Morphological comparison of artificial teeth position utilising denture space in glossectomy patients.

OBJECTIVE: This study aimed to compare the denture space of edentulous glossectomy patients with that of a control group from the perspective of artificial teeth positioning by using three-dimensional techniques. BACKGROUND: It is known that the shape of the denture space may be affected by tongue resection or reconstruction. However, the details of artificial teeth positioning in these patients remain unclear. MATERIALS AND METHODS: Six edentulous glossectomy patients aged 73-83 years and six normal participants aged 74-85 years participated in the study. Piezography was used to elucidate the characteristics of the denture space. For visualisation, piezographic records were scanned using cone beam computed tomography and the data were converted into stereolithographic format. Three-dimensional images of piezographic records were then constructed. Bucco-lingual widths of the mandibular occlusal surface were reproduced, and the camber line of the occlusal surface was set so as to simulate the position of the artificial teeth. The maximum chord of the occlusal surface on the left and right sides was recorded and measured. The discrepancy and ratio of the larger chord to the smaller chord between the right and left sides was calculated and subjected to statistical analyses using the Mann-Whitney U test. RESULTS: There were significant differences in discrepancy and ratio between the left and right in the control group and the glossectomy patients (P Ë‚ .01). The glossectomy patients showed a greater discrepancy and ratio than the control group. CONCLUSIONS: The simulated artificial teeth positions on the occlusal surface between the right and left side were asymmetric in glossectomy patients.

Color change of airborne particle-abraded acrylic resin surfaces: A palatography method.

STATEMENT OF PROBLEM: A palatogram aids prosthodontists and speech pathologists in evaluating the precise prosthetic treatment needed and the effectiveness of such treatment to improve speech intelligibility. Powder is commonly used to visualize tongue-palate contact, where wetted areas of powder in the oral cavity reveal such contact during palatography. However, discomfort and the risk of aspiration are among the shortcomings of this method, and an improved method is needed. PURPOSE: The purpose of this in vitro study was to examine the feasibility of a new method of palatography that uses airborne-particle-abraded acrylic resin so that wet areas can be easily distinguished from dry areas. MATERIAL AND METHODS: Seventy-two specimens of heat-polymerized acrylic resin were prepared in 6 different resin colors. After the specimens had been airborne-particle abraded, CIELab color values for each specimen were measured using a colorimeter under dry and wet conditions and recorded. Color difference (ΔE) was then computed, and a paired Student t test, 1-way analysis of variance, and multiple comparison using the Tukey post hoc analysis were applied (α=.05). RESULTS: A significant color difference was found between the 2 conditions in all acrylic resin specimens examined. Mean ΔE ranged from 5.58 to 6.76. CONCLUSIONS: The results indicated that an airborne-particle-abraded acrylic resin surface can show color differences made by wetting on palatograms.

Digitized Speech Characteristics in Patients with Maxillectomy Defects.

PURPOSE: Accurate evaluation of speech characteristics through formant frequency measurement is important for proper speech rehabilitation in patients after maxillectomy. This study aimed to evaluate the utility of digital acoustic analysis and vowel pentagon space for the prediction of speech ability after maxillectomy, by comparing the acoustic characteristics of vowel articulation in three classes of maxillectomy defects. MATERIALS AND METHODS: Aramany's classifications I, II, and IV were used to group 27 male patients after maxillectomy. Digital acoustic analysis of five Japanese vowels-/a/, /e/, /i/, /o/, and /u/-was performed using a speech analysis system. First formant (F1) and second formant (F2) frequencies were calculated using an autocorrelation method. Data were plotted on an F1-F2 plane for each patient, and the F1 and F2 ranges were calculated. The vowel pentagon spaces were also determined. One-way ANOVA was applied to compare all results between the three groups. RESULTS: Class II maxillectomy patients had a significantly higher F2 range than did Class I and Class IV patients (p = 0.002). In contrast, there was no significant difference in the F1 range between the three classes. The vowel pentagon spaces were significantly larger in class II maxillectomy patients than in Class I and Class IV patients (p = 0.014). CONCLUSION: The results of this study indicate that the acoustic characteristics of maxillectomy patients are affected by the defect area. This finding may provide information for obturator design based on vowel articulation and defect class.

