Association between posterior occlusal support and tooth loss in a population-based cohort: The OHSAKA study.

OBJECTIVES: This study aimed to assess the association between posterior occlusal support (POS) and the risk of tooth loss in older adults aged ≥75 years. METHODS: This longitudinal study analyzed 94,422 participants who participated in multiple dental check-ups provided as part of the public healthcare services in Osaka, Japan, from 2018 to 2022. The participants were categorized into nine groups (A1-3, B1-4, and C1 and C2) according to their POS status using the Eichner index at baseline. The dental charts were compared between the initial and final assessments to assess tooth loss. Logistic regression analysis was used to examine the association between POS status and tooth loss, adjusted for several covariates, including age, sex, body mass index, periodontal status, oral hygiene, history of diabetes, history of hypertension, attendance at the annual dental check-up, and observational period. Furthermore, stratified logistic regression analyses were conducted using anterior or posterior tooth loss. RESULTS: After controlling for confounders, POS status was associated with tooth loss. The odds ratios (ORs) with A1 as the reference were 1.74 in A2, 2.55 in A3, 3.40 in B1, 4.74 in B2, 5.79 in B3, 6.00 in B4, 4.44 in C1, and 3.00 in C2, respectively. The ORs for anterior tooth loss were higher than those for posterior tooth loss, with the highest OR observed in B4 (21.4). CONCLUSIONS: This large population-based cohort study showed that a decreased POS was a risk indicator for tooth loss; furthermore, the risk increased even further in the anterior teeth region.

Collagen-derived dipeptide prolyl-hydroxyproline cooperates with Foxg1 to activate the PGC-1α promoter and induce brown adipocyte-like phenotype in rosiglitazone-treated C3H10T1/2 cells.

Background: The global obesity epidemic is a significant public health issue, often leading to metabolic disorders such as diabetes and cardiovascular diseases. Collagen peptides (CP) and their bioactive component, Prolyl-hydroxyproline (Pro-Hyp), have shown potential in reducing adipocyte size, with unclear mechanisms concerning brown adipocyte differentiation. Methods: We investigated the effects of Pro-Hyp on the differentiation of brown adipocytes in C3H10T1/2 mesenchymal stem cells, focusing on its impact on adipocyte size, gene expression related to brown fat function, and mitochondrial activity. Results: Pro-Hyp treatment decreased adipocyte size and upregulated brown fat-specific genes, including C/EBPα, PGC-1α, and UCP-1. Remarkably, it did not alter PPARγ expression. Pro-Hyp also elevated mitochondrial activity, suggesting enhanced brown adipocyte functionality. A Pro-Hyp responsive element was identified in the PGC-1α gene promoter, which facilitated the binding of the Foxg1 transcription factor, indicating a novel regulatory mechanism. Conclusion: Pro-Hyp promotes brown adipocyte differentiation, potentially offering a therapeutic strategy for obesity management. This study provides a molecular basis for the anti-obesity effects of CP, although further in vivo studies are needed to confirm these findings and to investigate the potential impact on beige adipocyte differentiation.

Exploring the association between number of teeth, food intake, and cognitive function: A 9-year longitudinal study.

OBJECTIVES: This study aimed to investigate the association between the number of teeth, food intake, and cognitive function in Japanese community-dwelling older adults. METHODS: This 9-year longitudinal study included a total of 293 analyzable participants who participated in baseline and follow-up surveys. Dental status (number of teeth and periodontal pocket depth), dietary assessment using the brief-type self-administered diet history questionnaire, cognitive function, and the following confounding factors were evaluated: educational level, financial satisfaction, living situation, smoking and drinking habits, history of chronic diseases, apolipoprotein E-ε4 carrier, body mass index, handgrip strength, instrumental activities of daily living, and depressive symptomatology. The Japanese version of the Montreal Cognitive Assessment was used to evaluate cognitive function. A multinomial logistic regression analysis for the intake level of each food categorized into three groups (low, moderate, high), and a generalized estimating equation (GEE) for cognitive function over nine years were performed. RESULTS: After controlling for confounding factors, the number of teeth was shown to be associated with the intake of green-yellow vegetables and meat. Furthermore, the GEE indicated that the lowest quartile of intake of green-yellow vegetables significantly associated with lower cognitive function (unstandardized regression coefficient [B] = -0.96, 95 % confidence interval [CI]: -1.72 to -0.20), and the lowest quartile of intake of meat significantly associated with lower cognitive function (B = -1.42, 95 % CI: -2.27 to -0.58). CONCLUSIONS: The intake of green and yellow vegetables and meat, which is influenced by the number of teeth, was associated with cognitive function in Japanese community-dwelling older adults. CLINICAL SIGNIFICANCE: There are few studies that have examined the association between oral health, food intake, and cognitive function. This 9-year longitudinal study suggests that it is important to maintain natural teeth to enable the functional means to consume green-yellow vegetables and meat, and thereby help maintain cognitive function.

