Gender differences among professionals dedicated to Oral Implantology in Spain: An observational study

Background Despite the development of society and the educational progress achieved at the university education level, women continue to face obstacles that hinder their professional development. This study aims to determine whether there are gender differences in a representative sample of professionals dedicated to Oral Implantology in Spain. Material and Methods This is a cross-sectional observational study based on the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. An electronic survey consisting of two blocks of questions was sent to members of the Spanish Society of Implants. The data were analyzed using descriptive analysis. Results A total of 303 participants (20.8%) responded to the questionnaire, of which 219 were men (72.3%) and 84 women (27.7%). Up to the age of 40 years, women predominate, whereas men predominate from the age of 51 years onwards, which is influenced by a greater number of years of experience in implant placement and a higher number of implants placed per year. Despite this, women have a higher level of training in Oral Implantology, as a greater proportion are trained through master’s degrees. Conclusions The greater representation of men in the study is associated with the ageing of the sample. The results obtained from the present study anticipate the trend of a greater presence of the female gender in Oral Implantology in Spain in the coming years. Key words:Sex differences, dentistry, oral implantology, feminism, gender.


Introduction
In recent years, there has been a significant increase in the number of women in the health sciences undergraduate degrees and, by extension, in dentistry (1,2). Despite this, women often encounter challenging attitudes and/or barriers to continuing or advancing in their profession. These include reasons such as lack of female mentors and role models, a greater burden of responsibility for parenting, lack of parity in rewards such as career advancement and salary, gender discrimination and sexual harassment (3). The influences of biological sex and gender, as well as the interactions between them, need to be explored to understand the challenges women dentists face in their careers. "Sex" is a biological concept and "gender" is a social construct that specifies the roles that men and women must follow socially and culturally (4). In this sense, family care responsibilities continue to fall disproportionately on women. This may explain why women abandon their careers at an advanced stage. Thus, although the profile of the dental profession has changed, career paths in dentistry, in many cases, continue to be gender-biased. A distinction can be made between horizontal and vertical gender segregation. Horizontal segregation is evident from differences in the choice of speciality, with female dentists preferring paediatric dentistry or orthodontics, and less interested in others, such as oral surgery, which are more associated with the male gender (5) In contrast, vertical gender segregation is reflected in the dental hierarchy. The highest positions in the academic field are mainly occupied by male dentists (6). On the other hand, a recent literature review showed that there are usually fewer female dental centre owners, they work 4-6 h less per week and see fewer patients than men, which ultimately translates into a wage gap. Also, there tends to be a lower proportion of women specialists, in university positions and leadership roles (7). This study aims to determine whether there are gender differences in a representative sample of professionals dedicated to Oral Implantology in Spain.

Material and Methods
-Study design A cross-sectional observational study was carried out following STROBE (8) (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Prior to the study, approval was obtained from the Ethics Committee of the Spanish Society of Implants (SEI -Sociedad Española de Implantes).
-Questionnaire A questionnaire was sent via Google Drive and was open to respondents from April to July 2020, during which time two reminders were sent so that those who had not answered the questionnaire could do so. The survey consisted of two blocks of closed questions. The first of these, consisting of 8 closed questions, inquired about general data relating to the professionals surveyed, such as demographic data, data related to academic training in the field of Oral Implantology, Oral Surgery, Periodontology, and/or their combinations, and professional data. Finally, a second block inquired about the treatments related to the implant placement.
-Participant Recruitment The survey was sent to all SEI members who did not express their wish not to receive e-mails (n= 1,460). Completion of the survey implied the participant's consent to the collection of this information. The final sample size consisted of those professionals who chose to fully respond to the survey (n= 303). Each participant could only respond to the electronic survey once, and the options for each question, as well as the questionnaire variables, are shown in Tables 1 and 2. There could be no selection bias, as the electronic survey was sent to all dentists registered in the SEI.
-Statistical analysis Questions were entered into Google Forms for electronic distribution and data collection. Data was exported to Microsoft Excel for cleaning and manipulation of variables for further analysis. The collected data were analyzed using IBM® SPSS Statistics v.26 (IBM® Corp., Armonk, NY, USA); 95% confidence intervals (CI) were applied. All study variables were treated quantitatively. A normality test was previously applied, observing that no variable followed a normal distribution, so the Mann-Whitney U test was applied for the crossover for dichotomous variables and Kruskal-Wallis for variables with more than two categories. The chi-squared test was used.

-Demographics
A total of 303 responses were obtained, representing a response rate of 20.8%. Being one of the three scientific societies currently existing in Spain related to implant placement, the study sample is considered representative. All the participants answered all the questions in the survey, as all the questions were established as compulsory, i.e., if a question was not answered, it was not possible to move on to the next one.

Discussion
The number of men surveyed was 44.6% higher than that of women (72.3% vs. 27.7%, respectively). Women's access to Spanish universities was regulated in 1910. Since then, their presence has gradually increased. In this sense, in the studies of Medicine, the female gender went from 5.5% in the academic year 1940/41 to 20.2% in the academic year 1969/70 (9) In the last quarter of the 20th century, coinciding with the democratic period, there was a substantial change for women at the university level (10). Data published by the Spa-nish Ministry of Education (11) show that, during the 2008/09 academic year, the percentage of women enrolled in Spanish universities was 54.4% compared to 45.6% of men. In the 2017/18 academic year and, for the undergraduate level of education, the rate of female enrolment was 52.3% compared to 33.8% of male enrolment. In the 2019/20 academic year, the representation of women in the Health Sciences field was 70.8% (1). These data are in line with those obtained in this study, observing a clear female predominance in ages younger than 41 years, matching the male gender in the age category from 41 to 50 years, and a notable increase of men from 51 years onwards, the latter age range representing 59.74% of the sample (n= 181). An additional reason for the lower proportion of women in our study could be a lower preference for surgical specialities (including Oral Implantology) (12,13), perhaps because, in general, men place more value on financial rewards and manual dexterity skills when choosing their "speciality", while women's motivation is focused on personal rewards (14,15), with specialities such as Orthodontics and/or Paediatric Dentistry being more attractive. Even though male representation is significantly higher in the sample studied, it is foreseeable that in approximately 15 years there will be a clear feminisation of Oral Implantology in Spain, coinciding with the retirement of professionals who are currently over 51 years of age. Feminisation can be defined as (a) an increase in female representation in a given profession and/or (b) changes in the current practices of a profession given the participation of women (16). This feminisation is not only manifested in the subgroup of oral implantologists but also the profession in general. In this regard, the General Council of Dentists of Spain observed an increase in the number of women from 1994 (29.54%) to 2020 (44.37%) (2).
-Limitations and future lines of research As this is a survey-based study, it is not possible to establish with certainly the veracity of the answers provided by the participants. Future lines of research should be aimed at finding out whether there are differences in salaries and on the possibility of being able to combine personal and family life with work, to identify barriers that could equal professional development for men and women.

Conclusions
The gender differences found in this study are related to the latter access of women to the university environment. However, the greater representation of men in the sample studied is associated with a greater presence of older respondents. This fact means that the male respondents have more experience in years of practice with a lower level of postgraduate training compared to the female gender. The results obtained from the present study anticipate the trend of a greater presence of the female gender in Oral Implantology in Spain.