Oral Health Status of Workers in Acid Exposure Environments in Japan: A Cross-sectional Study.

Although the working environment may play a role in dental acid erosion, few studies have been conducted on this in Japanese workers in recent years. The purpose of this study was to investigate oral health status, including dental erosion, in workers who may have been exposed to an acidic environment. The study participants were recruited by an online research company. Oral examinations and questionnaire surveys were conducted on this cohort in January 2023. A total of 144 participants were finally included. Workers exposed to an acidic environment showed more use of protective equipment and underwent more dental examinations at the workplace (p<0.001). Possible dental erosion was observed in only 3 out of the total of 144 participants (2.1%), however. No significant difference was observed in the number of teeth, caries experience, or dental erosion according to the number of years of acid exposure in the workplace. The results of this study suggest that acid exposure exerts a relatively small effect on the oral health status of workers in Japan.

Survival Rate of 3-unit Fixed Partial Dentures Replacing First Molars: A Retrospective Cohort Study.

Fixed partial dentures (FPDs) made of 12% Au-Pd alloy are covered under Japan's national health insurance system. The survival rate of such 3-unit fixed FPDs remains unknown, however. The purpose of this retrospective study was to assess their survival rate in the replacement of first molars. A total of 140 FPDs were included, and the endpoint was removal of an FPD. During the observation period, 43 FPDs were removed. The FPD survival rate was 70.2% at 10 yr, 58.2% at 15 yr, and 42.1% at 20 yr according to the Kaplan-Meier method. The estimated mean survival period was 19.4 yr. The main reasons for FPD loss were dental caries (27.9%), separation from the abutment tooth (18.6%), and pulpitis (18.6%). Single factor analysis using the log-rank test showed that two factors influenced FPD survival: a smaller gonial angle and deep pockets around the abutment teeth. This effect was not statistically significant in either case, however (p>0.05). The present results suggest that the prevention of caries and of the separation of the dentures from the abutment teeth are important factors in the long-term survival of FPDs.

Survival Rate of Removable Partial Dentures with Mandibular Bilateral Free End Saddle: A Retrospective Study.

The purpose of this study was to investigate the survival of removable partial dentures with a mandibular bilateral free end saddle (BFES) and abutment teeth in a clinical setting. Only mandibular dentures with a BFES were included (10 or fewer present teeth, and fewer than 4 occlusal units). The endpoints were replacement of denture and loss of abutment teeth. A total of 128 dentures and 595 abutment teeth were analyzed. Nineteen dentures had to be replaced during the observation period (mean duration: 11.4±6.9 years; range: 3 to 36 years). According to Kaplan-Meier analysis, the survival rate was 93.2% at 10 years and 68.6% at 20 years. The estimated mean survival period was 27.8 years. Single-factor analysis using the log-rank test showed that no factor investigated had a significant influence. The main reason for denture replacement was loss of abutment teeth (47.4%). The survival rate of the abutment teeth was 91.3% at 10 years and 77.3% at 20 years. The analysis revealed 4 significant risk factors: male sex (hazard ratio [HR]: 1.78); premolars (HR: 1.67); a lower number of abutment teeth (HR: 3.24); and history of endodontic treatment (HR: 2.79). The removable partial dentures with a mandibular BFES in this study lasted over 20 years, and their survival was influenced by loss of abutment teeth. Dentures are used continuously over long periods of time and should therefore be designed to allow easy adjustment when abutment teeth are lost.

Survival rate of removable partial dentures with complete arch reconstruction using double crowns: a retrospective study.

OBJECTIVES: The purpose of this study was to clinically investigate double-crown-retained removable partial dentures (DRPDs) and abutment teeth at dental clinics. MATERIALS AND METHODS: Only cases with complete arch reconstruction were included. Endpoints were replacement of denture and loss of abutment tooth. A total of 213 dentures with 1030 abutment teeth were analyzed. RESULTS: During the observation period, 32 dentures were replaced. The mean observation period was 12.7 (± 6.6) years (range 3 to 36). By the Kaplan-Meier method, survival rate at 10 years was 94.7% and at 20 years was 70.8%. Estimated mean survival period was 27.1 years. Cox regression analysis showed that risk factor for replacement was good occlusion as indicated by Eichner index groups A to B3 (HR 2.81). The main reason for denture replacement was loss of abutment teeth. Survival rate of abutment teeth at 10 years was 83.8% and at 20 years was 66.3%. The analysis revealed six risk factors: male gender (HR 1.76), age range 65-89 years (HR 1.51), posterior teeth (HR 1.60), higher number of present teeth in opposite jaw (HR 1.69), lower number of abutment teeth (HR 1.76), and short inner crown (HR 2.28). CONCLUSION: DRPDs last over 20 years, making them a durable investment in one's oral health; their survival is influenced by loss of abutment teeth. CLINICAL RELEVANCE: In cases where there are few teeth remaining in a jaw, DRPDs represent a suitable treatment that makes use of the remaining teeth, even if the abutment teeth are non-vital.

