Gender variation in the prevalence of class III dental caries in mesial and distal aspects of teeth: A hospital based retrospective study

Dr Greene Vardiman Black in the year 1896 classi ied dental caries into VI classes based on the site of occurrence, among which class III and class IV are exclusively associated with anterior teeth. There are very minimal studies in the literature emphasising on the prevalence of dental caries in the anterior teeth region. Caries involving the anterior teeth signi icantly affects aesthetics and which in turn affects the con idence levels of the affected person. Grossly decayed anterior teeth also affect phonetics and mastication. The aim of this study was to determine the prevalence and gender variations of class III dental caries among patients who have visited Saveetha Dental College and have undergone treatment for the same. A Retrospective studywas conducted, and data collection was done from dental archives pertaining from June 2019 to April 2020. Data consisted of all the patients who underwent therapeutic procedures for class all dental caries. Data was imported to IBM SPSS Version 20 for statistical analysis. Results were tabulated. Prevalence of class III dental caries was more among females as compared to males. Maxillary anterior are more affected thanmandibular anterior. Prevalencewasmore among patients belonging to the third and fourth decade of life. Therewas a statistically significant association between age, and proximal surface –majority ofmesial caries decreases with age and distal caries increases with age. As the age increases, the number of decayed surfaces increases (not statistically signi icant). This study was conducted in a single centre. Extensive multi-centre studies need to be done.


INTRODUCTION
Dental caries is the localised destruction of the susceptible hard tissues of teeth by acidic by-products produced by bacterial fermentation of dietary carbohydrates (Longbottom et al., 2009;Fontana et al., 2010). It is a bacterial driven disease, which is chronic in nature, the multifactorial, site-speci ic, dynamic disease process that results due to imbalance in physiologic equilibrium between the tooth mineral content and the plaque luid, i.e. when the pH drop results in net mineral loss over time (Fejerskov et al., 2008;Fontana et al., 2010). Over 100 years ago Dr Greene Vardiman Black in the year 1896 classi ied dental caries into Vl classes based on the site of occurrence, among which class III and class IV are exclusively associated with anterior teeth (Black and The pathology of the hard tissues of the teeth, 1920). The proximal contacts between the anterior teeth (Hudson, 1956) and the presence of malocclusion (Helm and Petersen, 1989) greatly in luence the development of proximal caries in the anterior teeth. In infants, frequent nocturnal bottle or breastfeeding leads to the development of caries in the anterior teeth-"nursing bottle caries" (Ripa, 1978;Veerkamp and Weerheijm, 1995) Caries starts as a white spot lesion (demineralization of enamel -Remineralizing agents are used for treatment) (Nasim and Nandakumar, 2018;Rajendran et al., 2019), which progress towards dentin leading to dentin hypersensitivity and Ellis class II fracture (Jose et al., 2020), in case of class lV caries. Treatment is done by composite restorations or veneering (Ravinthar and Jayalakshmi, 2018) along with pulp protecting agents (if required)  Caries may further progress into the pulp causing severe pain (Ramesh et al., 2018) and in long-standing cases, the pulp becomes non-vital (Janani et al., 2020). In these cases, root canal therapy is the treatment of choice (Ramamoorthi et al., 2015;Ramanathan and Solete, 2015;Teja and Ramesh, 2019). Long-standing class III or class lV caries involving pulp weakens (Noor, 2016;Kumar and Antony, 2018) the tooth structure often leading to crown/root/crown and root fractures (Rajakeerthi and Nivedhitha, 2019).
This study was done for epidemiological signi icance to check the prevalence of class all dental caries among patients who visited Saveetha Dental College and have undergone therapeutic treatment for the same. To check the prevalence pattern of class lll dental caries among different age groups and gender. To check if gender has any statistically signi icant association with the prevalence of class lll dental caries and site involved -maxilla/mandible; Tooth number (to check the most vulnerable tooth developing caries), surfacemesial/distal.

Study setting
A retrospective study was conducted in Saveetha Dental College by obtaining data from dental archives (single centre study). Ethical approval was obtained from the institutional ethics committee.

Sampling, data collection and tabulation
Non-probability convenience sampling method was employed. The data included records of patients who presented with class III dental caries and underwent restorative treatment for the same. Data entries from June 2019 to April 2020 were obtained for the same and were tabulated. All the available data were included (without any sorting process) to reduce sampling bias. Data were analysed, and censored data were excluded. The data was then veriied by one external reviewer. A data of 708 patients (males -36.9%; females -261%) 18 years -75 years with 1457 proximal restorations (Mesial -66.3%; Distal -491%) was obtained.

