Takafumi Otomaru

Comparison of food mixing ability among mandibulectomy patients

Many papers have been published on surgical mandibulectomy and reconstruction. However, only a few reports refer to masticatory function after prosthodontic treatment in mandibulectomy patients. The aim of this study was to investigate the masticatory function of mandibulectomy patients. Twenty-three subjects (10 males and 13 females, with an average age of 63 years) participated in this study: 11 subjects who had undergone unilateral marginal mandibulectomy, six subjects with unilateral segmental mandibulectomy with reconstruction and six subjects with hemimandibulectomy without reconstruction. Mixing Ability Index (MAI) was used to measure masticatory function on the non-defect side and on the defect side with a prosthesis installed. Comparisons were carried out among the marginal, segmental and hemimandibular groups and between the non-defect side and the defect side. Consequently, our study indicates these results. On the non-defect side, a significant difference was found between the marginal and the segmental groups, and between the marginal and the hemimandibular groups. In the marginal and the segmental groups, a significant difference was found between the non-defect and the defect sides. In conclusion, our study suggests that MAI is an adequate tool to study the masticatory function in mandibulectomy patients, the masticatory function of the mandibulectomy patients is more impaired than that of the ordinary removable partial denture patients, and that surgical intervention affects the masticatory function on not only the defect side but also the non-defect side in mandibulectomy patients.

Investigation of factor affecting health-related quality of life in head and neck cancer patients

OBJECTIVES Head and neck cancer (HNC) patients have profound illness of physical, social and psychological factors that affects quality of life (QOL). The purpose of this study is to investigate the factors affecting HRQL in patients with intra-oral prostheses. BACKGROUND Some cross-sectional studies have been performed to investigate HRQL in patients with HNC, but these studies did not report in detail how factors affect the HRQL of maxillectomy and mandibulectomy and/or glossectomy patients. MATERIALS AND METHODS The University of Washington Quality of Life version 4 questionnaires (Japanese version) was administered to 50 maxillectomy and 50 mandibulectomy and/or glossectomy patients with intra-oral prostheses who were selected according to inclusion and exclusion criteria. Gathered data were statistically analyzed to investigate how a number of factors, namely, age, sex, pathologic diagnosis, neck dissection, resection size, radiotherapy and dental condition affect HRQL. RESULTS In the maxillectomy patients, there were no significant differences between malignant and benign tumor in pathological diagnosis or between dentate and edentulous in dental condition. Age, sex, neck dissection and radiotherapy affected HRQL. In the mandibulectomy and/or glossectomy patients, there was no significant difference between dentate and edentulous in dental condition. Age, sex, glossectomy, neck dissection and radiotherapy affected HRQL. CONCLUSIONS The factors affecting HRQL in the maxillectomy patients were different from those in the mandibulectomy and/or glossectomy patients. Though they wore stable prostheses; we were still able to show that resection size, radiotherapy and neck dissection affected HRQL.

Investigation of predictors affecting food mixing ability in mandibulectomy and/or glossectomy patients

PURPOSE Several previous reports have described factors that affect masticatory function. However, there are no known predictors that affect the food mixing ability of the masticatory function, and it has been impossible to predict masticatory function in mandibulectomy and/or glossectomy patients. The purpose of the present study was to develop a numerical formula that could predict the food mixing ability of the masticatory function among mandibulectomy and/or glossectomy patients. The null hypothesis of the study was that five predictors, namely mandibulectomy, mandibular continuity, number of residual mandibular teeth, occlusal units and tongue movement score, were unable to account for the mixing ability index (MAI) in mandibulectomy and/or glossectomy patients. METHODS The subjects were 20 patients who had undergone mandibulectomy and/or glossectomy. The above-described five predictors were assessed. Tongue movement was evaluated with a tongue movement test and the MAI was evaluated with a mixing ability test. Multiple regression analysis was used to examine whether the five predictors affected the MAI after prosthetic treatment. RESULTS A regression equation was determined for the five predictors (R(2)=0.83; adjusted R(2)=0.77; p<0.001). CONCLUSION The obtained regression equation could successfully account for the MAI in mandibulectomy and/or glossectomy patients.

A new simple evaluation method of the monosyllable /sa/ using a psychoacoustic system in maxillectomy patients

PURPOSE An objective assessment of speech would benefit the prosthetic rehabilitation of maxillectomy patients. This study aimed to establish a simple, objective evaluation of monosyllable /sa/ utterances in maxillectomy patients by using a psychoacoustic system typically used in industry. MATERIALS AND METHODS This study comprised two experiments. Experiment 1 involved analysis of the psychoacoustic parameters (loudness, sharpness and roughness) in monosyllable /sa/ utterances by 18 healthy subjects (9 males, 9 females). The utterances were recorded in a sound-treated room. The coefficient of variation (CV) for each parameter was compared to identify the most suitable parameter for objective evaluation of speech. Experiment 2 involved analysis of /sa/ utterances by 18 maxillectomy patients (9 males, 9 females) with and without prosthesis, and comparisons of the psychoacoustic data between the healthy subjects and maxillectomy patients without prosthesis, between the maxillectomy patients with and without prosthesis, and between the healthy subjects and maxillectomy patients with prosthesis. RESULTS The CV for sharpness was the lowest among the three psychoacoustic parameters in both the healthy males and females. There were significant differences in the sharpness of /sa/ between the healthy subjects and the maxillectomy patients without prosthesis (but not with prosthesis), and between the maxillectomy patients with and without prosthesis. CONCLUSION We found that the psychoacoustic parameters typically adopted in industrial research could also be applied to evaluate the psychoacoustics of the monosyllable /sa/ utterance, and distinguished the monosyllable /sa/ in maxillectomy patients with an obturator from that without an obturator using the system.