Relationship between Obesity Indicators and Gingival Inflammation in Middle-aged Japanese Men.

The purpose of this study was to investigate the relationship among the waist-to-height ratio (WHtR) and the body mass index (BMI) as obesity indicators and gingival inflammation as determined by bleeding on probing (BOP). The participants comprised employees of a milk products company based in Tokyo, Japan. A total of 159 non-diabetic men aged 40 to 59 yr and with a minimum of 28 teeth were included. Multiple logistic regression analysis controlling for age, smoking status, pocket depth, frequency of daily brushing, frequency of weekly interdental brushing, and regular dental attendance was performed to compare the relationships among the obesity indicators and BOP. Participants with good oral hygiene had significantly less BOP than those with poor oral hygiene (p<0.001). No significant differences were observed among the other items investigated. A significant association was observed between WHtR and BOP (odds ratio: 2.40, 95% confidence interval: 1.11-5.22); no such association was observed with the BMI, however. The present results showed that obesity, as determined according to a visceral fat index, was associated with BOP, but not with BMI. This suggests that the WHtR is a more accurate index of obesity than the BMI in studies on BOP.

Perceived Body Distortion Rather Than Actual Body Distortion Is Associated With Chronic Low Back Pain in Adults With Cerebral Palsy: A Preliminary Investigation.

OBJECTIVES: The aim of the present study was to investigate whether distorted body perception is a feature of the low back pain (LBP) experience in people with cerebral palsy (CP) and whether any distortions noted are confounded by the presence of motor and postural impairments commonly seen in CP. METHODS: Forty-five individuals participated in this study: 15 adults with CP with LBP (CP_Pain group), 15 adults with CP without LBP (CP_noPain group), and 15 age-matched adults with LBP but no CP (Pain group). Body perception was evaluated using the Fremantle Back Awareness Questionnaire (FreBAQ) and by assessing 2-point discrimination thresholds over the low back. A comprehensive assessment of motor function was also undertaken in the CP population, and postural function was assessed in all 3 groups. RESULTS: Significant differences between the 3 groups were found for FreBAQ scores (P < 0.0001). The TPD threshold in the low back of the CP_Pain group was significantly larger than that of the CP_noPain group (P = 0.01), though we found no difference between the CP_noPain group and the Pain group (P = 0.21). We found no difference in motor or postural function between the 2 CP groups. DISCUSSION: The present results suggest that body image is disrupted in people with CP who experience LBP. The disruptions in perception were similar to those seen in people with LBP and no CP, suggesting that the distortions may be more related to the presence of pain than the presence of CP.

Factors Associated with Untreated Decayed Teeth in Male Sales Workers: An Internet Survey.

The purpose of this study was to identify factors associated with untreated decayed teeth (DT) in male sales workers. The participants were recruited by screening a pool of Japanese registrants in an online database for eligibility for inclusion in the study. Between 20 February 2015 and 11 March 2015, those deemed eligible were asked to complete a questionnaire on the status of their oral health. Responses from a total of 142 male sales workers aged between 30 and 49 years were analyzed. Of these, 40 reported DT and 102 no untreated decayed teeth (NDT). The percentage of participants with DT was higher than that with NDT among night shift workers (p<0.001). A higher percentage of participants with DT reported pain when eating or drinking something cold (p=0.041), pain in the teeth or gingiva (p<0.001), or frequent stomatitis (p=0.030). A higher percentage of participants with DT reported eating between meals (p=0.027) and a lower percentage visiting a dental clinic in the past 6 months (p=0.017) compared with among participants with NDT. Those with NDT were more likely to report an inability to visit a dental clinic when they wanted to (p=0.033), but those with DT were more likely to report that their reasons for not visiting a dental clinic were that multiple visits were required for treatment (p=0.012) or that they did not like the treatment (p=0.005). Working the night shift (Odds Ratio [OR], 3.492; 95% Confidence Interval [CI], 1.347-8.725) and visiting a dental clinic in the past 6 months (OR, 0.084; 95%CI, 0.010-0.733) were identified as independent variables correlated with leaving DT untreated. Requiring oral health education and dental checkups at least once every 6 months may have a positive effect on oral health among male sales workers, especially those doing night shifts.