Pneumocystis Pneumonia in Locally Advanced Breast Cancer Despite Prophylactic Use of Trimethoprim-Sulfamethoxazole During Prednisolone Treatment for a Pembrolizumab-Induced Immune-Related Adverse Event: A Case Report.

Pneumocystis pneumonia (PCP) primarily affects immunosuppressed patients, with trimethoprim-sulfamethoxazole (TMP-SMX) commonly used for prophylaxis. However, there is insufficient information on PCP occurrence despite TMP-SMX prophylaxis. We encountered a 57-year-old woman with locally advanced breast cancer developing PCP despite prophylactic intake of TMP-SMX, during treatment with prednisolone for Stevens-Johnson syndrome (SJS) induced by pembrolizumab. This case underscores the need to pay attention to the possibility of PCP development even during TMP-SMX prophylaxis. Dosage and duration adjustments according to the patient's condition and weight may be required.

Survival time analysis of remaining teeth following replacement of unilateral free-end missing teeth: A comparison between fixed implant-supported prostheses and removable partial dentures.

OBJECTIVES: This retrospective study aimed to investigate the differences in tooth loss rate between fixed implant-supported prostheses (FISPs) and removable partial dentures (RPDs) in cases of unilateral free-end missing teeth. MATERIALS AND METHODS: The data of 324 patients who underwent treatment with FISPs or RPDs for unilateral free-end missing teeth and satisfied the applicable criteria, were evaluated (47 in the FISPs group and 277 in the RPDs group). After propensity score (PS) matching, which was used to extract patients with similar background factors related to prosthetic selection at baseline, survival time analyses were performed with tooth loss as the endpoint. The adjusted variables were age, sex, number of restored teeth, periodontal status, and the practicing dentist's experience in years. The remaining teeth were classified into subcategories in relation to the missing molars. RESULTS: Overall, 58 patients (29 in each group) selected by PS matching were evaluated in the final analysis. The total number of lost teeth was 35 (FISPs group: n = 10; RPDs group: n = 25). The mean (±SD) period to tooth loss and the 10-year survival rates in the FISPs and RPDs groups were 51.6 (±30.1) months and 42.3 (±29.7) months, 70.5% and 16.4%, respectively. The log-rank test showed that significantly longer survival time in FISPs compared with RPDs. CONCLUSIONS: After adjustments for confounding factors using PS matching, replacing unilateral free-end missing teeth with FISPs may exhibit a lower tooth loss rate in adjacent and contralateral teeth compared to replacing with RPDs.

Masseter and digastric muscle activity evaluation using a novel electromyogram that utilizes elastic sheet electrodes.