Relationships between perceived chewing ability, objective masticatory function and oral health-related quality of life in mandibulectomy or glossectomy patients with a dento-maxillary prosthesis

PURPOSE This preliminary study examined whether the type of surgery performed for head and neck lesion was associated perceived chewing ability, objective masticatory function, and oral health-related quality of life (OHRQoL) in patients who required a dento-maxillary prosthesis postoperatively. METHODS Thirty-eight patients with a dento-maxillary prosthesis were divided into three groups according to the type of surgery received: marginal mandibulectomy, segmental mandibulectomy with bony reconstruction, or glossectomy. Perceived chewing ability, objective mixing ability, and OHRQoL were evaluated using a food intake questionnaire, color-changeable chewing gum, and the Geriatric Oral Health Assessment Index (GOHAI), respectively. Differences in the scores obtained by the three measures were compared between the surgical groups using the Kruskal-Wallis test, and associations between the scores in each group were analyzed by Spearmans rank correlation analysis. RESULTS Objective mixing ability was found to be significantly low only in patients who underwent glossectomy. No other measures differed significantly between the surgical groups. Perceived chewing ability and objective mixing ability were significantly associated in the marginal mandibulectomy and glossectomy groups but not in the segmental mandibulectomy group. Furthermore, GOHAI score was significantly associated with perceived chewing ability and objective mixing ability in the marginal mandibulectomy group. CONCLUSIONS Within the limitations of this study, the present findings suggest that the type of surgery received might influence food mixing ability. Associations among food mixing ability, perceived chewing and OHRQoL are not accountable depending on the type of surgery received, indicating the presence of other contributing factors to be considered.

Effects of a denture adhesive in edentulous patients after maxillectomy

OBJECTIVE The objective of this study is to evaluate the usefulness of a denture adhesive in edentulous patients after maxillectomy. BACKGROUND Maxillectomy patients suffer from functional impairments. Denture adhesives (DAs) are the solution in such patients. However, little is known about DAs in maxillectomy patients. MATERIALS AND METHODS Eight edentulous patients who had undergone maxillectomy were included and divided into three groups. Group 1 (half ≤ remaining residual maxilla), Group 2 (quarter < remaining residual maxilla < half) and Group 3 (remaining residual maxilla ≤ quarter). They were evaluated by a speech intelligibility test and a mixing ability test, respectively. A cream-type DA called New Poligrip(®) (GlaxoSmithKline, Tokyo, Japan) was used. RESULTS Applying the DA, speech intelligibility showed a higher score than the data without DA. CONCLUSION The effects of using a DA depend on the amount of the remaining residual maxilla. Our study showed that if the remaining residual maxilla is less than a quarter (Group 3), it is difficult to have confidence in the effectiveness of the DA to improve masticatory function. On the other hand, the use a DA showed improved speech intelligibility test values in all groups.

Masticatory function and oral health-related quality of life in patients after partial maxillectomies with closed or open defects

Statement of problem. The healing pattern after surgical resection of tumors of the oral cavity involving the maxilla may vary from one patient to another. The result may be open communication between the oral and nasal cavities (open defect) or complete oronasal separation after healing of the defect area (closed defect). Purpose. The purpose of this clinical study was to compare masticatory function and oral health‐related quality of life (OHRQoL) between patients with closed and open defects who had undergone a partial maxillectomy and were wearing dentomaxillary prostheses. Material and methods. Thirty‐eight participants who had undergone a partial maxillectomy and who were wearing dentomaxillary prostheses were enrolled between September 2014 and April 2016. Participants were assigned to 2 groups according to the type of defect after healing: 19 participants had a closed defect, and 19 participants had an open defect. Masticatory function was evaluated objectively and subjectively. The objective measurement was food‐mixing ability, which was assessed using color‐changeable chewing gum. The subjective measurement was perceived mastication ability, rated as a masticatory score based on the patients responses to a 35‐item food intake questionnaire. OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI). The GOHAI questionnaire consists of 12 items reflecting 3 hypothesized domains of the impact of oral disease: physical function, psychosocial function, and pain or discomfort. Differences in the scores obtained by the 3 measurements were compared between the 2 groups, using the Wilcoxon rank‐sum test (&agr;=.05). Results. No significant differences were seen between the 2 groups in objective mixing ability, subjective masticatory score, or GOHAI (P>.05). Regarding the GOHAI physical function domain, only the swallowing item was significantly lower (P=.025) in participants with an open defect than in participants with a closed defect. Regarding the GOHAI psychological function domain, the item related to patients’ psychological worries or concerns about their teeth, gingival tissue, or dentures was significantly lower (P=.045) in patients with an open defect than in those with a closed defect. Other items related to physical function, psychological function, and pain or discomfort were not significantly different (P>.05) between the 2 groups. Conclusions. The closed or open defect in patients who had undergone a partial maxillectomy may not influence patients’ masticatory function and overall OHRQoL if they have adequate prosthetic rehabilitation. However, special consideration should be given to patients with an open defect with regard to swallowing function and psychological concerns in order to improve their OHRQoL.

