• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.311-321
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• 1995

This study was undertaken to investigate the distribution of the chewing side preference and variations in the maximum bite force and facial morphology according to chewing side preference since unilateral chewing may cause morphologic and functional anomalies. 50 dental students who had no signs or symptoms of masticatory system and Angle's Class I relationship in posterior segments were selected, and divided into two groups, that is, 25 in bilateral chewing group(19 male and 6 female) and 25 in unilateral chewing group(10 male and 15 female). Maximum bite force was estimated ana posteroanterior cephalogram were measured ana statistically analyzed. The results were as follows : 1. Their were more students with bilateral chewing side preference($68\%$) and unilateral chewing side group consisted of right side preference($68\%$) and left side preference($32\%$). 2. There was no significant difference in the strength of max. bite force between the right and left side in bilateral chewing group. The bite force of the chewing side nab greater in the unilateral chewing group but less in the non-chewing side compared to those of bilateral chewing group with Bo significant difference. Max. bite force of chewing side was greater than that of non-chewing side in the unilateral chewing group(Female p<0.05). Max. bite force of males was about twice in that of females in both groups(p<0.05). Max. bite force of chewing side of the unilateral chewing group was similar to that of the bilateral chewing group, but that of non-chewing side was less than that of the bilateral chewing group. 3. In comparison of the facial morphology, there was no statistically significant difference in the size between the right and left side of the bilateral chewing group and between chewing and non-chewing side of the unilateral chewing group.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.4
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• pp.565-572
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• 1994

According to the classification of dental arch form and the analysis of patterns of chewing movement, the patterns of chewing movement in each group were evaluated and compared with those of the normal group. Results were summarized as follows ; 1. Opening phase in chewing movement In the group which the maxillary second molar positionsbuccal side, the chewing patterns which have the Vertical Guide Openings in frontal plane, the Posterior Guide Openings in hjorizontal plane were observed. In the group which the maxillary premolars position lingual side, the chewing paterns which have the Protrusive Shift Openings in horizontal plane and sagittal plane were observed. 2. Closing phase in chewing movement. In each group except for the normal group, the chewing patterns which have the Concave Closure in frontal plane and in Horizontal plane were observed. In the group which the maxillary premolars position buccal side, the chewing patterns which have the Lateral Guide Closure in frontal plane and in horizontal plane, the Vertical Guide Closre in sagittal plane were observed: From the results, as the characteristics of the dental arch form have appeared in chewing movement, the close relationships were found between dental arch form and chewing movement. It is suggested that the evaluation of dental arch form is effective in the diagnosis of function of stomatognathic system.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.291-306
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• 1995

Mandibular movement is composed of border movement and functional movement. Border movement such as maximal mouth opening, hinge opening ad lateral eccentric movement has good reproducibility, but functional movement such as chewing, swallowing and speech has also reproducibility. Especially for chewing movement, individual reproducibility has been confirmed by many studies. Study of chewing pattern is still in controversy. In new approach for raising the diagnostic value, numeric parameters and morphologic characteristics could be used for evaluation of chewing pattern. This study was performed to investigate the differences between chewing pattern in controls and in patients with temporomandibular disorders. Sixty-three patients with temporomandibular disorders participated in this study, and they were divided into unilaterally affected subjects or bilaterally affected subjects. Then unilaterally affected subjects were classified into closed lock group, disk displacement with reduction group, and degenerative joint disease group. For recording of chewing pattern, subjects were asked to chew one piece of presoftened chewing gum on both sides, and the chewing movement was recorded with the Electrognatho- Graphy(Bio-Research Associates Inc., U.S.A.). Tooth contact pattern for occlusal stability (Total left-right statistics )was also recorded with T-Scan(Tekscan Co., U.S.A.). The dta related to chewing pattern and total left-right statistics were statistically analyzed by SAS/stat program. The obtained results were as follows : 1. In patient group, mean value of A-P distance and the ratio of A-P distance to vertical distance were larger than control group, but the value of lateral distance in affected side and the closing velocity in unaffected side were smaller than that of control group, respectively. 2. In case of unilateral affected patients, chewing pattern of other side had tendency to restricted movement and slow velocity in closed lock group or degenerative joint disease group than control group or disk displacement with reduction group. 3. In bilateral degenerative joint disease patients, contralateral side had tendency to large range of motion and slow chewing velocity than preferred chewing side. 4. The patients with restricted mouth opening below than 35mm had higher value of total left-right statistics than patient group mouth opening above 35mm. Also closed lock group had higher total left-right statistics than disk displacement with reduction group, degenerative joint disease group and control group. 5. There was some difference in morphologic characteristics of chewing pattern between in control group and in affected side of unilateral patient group, but no difference between control group and unaffected side of unilateral patient group. 6. There were positive correlations between vertical distance and A-P distance, between vertical distance and chewing velocity, between A-P distance and chewing velocity, and between opening velocity and closing velocity in unilateral affected patients.

