Maxillofacial prosthodontics is the art and science of anatomic, functional, or cosmetic reconstruction by means of non-living substitutes of those regions in the maxilla and mandible that are missing or defective because of surgical intervention, trauma, pathology, or developmental or congenital malformation.Patients suffer from functional impairments affecting such areas as speech, mastication and swallowing.Among them, speech is a great concern for the patients. In this manuscript, maxillofacial prosthodontics is described from the point of view of speech evaluation.

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[in Japanese]

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For the subject: “regarding the significance and philosophy of occlusal contacts in clinical prosthodontics and related examination methods”, references were searched from MEDLINE, EMBASE, and Igaku Chuo Zasshi (ICHUSHI) as secondary databases. Setting “Occlusion & Intercuspal position” or “Kougou sessyoku & Koutou kangoui in Japanese” as words for retrieval, I obtained references published between January 1, 1990 and December 31, 2013.
Focusing on original articles on permanent adult dentition, the following were excluded: 1. Papers written in languages other than English or Japanese, 2. Articles on simulation using casts or mathematical models, 3. Studies in which occlusal interference was experimentally simulated, 4. Books, Case reports and Reviews. Furthermore, a manual hand-search was performed to select original articles whose abstracts and methods were clinical.Based on occlusion being contact between viscoelastic structures, normal intercuspation was reviewed, referring to the reliability of the detecting methods of occlusal contacts.

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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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[in Japanese]

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Purpose: Considerations of healthcare economics make it important to clarify the time required for each type of dental treatment. In this study, we conducted a survey of dentists’ estimates of the time that would be required to treat certain patients after reading the clinical information about their particular cases. The purpose of this paper was to elucidate the relationship between estimated times and affected in case of difficulty, based on the results of this survey.
Methods: Three patients with edentulous jaws requiring treatment of varying degrees of difficulty were treated by a specialist with 14 years of clinical experience, and the time required to perform each treatment was recorded. The information on the three patients was presented to 196 dentists of seven dental schools in Japan. We asked them to estimate the time each treatment step would take and the frequency of performance of these steps. At a later date, they were again asked to give their estimates of the treatment time, the consciousness (mean time) and standard deviation of each treatment step were shown, and a similar investigation was conducted (Delphi technique). All dentists with at least five years of clinical experience (95 dentists) were analyzed using one-way ANOVA.
Results: A significant difference by degree of difficulty was found in the estimated total treatment time. For those treatment steps upon which the skill of the practitioner has a considerable impact, Final impression and Maxillomandibular registration obtained, and dentists’ consciousness (treatment times) became longer as the degree of difficulty of the treatment steps became greater. However, clinical experience and consciousness (treatment times) were not significantly affected in cases of difficulty.
Conclusions: It was suggested that the degree of treatment difficulty in complete denture construction affects the estimates of treatment time (consciousness).

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Purpose: The shift of condylar position was three-dimensionally measured to clarify the effect of repeated opening and closing movements without any teeth contact on the condylar position when the mouth was closed, and the relationship between that movement and the condylar position was evaluated.
Methods: Thirty-two dentulous subjects were enrolled. Prior to the measurement, they were examined for muscle tenderness. Then, bilateral deviations of condylar points were measured after repeated opening and closing movements by the “Win Jaw System^®”. Mouth-opening range was classified into three levels: “maximal voluntary opening”, “intermediate opening”, and “slight opening”. The number of times of opening and closing movements was classified into 12 levels: 0, 1, 2, 4, 6, 10, 12, 14, 16, 18 and 20 times.
At each time, three-dimensional shifts of condylar point were measured and were evaluated according to each condition such as presence of muscle tenderness or not, mouth-opening range, and number of times of mouth opening and closing movements.
Results: The positional deviation of condylar point was significantly different in the number of times of mouth opening and closing at “maximal voluntary opening”. A significant difference was found on the vertical shift in the group without muscle tenderness, and in the group with muscle tenderness that was found on anteroposterior and vertical shift. The degree of these shifts grew larger in accordance with the number of times of opening and closing movements.
Conclusions: The shift of condylar position was caused by the repeated maximal opening and closing movements without any tooth contact, and its degree increased according to the number of that particular movement. These results will be useful for occlusal treatment.

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Patient: The patient was a 43-year-old female whose chief complaint was masticatory disturbance at meals. The patient had a rotated tooth of |3 and a medial inclination of 6|, making it difficult to correctly set the retainer of the partial denture. After limited orthodontic correction of the rotated tooth, new full dentures on the maxilla and partial dentures with an occlusal rest of the onlay type on the mandible were set, which resulted in recovery of appropriate occlusion and improvement of masticatory efficiency.
Discussion: It was suggested that the orthodontic treatment of irregular abutment teeth and partial denture with an occlusal rest of the onlay type induced stability of the denture, and masticatory efficiency was improved.
Conclusion: The final denture with adequate occlusal plane after orthodontic treatment helped to enhance the aesthetic outcome and improved the oral function.

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Patient: A 78-year-old edentulous female complained of masticatory dysfunction. She had undergone segmental mandibulectomy 55 years earlier, and her mandibular denture had poor stability. The position of an artificial tooth was arranged in an appropriate manner and the shape of the polished surface was determined using the flange technique.
Discussion: It was considered that the new denture obtained stability of functional movement by improving the position of the artificial tooth arrangement and the shape of the polished surface using the flange technique.
Conclusion: In this case, the poor stability of the mandibular denture of the patient with mandibulectomy was improved by appropriate prosthodontic examination, diagnosis and treatment.

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Patient: A 74-year-old male complained of difficulty in mastication after hemimandibulectomy. Occlusal support of the remaining teeth in the healthy side of the mandible was extremely compromised because of severe periodontal disease, and the mastication score according to Sato et al. (1989) was 5 (100 as full score). Four implants were placed in the healthy side of the mandible, and were firmly splinted by bar attachments. An implant-supported overdenture was then delivered.
Discussion: Mastication score was improved to 60 after delivery of the implant overdenture. It was considered that masticatory function was recovered by establishing occlusal support in the healthy side of the mandible with implants.
Conclusion: Masticatory function was recovered by means of implant overdenture in this case with masticatory dysfunction after hemimandibulectomy.

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