Indications for Permanent Teeth Exodontia: A Comparative Analysis of Two Tertiary Institutions In South-Western Nigeria

Background: Exodontia is a global public health concern and studies have shown that reasons for tooth extraction vary from one country to another. We embarked on this study to examine and compare the reasons for exodontia and patients’ sociodemographic parameters across two tertiary institutions in south-western Nigeria. Methods: Data of patients referred for exodontia at the dental clinics of University College Hospital, Ibadan [UCH] and Ekiti State University Teaching Hospital, Ado-Ekiti [EKSUTH] were obtained on individual proforma. Patients’ age, sex, dental history, reasons for exodontia and level of education were documented and analyzed using SPSS version 20. Result: Overall, 802 patients participated in this study [UCH: 378, EKSUTH: 424] with exodontia of 1058 teeth [1.3 exodontia per patient]. The age and gender distribution across both institutions were comparable. Periodontal diseases [51.60%] accounted for a statistically significant higher cases of exodontia at EKSUTH [p=0.02]] while dental caries [36.17%] was the commonest at UCH [p==0.14]. EKSUTH recorded a statistically significant higher cases of deliberate exodontia [p=0.008]. A higher proportion of the patients were not educated up to the secondary level [EKSUTH; 63.7%, UCH; 50.6%]. However, the proportion of those who lacked formal education was significantly higher at EKSUTH [p=0.04]. Conclusion: There was a contradiction in the relative contribution of dental caries and periodontal disease to exodontia across the two institutions studied. There was also a high incidence of deliberate exodontia and a higher proportion of patients lacked formal education. We recommend continual advocacy and patients’ education in preventing tooth loss.


Introduction
The final consequence of most dentoalveolar diseases is tooth loss, mostly through routine tooth extraction and reasons for routine exodontia have been widely discussed in the dental literature [1][2][3]. Although exodontia has been reported as the most common dental procedure globally [2][3][4], it continues to be a major public health problem, and studies have shown that causes of tooth extractions have wide geographical, socioeconomic and cultural variation [1][2][3][4][5][6]. Incidence of exodontia is said to be on the decline in many developed nations because of advances in conservative dental treatments, however, tooth extraction continues to be a common practice in the developing and underdeveloped countries including Nigeria [6][7][8].
Extraction of permanent teeth is carried out for several reasons such as dental caries, periodontal diseases, orthodontic treatment, traumatic injuries, prosthetic indications and tooth impaction [2,4,[8][9][10][11][12][13]. Dental caries and periodontal diseases are generally regarded by most authors as the main reasons for tooth loss [11][12][13][14]. Apart from Ong et al [15] who reported almost equal percentages (35.8% and 35.4%) of extractions due to periodontal disease and caries respectively, other studies differ considerably in the relative contribution of either caries or periodontal diseases to tooth mortality [4]. WhileCahen et al. [11], Corbet and Davies [16] and similar studies from Europe [17,18] and Canada [19] reported caries to be the main reason for tooth loss, other studies from sub-saharan Africa gave conflicting reports regarding the main reason for exodontia. [20] Odusanya [21] and Akpabio [22] established periodontal disease as the main cause of tooth mortality while Sahib and Sede [5], Oginni [4] and Kaimenyi et al [9] reported dental caries to be the leading cause of tooth mortality.

Studies by Danielson et al
Despite numerous reports about reasons for exodontia in the dental literature, there is contrasting information on reasons for exodontia and patients' sociodemographic parameters in Nigeria and other countries in sub-Saharan Africa. This study was therefore designed to examine and compare the reasons for exodontia and patients' sociodemographic indices across two tertiary institutions in southwestern Nigeria. Of note is the gender differences in the reasons for extraction too [ Figure 2]. In both institutions, more females had exodontia as a result of sequelae of dental caries while more males suffered from periodontal causes of tooth extraction. It is worthy to note that the proportion of deliberate extraction was comparatively high at EKSUTH [x 2 =25.2, p=0.008] compared to UCH.

Methods
Although there was a higher frequency of exodontia at EKSUTH during the study period than UCH, the pattern of exodontia at the two institutions was similar and comparable [ Figure 3]. Also, the mandibular molars were the most

Discussion
The literature has shown that there is geographic and cultural variation in tooth mortality among different populations [1,4,5,13,23]. As such, periodic evaluation of exodontia at any dental facility is necessary as extrapolation of results from previous studies cannot provide reliable data for policy making. The present study was carried out at the UCH, Ibadan This study found a higher female preponderance across both institutions in agreement with other authors [3,4,9,15]. On the contrary, some authors found a higher male to female ratio in their respective studies [5,18,22]. It has been proposed that women tend to have better healthcare seeking attitude in some climes and this may be an explanation for a higher female population among dental clinic attendees. More females also had extraction due to dental caries while more males had periodontal problems necessitating exodontia. This contrast was also reported in similar studies [2,5,21]. Generally, it is believed that females tend to be more meticulous with oral hygiene techniques than males. Moreover, habits such as smoking, alcoholism and poor oral hygiene practices may be responsible for the high male preponderance with regards to periodontal causes of exodontia [24,25].
In agreement with previous reports, Dental caries accounted for the commonest cause of exodontia among patients below 40 years in this study. This age group is responsible for consumption of refined carbohydrates which has been implicated in aetiology of dental caries. Also, most studies reported dental caries as the leading cause of tooth mortality, we however found periodontal diseases to be the overall leading cause of tooth extraction in the present series and this was corroborated by similar studies [19][20][21][22]. Although 6 we noticed a disagreement between the relative contribution of dental caries and periodontitis to exodontia in the two institutions studied, this lends credence to the raging controversy on the leading cause of exodontia between these two dental conditions. Some studies have reported some correlations between patients' educational status and tooth loss [13,[28][29][30]. We found a significant relationship between educational level and exodontia among the participants. This was also supported by Paulander J et al [28] who observed a high correlation between lack of formal education and tooth mortality. Although the study by Osaghae and Azodo [30] had a lower proportion of patients who have no formal education, this may be due to the fact that their study was community based. The fact that a higher proportion of our patients had either primary or no formal education support the notion that the level of education has a role in prevention of dental diseases [13,28].

Conclusion
Although Dental caries and periodontal diseases remain the leading cause of tooth loss, this study has shown that there is wide variation in the relative contribution of these conditions to exodontia across different health institutions even within the same country. It is also imperative to continue to advocate for patients' education on preventive measures to curb these diseases and the rising spate of deliberate exodontia in our environment.