PURPOSE: To evaluate the reproducibility and reliability of a novel electromyogram (EMG) device with a flexible sheet sensor for measuring muscle activity related to mastication and swallowing. METHODS: We developed a new EMG device made of elastic sheet electrodes to measure the masseter and digastric muscle activities for evaluating mastication and swallowing. To examine the measurement reproducibility of the new EMG device, masseter muscle activity was analyzed using the intraclass correlation coefficient (ICC). Further, we measured the maximum amplitude, duration, integrated value, and signal-to-noise ratio (SNR) using the new EMG device and conventional EMG devices and evaluated the reliability using ICC and Bland-Altman analysis. RESULTS: We confirmed high ICC (1,1) and ICC (2,1) scores (0.92 and 0.88, respectively) while measuring the reproducibility of the new EMG device. When compared to the active electrode EMG device, we found a high correlation for the maximum amplitude (0.90), duration (0.99), integrated values (0.90), and SNR (0.75), with no observation of significant fixed errors. Moreover, the regression coefficient was not significant for any of the evaluation items and no proportional error was observed. Compared with the passive electrode EMG device, the maximum amplitude and duration were highly correlated (0.73 and 0.89). In addition, the SNR exhibited a significant fixed error. In contrast, the regression coefficient was not significant for any of the evaluation items and no proportional error was observed. CONCLUSIONS: Our results suggest that the new EMG device can be used to reliably and reproducibly evaluate muscle activity during mastication and swallowing.

Long-term Experience on Breast Cancer-related Lymphedema in the Coastal Area of Fukushima, Japan After the 2011 Triple Disaster.

BACKGROUND/AIM: Disasters can jeopardize breast cancer care and Japan's triple disaster in 2011 (earthquake, tsunami, and nuclear accident) is no exception. However, detailed information is lacking regarding the care of breast cancer related lymphedema (BCRL) following the disaster. We aimed to explore the process by which local patients become aware of BCRL, the problems faced, and the support they require. We also aimed to clarify the effects of the 2011 disaster on experiences related to lymphedema in the target population. PATIENTS AND METHODS: Patients who developed BCRL after breast cancer treatment were recruited from Iwaki city, a municipality located in the southern coastal region of Fukushima (N=16). In-depth, semi-structured, face-to-face interviews were conducted, and the obtained data were appraised using thematic analysis. RESULTS: Five themes related to BCRL were identified: 1) the process of becoming aware of BCRL, 2) troubles or worries/concerns due to BCRL, 3) information sources regarding BCRL management, 4) strategies to cope with BCRL, and 5) the adverse impacts of the 2011 disaster on BCRL management. CONCLUSION: Except for the disaster context, the themes are in line with those of previous studies conducted in the non-disaster context. Nonetheless, there were limited but non-negligible adverse effects of the 2011 disaster on long-term local BCRL management. The findings of this study demonstrate the necessity for individualizing coping strategies against BCRL among healthcare professionals in the Fukushima coastal area and beyond.

Factors related to subjective evaluation of difficulty in chewing among community-dwelling older adults.

AIM: Awareness of difficulty chewing may limit the diversity of food intake in older adults. However, few studies have clarified which factors are related to subjective difficulty in chewing. The aim was to identify factors related to subjective difficulty in chewing in 70- and 80-year-old Japanese older adults. METHODS: A total of 1680 participants (792 men, 888 women) were surveyed. Difficulty in chewing was assessed with questionnaires regarding food intake, such as rice, apples, beef, and hard rice crackers. The participants were classified into two groups, the "with difficulty" group (participants who answered "cannot eat," "can eat with difficulty," and "can eat if small") and the "without difficulty" group (participants who answered "can eat without problems"), according to their answers to questionnaires for each food. A logistic regression analysis with subjective difficulty in chewing as the dependent variable was performed for each food. RESULTS: Subjective difficulty in chewing was associated with age, occlusal force, and depression for rice; age, number of remaining teeth, occlusal force, and depression for apples; number of remaining teeth, occlusal force, and depression for beef; and number of remaining teeth and occlusal force for hard rice crackers. CONCLUSIONS: Age, number of remaining teeth, and occlusal force, as well as depression, might be related to subjective evaluation of difficulty chewing in community-dwelling Japanese older adults. Geriatr Gerontol Int 2024; 24: 327-333.

Telepathology in intraoperative frozen section consultation of breast cancer sentinel node biopsy in Fukushima, Japan following the 2011 triple disaster: diagnostic accuracy and required time during the early implementation phase.

