Young Mature Group

Subject and methods: The sample included 28 patients divided into two groups. A "young adult" group consisting of 14 patients, aged from 15.5 to 21 years, and a "mature adult" group consisting of 14 patients, aged from 40 to 55 years. All patients presented missing anterior teeth, requiring insertion of 40 implant fixtures (16 central incisors, 12 lateral incisors, 12 canines). The implants were of the Straumann Dental Implant System, clinically and radiologically re-evaluated 1 year or more after the surgical procedure (mean interval=4.2 years). Assessment of the eruption of the adjacent teeth was performed using the implant as a stable point of reference: measurements of the different reference points were compared after implant placement and at follow-up examination.

young mature group

Results: In the "young adult" group, all patients showed infra-occlusion of the implant-supported crowns: the vertical step measured on radiographs varied between 0.1 and 1.65 mm. In the "mature adult" group, all patients showed a vertical difference between the teeth adjacent to the implant-supported crown and the implant: the measured step ranged from 0.12 to 1.86 mm. No difference was found in the amount of vertical eruption between male and female patients, nor according to localization of the implant.

Conclusion: Mature adults can exhibit major vertical steps after anterior restorations with osseointegrated fixtures to the same extent as adolescents or "young adult" individuals with residuous growth potential.

As a special driving behavior, distracted driving has also been the focus of studies regarding individual executive function differences. For example, Hayashi et al. investigated the relationship between executive functions and texting while driving in college students, Texting while driving was found to be strongly correlated with a low level of impulse control [23]. A study by Louie and Mouloua found that higher working memory capacity could improve the distracted driving performance of undergraduate students [24]. These studies mainly focused on younger population, as they still developed for executive functions until the age of 25 [9]. In addition, Pope et al. investigated the relationship between age, executive function, and self-reported distracted driving behaviors. The results revealed that global executive difficulty was significantly related to distracted driving behaviors, and the relationship between age and distracted driving behavior was partially mediated by global executive difficulty [25]. Previous studies have suggested risky behaviors, such as the willingness to engage in distracted driving, are dependent on the balance between cognitive control and socioemotional systems. The cognitive control system consists of multiple executive functions, such as planning, working memory, and impulse control, which enables the prevention of risky behavior and adaptation to task goals. Socioemotional systems are involved in response to emotions, thrills, social cues, and environmental sensations, which can lead to risk-taking [26, 27]. This suggests that mature drivers (25 years old and over) may also need to employ the cognitive control system to withstand willingness to engage in distracted driving as young drivers (below 25 years old) do. However, it is not clear whether the role of specific executive functions differ considerably in different age groups.

Therefore, further research is required to analyze the effect of executive function on distracted driving behaviors in young and mature drivers. In the present study, the correlations between executive functions and distracted driving behaviors are re-examined in different aged populations. Executive Function Index (EFI) has been developed to assess the level of executive functions in a normal population and verified as highly effective in the study of driving behaviors [28, 29], and is used in this study. A distracted driving questionnaire, including various distracted behaviors in daily life, is applied for the assessment of distracted driving behaviors [30]. Furthermore, according to the results of previous research, two hypotheses are proposed. The first is that mature drivers perform better in executive functions and distracted driving behavior than young drivers. The second is that the effect of executive functions on distracted driving behavior is comparable for young and mature drivers.

In the present study, a composite score of distracted driving behavior was investigated as a dependent variable. Similar to previous studies, to examine the differences between two age groups, all participants were classified into a young group (younger than 25 years) or mature group (25 years and above) [33]. About 50.7% of the participants were classified as the young group and the remaining 49.3% as the mature group. No significant age differences were found between male and female participants (F(1, 136) = 1.337, p = 0.250). First, independent sample t-tests were conducted for five executive functions and distracted driving variables to examine any differences between the young and mature groups. Second, to compare and determine the differences between younger and older drivers, correlation tests between each executive function score and distracted driving behavior were performed. The correlation coefficients were calculated separately for young drivers and mature drivers, then a z-score of the comparisons between age groups was calculated to identify the statistical difference of the correlation coefficients [22]. Finally, to further determine the relative contributions of age, gender, and the five executive functions on distracted driving behaviors, multiple hierarchical regression modeling was carried out using a forward step-wise strategy. The computer software SPSS 22.0 was used in the present study.

Results of independent sample t-tests for major variables are presented in Table 1, revealing that mature drivers had significantly higher IC (p = 0.004) and EFI (p = 0.049) scores than younger drivers. A significant age difference was also found in driving performance, with mature drivers performing better on the measure of distracted driving behavior (p = 0.030) than young drivers. The score of EFI total and distracted driving behavior for young and mature groups is provided in Fig 1.

Partial correlation analysis was conducted between each executive function variable and distracted driving behavior while controlling the variables of age and gender (see Table 2). For young drivers, distracted driving behavior was significantly negatively correlated with scores of MD (r = -0.469, p

To compare the relationships between each executive function variable and distracted driving behavior, the z-score of the correlation coefficient comparisons between young and mature groups was calculated, as shown in Table 3. The results revealed the z-scores of these comparisons were less than 1.96 and greater than -1.96 (p > 0.05), suggesting that the relationship between distracted driving behavior and executive functions did not significantly differ between young and mature drivers.

As seen in Table 4, the full hierarchical regression model among young drivers was found to be significant, F(5, 64) = 6.466, p

As seen in Table 5, the full hierarchical regression model among mature drivers was also found to be significant, F(5, 62) = 4.368, p = 0.002, accounting for 26.0% of the total variance. The full model revealed that IC (p = 0.031) and MD (p = 0.002) significantly contributed to the predictive model, the negative coefficients of IC (-0.272) and MD (-0.391) suggested that the frequency of distracted driving behavior increased as the score of IC or MD decreased. Other predictors, including EM, ORG, and SP, were not found to be significant in the full model. The final model revealed the relative contribution of significant predictors on the distracted driving behavior of mature drivers, MD did significantly contributed to the model at step one, F(1, 66) = 15.745, p

The current study aimed to explore and compare the behavioral and cognitive processes underlying distracted driving behaviors in young and mature drivers. Five subcategories of executive function, including motivational drive, organization, strategic planning, impulse control, and empathy, were investigated as independent variables, and distracted driving behaviors were investigated as dependent variables. The first hypothesis regarding mature drivers performing better in executive functions and distracted driving behavior than young drivers was partly supported. In particular, mature drivers had significantly higher IC and EFI scores than young drivers, and a notable age difference was also found in the measure of distracted driving behavior. The results of our study also supported the second hypothesis that the effect of executive functions on distracted driving behavior would be comparable for both age groups, with an insignificant z-score of the correlation coefficient comparisons between young and mature groups. Furthermore, the relative influence of specific executive function on distracted driving behavior was found to be significantly different, IC and MD contributed more to distracted driving behavior than others in the hierarchical regression models. 041b061a72