Relationship between Blood HbA1c Level and Decayed Teeth in Patients with Type 2 Diabetes: A Cross-sectional Study.

The purpose of this cross-sectional study was to determine whether there is an association between hemoglobin A1c (HbA1c) level and the presence or absence of decayed teeth in patients with type 2 diabetes mellitus. The patients and data on their age and sex, the presence or absence of dental claims, medical history of diabetes mellitus, and workplace dental examinations were obtained from a Japanese healthcare database available for epidemiological studies. The HbA1c levels were obtained from results of the Specific Health Checkups and Specific Health Guidance tests conducted by the Japanese Ministry of Health, Labour and Welfare. Data on a total of 1,897 patients were analyzed. Patients with poorly controlled diabetes (HbA1c≥6.5, n=779) had more decayed teeth than those in whom it was well controlled (HbA1c<6.5, n=1,118). Multiple logistic regression analysis with the presence or absence of decayed teeth as a dependent variable revealed a significant association between an HbA1c level of ≥8.0 and decayed teeth (odds ratio: 1.69; 95% confidence interval, 1.24-2.29), even after adjusting for dental attendance. This suggests that a poorly controlled blood HbA1c level is a risk factor for dental caries. More thorough oral hygiene instruction and education on preventive treatment for dental caries in patients with poorly controlled diabetes are needed.

Duration from Initial Symptoms to Diagnosis of Vertical Root Fracture in Dental Offices.

Diagnosing vertical root fracture (VRF) is difficult. Here, we retrospectively investigated the duration from initial symptoms to a definite diagnosis of VRF in dental offices. Data were collected on patients with VRF between July 2013 and June 2015. Initial symptoms were ascertained from clinical records. The focus was on the maxillary second premolars and mesial roots of the mandibular first molars, where VRF is most frequent. All VRF in the bilateral dentition was analyzed. Only cases in which the buccal-lingual plane of the root was fractured were included. Data from 31 dental offices revealed a total of 39 VRFs in the maxillary second premolars and 43 in the mandibular mesial roots of the first molars. The patients comprised 42 males and 40 females, and the average age was 59.7±11.6 years at initial onset of symptoms. The mean duration from initial symptoms to a definite diagnosis in the maxillary second premolars was 18.3±22.5 months, while that in the mandibular first molars was 16.1±17.8 months. The cumulative diagnostic rate was 48.7% at 12 months and 79.5% at 24 months in the maxillary second premolars, and 38.1% at 12 months and 86.0% at 24 months in the mandibular first molars. No significant difference was observed between tooth type. If VRF is suspected, doctors should explain the risks of tooth extraction and begin considering treatment options. The present results revealed that 80% of VRFs were diagnosed within 2 years of initial onset of symptoms.

Relationship between Time from Full Pulpotomy to Definitive Diagnosis of Vertical Root Fracture and Patient Age.

The goal of this study was to investigate length of time between full pulpotomy and a definitive diagnosis of vertical root fracture (VRF), as well as the age at which this was made. The participants comprised 63 dental patients (40 men and 23 women) with a mean age of 65.7±10.4 years in whom a definitive diagnosis of VRF had been made between July 2013 and June 2015, and who had also undergone a full pulpotomy. The data on all these cases were obtained from 22 dental clinics belonging to a clinical study group. The mean duration between a full pulpotomy and a definitive diagnosis of VRF was 141.0±88.9 months. The results showed no differences in terms of sex, mandible/maxilla, or tooth type. No relationship was observed between age at which the diagnosis was made and length of time between full pulpotomy and diagnosis (Pearson correlation coefficient = 0.162) (p>0.05). Most diagnoses of VRF were made in patients aged over 50 years, irrespective of length of time between full pulpotomy and the diagnosis. These results suggest that age is a stronger indicator of VRF than length of time between full pulpotomy and a definitive diagnosis.

Working Environment Factors Associated with Regular Dental Attendance.