In breast cancer surgery, some medical facilities lack the necessary resources to conduct sentinel lymph node biopsy and its intraoperative frozen section consultation. In the coastal rural area of Fukushima, Japan, which has suffered from physician undersupply following the 2011 triple disaster of earthquake, tsunami and nuclear disaster, we explored the feasibility of telepathology by evaluating the diagnostic accuracy in remote intraoperative frozen section consultation of sentinel lymph node biopsy and its required time. Although examination time has room for improvement, telepathology can be one possible solution in resource-limited areas.

The relationship between changes in occlusal support and masticatory performance using 6-year longitudinal data from the SONIC study.

OBJECTIVES: Reduced occlusal support is thought to be related to a decline in masticatory performance. However, previous research in this field was based on cross-sectional studies. In this study, we conducted a 6-year longitudinal observation of older adults living in the community and examined the associations of changes in occlusal support with masticatory performance. METHODS: Of the 864 participants aged 72-74 years in the SONIC study, 488 who were followed up (median follow-up period 5.92 years) and had no missing data were included in this study. Participants were divided into three groups according to the number of occlusal support zones in the posterior area: Complete occlusion (four zones), Reduced occlusion (one to three zones), and Collapsed occlusion (no occlusal support zone). Longitudinal analysis of the relationship between occlusal support and masticatory performance was undertaken with linear mixed-effects models. RESULTS: Sex, occlusal force, number of unreplaced missing teeth, aging, and occlusal support change were significantly related to masticatory performance. Furthermore, the interaction term between change in occlusal support and aging was a significant explanatory variable for the decline in masticatory performance. The interaction was strongest in the group that changed from Complete or Reduced occlusion to Collapsed occlusion. This result indicates that the loss of occlusal support is a major factor contributing to declining masticatory performance. CONCLUSIONS: The decline of occlusal support was greatly associated with the deterioration of masticatory performance. Our results suggest that older adults need to prevent the collapse of posterior occlusal support to maintain their masticatory performance. CLINICAL SIGNIFICANCE: Occlusal support is important for preserving masticatory performance in older adults. Preventing the loss of molars and retaining occlusal support may contribute to maintaining food intake diversity and nutritional status, thereby improving quality of life. Dental professionals need to carefully examine dental status to assess the risk of occlusal collapse.

Radiographic bone level and soft tissue dimensional changes following explantation of implants affected by peri-implantitis: A retrospective exploratory evaluation.

BACKGROUND: While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation. AIM: To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation. MATERIAL AND METHODS: Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone. RESULTS: A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone. CONCLUSION: The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss.

The necessity of proactive measures from healthcare providers highlighted by delayed breast cancer diagnosis due to COVID-19: A case report.

Key Clinical Message: During disasters, multiple factors can cause significant delays in medical visits. Regular patient monitoring, high-risk individual alerts, and telemedicine enhancements can potentially alleviate these issues and ensure timely interventions. Abstract: During the COVID-19 pandemic, a Japanese woman in her 70s delayed her regular breast cancer checkup for over 2 years. During disasters, health priorities tend to decline, necessitating proactive measures from healthcare providers, such as augmenting collaboration among healthcare professionals and identifying high-risk individuals.

Experience-Related Factors in the Success of Beginner Endoscopic Ultrasound-Guided Biliary Drainage: A Multicenter Study.

Endoscopic ultrasound-guided biliary drainage (EUS-BD) has become comparable to endoscopic retrograde cholangiopancreatography and is now considered a first-line intervention for certain biliary obstructions. Although analysis of experience-related factors may help achieve better outcomes and contribute to its wider adoption, no concrete evidence exists regarding the required operator or institutional experience levels. This study aimed to analyze experience-related factors at beginner multicenters. Patients who underwent EUS-BD using self-expandable metal stents and/or dedicated plastic stents during the study period (up to the first 25 cases since introducing the technique) were retrospectively enrolled from seven beginner institutions and operators. Overall, 90 successful (technical success without early adverse events) and 22 failed (technical failure and/or early adverse events) cases were compared. EUS-BD-related procedures conducted at the time of applicable EUS-BD by each institution/operator were evaluated. The number of institution-conducted EUS-BD procedures (≥7) and operator-conducted EUS screenings (≥436), EUS-guided fine-needle aspirations (FNA) (≥93), and EUS-guided drainages (≥13) significantly influenced improved EUS-BD outcomes (p = 0.022, odds ratio [OR], 3.0; p = 0.022, OR, 3.0; p = 0.022, OR, 3.0; and p = 0.028, OR, 2.9, respectively). Our threshold values, which significantly divided successful and failed cases, were assessed using receiver operating characteristic curve analysis and may provide useful approximate indications for successful EUS-BD.

