Clinical guidelines or definitive criteria for “Occlusal consideration for fixed implant prosthesis in mandibular posterior region” have not been established yet although the dental implant is an essential treatment option for current prosthetic dentistry. This position paper aimed to propose a critical recommendation and consequently indicate a tentative practice guideline. In this paper, the first and second molar missing in the mandible was assumed as the most typical partial edentulous jaw. A panel of clinical experts concerning dental implant practice was selected from the members of the Japan Prosthodontic Society, and a meeting was held to collect clinical data obtained from daily practice and to estimate expert opinions. As a result, general remarks were presented regarding shapes of prostheses, position and number of occlusal contact points, occlusal contact during lateral excursion, displacement of periodontal ligament, and materials of occlusal surface. However, the expert opinions described above have not been supported by clinical evidence. Moreover, neither the effect of those therapies nor long-term prognosis has been thoroughly investigated. Thus, further study for collecting the clinical evidences is required to formulate the clinical guideline.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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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 65-year-old man with the chief complaint of masticatory disturbance by apical periodontitis in the right side of the mandibular molar region. For this case, a dental implant and fixed dental bridge were used due to the loss of occlusal support.
Discussion: We achieved occlusal stability by using a fixed dental bridge of the upper and lower sides and a fixed prosthetic appliance by oral implant. The occlusal relations remained stable in the maintenance period.
Conclusion: We recovered occlusal stability by simultaneously using a fixed dental bridge for residual teeth and a fixed prosthesis by implant for the free-end missing, in a case of masticatory disturbance complicated with poor occlusal plane.

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Patient: A 58-year-old female patient diagnosed with metal allergy at a different clinic visited with a request for treatment of an esthetic disturbance due to the detachment of metal crowns from the upper- and lower-left molar parts. The esthetic disturbance and allergy symptoms were improved with zirconia crowns and bridge matching the shade of the natural teeth.
Discussion: The occlusal function and periodontal tissues have remained in good condition for more than three years. No allergic reactions have been observed.
This suggests that rehabilitation with zirconia prostheses after removing the metal is effective for patients suffering from metal allergy.
Conclusion: The zirconia crowns improved the patient’s metal allergy and esthetic disturbance.

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Patient: A 73-year-old male patient diagnosed as left maxillary cancer was referred to our prosthodontic clinic by an oral surgeon before oral surgery. An early post-operative maxillary denture for a defective jaw was fabricated 15 days after the surgery, and the final maxillary denture for the defective jaw was fabricated 12 months after surgery. However, because there was a liquid flow into the nasal cavity, the obturator was improved by dynamic impression and indirect relining.
Discussion: The technique of improving the sealing ability of the obturator by dynamic impression and indirect relining was useful for blocking the liquid flow into the nasal cavity.
Conclusion: Liquid flow into the nasal cavity was improved by dynamic impression and indirect relining. As a result, patient satisfaction was obtained.

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Patient: A patient (65 years old, female) visited our hospital with the chief complaint of esthetic and masticatory impairment caused by severe periodontal disease. Maxillary anterior teeth showed flare-out, and all teeth were affected by periodontal disease at the first examination. After MTM, provisional restorations were placed. A porcelain fused metal bridge was placed as the final restoration.
Discussion: Flare-out and diastema of maxillary anterior teeth were corrected by MTM, which made it possible to avoid having to perform pulpectomy for most abutment teeth.
Conclusion: Esthetic and masticatory impairments caused by flare-out were improved by MTM and rehabilitation with the porcelain fused metal bridge.

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Patient: A 63-year-old male visited our hospital with a complaint of difficulty in chewing due to excessive mobility of an upper right fixed partial denture. He had secretory dysfunction of the salivary glands after radiotherapy of 70Gy for oropharyngeal cancer. Caries and periodontitis were observed in every tooth. Prosthodontic treatment was performed taking into account the prevention of osteoradionecrosis and plaque control.
Discussion: Considering the availability of tooth extraction, teeth as highly infectious sources of diseases such as severe periodontitis were removed. It was thought that osteoradionecrosis was prevented as a result.
Conclusion: Prevention of osteoradionecrosis and plaque control resulted in good treatment outcome in the case of this patient with late complication after radiotherapy.

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Patient: A 35-year-old female complained of pain in her right temporomandibular joint (TMJ) during functional movements and masticatory dysfunction due to injury. Her unilateral open bite on the right side appeared to be caused by a maxillary fracture. Therefore, her mandibular position and occlusal contacts were unstable.
To obtain stability of the mandibular position and relieve her of TMJ pain, a splint was applied. After confirming the effect of the splint, a maxillary alveolar osteotomy was carried out. Finally, to achieve appropriate occlusal contacts, prosthodontic treatment was applied.
Discussion: At follow-up, a slight mandible deviation and an elongation of her right lateral incisor appeared due to aging. This case suggested the importance of considering the vital reaction for surgical and mechanical stresses for treatment outcome.
Conclusion: In this patient with unilateral open bite, a favorable outcome was achieved by orthognathic surgery and prosthodontic treatment.

