• Journal of Oral Medicine and Pain
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• v.38 no.1
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• pp.53-67
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• 2013

This study was aimed to evaluate the masticatory efficiency after botulinum toxin type A (BTX-A) injection during 12 weeks using objective and subjective test. Also, we compared the difference of masticatory efficiency between group that injected into the masseter muscle only (M-group) and group that injected into the masseter and temporalis muscle (M-T group). The mixing ability index (MAI) was used as the objective indicator, and visual analogue scale (VAS) and food intake ability (FIA) index were used as the subjective indicators. It was concluded that masticatory efficiency was significantly lowered after a BTX-A injection into the masticatory muscle, but it gradually recovered in a predictable pattern by the 12 weeks. The disturbance of subjective masticatory efficiency was lasted longer than objective masticatory efficiency. The masticatory efficiency was lower in M-T group than M group. It was statistically significant in the VAS and FIA at 4 weeks, but the MAI showed no significancy. After 4weeks, there was rapid recovery of muscle function in M-T group, and the difference between two groups was not significant. It could be concluded that there will be no serious disturbance of mastication compared to injection is done only into the masseter muscle, even if injection is done into the masseter and temporalis muscle in dose of this study. According to the food properties, it was confirmed that people feel more discomfort on taking hard and tough foods after BTX-A injection and not only hard foods, but also intake of soft and runny foods were influenced by botulinum toxin injection.

• Physical Therapy Korea
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• v.29 no.4
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• pp.255-261
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• 2022

Background: For the elderly, masticatory function is one of the most important oral functions and the masticatory ability is related to the wearing of dentures. Many older people wear dentures for their masticatory function, but a significant number of older people who use dentures have found that they feel uncomfortable when performing their daily activities, such as performing masticating functions or talking. Objects: The purpose of this study is to investigate how the forward head posture (FHP), respiratory function and thickness of masseter (MS), and sternocleidomastoid (SCM) are affected by the presence or absence of dentures in the elderly, and what kind of correlation there is between these variables. Methods: The study was conducted on 11 patients in the normal group and 13 in the denture group. The participant's cognitive ability was evaluated using Mini-Mental State Examination Korean (MMSE-K), and the FHP was evaluated by measuring the craniovertebral angle (CVA). The thickness of the MS and SCM muscles were measured using ultrasound, and respiration was measured with a spirometry. As for the statistical method, the correlation of each variable was investigated using Spearman's correlation coefficient. Results: In the normal group, there was a significant correlation between forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) (p < 0.001), and in the denture group, FVC and FEV1 (p < 0.001), maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) (p < 0.001), CVA and Lt. MS (p = 0.012). Conclusion: CVA and Lt. MS of the denture group have a high negative correlation, it is related that the thickness of MS may be thick when the elderly wearing dentures are FHP.

• The korean journal of orthodontics
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• v.47 no.3
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• pp.151-157
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• 2017

Objective: The objective of this study was to investigate the differences in masticatory efficiency among patients with different Angle's classes of malocclusion and to assess the correlation between masticatory efficiency and the occlusal contact area. Methods: The mixing ability index (MAI) was calculated for measuring masticatory efficiency of 61 adult patients according to Angle's classifications of malocclusion. The study included 25, 15, and 21 patients with Angle's Class I, II, and III malocclusions, respectively. Silicone interocclusal recording material was used to measure the occlusal contact area. Results: Both the MAI and occlusal contact area showed the highest average values in the Class I malocclusion group, followed by the Class II and Class III malocclusion groups. No significant difference was observed in the MAI values between the Class I and Class II malocclusion groups (p > 0.05), whereas a significant difference was observed between the Class I and Class III malocclusion groups (p < 0.01) and between the Class II and Class III malocclusion groups (p < 0.05). A weak positive correlation was also observed between the MAI and occlusal contact area (p < 0.01, $r^2=0.13$). Conclusions: The results of this study indicated that masticatory efficiency was the highest in patients with Angle's Class I malocclusion, followed by those with Angle's Class II and Angle's Class III malocclusions. Moreover, a weak positive correlation was observed between masticatory efficiency and the occlusal contact area.

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.87-103
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• 2007

The purpose of this study is to widen the subject of research to the whole social activity, which is divided into the following four categories in the previous study on "Reality of social activity of senior citizen": 1. work 2. social participation and volunteer activity 3. learning activity 4. individual activity, and to clarify which category is most related to the masticatory ability. There were 57korean subjects in the survey: aged 65 through 85 (73.8$\pm$5.5), 81 women: aged 65 through 85 (74.3$\pm$5.3), a total of 138: aged 65 through 85 (74.1$\pm$5.4), in College for senior citizen of A city, Buddhist College for senior citizen of A city and senior citizen's welfare facility of A city who gave consent to the research The Japanese subject were 38 men: aged 65 through 85(75.3$\pm$5.4), 54 women: aged 65 through 85(75.5$\pm$5.2), a total of 92: aged 65 through 85(75.4$\pm$5.2) in women's division of F city Federation of Senior Citizens' Club, Otsuka division of B ward Federation of Senior Citizens' Club and S ward Federation of Senior Citizens' Club who gave consent to the research. The major findings were as follows: A social activity, individual activity were active in a social activity domain on a day so that people of Japanese advanced age had you, and writing ability was high, and, as for freezing, learning activity was active for people of Korean advanced age in a social activity domain so that writing ability was high.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.2
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• pp.170-179
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• 2022

This study aimed to evaluate the masticatory performance of Korean children and adolescents and to investigate related factors. Early loss of primary molars, degree of occlusion of first molars, occlusal relationship of first molars, and presence of anterior crossbite were considered. From March 2020 to July 2021, 56 children and adolescents between the ages of 6 and 12 were included. The mixing ability index (MAI) was calculated to evaluate the masticatory efficiency of children and adolescents. The subjects were classified into three groups according to the number of early lost primary molars; normal dentition, 1 - 2 teeth lost, more than 3 teeth lost. The number of participants are 23, 18, and 15, respectively. There was no difference in the MAI values between the normal dentition group and the group has 1 - 2 teeth lost. However, when 3 or more primary molars were lost, the MAI value decreased and a significant difference was observed. This study is the first study to evaluate the masticatory performance of children and adolescents in Korea, and it will be helpful to pediatric dentists who evaluate the masticatory performance of children and adolescents and strive to improve the masticatory efficiency of children and adolescents in clinical practice.