The aim of this study was to identify factors in the working environment associated with regular dental attendance. Thirty-three general practitioners provided data on 488 patients who underwent dental maintenance between 2003 and 2015. The age of the patients ranged from 40 to 65 years. Appointment adherence, employment format, overtime work, night work, and subjective evaluation of work were investigated. Multiple logistic regression analysis was performed to identify factors associated with regular dental attendance. Among all participants, 296 (60.7%) were female, 320 (65.6%) worked full-time, 193 (39.5%) worked overtime, and 34 (7.0%) worked nights. The results of the analysis revealed that only night work was a significant factor after adjusting for sex, age, and employment format (odds ratio, 0.220; 95% confidence interval, 0.088-0.550). The results of this study suggest that night work disturbs regular dental attendance.

Number of Non-vital Teeth as Indicator of Tooth Loss during 10-year Maintenance: A Retrospective Study.

The purpose of this study was to investigate whether number of non-vital teeth was an indicator of tooth loss during maintenance. Thirty-three general practitioners provided data on 321 patients undergoing maintenance over 10 years. The number of present teeth (PT), smoking status, level of bone loss, number of non-vital teeth, and reason for tooth loss during that period were investigated. Multiple logistic regression was performed to identify whether the number of non-vital teeth was associated with tooth loss. The average number of lost teeth was 1.07±1.82; that of PT at baseline was 24.4±3.9; and that of non-vital teeth at baseline was 5.4±4.5. Multiple logistic regression revealed a significant association between >8 non-vital teeth and tooth loss during maintenance (odds ratio [OR]: 2.40; 95% confidence interval [CI]: 1.18-4.87). It also demonstrated relationships between >8 non-vital teeth and root fracture or caries (OR: 3.90; 95%CI: 1.68-9.03 or OR: 2.85, 95%CI: 1.14-7.10, respectively). The number of non-vital teeth was associated with tooth loss during maintenance. The results suggest that patients with many non-vital teeth before commencement of maintenance are particularly at risk of tooth loss due to root fracture or caries. Therefore, the number of non-vital teeth offers a useful indicator of potential tooth loss.

Tooth Loss in Problem-oriented, Irregular, and Regular Attenders at Dental Offices.

The aim of this retrospective study was to compare number of teeth lost among regular attenders (RAs), irregular attenders (IRAs), and problem-oriented attenders (POAs) at dental offices over a 10-yr observation period. Information on tooth loss was obtained from general practitioners. Patients were divided into 3 groups based on appointment adherence. A total of 1,886 teeth were lost in 1,400 patients. The mean number of teeth lost in men was 2.2±2.6 per patient over 10 yr in POAs, 1.2±1.7 in IRAs, and 1.5±1.5 in RAs. This number was significantly lower in IRAs (p = 0.011) or RAs (p=0.012) than in POAs. When the dependent variable was defined as "a patient with at least 2 or more extracted teeth", the independent variables showed the following correlations with tooth loss: IRAs (OR: 0.54; 95%CI: 0.35-0.84), RAs (OR: 0.65; 95%CI: 0.47-0.89), man (OR: 1.43; 95%CI: 1.11-1.83), hypertension (OR: 1.38; 95%CI: 1.04-1.85), 20-25 present teeth (OR: 2.41; 95%CI: 1.81-3.22), and 1-19 present teeth (OR: 3.75; 95%CI: 2.73-5.16). The risk of tooth loss showed a 0.65-fold increase in RAs undergoing maintenance compared with POAs. Motivating patients to visit the dentist more regularly and undergo maintenance is important. The present results may be of use to dental professionals in providing patients with detailed information on potential tooth loss and associated risk factors with the aim of achieving such a change in behavior.

Relationship between Obstructive Sleep Apnea and Self-assessed Oral Health Status: An Internet Survey.

