• The Journal of the Korean dental association
• /
• v.12 no.4
• /
• pp.241-244
• /
• 1974

The author measured the masticatory efficiency in the 50 children with normal sound dentition, in the 20 children with amalgam filling and in the 20 children with fixed type space maintainer i.e. in the 90 children in total and got the following results. 1. the masticatory efficiency were 53.8% in children with normal sound primary dentition. 2. The masticatory efficiency 48.3% in children with amalgam filling and 40.0% in children with fixed type space maintainer 3. The masticatory efficiency of children were 60.0% of adult's in normal dentition.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.1 no.1
• /
• pp.31-34
• /
• 1974

The author studied for the masticatory efficiency on the subject of 20 fixed spacemaitainer wearers and 20 removable spacemaintainer weares compared with the control group in children. The following results were obtained on 10 Mesh Screen. 1. The masticatory efficiency was 28.8% in removable spacemaintainer wearers. 2. On the subject of fixed spacemaitainer wearers, the masticatory efficiency was 27.4%. 3. The masticatory efficiency was 48.3% in control group.

• The korean journal of orthodontics
• /
• v.47 no.3
• /
• pp.151-157
• /
• 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 Oral Medicine and Pain
• /
• v.38 no.1
• /
• pp.53-67
• /
• 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.

• The Journal of the Korean dental association
• /
• v.12 no.2
• /
• pp.131-134
• /
• 1974

The author had studied the masticatory effience on three different types; on missing of the first molar, on replacing the missed first molar with crown & bridge and on natural dentition. This study was made from the parched soybeans as testfood by means of mesh technique. As a result of this study on 25 of natural dentitions, 20 of crown & bridges and 25 of missing of the first molars, the following were come out. 1. Masticatory efficiency of natural dentitions was 75.8%, that of crown & bridges was 66.4%, and that of missing of the first molars was 43.7%. 2. Difference of masticatory efficiency of crown & bridges to natural dentitions was 9.4%, that of natural dentitions to missing teeth was 32.1%, and that of crown & bridges to missing teeth was 22.7%.

• Journal of Oral Medicine and Pain
• /
• v.35 no.2
• /
• pp.135-147
• /
• 2010

In this study, the objective masticatory efficiency of two groups of temporomandibular disorder patients, pain and sound groups, was compared with that in a normal group using the MAI (mixing ability Index). The subjective chewing ability was evaluated using questionnaires, such as the Food Intake Ability Index (FIA) and Visual Analogue Scale (VAS). The Oral Health Impact Profile (OHIP)-49K of the patients was also examined to measure the oral health-related quality of life. The results were as follows: 1. The MAI, FIA and VAS in the pain group were significantly lower than in the normal and sound groups. This shows that the chewing efficiency of the pain group was lower than the normal and sound groups (P<0.05). However, there was no significant difference between the sound and normal groups. 2. The OHIP-49K for the oral health-related quality of life showed a significant increase in both the pain and sound groups compared with normal group. This means that the oral health-related quality of life was lower in both the pain and sound groups. 3. There was a correlation between the MAI, FIA and VAS (P<0.01) in all subjects (71 persons). The OHIP-49K was associated with the FIA and VAS. 4. There was a correlation between the FIA and VAS (P<0.05) in the sound group but no correlation in the other groups. 5. There was a correlation between the FIA and VAS in all groups. 6. The VAS was increased significantly in the pain group according to the level of pain reduction after treatment (P<0.05). However, there was no significant increase in the MAI, even though there was an improvement in masticatory efficiency. In addition, there was no difference in the FIA and OHIP-49K according to the level of pain reduction after treatment. In this study, it is believed that pain is a main factor decreasing the masticatory efficiency in patients with temporomandibular disorders. Moreover, TMJ sounds decrease the quality of life but do not decrease the masticatory efficiency. Therefore, it is important to control the pain in order to improve the masticatory efficiency in temporomandibular disorder patients. Moreover, managing both pain and sound can improve the quality of life.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.49 no.2
• /
• pp.170-179
• /
• 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
• /
• v.30 no.3
• /
• pp.361-373
• /
• 2005