A chairside technique to add customized anterior acrylic resin teeth to a surgical obturator.

A surgical obturator may need to be modified during the healing process after tissue resection. Apart from relining the fitting surfaces to accommodate the healing wound and changes in the surrounding tissues, other modifications such as adding teeth are sometimes required to improve esthetics and speech. This article describes a chairside technique to add customized acrylic resin teeth to an existing surgical obturator.

Effect of Experimental Palatal Prosthesis on Voice Onset Time.

PURPOSE: Objective evaluation of a patient's speech is needed in prosthetic dentistry because the prostheses can affect the intelligibility of speech. Measurement of voice onset time is one evaluation method of consonant production used in phonetic science. The purpose of this study was to confirm the influence of a palatal prosthesis on consonant production by measuring voice onset time. MATERIALS AND METHODS: In this study, voice onset time was measured in 10 healthy women (mean age 26.5 years) under two conditions: with and without an experimental palatal prosthesis. In this study, voice onset time of /ta/ and /ka/ were used to determine the effect of wearing a palatal prosthesis; /pa/ was tested as a control, with the null hypothesis that voice onset time of /ta/ and /ka/ would not change when wearing a palatal prosthesis. RESULTS: Medial voice onset time of /pa/, /ta/, and /ka/ syllables without the palatal prosthesis was 22.5 ms, 19.5 ms, and 42.5 ms, whereas that with the palatal prosthesis was 22.5 ms, 23.5 ms, and 55.0 ms. Voice onset times for /ta/ and /ka/ were prolonged when wearing the experimental palatal prosthesis, whereas /pa/ showed no significant difference. CONCLUSION: Consonant production was affected by wearing a palatal prosthesis, and this change in sound was detected by measuring voice onset time.

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 patient's 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 patient's oral function during the use of the obturators was evaluated objectively. Marked improvements in oral function were seen during both treatment phases. The patient's ability to perform psychosocial functions at school also improved during the use of the obturators.

Sleep quality in long-term survivors of head and neck cancer: preliminary findings.

PURPOSE: This preliminary study evaluated sleep quality in long-term head and neck cancer survivors, using demographic data and clinical features of the cancers as assessment criteria. In addition, a possible correlation was examined between scores on self-rated questionnaires of sleep quality and assessments of quality of life and oral health status. METHODS: Subjects were 77 head and neck cancer survivors. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale. Oral and general health status was assessed using The Oral Health Impact Profile (OHIP-14) and the Short-Form Health Survey (SF-36), respectively, and correlated with clinical parameters. Spearman's correlation coefficients were calculated to examine relationships between variables. Logistic regression analysis was performed to identify independent variables associated with poor sleep quality. RESULTS: Eighty-three percent of patients had poor sleep quality (global scores ≥5) and 40% had a global Pittsburgh Sleep Quality Index score ≥8, indicating significantly poor sleep quality. Nocturnal enuresis, daytime sleepiness, and early morning awakening were the most common complaints. Extensive neck dissection, a lower SF-36 mental component score, and a higher OHIP-14 psychological disability score were independently associated with poor sleep quality. OHIP-14 global score was linked independently with daytime sleepiness. CONCLUSION: This is the first study to demonstrate a high prevalence of poor sleep quality in long-term head and neck cancer survivors. Extensive neck dissection, poor mental health, and psychological disability may contribute to poor sleep quality. Maintaining good oral health-related quality of life could promote better sleep in these patients.

Orientation of handle for successful prosthetic treatment in patients with an anatomic compromise after a maxillectomy.

This clinical technique provides a key procedure for successful prosthetic treatment in patients with an anatomical compromise after a maxillectomy. When making a preliminary impression, the clinician must keep the handle of the stock tray parallel to the patient's interpupillary line extraorally to maintain the correct position of the tray and to make a record of the inclination of the occlusal plane. This simple consideration during this first step of making a preliminary impression can be an important guide for both dentists and dental technicians. Information about the correct positioning of the tray and the inclination of the occlusal plane obtained by using a stock tray handle will greatly reduce the stress experienced by dentists, dental technicians, and patients during the fabrication of the prosthesis and will ultimately lead to successful prosthetic treatment in patients with anatomic compromise resulting from a maxillectomy.