Relationship between occlusal force and psychological frailty in Japanese community-dwelling older adults: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

BACKGROUND: Frailty increases the risk of negative health-related events, such as falls, disability, hospitalizations, and death. Although the association between oral health and physical frailty is well established, the relationship between oral health and psychological frailty has not yet been investigated. Therefore, we conducted a cross-sectional study to examine the association between maximal occlusal force and psychological frailty in Japanese community-dwelling older adults. METHODS: Psychological frailty was defined as a World Health Organization-5 scale (WHO-5) score of <13, cognitive and functional status was defined as a Japanese version of the Montreal Cognitive Assessment (MoCA-J) score of <23, and psychological robustness was defined as a WHO-5 score of ≥13 and a MoCA-J score of ≥23. We used a cross-sectional study design to measure maximal occlusal force in 1810 participants, and examined the following factors relevant to psychological frailty: educational level, financial status, living situation, history of chronic diseases, handgrip strength, and instrumental activities of daily living. We used propensity score matching to match the psychological frailty and psychological robustness groups according to demographic and confounding factors. This process, resulted in 344 participants, of whom 172 were in the psychological frailty group and 172 were in the psychological robustness group. In the matched cohort, differences between groups with and without psychological frailty were compared using generalized estimating equations for maximal occlusal force after adjusting for the number of teeth. RESULTS: After controlling for potential confounding factors of frailty, the psychological frailty group showed lower maximal occlusal force compared with the psychological robustness group (unstandardized regression coefficients = -72.7, 95% confidence interval: -126.3 to -19.1). CONCLUSIONS: Maximal occlusal force was associated with a reduced prevalence of psychological frailty among Japanese community-dwelling older adults participating in our study.

Effective oral function improvement by restoration-driven implant treatment after mandibular resection with a scapular flap: a case report.

BACKGROUND: The extensive loss of teeth and surrounding tissues due to mandibulectomy for an oral tumor not only impacts negatively on appearance, but also often causes various functional disorders, decreasing quality of life (QOL). In the present case, reconstruction with a scapular flap was carried out along with segmental mandibulectomy, aiming for functional restoration through restoration-driven implant treatment. A good outcome was obtained, with improvement of masticatory function and QOL following the prosthetic treatment. CASE PRESENTATION: The patient was a 37-year-old woman diagnosed with ossifying fibroma in the left side of the mandible. Segmental mandibulectomy and reconstruction with a scapular flap were carried out. Implant diagnostic simulation was performed, and based on the result, secondary reconstruction using a particulate cancellous bone and marrow graft was carried out by an oral surgeon. After wound healing was complete, implant placement was performed twice, and the final prosthodontic treatment was completed. Masticatory performance and maximum bite force, which are indices of masticatory function, were improved from before to after prosthetic treatment. In addition, oral health-related QOL was improved from before to after prosthetic treatment. CONCLUSION: In the present case, restoration-driven implant treatment was performed in a patient following segmental mandibulectomy for a mandibular tumor, with a good outcome. Planning the treatment measures with a focus on the final prosthetic vision can lead to improvement of oral function in patients with extensive mandibular defects.

Maintenance issues of elderly patients requiring nursing care with implant treatments in dental visiting: position paper.

