Introduction

Tooth loss is one of the most frequent conditions that have a high impact on oral health [1-3]. It constitutes an important challenge to both the patient and the healthcare provider. It affects the quality of life of the patients and their general health. The number of extracted teeth in a population can be used as a determinant of oral hygiene status, especially when a comparison reflects a correlation between the incidence of tooth loss and oral hygiene level.

The quality of life has been affected in many ways considering the attitudes and behaviors of people and the ability of the person to perform daily activities. In brief, losing teeth, either as a categorical variable or continuous factor, is the most impactful element with its confounding effect on oral health-related quality of life.

Moreover, the social presentation presents a remarkable communication limitation in personal and job interviews, speaking, smiling and confidence related to the esthetic factor. It is especially associated with anterior teeth loss and their impact on the person’s appearance affecting his social life, clear speech with proper letter exits, and articulation. From the functional aspect, tooth loss has undoubtedly a direct negative effect on nutrition. Mastication difficulties are encountered as well as new adaptive eating habits are especially linked to the loss of one or more posterior teeth, especially during chewing. The effect of the inability to chew properly does not cause digestion problems solely, but it will rather influence people’s self-esteem during meal gatherings and social events [4]. It has been ironically reported that daily intake and vitamins are significantly lower in edentulous patients affecting their nutritional status [5]. The necessity of eating properly and having an appetite was regarded as essential in assessing the quality of life of elderly persons. In this sense, the use of dentures is still linked to the importance of dental health in forming connections [4].

Furthermore, one of the main important reported factors leading to teeth extractions, in the literature were teeth impaction and malocclusion especially in patients less than 20 years of age.

Researchers studied comprehensively, the relationship between malocclusion and the quality of life focusing on its influence on social, physical, and other psychological characteristics, exerting a major contributing role in social acceptance and interactions [4]. Regarding the oral hygiene factor in causing tooth loss, a noticeable association has been established in a patient with orthodontic treatment and actual neglect of their oral hygiene with presenting potential variability of tooth loss [4].

The influential outcome of education revealed that people with limited or incomplete education levels depicted a higher number of lost teeth when compared with those with higher education levels persons [6].

The progression of dental problems such as caries and periodontal diseases is associated with poor oral health maintenance encountered in people with low economical income levels [7]. Moreover, a direct correlation exists between the pattern of tooth loss, the regular dental visit, and the self-conceptual understanding of the needed dental care and treatment [8].

A strong association exists between early tooth extraction and the presence of plaque biofilm, multiple dental caries and cavities, and periodontal disease. These findings had strong collaboration relative to the planning of health policies considering social equity as part of health strategies in primary health care [8].

The socioeconomic inequality displayed trends in tooth loss, peculiar to dentate adults and the entire population. Studies in the UK in the last two decades demonstrated that total tooth loss decreased by almost 80% among the high social class and only by 48% in the lower social class population [9]. Moreover, the social and economic status is deflectable and is attributable to neglect or inability to withstand the economic burden of the treatment costs.

Tooth loss is a reflection of an individual's dental disease history and their treatment through regular dental care throughout their lives, which results, in the capture of a lifetime's worth of experiences. The drivers of inequalities in tooth loss must be recognized and avoidable determinants addressed to minimize socioeconomic inequality's effect on tooth loss. Preventing dental and oral disorders and managing the reasons for any chronic illness, should receive more emphasis [9].

Regarding gender and tooth loss, a greater percentage of tooth loss was observed more frequently, in male patients. In the female population, the loss of teeth was mainly secondary to both caries management and/or orthodontic treatment. The males, on the other hand, revealed that periodontal disease was the main cause of extraction [10]. The variation in frequency and the etiological differences between both genders were related to the inherited belief that men are less motivated toward rehabilitation therapies. Furthermore, these discrepancies might be partly mediated by the morphological differences occurring during the adolescent period, when the sex hormones function actively, and by the associated proportionally increasing amount of functional masticatory force affecting the temporomandibular joint [11]. In addition, unilateral mastication due to teeth loss might increase the masticatory load at the temporomandibular joint, the nonfunctional side. Accordingly, extraction of the posterior teeth unilaterally may lead to a compensative remodeling action of the articular eminence over a long time [11].