The purpose of this study based on a cross-sectional internet survey was to investigate the relationship between risk of obstructive sleep apnea (OSA) and self-assessed oral health status. The participants, who comprised individuals registered with an online research company, were required to complete a self-reported questionnaire. Those answering in the affirmative to both of the following two questions were placed in the OSA-risk group, while those answering in the negative were assigned to the control group: 'Have other people noticed pauses in your breathing while you are sleeping?' and 'Do you feel excessively sleepy during the daytime?'. A total of 493 were included in the OSA-risk group and 2,560 in the control group. Among the total 3,053 respondents, the highest prevalence for OSA risk in men was in the 50-59-year age range, although this tended to level off after age 60 years. No such trend was observed in women, however. Multiple logistic regression analysis was performed to identify the relationship between risk of OSA and self-assessed oral health status. Significant correlations were observed with the following parameters: difficulty in opening mouth (odds ratio [OR]: 2.66; 95% confidence interval [CI]: 1.647-4.311), dry mouth (OR: 2.11; CI: 1.544-2.876), bad breath (OR: 1.69; CI: 1.309-2.186), gingival bleeding (OR: 1.48; CI: 1.134-1.932), and gingival swelling (OR: 1.44; CI: 1.046-1.981). These results suggest a relationship between risk of OSA and self-assessed oral health status, indicating that treating OSA might improve oral health status. Further study is needed to demonstrate a causal relationship between OSA and self-assessed oral health status, however.

Prevalence of vertical root fracture as the reason for tooth extraction in dental clinics.

OBJECTIVES: The aim of this study was to investigate the prevalence, by gender, of vertical root fracture (VRF) as the main reason for the extraction of permanent teeth in dental clinics in Tokyo. MATERIALS AND METHODS: Participating dentists were requested to provide information about extractions of permanent teeth they had performed from 1 January 2013 to 30 June 2013. The main reasons for extraction were categorized as follows: VRF, caries (horizontal root fracture included), periodontal disease and others. RESULTS: At a total of 24 clinics, 736 teeth were extracted from 626 patients during the 6-month period. A total of 233 teeth were extracted by VRF (31.7%), and 93.6% of these were endodontically treated teeth. Among non-vital extracted teeth, 82.1% (179/218) had cast posts or screw posts. The percentage of extraction due to VRF was 29.4% in males and 34.7% in females. In females, the percentage of extractions due to VRF (34.7%) was higher than for periodontal disease (28.1%). In males, the percentage of extractions due to VRF increased with age (p < 0.05). The tooth types with the highest percentage of extractions due to VRF were the upper canine (46.7%), lower second premolar (48.0%) and lower first molar (50.0%) in males and the upper first premolar (43.3%), upper second premolar (44.4%), lower second premolar (53.8%) and lower first molar (54.5%) in females. CONCLUSIONS: These results indicate that we need to pay more attention to maintaining vital teeth while being aware of the particular tooth types in which VRF most frequently occurs.

Estimated tooth loss based on number of present teeth in Japanese adults using national surveys of dental disease.

Oral health instruction for adults should take into account the potential effect of tooth loss, as this has been suggested to predict further tooth loss. Therefore, the purpose of this study was to determine whether further tooth loss could be predicted from the number of present teeth (PT). We employed the same method as in our previous study, this time using two national surveys of dental disease, which were deemed to represent a generational cohort. Percentiles were estimated using the cumulative frequency distribution of PT from the two surveys. The first was a survey of 704 participants aged 50-59 years conducted in 2005, and the second was a survey of 747 participants aged 56-65 years conducted in 2011. The 1st to 100th percentiles of the number of PT were calculated for both age groups. Using these percentiles and a generational cohort analysis based on the two surveys, the number of teeth lost per year could be calculated. The distribution of number of teeth lost generated a convex curve. Peak tooth loss occurred at around 12-14 PT, with 0.54 teeth being lost per year. The percentage of teeth lost (per number of PT) increased as number of PT decreased. The results confirmed that tooth loss promotes further tooth loss. These data should be made available for use in adult oral health education.

Sex- and age-based differences in single tooth loss in adults.

The aim of this study was to investigate sex- and age-based differences in single tooth loss in adults. The data were obtained from the results of a periodontal disease examination carried out under a health promotion law in a city in Japan in 2005. Baseline data from a total of 3,872 participants aged 40 or 60 years comprising 1,302 men and 2,570 women were available. Only participants with 27 present teeth were eligible for inclusion in the analysis, giving a total of 218 men and 428 women. Third molars were excluded from the study. The bilateral total of each type of tooth was obtained. The mandibular first molar was missing in 26.7% of the men and 36.2% of the women among 40-year-olds and 35.3% of the men and 29.8% of the women among 60-year-olds. The mandibular second molar was missing in 14.7% of the men and 12.5% of the women among 40-year-olds, and 17.6% of the men and 18.4% of the women among 60-year-olds. Significant differences were observed between men and women in the mandibular second premolars and first molars among 40-year-olds. These results suggest that we need to pay more attention to individual teeth which are at particularly high risk for tooth loss, namely the mandibular first and second molars, and especially the mandibular first molars in middle-aged women.

