations and treatment with removable partial dentures (RPDs). The mandibular position was recovered, and the definitive prosthesis was applied after reassessment of his oral condition.
Discussion: The definitive RPDs were designed based on rigid support by proper bracing elements of RPDs and the occlusal relationship since there was severe residual ridge resorption after removing the implants, leading to the stability of RPDs.
Conclusion: This case was successfully rehabilitated since the definitive prosthesis was applied after restoring the mandibular position and the centric occlusion.

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Patient: The patient was a 56-year-old female, postoperative for left maxillary cancer and with a chief complaint of unconformable dentures. For the incompatibility of the dentures and the problem with residual teeth, dento-maxillary prosthesis with improved stability and obturation was approved, and the removable partial denture was refabricated. As a result, the improvement of the chief complaint was noticed.
Discussion: In a prosthetic treatment, it is important to pay attention to the design of dentures, occlusal supporting maintenance and the management of residual teeth.
Conclusion: The treatment outcome with dento-maxillary prosthesis depends on careful maintenance, stability of prosthesis, and, moreover, appropriate obturation.

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Patient: A 26-year-old female patient visited our institution requesting esthetic treatment for congenitally missing teeth in the area of the upper-left lateral incisor and a maxillary median diastema. Following the completion of orthodontic treatment, the maxillary midline and diastema between the upper-left canine and first upper-left premolar were closed. The edentulous space between the upper-left lateral incisor was restored with an implant-supported fixed prosthesis. Porcelain fused to a metal crown was used as the final restoration, and the patient received a good prognosis for four years.
Discussion: Some factors increase labial bone resorption. Clinicians must carefully follow changes in the labial bone and gingiva.
Conclusion: This case suggests that implant-supported fixed prostheses are possible treatments for congenitally missing teeth in the area of the upper-left lateral incisors.

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Patient: The patient was a 47-year-old woman whose chief complaint was difficulty in chewing and esthetic dissatisfaction caused by the discomfort of removable dentures. Examinations by CT and lip line were carried out, then fixed-implant superstructures were fabricated for the edentulous maxilla. The prognosis has been excellent during 5-year follow-up.
Discussion: Neither bone resorption around implants nor detachment of the superstructures was detected. However, it is necessary to carefully observe the changes of occlusal contact and the conditions of the periodontal tissues around the residual teeth, since the furcation involvement of the natural teeth is progressing.
Conclusion: Osseointegrated implant therapy with fixed superstructures for maxillary edentulous jaw improved the patient’s chief complaint of esthetic dissatisfaction and difficulty in chewing.

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Patient: A 56-year-old man presented with the chief complaint of difficulty in chewing caused by missing lower molars and the mobility of upper incisors. In this case, implant-retained porcelain-fused-to-metal prostheses were fabricated for the mandibular unilateral free-end space to reestablish proper occlusal support. For the upper incisal defect region, teeth-retained splinted porcelain-fused-to-metal prostheses were fabricated. The patient was followed for more than three years after treatment, and a slight chipping of porcelain was observed in the prosthesis of the lower-left second molar during the follow-up period. The chipping was treated by surface modification and polishing of the surface.
Discussion: The vertical shear stress caused by occlusal interference at the time of mandibular front exercise, due to the metal frame being small, is considered to have caused the chipping.
Conclusion: Functional problems caused by loss of occlusal support were successfully rehabilitated using implant-retained fixed partial dentures.

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Patient: The case was a 56-year-old female patient with decreased occlusal vertical dimension. The patient showed tenderness of her bilateral masseter and temporal muscles. Her mandibular position and occlusal contacts were corrected using removable partial dentures (RPD) for the maxilla and an occlusal splint combined with RPD for the mandible. The mandibular position was stabilized, and the symptoms of temporomandibular disorders (TMD) disappeared. After observation for four months, final prostheses were fabricated.
Discussion: The patient was followed for four years after the treatment. Although minor fractures were observed in some prostheses, the patient was highly satisfied with the prostheses and had no symptoms of TMD.
Conclusion: The corrections of mandibular position and occlusal contacts with a sequence of prosthodontics including the insertion of RPD and occlusal splint were effective for this case with decreased occlusal vertical dimension accompanied by TMD.

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