Data analysis
The tabulated data were statistically analysed by IBM SPSS Version 20 to check the prevalence of class III dental caries among different age groups, gender, location -maxilla, mandible; tooth involvedto determine the tooth which is more vulnerable to develop class III caries; proximal surface -mesial or distal; also the check it's a correlation with gender. Data was imported and variables were analysed. Pearson's Chi-square test, Phi and Crammers test were used. Results were tabulated, and bar charts were plotted.
Graph 1 , The X-axis shows gender, and Y-axis indicates the number of patients with class III dental caries. This graph shows that there is an increase in the female predilection (63.1%) to class III dental caries compared to males (36.9) Graph 2 , The X-axis represents the age groups, and Y-axis represents the number of patients with class III dental caries. It is found to be high in the 3 rd and 4 th decade. Also, there is a progressive decrease in the prevalence with increasing age. < 21 years -4.4%, 21-30 years -27.5%, 31-40 years -26.8%, 41-50 years 23.4%, 51-60 years -13.1%, 61-70 years -4.4%, 71-80 years -0.3% Graph 3 , The X-axis represents the number of decayed bodies, and Y-axis represents the number of patients with class III dental caries. Majority of the patients had only one degraded surface followed by two decayed surfaces. One decayed surface 41%, two decayed surfaces 32.9% three decayed surfaces 12.9%, four decayed surfaces 8.1%, ive decayed surfaces, 3.2%, six decayed surfaces 1.6%, seven decayed surfaces 0.4%.
Graph 4 , The X-axis represents the proximal side mesial/distal, and Y-axis represents the number of patients with class III dental caries. Mesial caries was more prevalent (66.3%) compared to distal caries (33.7%).
Graph 5 , The X-axis shows the site of caries occurrence -maxillary/mandibular anterior. Y-axis shows the number of patients with class III dental caries. Caries in maxillary anterior was more prevalent (86.9%) compared to mandibular anterior (13.1%).
Graph 7 , The X-axis shows age group and Gender. Yaxis shows the number of patients with class III dental caries. Here the green bar represents Males, and the blue bar represents females. There is a female predilection in all age groups with an exception in the second decade. It shows a statistically signi icant association between gender and age (p=0.000; chi-square test -p<0.05 -statistically signi icant).
Graph 8 , The green bar represents males, and the blue bar represents females. There is a signi icant female predilection. 11 is the most commonly affected tooth in both males and females. There is a statistically signi icant association between tooth number and gender (p=0.000; chi square test -p<0.05 -statistically signi icant).
Graph 9 , The X-axis denotes the proximal surface and gender. Y-axis shows the number of patients with class III dental caries. Blue bar represents females, and the green bar represents males. There is a statistically insigni icant association P value 0.192 (p>0.05; chi square test -statistically insignificant).
Graph 10 , The X-axis shows the number of decayed surfaces and gender. Y-axis shows the number of patients with class III dental caries. Blue bar represents females, and the green bar represents males. It is not statistically signi icant P value 0.174 (p>0.05; chi square test -statistically insigni icant).
Graph 11 , The X-axis shows the number of decayed surfaces and age groups. Y-axis shows the number of patients with class III dental caries. There is an increase in the number of surfaces affected with an increase in age. The association is statistically insigni icant, P value 0.530 (p>0.05; chi square test -statistically insigni icant).
Graph 12 , The X-axis shows age groups and Y-axis shows the number of patients with class Iii dental caries. Blue bar represents mesial caries, and the green bar represents distal caries. This shows that as the age increases, there is an increase in the prevalence of distal caries and decrease in the prevalence of mesial caries. It is statistically signi icant (p=0.000; chi square test)
Graph 1: This bar graph represents the gender variations among patients presenting with class III caries.
Graph 2: This bar graph represents the trends of class lll dental caries pertaining to different age groups.

The number of decayed surfaces and location
Among the 708 patients, 290 patients (41%) had only one decayed surface. 223 (32.9%) had two decayed surfaces, followed by 91 patients (12.9%) with three decayed surfaces. Fifty-seven patients (8.1%) with four decayed surfaces. 23 (3.2%) with ive decayed surfaces. Eleven patients (1.6%) with Graph 3: This bar graph represents the number of decayed surfaces in the given population with class III dental caries.
Graph 4: This bar graph represents the proximal surface predominantly affected among class III dental caries patients.
Graph 5: This bar graph represents the involvement of maxillary and mandibular teeth.
Graph 6: This bar graph represents the tooth that is predominantly involved and least involved in class III dental caries.
Graph 7: This bar graph represents the association between age and gender.
Graph 8: This bar graph represents the association between tooth number and gender.
Graph 9: This bar graph depicts the association between gender and proximal surface, I.e., mesial and distal surface.
Graph 10: This Bar Graph represents the association between a number of decayed surfaces and gender.
Graph 11: This bar graph represents the association between the number of decayed surfaces and age group.