Risk factors affecting third molar autotransplantation during 5 and 10 years.

The aim of this study was to investigate risk factors affecting 5- and 10-year survival in autotransplantation of third molars with complete root formation at dental clinics. Participating dentists were requested to provide information on transplantations performed between 1 January 1990 and 31 December 2009. After data screening and elimination, 183 teeth in 171 men aged 20-72 years (mean, 44.8 years) and 205 teeth in 189 women aged 20-74 years (mean, 42.0 years) were included in the study. A single-factor analysis using the log-rank test revealed that the following factors had a significant influence (p<0.05) on 5-year survival in transplanted teeth in men: recipient site in the maxilla and fewer than 25 present teeth; those for 10-year survival, on the other hand, were recipient site tooth extraction due to periodontal disease, recipient site in the maxilla, fewer than 25 present teeth, and Eichner index Group B1 to C. Cox regression analysis revealed that the odds ratio for 5-year survival for recipient site in the maxilla was 2.873 (95% CI, 1.073-7.695), while that for 10-year survival was 3.713 (95% CI, 1.601-8.609) for recipient site extraction due to periodontal disease, 2.190 (95% CI, 1.021-4.700) for recipient site in the maxilla, and 3.110 (95% CI, 1.470-6.581) for fewer than 25 present teeth. In women, the log-rank test indicated experience of less than 10-year in performing treatment as a significant factor (p <0.05) in 5-year survival. These results suggest that medium-term survival in transplanted teeth is influenced by operational risk factors in women, while long-term survival in transplanted teeth is influenced by individual oral status in men.

Estimated percentile curves of occluding pairs in an adult population.

The purpose of this study was to provide the estimated percentile curves of occlusal pairs (OPs) in adults for use in oral health instruction. Data on number of present teeth (PT) were obtained from the National Report on the Survey of Dental Disease in 2005. Data from 1,535 males and 2,248 females, ranging in age from 18 to 82, were analysed. The mean number of OPs were used from our previous report. In that report we can be estimated OPs from the number of PT. In this study, PT data were replaced by the mean number of OPs. Estimated percentile curves in males, the 10th percentile of OPs was 13.7 at 60 years of age and 12.5 at 70. The 50th percentile of OPs was 12.2 at 50 years of age, 11.2 at 60 and 5.4 at 70. The 90th percentile of OPs was 7.6 at 50 years of age, 2.1 at 60 and 0 at 70. There appeared to be a cut off point after 10 OPs where the 50th to 97th percentile curves of OPs dropped off rapidly. In females, the 10th percentile of OPs was 13.4 at 60 years of age and 12.7 at 70. The 50th percentile of OPs was 11.5 at 50 years of age, 10.2 at 60 and 6.2 at 70. The 90th percentile of OPs was 7.1 at 50 years of age, 2.4 at 60 and 0 at 70. In females again the percentile curves dropped off after 10 OPs. Our results suggest that the loss of OPs may be accelerated when the number of OPs drops below 10. This means that patients need at least 10 OPs in order to maintain a stable oral status. The estimated percentile curves given in this study should be made available for use in adult oral health education.

Survival rate in autotransplanted premolars with complete root formation: a retrospective clinical survey.

The purpose of this study was to analyze the survival rate in autotransplanted premolars with complete root formation in dental clinics. Participating dentists were requested to provide information on transplantations they had undertaken between 1 January 1990 and 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. Data for other tooth types and for teeth with incomplete root formation were eliminated. In this study, data on 40 teeth in 35 patients were analyzed. Participants consisted of 17 men and 18 women ranging from 24 to 79 years in age (mean age, 43.7 years). The cumulative survival rate was 100% at the 5-year mark and 72.7% at 10 years, as calculated by the Kaplan-Meier method. Single-factor analysis revealed that "transplanted to the molar regions" was a significant risk factor (p<0.05) influencing the survival of transplanted teeth. However, a Cox regression analysis showed no significance. The results of this study suggest that, in cases where there is a suitable donor tooth and the oral condition is good, premolar autotransplantation is a viable treatment option, even when there is complete root formation in the donor teeth.