• Journal of Oral Medicine and Pain
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• v.45 no.3
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• pp.49-55
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• 2020

Purpose: This study investigated the association between the objective indicator of masticatory function assessment and the masseter muscle thickness (MMT) using ultrasound imaging. Methods: A total of 99 subjects (males: 24, females: 75, mean age: 76) were analyzed. The maximum bite force (MBF) was measured with a pressure-sensitive sheet and an image scanner. The mixing ability index (MAI) was calculated by image analysis after asking the subjects to chew a wax specimen. The MMT during rest and clenching were obtained with a diagnostic ultrasound system, and the difference in MMT during rest and MMT during clenching was defined as the difference in masseter muscle thickness (DMMT). Multiple regression analysis was performed to determine the independent variables affecting MBF and MAI. Results: The MBF showed correlation with the number of remaining teeth (β=0.346, p=0.002) and DMMT (β=0.251, p=0.011). The MAI correlated with only the number of remaining teeth (β=0.476, p<0.001). Conclusions: The DMMT reflects the state of masseter muscle contraction, and can be used as a predictor as well as the number of teeth when assessing masticatory function.

• Journal of Oral Medicine and Pain
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• v.43 no.4
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• pp.147-151
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• 2018

Disuse atrophy involves gradual muscle weakening due to inadequate usage and can cause temporomandibular disorder (TMD). A 45-year old man with TMD symptoms on the left side, who had disuse atrophy of the masticatory muscles on the right side following surgical removal of a trigeminal schwannoma on the right side, first visited the Department of Orofacial Pain and Oral Medicine at Kyung Hee University Dental Hospital with left jaw pain and difficulty in opening mouth and chewing. He had been experiencing difficulties in cognitive function, decrease in visual acuity, impaired speech, and writing deficits after brain surgery. Furthermore, he complained of abnormal occlusion on the right side, which interfered with his ability to chew comfortably and open his mouth effectively. Herein, we describe a contralateral TMD case due to ipsilateral disuse atrophy after brain surgery for a trigeminal schwannoma and our successful treatment with medication, physical therapy, and stabilization splint.

• Journal of Korean society of Dental Hygiene
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• v.16 no.1
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• pp.129-136
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• 2016

Objectives: The purpose of the study is to investigate the relationship between oral health status and body mass index (BMI) in adults over 65 years old. Methods: The study subjects were 4,550 adults over 65 years old from the 5th Korea National Health and Nutrition Examination Survey(KNHANES V) in 2010-2012. Mastication-related oral health status included the number of remaining teeth, and mean number of decayed, missing, and filled permanent teeth(DMFT). Body mass index(BMI, $kg/m^2$) was categorized as underweight(<18.5), normal weight (18.5-22.9), overweight(23.0-24.9), and obese(${\geq}25.0$). Multinomial logistic regression analysis was performed to examine the association of BMI categories with the number of remaining teeth and DMFT. Results: The mean number of DMFT was highest($13.0{\pm}0.7$) in the underweight group and lowest($8.8{\pm}0.3$) in the obese group. Those having less favorable masticatory ability, and fewer number of remaining teeth and no prosthesis, tended to be underweight. Those having a higher number of remaining teeth and prosthetic teeth tended to be overweight or obese. In the multinomial logistic regression analysis, compared with those having 20 or more remaining teeth, including prosthetic teeth, those having less than 20 remaining teeth and no prosthesis had 4.48 times higher odds ratio of being underweight. DMFT was positively associated with underweight, while negatively associated with overweight or obesity. Conclusions: The masticatory ability and dental caries prevention maintained the healthy body weight in adults of old age.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.284-292
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• 2023

Stable posterior occlusal support is crucial for adequate masticatory function and facial aesthetics. In elderly patients over the age of 65, masticatory ability has a significant impact on nutritional intake and overall health. This case report presents a prosthetic treatment of an elderly patient with edentulous maxilla and bilateral posterior edentulous mandible. The upper jaw was restored with a complete denture to establish an ideal occlusal plane, and the three-dimensional positions of the mandibular implants were determined accordingly. The implants were placed through computer-guided implant surgery and were immediately loaded with fixed provisional restorations. The implant-fixed zirconia final restorations were inserted in the lower posterior region, and the occlusal surface of posterior artificial teeth in the upper denture was substituted with cobalt-chrome alloy to resist occlusal wear. The patient's posterior occlusal support and masticatory function were promptly restored through this treatment process, and long-term stability against wear was also obtained.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.339-347
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• 1996

Prior to the advent of microvascular surgery, conventional prosthetic rehabilitation offered limited success to re-establish the physiological function in oromaxillofacial reconstruction. Microvascular surgery provided a new frontier and there are multitude of flaps. Each flap has the benefits and limitation for the application to various defects. Advantage of the scapular flaps over other reconstructive methods include the ability to design multiple cutaneous panels on a separate vascular pedicle allowing improvement in three-dimensional relationship and osseointegrated implants can be palced to restore occlusal and masticatory function. Here I present the detailed description of the important surgical anatomy as well as graft dissection and clinical application of free vascularized scapular flap.