Associations
Graph 7 shows a statistically signi icant association between gender and age which shows a female predilection (p=0.000). Female predilection seen in all age groups except in the 2nd decade. There is a statistically signi icant association between the tooth involved and the gender (p=0.000). Maxillary teeth are predominantly affected in both the genders (Graph 8). There is a statistically insigni icant association between the proximal surface involved (mesial/distal) and gender (Graph 9); a number of decayed surfaces and gender (Graph 10); a number of decayed surfaces and age (Graph 11) (p>0.005). There is a statistically signi icant association between the site of the decay (proximal surface -mesial/distal) and age. As the age advances, there is a simultaneous increase in the prevalence of distal caries and decrease in the prevalence of mesial caries (p=0.000) (Graph 12).
The study shows that the prevalence of class III dental caries is more in females (63.1%) compared to males (36.9) (Graph 1). This can be due to two reasons: the irst reason being that females are more aesthetically concerned compared to males. This is in accordance with a survey done by PK (Vallittu et al., 1996) where females were more concerned with dental aesthetics compared to males. This concern makes female patients report more frequently for dental visits, especially to those concerns pertaining to anterior teeth compared to males who usually neglect dental visits. This reason is in accordance with a study done by (Fukai et al., 1999) where subjects who had not visited a dentist in the previous year were more in males (52.7%) compared to females (36.7%) also with a study done by R Pradeep (Kumar and Shristi, 2015) where females visited more frequently and early compared to males. The second possible reason for female predilection might be poor maintenance of oral health in females. This reason is not in accordance with studies done by Kateeb (2010) and QD (Al-Omari and Hamasha, 2005) where females exhibited better oral hygiene practices compared to males. In a study done by (Poorani and Chandana, 2015), the prevalence of caries is more in females. There was increased female predilection in all the age groups (statistically signi icant p=0.000) studied except for patients belonging to the second decade, where males (8.04%) were more compared to females (2.23%) (Graph 7). The possible reason may be due to the growing concern and awareness about dental health among younger generations which makes the males report more to dental clinics.
In this study, it's been reported that patients belonging to the third decade have increased prevalence, followed by patients belonging to the 4th decade. In Graph 2, it is seen that as age increases, the prevalence is decreased with the 2nd decade as an exception. The decreased prevalence in the second decade may be due to the better oral hygiene measures taken by younger patients. The decrease in prevalence with increasing age may be because patients are becoming less aesthetically concerned with increasing age. This is in accordance with a study done by AC (da Costa et al., 2017), where older subjects exhibited lesser aesthetic concerns.
Majority of the patients had only one decayed surface (41%) followed by two decayed surfaces (32.9%) (Graph 3). There is a statistically insignificant association between the number of decayed surfaces and gender (p>0.05) as seen in (Graph 10). This may be due to the increased female samples in the study. Also, there is a statistically insignificant association between the number of decayed surfaces and age group. There is an increase in the number of surfaces affected with the increase in age (Graph 11) which is not statistically significant (p>0.05), especially in patients belonging to the fourth and ifth decade. This again explains that there is a lack of concern towards dental health with increased age.
It has been observed that mesial caries occurs more commonly (66.3%) compared to distal caries (33.7%) (Graph 4). According to (Jackson et al., 1972), the prevalence of distal caries increases with age and prevalence of mesial caries decreases with age. This is in accordance with the study where an increase in the prevalence of distal caries with a simultaneous decline in the prevalence of dental caries was observed and is statistically signi icant (p=0.000) (Graph 12). There is a statistically insigni icant association between the site (proximal side) and gender (p>0.005) (Graph 9). This is in accordance with a study done a by (Demirci et al., 2010), where there was the equal predilection of caries in the proximal surfaces of both genders.
It is observed that the prevalence of caries is higher in the maxilla (86.9%) compared to the mandible (13.1) (Graph 5). This is in accordance with the studies done by (Demirci et al., 2010;Tanner et al., 2013) this could be due to the increased salivary low to the lower anterior compared to upper anterior. Prevalence pattern in individual teeth was found to be higher in 11 (21.7%) followed by 21 (20.6%), and the least affected tooth is 31 and 41 (1.5%) (Graph 6). There is a statistically signi icant association between tooth number and gender (p>0.005). (Graph 8).
The study is a single centered study and samples were collected from a ixed time frame. Extensive research to be conducted -multi-centre approach with a larger time frame to improve the scope of research. Also, to evaluate the impact of geographical variations, race and habits in the prevalence, pattern and severity of class III dental caries.

CONCLUSIONS
From this study, it has been observed that prevalence of class III dental caries is more among females compared to males. Maxillary anterior are more affected than mandibular anterior. Prevalence is more among patients belonging to the third and fourth decade of life. There was a statistically signi icant association between age, and proximal surface the prevalence of mesial caries decreases with age and distal caries increases with age. As the age increases, the number of decayed surfaces increases (not statistically signi icant).