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 patient's 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 (α=.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.

Investigation of nutritional status using the Mini Nutritional Assessment-Short Form and analysis of the relevant factors in patients with head and neck tumour.

OBJECTIVE: The aims of this study were to reveal the nutritional status of patients after head and neck tumour treatment by using the Mini Nutritional Assessment-Short Form (MNA-SF) and to analyse the factors affecting nutritional status in patients with head and neck tumour. BACKGROUND: Elderly patients with loss of teeth and maxillary/mandibular bone due to head and neck tumour treatment could be at high risk of malnutrition. However, there are few reports on the nutritional status of these patients. MATERIALS AND METHODS: Forty-six participants (average age 74.7 years) were selected from patients who visited the maxillofacial prosthetics clinic of Tokyo Medical and Dental University Hospital Faculty of Dentistry in Japan. Nutritional status was evaluated using the MNA-SF. Multiple regression analysis was used to identify predictors affecting MNA-SF score. The candidate explanatory variables were age, sex, maxillofacial prosthesis use, number of residual teeth, resection side, neck dissection and treatment option. RESULTS: The results showed that approximately half of the patients were at risk of malnutrition, and a regression equation for MNA-SF score was developed using two predictors: maxillofacial prosthesis use and neck dissection. CONCLUSION: Use of a maxillofacial prosthesis can improve nutritional status. On the other hand, a medical history of neck dissection can decrease nutritional status.

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 patient's oral functions were improved when the prosthesis was stabilized by means of dental implants and custom abutments.

Sound analysis of a musical performance to evaluate prosthodontic treatment for a clarinet player.

Some dental patients use the orofacial region to play wind instruments; however, musical performance has not been objectively evaluated following prosthodontic treatment in such patients. The purpose of this report was to describe prosthodontic treatment for a clarinet player using sound analysis. The patient required a removable partial denture for his maxillary anterior teeth. Sound analysis was performed before and after denture adjustment, and the patient completed a questionnaire regarding his perceptions while playing his clarinet. After adjustment, the denture showed better performance, and patient satisfaction increased compared with that before adjustment.

Measurement of voice onset time in maxillectomy patients.

Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients for objective speech evaluation. We examined voice onset time for /ka/ and /ta/ in 13 maxillectomy patients by calculating the number of valid measurements of voice onset time out of three trials for each syllable. Wilcoxon's signed rank test showed that voice onset time measurements were more successful for /ka/ and /ta/ when a prosthesis was used (Z = -2.232, P = 0.026 and Z = -2.401, P = 0.016, resp.) than when a prosthesis was not used. These results indicate a prosthesis affected voice onset measurement in these patients. Although more research in this area is needed, measurement of voice onset time has the potential to be used to evaluate consonant production in maxillectomy patients wearing a prosthesis.

Influence of changes in the oral cavity on the performance of recorder players: a pilot study.

STATEMENT OF PROBLEM: Wind instrument players may dread dental treatment because changes in the oral cavity can affect their performance. However, few studies have investigated the influence of such changes, particularly prosthesis-induced morphologic changes, on the performance of wind instrument players. PURPOSE: The purpose of this study was to determine the effects of prosthesis-induced morphologic changes in the oral cavity on the performance of wind instrument players. MATERIAL AND METHODS: Seven women were asked to play a recorder with and without an experimental palatal appliance. Their performances were analyzed by psychoacoustic analysis, with loudness as a parameter, and by performable range analyses with Voice Range Profile software. The Wilcoxon signed rank test was used for the statistical analyses. RESULTS: Differences between moderately loud and very soft sounds (P=.043) and between very loud and very soft sounds (P=.027), as well as the performable range of frequency and intensity (P=.028), all decreased significantly in the presence of the palatal prosthesis. CONCLUSIONS: The results of this study suggest that changes in the oral cavity caused by the presence of a prosthesis affect the psychoacoustic features and the performable range of frequency and intensity during the playing of wind instruments.