PURPOSE: Japan, with an increasing number of elderly people needing long-term care in a super-aged society, urgent needs to develop the clinical guidelines on implant maintenance for elderly people with declining independence. The purpose is to categorize the troubles encountered in the care of patients with dental implants and to indicate actual practices and points of note. METHODS: From the members of the Japanese Society of Oral Implantology, 12 expert panelists who were experienced with many problems of implant maintenance during dental visits and were familiar with their solutions were selected. Through repeated discussions in the many panel meetings, the problems of implant maintenance during dental visits were distilled. RESULTS: During a dental visit, the oral cavity, general conditions, and background of elderly patients who cannot orally care for themselves must be grasped, and medical staff, care managers, and patients should understand the changes in these factors as time goes by. The solutions and responses that can be made differ greatly depending on the medical care facilities, the environment, differences in the experience of medical staff, and the patient's background. Thus, it is necessary to select safe treatments appropriate to each situation. CONCLUSIONS: This paper features many opinions based on clinical experiences. However, clinical guidelines on implant management during dental visits should be formulated in the future based on the accumulation of evidence through the implementation of clinical research.

Why only me? A case report of a breast cancer patient with unresolved trauma from a past disaster experience developing a mental disorder.

Little is known about how the psychological stress of having experienced a natural disaster affects cancer patients. We experienced a patient who was treated with breast cancer after having been stricken by a typhoon, which resulted in significant psychological damage. Treatment strategies should incorporate patients' mental health appropriately after disasters.

Spermine Suppresses Adipocyte Differentiation and Exerts Anti-Obesity Effects In Vitro and In Vivo.

Endogenous polyamines such as putrescine (Put), spermidine (Spd), and spermine (Spm) affect adipocyte differentiation. In this study, we investigated the effect of exogenously supplemented polyamines on mouse adipocyte differentiation and anti-obesity actions in vitro and in vivo. The preadipocyte cell line, 3T3-L1, was cultured with Put, Spd, or Spm, and lipid accumulation in the cells was measured by Oil Red O staining. Lipid accumulation was significantly suppressed by Spm. Suppression of CCAAT/enhancer binding protein α mRNA by Spm suggested that the decreased lipid accumulation was due to delaying the cell differentiation. The body weight and fat of obese mice induced with a high-fat diet were reduced by oral ingestion of Spm. In conclusion, oral supplementation of Spm has the ability to prevent obesity through inhibition of adipocyte differentiation.

Interruption of breast cancer care and importance of inter-hospital cooperation during the COVID-19 pandemic: A case report of advanced breast cancer in Fukushima, Japan.

We experienced the case of a patient with advanced breast cancer who failed to receive comprehensive care despite regular video conferencing with her physician during the COVID-19 pandemic, resulting in delayed detection of liver metastasis. Inter-hospital collaboration is required to provide uninterrupted cancer care to those disproportionately affected by crises.

Longitudinal study on the effect of keratinized mucosal augmentation surrounding dental implants in preventing peri-implant bone loss.

Background: Dental implant therapy is a well-established method of prosthetic rehabilitation of missing teeth. To maintain the health of the surrounding tissue, management of risk factors/indicators and daily maintenance are important. It still remains controversial whether a certain amount of keratinized mucosal width is essential for maintaining the health of peri-implant tissue. The purpose of this multicenter retrospective study was to assess the correlation between bone loss around dental implant and the amount of keratinized tissue width. Methods: A total of 1,644 implants were evaluated. Data was collected about participants' general and dental history, as well as implant details. Bone resorption around implant was calculated from intra-oral radiographs taken after 1 year and more than 3 years of function. Implants were classified into three groups; received free gingival graft or apically repositioned flap surgery for increasing the keratinized mucosa ≥2 mm width (group A), keratinized mucosa width ≥2 mm (group B), and keratinized mucosa width <2 mm (group C). These data were analyzed by propensity score analysis and a generalized linear regression analysis was performed to compare the bone resorption among groups. Results: Mean functional time was 55.8 months (SD = 20.5) in group A, 67.6 months (SD = 28.1) in group B, and 74.5 months (SD = 32.9) in group C. Mean bone resorption of groups A, B, and C were 0.08 mm (SD = 0.40), 0.18 mm (SD = 0.66), and 0.44 mm (SD = 0.40). Groups A and B had significantly lower bone resorption than group C. Conclusion: The results in this study show the importance of keratinized mucosa in maintaining the peri-implant bone. Our findings also suggest that mucosal transplantation is useful, as opposed to narrowing of the keratinized mucosa.