• Journal of Korean society of Dental Hygiene
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• v.19 no.5
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• pp.753-763
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• 2019

Objectives: To examine the association between chewing problems and depression in a representative sample of Korean adults. Methods: This study included 4,887 participants aged 19 years or older. Chewing problems were self-reported. Depression was measured using the PHQ-9 scale, which scored the frequency of symptoms over the last two weeks. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence intervals (CI). Results: There was a significant positive correlation between chewing problems and depression. Compared to those without chewing problems, participants with chewing problems had a 1.62 times higher risk of mild depression (OR=1.62; 95% CI:1.29-2.05), a 2.27 times higher risk of moderate depression (OR=2.27; 95% CI:1.52-3.38), and a 6.15 times higher risk of severe depression (OR=6.15; 95% CI:2.31-16.37). Conclusions: Results of this study indicate a significant association between chewing problems and depression. In addition, chewing problems were found to have a stronger relationship with higher severity levels of depression.

• Nutrition Research and Practice
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• v.11 no.2
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• pp.139-146
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• 2017

BACKGROUND/OBJECTIVES: Chewing difficulty is a factor contributing to a poor nutritional status in the elderly. The aim of this study was to examine disparities in food and nutrition intakes among Korean elderly people with and without chewing difficulty. SUBJECTS/METHODS: This study utilized data from the sixth Korea National Health and Nutrition Examination Survey conducted in 2013. The study subjects included males and females over 65 years of age who were not required to adhere to a special diet due to disease or sickness. They were divided into groups according to their chewing ability. Those who found chewing "very difficult" or "difficult", were combined to form the chewing difficulty group. Similarly, those who found chewing "moderately difficult", "easy", and "very easy" were combined to form the normal chewing group. RESULTS: Of the 999 subjects, 47.7% had chewing difficulties and the prevalence of chewing difficulty was higher in females than in males (P = 0.03) and higher in those 75 years of age and over than in younger individuals (P < 0.001). The chewing difficulty group had a significantly lower intake of fruits and vegetables (P < 0.05) and lower vitamin C and potassium intake than those in the normal group. Comparison of the percentages of Dietary Reference Intakes for Koreans (KDRIs) in the two groups indicated that the intake of most nutrients (energy, vitamin C, thiamin, riboflavin, niacin, calcium, phosphorus, sodium, potassium, and iron) were significantly lower in the chewing difficulty group than in the normal group. In particular, calcium intake was inadequate (51% of KDRIs) in the chewing difficulty group. CONCLUSIONS: The results indicate that chewing difficulty is closely related to food and nutrient intake in the elderly and can result in vitamin and mineral intake deficiencies. It is evident that the care of elderly subjects with chewing difficulty is essential for maintaining a healthy lifestyle.

• Journal of Korean society of Dental Hygiene
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• v.1 no.1
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• pp.89-99
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• 2001

Estimating by clinical index the efficacy of three cases, where chewing gum is mixed with nanoparticle containing chlorhexidine, where chewing gum doesn't contain neither of them, and where with chlorhexidine only, this study has come to the following conclusion. 1. The chewing gum with chlorhexidine and chlorhexidine nanoparticle has shown more reduction of plaque index and gingival index than that with no chlorhexidine. 2. There could be seen a difference between the gum with chlorhexidine and the gum with chlorhexidine nanoparticle. 3. The gum with chlorhexidine nanoparticle has shown less level of plaque index than that chlorhexidine, which difference was only slight. 4. The gum with chlorhexidine nanoparticle wasn't absorved any tooth coloring. To put these results together, it is proposed that mixing chewing gum with chlorhexidine nanoparticle can be an efficient application.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.225-229
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• 1990

Sixteen mature sheep were fed chaffed orchardgrass hay once a day. Jaw movement of the sheep was recorded for 24 hours before slaughter. Four sheep were slaughtered either prior to eating, 2, 8 or 16 hours after the commencement of eating to measure digesta pool size and particle size distribution in the reticulo-rumen. Eating time was restricted to 120 minutes. Rumination time and actual chewing time during rumination increased with time after the meal. Mean dry matter (DM) pool size before and 2 hours after the meal were 1.36 and 2.45 times of DM intake, respectively. The proportion of large particle (>1.18 mm; LP) in the DM ingested during the meal was caculated to be about 70%. The mean DM and LP pool sizes per DM intake and the mean proportion of LP in the DM pool decreased with time after the meal. There were close negative relationships between either DM or LP pool sizes per DM intake and the chewing activities either expressed as time spent rumination, actual chewing time during rumination or total actual chewing time(total of eating time and actual chewing time during rumination). The difference between DM intake and LP pool size were assumed to be LP degradation in the present experiment, and correlated positively with the chewing activities. A large proportion of the digesta load was comprised of small particles, in excess of the daily intake.