Rehabilitation of a Bilateral Maxillectomy Patient with a Free Fibula Osteocutaneous Flap and with an Implant-Retained Obturator: A Clinical Report

A 47-year-old man underwent surgical resection and reconstruction with a fibula osteocutaneous flap. After the surgery, a surgical obturator was placed and adjusted. After flap healing, a conventional obturator was fabricated with polymethyl methacrylate resin and retained by the anatomical undercuts around the reconstructed fibula bone flap and the posterior part of the defect. As the defect shape changed with time, a second conventional obturator was fabricated and fitted. No further recurrence of myoepithelioma was observed for 2 years, and the patient was satisfied with the obturator during mastication and speech; however, despite having no major complaints, the patient found it difficult to chew on the right side, and the obturator was displaced slightly downward when the mouth was opened wide and shifted when chewing hard and sticky food. Thus, an implant-retained obturator was suggested to provide better retention and stability. Four dental implants were therefore placed into the fibula bone, although one did not osseointegrate because either primary stability was insufficient or overload was affected in the nonloaded implant environment and was replaced. After fitting custom abutments with a magnet, an implant-retained obturator was placed, and the patient was satisfied with the outcome. During 3 years of follow-up, no issues were noted with the implant bodies, abutments, obturator, or reconstructed site. The conventional obturator was displaced slightly downward when the patient opened his mouth wide, and it shifted when chewing hard and sticky food because there was limited fibula bone at the reconstruction site and more available posteriorly. For better retention and stability, the implant-retained obturator was fabricated with a custom abutment and magnetic retention. The patient was satisfied with the results, as improved implant retention increased the stability of the prosthesis. This clinical report describes the rehabilitation of a bilateral maxillectomy patient with a free fibula osteocutaneous flap and an implant-retained obturator. The patients oral functions were improved when the prosthesis was stabilized by means of dental implants and custom abutments.

Association Between Masticatory Function and Oral Health-Related Quality of Life in Partial Maxillectomy Patients.

PURPOSE The aim of this study was to investigate associations between objectively and subjectively measured masticatory function and oral health-related quality of life (OHRQoL) in partial maxillectomy patients wearing dentomaxillary prostheses. MATERIALS AND METHODS A sample of 32 consecutively treated patients who had undergone a partial maxillectomy were enrolled. Masticatory function was assessed using two objective measures and one subjective measure. The objective measures were masticatory performance (MP), which was estimated by measuring the glucose extracted from gummy jelly, and food mixing ability (a*), which was assessed using color-changeable chewing gum. The subjective measure was perceived chewing ability, rated as masticatory score (MS) based on the patients responses to a food intake questionnaire. OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI). Relationships between the masticatory function measures and OHRQoL were analyzed using Spearman rank correlation coefficient. RESULTS The correlation coefficients (r) obtained were 0.57 (P = .001) for MS and GOHAI, 0.247 (P = .173) for MP and GOHAI, -0.173 (P = .343) for a* and GOHAI, 0.517 (P = .002) for MP and a*, 0.199 (P = .257) for MP and MS, and 0.019 (P = .919) for a* and MS. CONCLUSION Subjective MS showed a significant positive correlation with GOHAI score, suggesting that perceived chewing ability could be an important factor in the estimation of OHRQoL in partial maxillectomy patients.

Preschool and School Phases of Postmaxillectomy Prosthetic Rehabilitation in a Child: A Clinical Report

This report describes the postmaxillectomy prosthetic rehabilitation of a child with maxillary chondrosarcoma over an 8-year period. Specifically, it (1) describes the planning and rehabilitation procedures carried out during the period from before the operation to the time when the patient started elementary school and (2) reports the results of evaluations of the patients oral and psychosocial function conducted during the school phase. The prosthetic treatment plan was separated into two phases (the preschool and school phases) and was started prior to surgery, when an immediate surgical obturator was designed by the surgeons. After the operation, it was considered important to provide the patient and her mother with training regarding how the defect should be cleaned, trismus prevention, and how the prosthesis should be fitted. In addition, esthetic improvements and the ability to speak clearly were also targeted during treatment planning. After surgery, obturators were fabricated in a conventional manner and fitted at the ages of 2, 4, 6, 8, and 10 years. The patients oral function during the use of the obturators was evaluated objectively. Marked improvements in oral function were seen during both treatment phases. The patients ability to perform psychosocial functions at school also improved during the use of the obturators.