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.

[Three kinds of speech evaluation in maxillectomy patients during the fabrication process of a hollow-type obturator].

Speech evaluation is essential to the rehabilitation of maxillectomy patients. A speech intelligibility test has been frequently used for the evaluation because of its simplicity. However, the test needs human listeners and this has been a shortcoming of the test. Thus, objective evaluation methods have been discussed. One of them is formant analysis for vowel evaluation and another is psychoacoustic analysis for consonants. In this research, to evaluate the speech in five maxillectomy patients, the F2-range was examined as formant analysis and the sharpness of /sa/ was examined as psychoacoustic analysis, in addition to the speech intelligibility test, during the fabrication process of a hollow-type obturator. The objective evaluation of patients' speech was effectively performed using those three methods. The F2-range was larger, the sharpness of /sa/ was higher and the speech intelligibility was higher when patients wore an obturator compared to when patients did not wear an obturator. The difference in speech when changing the types of obturator was not clear. The method and the findings are important for future research in this field, since speech is one of the important factors in maxillofacial rehabilitation.

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.

Nutritional assessment in a maxillectomy patient from the preoperative period to definitive obturator insertion: A case report.

PATIENT: A 69-year-old Japanese male with squamous cell carcinoma of the right maxilla (T4M0N0) was referred to our department for a preoperative examination. An immediate surgical obturator was fabricated before surgery. He underwent surgical treatment, which included right subtotal maxillectomy and reconstruction with a split skin graft. One week postoperatively, the immediate surgical obturator was modified to expand the nasal cavity for obturator prosthesis. Oral intake was started 12 days postoperatively with an immediate surgical obturator in situ. The definitive obturator was fabricated after the wound surface had healed 8 months postoperatively. Assessment of the nutritional status included body mass index, serum albumin level, resting energy expenditure (REE) measured using indirect calorimetry, and predicted REE using the Harris-Benedict equation. These assessments were performed several times, from the time of admission until the definitive obturator was applied. DISCUSSION: Malnutrition occurs frequently in patients with head and neck cancer because this region is vital for swallowing and mastication. Maxillectomy patients require a maxillofacial prosthesis to improve their nutritional status from the preoperative period to recovery. This case report describes maxillofacial prosthetic treatment from the perspective of nutrition. The patient wore the immediate surgical obturator postoperatively, which was followed by marked weight loss after restoration, and then weight gain returned to the normal range when wearing the definitive obturator. CONCLUSION: Maxillofacial prosthetic treatments should make efforts to maintain nutritional status and achieve optimal function and quality of life in patients with head and neck cancers.

The effect of water on infrared spectra of DNA.

The effect of water on infrared (IR) spectra of DNA is studied by using first-principles calculations based on the hybrid density functional theory. Our calculations of frequencies of C = O stretching modes in DNA without water do not reproduce the IR spectra, whereas calculations for DNA surrounded by water reproduce the IR spectra well. We also find that the energy of adsorption of one water molecule around a C = O site is large ([Formula: see text] eV) owing to hydrogen bond formation. We therefore conclude that the effect of water plays an important role as regards IR spectra of DNA in a water solution.

Electron therapy for orbital and periorbital lesions using customized lead eye shields.

PURPOSE: To establish the protective efficacy against late complications of electron therapy using customized lead eye shields in cases with orbital and periorbital lesions. METHODS: Between 1982 and 2006, 16 patients with 22 orbital and periorbital lesions were treated by electron therapy. Customized lead eye shields were prepared and placed in the respective patients' eyes during each fraction of electron therapy. The toxicity and local control rates were analyzed. RESULTS: The preparation period for the customized lead eye shields was 2 days. The shields could be used throughout the treatment period in all the patients. No evidence of radiation cataract was observed in 15 of the 16 patients. None of the patients developed corneal ulceration or evidence of lead poisoning. CONCLUSION: Customized lead eye shields could be made relatively quickly, and electron therapy for orbital and periorbital lesions could be undertaken safely without any late complication.