Occlusal appliance therapy has been proven to be very useful and effective in reducing signs and symptoms of patients with TMD. However, there are no reports about the masticatory efficiency of the occlusal appliance. The purpose of this study was, first, to investigate the masticatory efficiency of the conventional stabilization appliance experimentally in normal healthy subjects, by comparing it with that of their natural dentition; and, second, to develop a modified stabilization appliance as an attempt to increase masticatory efficiency. Eleven subjects (mean age 25.3 years, range from 23 to 33) participated in this study. Six were men and five were women. They were healthy and had complete or near―complete natural dentition, and did not present with signs or symptoms of TMD. Two kinds of occlusal appliances―the conventional flat maxillary stabilization appliance (i.e., FSA) and a modified maxillary stabilization appliance with additional anatomic structures on its occlusal surface (i.e., ASA)―were made for every subject. Subjects chewed peanuts that were selected as a food to test the three masticatory conditions of the natural dentition, the ASA, and the FSA. The number of chewing strokes was counted during each 1-minute chewing period. Chewed peanut boluses were recovered and their hardness was measured by texture analysis. Statistical tests were performed. The following results were obtained. 1. The masticatory efficiency of the FSA was 38.6 percent that of the natural dentition. The efficiency of the ASA was 78.2 percent that of the natural dentition. 2. The number of chewing strokes in the natural dentition condition was measured to be 1.5 strokes per second. It decreased to 90 percent in the ASA and FSA conditions. These results indicate that the ASA could serve an improved masticatory capacity as well as its therapeutic effects in TMD. A clinical application of the ASA should be considered to extend the management of TMD patients.

• Journal of Periodontal and Implant Science
• /
• v.41 no.2
• /
• pp.79-85
• /
• 2011

Purpose: The aim of this study was to obtain objective and standardized information on masticatory function and patient atisfaction following second molar single implant therap. Methods: Twenty adult patient, who had restored second molar single implants more than 1 month before the study, were enrolled in this stud. All patients received a chewing test using peanuts before and after insertion of the implant prosthesi, with a questionnaire and visual analogue scale (VAS) to evaluate the effect of second molar single implant therap. Results: his study obtained standardized information on the masticatory function objectively (e.g., P, R, $X_{50}$) before (Pre-insertion) and after insertion (Post-insertion) of the implant prosthesis. Masticatory performance (P) after insertion of the implant prosthesis significantly increased from $67.8{\pm}9.9$ to $84.3{\pm}8.5$% (P<0.0001). With the implant prosthesis, the P value increased by 24%. The masticatory efficiency index (R) of Post-insertion is higher than that of Pre-insertion (P<0.0001). With the implant prosthesis, the R value increased by 29%. The median particle size ($X_{50}$) of Post-insertion is lower than that of Preinsertion (P<0.0001). More than 90% of the patients were satisfied with the second molar single implant therapy from a functional point of view. Conclusions: These findings indicate that a second molar single implant can increase masticatory function.

• The Journal of Korean Academy of Prosthodontics
• /
• v.36 no.1
• /
• pp.81-103
• /
• 1998

The purpose of this study was to compare and evaluate the differences in masticatory performance, muscle activity, and patterns of occlusal contact between persons with natural dentition and removable partial denture wearers. Twenty healthy adult subjects with more than 28 teeth and thirteen removable partial denture wearers that classified Kennedy classification I was selected. The degree of pulverized rice and peanut was measured and analyzed by means of sieving method to compare the masticatory performance. For the muscle activity, EMG was recorded in selected muscles(Temporalis and masseter muscle) during mastication and resting state. The occlusal record in maximal intercuspation was taken with a silicone occlusal bite registration material for analysis of the patterns of occlusal contact. The obtained results were as follows: 1. When chewed peanuts, masticatory performance ratio at 10-sieve size was 81.31% in natural dentition group. In removable partial denture wearer, 27.01% without RPD and 69.09% with RPD. When chewed rice, 42.04%, 11.87%, and 21.58%, respectively. The differences of masticatory performance ratio between groups were statistically significant at the 0.05 level. 2. The mean EMG value in resting state was $1.06{\mu}V$ on temporal muscle, $0.98{\mu}V$ on masseter muscle in natural dentition group. In removable partial denture wearers, $1.13{\mu}V$ on temporal muscle, $1.05{\mu}V$ on masseter muscle without RPD and $1.11{\mu}V$ on temporal muscle, $1.04{\mu}V$ on masseter muscle with RPD. 3. The mean EMG value during mastication was $45.64{\mu}V$ in natural dentition group, and in removable partial denture wearers, $22.06{\mu}V$ without RPD and $31.01{\mu}V$ with RPD when chewed peanuts. When chewed rice, $45.24{\mu}V,\;25.53{\mu}V\;and\;32.14{\mu}V$, respectively. The differences of mean masticatory EMG value between groups were statistically significant at the 0.05 level. 4. The number of posterior occlusal contact point was 20.15 in natural dentition group and 11.92 in removable partial denture wearers. The area of perforated surface was $16.50mm^2$ in natural dentition group and $6.06mm^2$ in removable partial denture wearers. The area of contact surface was $78.93mm^2,\;51.52mm^2$, respectively. 5. The area of contact surface was effective to masticatory performance ratio in natural dentition group and removable partial denture wearers (p<0.05). From these results, it is concluded that in partially edentulous patient, masticatory efficiency can be improved by removable partial denture wearing, and for efficient mastication, tight occlusal contact surface shoud be maintained by maximum support that is provided from mucosa.