Furthermore, despite the fact, the degree of tooth loss could not be solely justified by physiological aging, its prevalence grows with time, peaking at 64 years of age [12]. Studies mentioned that a positive relationship exists between previous dental loss as a strong predictor of additional new dental losses, whether being patient preference related, or dentist preferable approach, especially in the patient presenting with severe associated pain.

As previously stated, it is obvious that the etiology of tooth loss is variable and even multifactorial. It can be associated with a personal habit such as smoking, concurrently with poor oral conditions including, high caries incidence and periodontal pathology. The general health and medical conditions with concurrently occurring systemic diseases such as diabetes jeopardize oral health and accelerate the potential tooth loss.

Lifestyle and behavioral factors such as smoking show significant predictors of tooth loss. It is related to the increase of the risk factor of the high incidence of tooth loss among the smokers' population. It was proven that people with cigarette smoking, have a remarkably low buffering capacity of saliva. The oral flora inhabitants in the smokers’ saliva revealed that Streptococcus mutans and Lactobacilli show a prevailing number, significantly higher when compared to non-smokers. This complex effect of the increased level of cariogenic bacteria in combination with the decreasing buffering capacity of the saliva will undoubtedly produce high caries incidence, which will eventually lead to tooth extraction. Smoking and losing six or more teeth is a significant positive relationship [13]. On the other hand, periodontal disease-related factors in smokers are due to the chemicals in the cigarette and the eventual free radicals production by the host as an immune response to bacterial stimulation, resulting in damage of the periodontium, thus increasing the person's tendency to tooth loss [14]. Furthermore, scientists claim that nicotine reduces bone density and mineral content by increasing the secretion of bone-resorbing proteins or decreasing calcium uptake in the intestine. Interestingly, smoker females exhibited a low level of Estrone and Estradiol which affects postmenopausal and body health [14].

Diabetes mellitus as a chronic systemic disease

Is considered a high-risk factor associated with periodontal disease causing tooth mobility and extraction. Routine dental visits are recommended regularly since, treating periodontitis can improve outcomes (i.e. glycemic control) [15]. Diabetic patients show an increase in the inflammatory mediators, as the cytokines present in the gingival fluid lead to normal periodontitis. Moreover, the periodontal pathogens present in diabetic patients, can initiate a devastating cycle of tissue destruction and delayed healing, which might eventually lead to the loss of teeth [13].

Although periodontal factors and a high incidence of caries are the most frequent reasons for tooth loss, research has shown that other factors such as orthodontics, prosthetics, impaction, trauma, and failure of earlier therapy can also influence tooth removals. Extraction for orthodontic treatment recorded the highest percentage between 11 and 20 years old, while the percentage of prosthetic extractions reached its highest level among the older age group 51-60 years. People over the age of 40 years had the highest percentage in the number of extractions due to periodontal disease for reasons of tooth loss exceeding those for various causes [16].

Dental caries is a condition that affects adults, with an incidence rate that is comparable to that of children and adolescents. Caries presents a chronic, progressive and cumulative illness that worsens with advancing age. Periodontal disease is distributed differently across the lifespan of an individual. Periodontitis, presenting as a periodontal pocket of 4-5 mm in depth, showed prevalence in 9.1% of adolescent patients, while only 27.7% was found in adults, and from the elderly population, 30.6 percent suffered from this condition. Severe periodontitis being progressive, worsens with age, peaking around 40 years of age, and then stabilizes in old age. In brief, it could be stated that, since among the most common reasons for tooth extractions are dental caries and periodontal disorders, it is a logical advocation that this problem shows higher prevalence with age [17].

It has been hypothesized that the combined multifactorial outcome in a person with high caries incidence, advanced periodontal disease, bad oral hygiene, habits such as smoking, and systemic medical conditions with oral manifestations such as diabetes will eventually predispose this patient to earlier tooth loss in comparison to healthier patients with same age group.

