Age and gender related tooth loss and partial edentulism among the adulthoods

Aim: Despite the improvements in preventive measures and restorative techniques in dentistry, tooth loss still remains as a significant problem. The determination of the edentulism prevelance may provide a new perspective for the patientoriented treatment alternatives. The aim of the study was to evaluate the influence of gender and age on the prevelance of tooth loss. Material and Methods: The data were gathered from the randomly selected 722 diagnostic models obtained from the patients consulting to the Ankara University, Faculty of Dentistry, between 2015 and 2016. Models were evaluated under 6 groups as followings; full dentition, Kennedy Class I-IV and total edentulism. Each model was classified according to the gender and age. Statistical analysis were performed by using Chi-Square test and log-linear model analysis and odds ratios also calculated (p<0,05). Results: Gender has no effect on the edentulism whereas age significantly affects the number of tooth loss and the prevelance of edentulism. The loss prevelance of teeth 34, 36 and 37 was higher in females, while the tooth 24 loss was more common in male patients (p<0,05). Conclusion: The number of tooth loss and edentulism significantly increase with the age. However, there was no relation between gender and prevelance of tooth loss and edentulism. prevention measures for oral health should be increased in elderly people.


Introduction
Despite the advances in preventive dentistry, there is still an increase in the rate of edentulous patients [1,2]. Oral health, affects general health considerably, is directly related to quality of life. Until recently, the importance of general health status in terms of quality of life has been more important, but over time the relationship with oral health has gain popularity [3].
Tooth loss, one of the most important indicators of oral health, is in the relationship with specific diseases, age, sex, oral hygiene, socioeconomic factors, uncontrolled chewing forces, gingivitis, and periodontitis. Functional, phonation and aesthetic disorders resulting from tooth loss are the factors that affect the dental, general health and quality of life of the patient and should be treated [1]. According to the World Health Organization, an adult must have a minimum of 21 functional teeth in order to be able to function properly [4]. The Kennedy classification is subdivided into subclasses called modification for classes with additional toothless area with the modification classification of Applegate and this clasification is the most widely accepted classification in dentistry [6].
In 1920, Dr. E. Cummer reported that there were about 65,000 combinations between teeth and toothless area in a single jaw, in the classification of partial edentulousim and that the maxilla had more than 131.30 in this variety [7]. Some studies stated that tooth loss was more common for male than female, contrary to this; some studies stated that females lost more teeth than males and were more prone to toothloss than males. In addition, in some studies it has been determined that premolar and molar teeth are the most commonly missed teeth [10,11,12].
It was stated that the most common class in most countries was Kennedy Class III [13,14], whereas in Turkish pouplation the most common partial edentulousim was Kennedy Class I and the least common partial edentulousim was Kennedy Class IV and the prevelance of tooth loss was high (73%) [15].
The aim of this study is to evaluate the effect of age and gender on the partial edentulism classification and tooth loss of the Turkish population in Ankara region. The nullhypothesis of this study is that age and gender have no effect on tooth loss and partial edentulism distribution, and no differences on the distribution rate of Kennedy classification in Ankara region.

Material and Methods
This study was conducted in Ankara University, Faculty of  (Table 1). This study has been provided local ethics committee and informed consents were obtained from all participants.

Statistical Analysis
Chi-Square test and logarithmic linear model analysis were used to determine the statistical significance (p<0,05). Odds ratios between the variables were also calculated to confirm the statistical data.

Results
The percentage of Kennedy classification for maxilla and mandible from high to low is Kennedy I, II, III, full dentate, total edentulism and Kennedy IV respectively. According to results of the study, tooth loss and Kennedy classification differences observed between female and male individuals (sex) were not statistically significant.
The age factor was found to be statistically significant (p≤0.05).
The Kennedy classifications showed statistically different percentage for both maxilla and mandible in age groups ( Figure 1). Age factor also have significant effect on the tooth loss for both maxilla and mandible in age groups. The highest prevelance of missing teeth according to sex factor was 46 (female 42.7% male 37.45%), 16 (f 39.3%, m 38%) and 36 (f 42.7%, m 34.3%), respectively and the lowest prevelance was 43 (f 10.5%, m 7.2%) and 33 (f 9.7%, m 8.9%), respectively, but these differences were not statistically significant ( Figure  2). Females lost their 35, 36 and 37 (p ≤ 0.10) more than males, while the males lost their 24 (p ≤ 0.05) more than females.

Discussion
Null hypothesis of the study, age and gender have no effect on tooth loss and partial edentulism distribution, and no differences on the distribution rate of Kennedy classification in Ankara region, was mainly rejected. The findings confirmed that age have a significant effect on the prevelance of tooth loss and partial edentulism, but it was found that gender have no effect on the prevelance of tooth loss and partial edentulism. In addition, it was found that Kennedy Class I have the highest distrubition rate.
The prevalence of tooth loss and partial edentulism may differ between countries and regions due to different factors such as socioeconomic status, education, gender and age. In our study, the effect of age and gender factors on the prevelance and classification of tooth loss and partial edentulism were investigated. Although the prevelance of partial edentulism showed differences between the male and female, these differences were not statistically significant. Doğan and Gökalp also reported similar results with our study [1]. In our study, it was found that women lost their 35, 36 and 37 number teeth more than males and males lost their 24 more than females, but these results are not statistically significant.
Previous studies, conducted on patients using partial were molars [17]. These results suggest that the molar teeth are the earliest lost and it may be assosicated with earliest eruption and rotten. Our study was performed on randomly selected diagnostic models of the patients who were randomly referred to Ankara University Faculty of Dentistry Department of Prosthodontic, thus socio-demographic characteristics of the study is below a certain limit . Other studies, conducted in different countries and state hospitals, also have certain sociodemographic characteristics which parellel to our study [18,19] .Kennedy Class I was the most commonly partial edentulism in for both maxilla and mandible and Kennedy Class IV was observed in the lowest commonly partial edentulism. Our findings are similar with studies conducted in Japan [15,21].
In addition some studies show that Kennedy Class III is more prevalent partial edentulism in developing countries (Jordan, Kazakhstan, Saudi Arabia) [14,15,22].
Sadig and Idowu reported that prevelance of Kennedy Class I and II were the highest in female aged 45-64 due to increasing tooth loss with increasing age [14]. In parallel to our study,

Conclusion
With the limitation of the study it can ben concluded that; Age has a significant effect on the partial edentulism distribution and tooth loss for both maxilla and mandible (p≤0.05).Gender has no significant effect on partial edentulism distribution and tooth loss. The most common partial edentulism is Kennedy I and the least common partial edentulism is Kennedy IV.
Premolar teeth were lost in mandible more then maxilla for over 46 years age people. Incisors have been lost more for 56-65 age range and molar teeth are the most common lost teeth. Women lost their lower premolar teeth more than men.
Health care maintanence and preventive measures should be encouraged in the elderly.