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Patient: A 54-year-old male patient complained of masticatory disturbance caused by severe tooth wear. To address the decreased occlusal vertical dimension (OVD) and aesthetic disturbance, provisional restorations which provided an appropriate occlusal relationship aesthetically and functionally were applied. The provisional restorations were regularly adjusted based on the findings of Gothic arch tracing for 14 months. After verifying the improvement in aesthetic and masticatory function, the final prostheses were applied to the patient. The prognosis has been excellent during the 4-year follow-up.
Discussion: In this patient with oral rehabilitation including the correction of OVD, the adjustment of provisional restorations using Gothic arch significantly contributed to the determination of mandibular position. As a result, his occlusal relation after the occlusal reconstruction could be maintained stably.
Conclusion: In this patient with infraocclusion, a stable outcome was achieved by adjusting the provisional restorations based on the long-term assessment of mandibular movements.

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Patient: A 57-year-old male complained of masticatory disturbance due to mobility of an upper right fixed partial denture. Decreased occlusal vertical dimension and incorrect occlusal plane due to factors such as untreated teeth loss, supra eruption, and attrition were found at the initial intraoral examination. To solve those problems, occlusal reconstruction was performed with prosthetic treatment.
Discussion: A suitable mandibular position was investigated using diagnostic wax-up. After confirming the patient’s adaptation to the new mandibular position using provisional restorations, the final prosthesis was delivered, resulting in a favorable prognosis.
Conclusions: When occlusal reconstruction is required, the treatment plan should be established based on a thorough examination, and the final prosthesis should be delivered after performing reversible treatment to confirm the absence of functional and aesthetic issues.

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Patient: The case was a 62-year-old female patient with a complaint of pain in her left temporomandibular joint, and masseter, temporal and digastric muscles. As the initial treatment, an occlusal splint combined with a removable partial denture (RPD) for the maxilla was used to stabilize the mandibular position. Then, after her symptoms of temporomandibular disorder (TMD) had disappeared, prosthodontic treatments with an RPD and cast crowns were performed.
Discussion: The patient was followed for more than six years after the treatment. The patient was satisfied with the masticatory function and had no symptoms of TMD.
Conclusion: Restoring occlusion and improving TMD symptoms by inserting an occlusal splint combined with an RPD are effective treatment options for partially edentulous patients with TMD.

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Patient: The patient was a 73-year-old woman with a chief complaint of discomfort when wearing dentures. There was no indication that residual teeth or the prosthesis were causing the symptom; the symptom was thought to be caused by excessive occlusal vertical dimension. Thus, a treatment denture was used to adjust the occlusal vertical dimension, and it resolved the discomfort.
Discussion: The occlusal vertical dimension without any discomfort was 3 mm smaller than that with the symptom at the initial visit. A facial measurement method alone may have been used by a former practitioner to determine the occlusal vertical dimension when producing a new prosthesis.
Conclusion: In this patient with non-vertical stop occlusion and inadequate occlusal vertical dimension, the treatment denture effectively resolved the symptom.

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Patient: A 71-year-old woman presented with a chief complaint of difficulty in chewing caused by unstable lower complete dentures. The edentulous patient with insufficient mandibular complete denture retention was treated using the flange technique.
Discussion: The position and shape of the polished surface of dentures were adjusted with the flange technique.As a result, the artificial teeth were arranged to the buccal position. Combined with lingualized occlusion, denture stabilization could be achieved, which may lead to high patient satisfaction and good long-term results.
Conclusion: New dentures fabricated using the flange technique achieved high patient satisfaction.

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Patient: The patient was a 15-year-old male who complained of unattractive appearance of his mouth, related to excessive wear of the mandibular deciduous teeth. He lacked 23 permanent teeth congenitally, and was diagnosed as having aesthetic impairment and infraocclusion due to non-syndromic oligodontia. Occlusal splint therapy was started immediately to rehabilitate the vertical dimension of occlusion. After several deciduous teeth were lost, removal overdentures which covered the residual deciduous teeth were fabricated to repair the missing permanent teeth.
Discussion: The purposes of prosthodontic treatment for patients with oligodontia include occlusal management through the growing years as well as the resolution of aesthetic and/or masticatory problems. In this case, occlusal splint therapy which preceded the loss of deciduous teeth and prosthodontic replacement of missing teeth were effective in maintaining adequate occlusion during growth spurts.
Conclusion: Prosthodontic management of occlusion during the growth period is effective for patients with oligodontia.

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