• Journal of Korean society of Dental Hygiene
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• v.21 no.4
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• pp.383-391
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• 2021

Objectives: Based on the 7th National Health and Nutrition Examination Survey 1,135 adults aged 19 years were selected as the final study subjects to investigate the relationship between oral health and chewing difficulty in adults. Methods: Frequency analysis, chi-square test, and logistic regression analysis were performed for general characteristics, oral health behaviors, awareness symptoms, and oral health using SPSS Program 21.0. Results: Regarding factors related to chewing difficulty, the oral health was 0.44 times lower than the average level and 0.28 times lower than the good condition. In the case of oral examination, chewing difficulty was 0.85 times lower. The speaking problem was 0.11 times lower in usually than inconvenient and 0.06 times lower in not inconvenient. In the case of un-treatment, it was 0.40 times lower than that in the case of treatment. The chewing difficulty was significantly higher by 2.09 times in the case of experience of tooth pain and 1.36 times in the case of periodontal disease. Conclusions: Based on the above results, it is thought that prevention and treatment are actively needed to identify factors of oral health to improve oral health, to solve chewing difficulty and to improve chewing function.

• Journal of Korean society of Dental Hygiene
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• v.24 no.3
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• pp.243-251
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• 2024

Objectives: This study used secondary data from the 2021 Community Health Survey to identify the impact of dysphagia on mental health-related characteristics among older adults, selecting 73,970 individuals aged 65 years and older. Methods: Frequency analysis, χ²-test, and multiple logistic regression were conducted to identify risk factors affecting mental health-related characteristics among older adults. Results: Dysphagia was most common among individuals with the following demographic characteristics: female, aged 85 years and older, three-generation household and household income in the 1st quintile. Chewing discomfort according to mental health-related characteristics was higher in older adults with cognitive impairment and depression. Sex, age, education level, household income, and chewing discomfort were significant for cognitive impairment, whereas sex, age, household type, education level, household income, and chewing discomfort were significant for depression. Conclusions: The above results confirmed that chewing discomfort contributes to mental health issues such as cognitive impairment and depression. It is therefore necessary to recognize chewing discomfort as an important health problem affecting the mental health of older adults, and to develop a multifaceted dental hygiene approach to target community-dwelling older adults who suffer from chewing discomfort.

• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.25-45
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• 1994

The purposes of this study were to investigate the effect of pilocarpine-containing chewing gum for the treatment of xerostomia and to compare the effect of pilocarpine-containing chewing gum with that of pilocarpine oral administration. The 20 subjective and objective xerostomic patients were included in this study and divided into 3 groups. Five subjects were included in gum base chewing group, 10 in pilocarpine-containing gum chewing, and 5 in pilocarpine oral administration. The author measured unstimulated whole salivary flow rate, stimulated parotid salivary flow rate, pH of resting whole saliva, viscosity of stimulated whole saliva, and subjective symptoms and discomforts using VAS(visual analogue scale) at the beginning of the experiment. And the author investigated the changes of these factors at 1, 2, 3, and 4 week after. The obtained results were as follows : 1. There were significant increases in the unstimulated whole salivary flow rate in pilocarpine-containing gum chewing and pilocarpine oral administration groups. But there was no significant difference between pilocarpine-containing gum chewing and pilocarpine oral administration groups. 2. There was a significant increase in the stimulated parotid salivary flow rate in pilocarpine- containing gum chewing group. But there was no significant difference between pilocarpine- containing gum chewing and pilocarpine oral administration groups. 3. The change of salivary pH showed the increasing pattern in all groups. But there was no significant difference among groups. 4. There were no significant changes in the values of salivary viscosity in all groups through the experimental period. 5. There were significant decreases of VAS(visual analogue scale) in the degree of subjective symptoms and discomforts in pilocarpine-containing gum chewing and pilocarpine oral administration groups. But there was no significant difference between pilocarpine- containing gum chewing and pilocarpine oral administration groups.