The aim of the study

Our present study mainly aims at evaluating the causes of tooth loss and correlating them to related risk factors in adult patients, who are frequenting King Abdulaziz, University Dental Hospital in Jeddah. The evaluation criteria were based on the patient's demographic data including age, gender, and education. The social history included personal oral health, flossing frequency, and smoking habits. Medical history was concerned with systemic conditions with oral manifestations that could jeopardize the oral conditions. Past dental histories involved the number of previously extracted teeth and the associated reasons for their extractions. The number of these extracted teeth was recorded after thorough clinical and radiological examinations. All these variables were correlated to the current clinical oral conditions and their association with the causes of tooth/or teeth loss.

The previewed conclusion will necessarily help in increasing the awareness and prevention of early tooth loss among adults. The main impact of the study is to help our patients understand the reasons and factors that cause early extraction. Educating the patients and developing ways to encourage and reinforce their self-motivation towards improving their oral and body health to preserve their dentition and prevent early tooth loss is another important task that should be adopted.

Materials and Methods

This is an observational, population-based study with adults participating in an epidemiological survey of oral health at King Abdulaziz University dental hospital. Ethical approval (no. 325-11-21) was obtained. A random sample was selected from patients visiting the surgery clinic at King Abdulaziz University Dental Hospital for four months (January-April 2022), the researchers collected the data from participating dentists weekly.

The survey was based on a validated questionnaire designed on different sections: demographic data, socioeconomic status, past medical, and dental histories, and clinical examinations.

There are two portions to the information in the record form. The first part included information on the patient's age, gender, medical status, educational level, income, and oral hygiene brushing and flossing frequency. The second part included the number of teeth to be extracted and the causes for dental extractions if the patient had previous extraction and for what reason, the number, and location of teeth to be extracted, DMFT score, and level of bone loss. The questionnaire carrying these questions was filled out by the participating intern dentists.

Data collected from this questionnaire included the patient's demographic data, gender, age, an education level (University, illiterate, primary, middle, and high school), medical condition, history of habit such as smoking, daily oral hygiene (brushing and flossing), previous dental extraction visit, mentioning the tooth type and the reason for each extraction. Several teeth were extracted in the current visit and the reason associated with it.

The medical record was checked for endorsement of the medical history. The decayed missing and filled tooth (DMFS) score was evaluated. A radiographic examination was also performed.

The inclusion criteria were any patient with permanent dentition, 14 years and above with one or more lost tooth/teeth. Exclusion criteria included any patient with syndromes affecting oral health.

Data such as tooth loss decayed missing and filled teeth (DMFS), bone loss, and oral hygiene were collected and statistically analyzed, using Statistical Package for the Social Sciences (SPSS) to verify the possible hypothesized outcome associated with early tooth loss causes to the following factors caries, periodontal disease, smoking history, orthodontic treatment, and trauma.

Statistical analysis

The data collected were analyzed statistically using the Statistical Package for the Social Sciences (SPSS) version 26. Quantitative and qualitative variables were represented by the chi-square test, descriptive mean ± SD.

Results and Discussion

Descriptive statistics

The participant patients’ main age was 34.49 ± 15.8. I ranged from 14 to 85 years. Males showed higher preponderance (51%). The medical status revealed that 108 (70.6%) of the patients were healthy, while only 45 (29.4%) were diagnosed and controlled for diabetes and hypertension, asthma, and cancer. A total of 52 patients had variable smoking habits (34%) using different types of cigarettes and vaping. Most of the treated patients reported average income (77.8%) and low income (20.9%) which is understandable, since the governmental hospital charge no fees. People with limited education, that stopped at the high school level were the most common (44.4%), followed by only (34.6%) with a university level of education. The majority of patients reported brushing twice a day (45.1%). However, only (17%) reported using floss and water floss. The number of teeth extracted per session was requested by most of the patients to be one tooth only (56.2%). The most common cause of teeth extractions proved to be dental caries (82.4%) followed by periodontal disease (12.4%). The presented results depicted that upon clinical examination, (71.9%) of the patient had previous extraction performed. The most commonly extracted teeth were the maxillary posterior teeth (54.2%) followed by the mandibular posterior teeth (47.7%) (Table 1).

Table  1. Demographic information of collected data

Causes for tooth extraction

The results depict the correlations between tooth extraction reasons. Males had more teeth removed than females because of caries, followed by periodontal disease, residual roots, impacted teeth, and prosthodontics reasons, although the differences were yet statistically insignificant.

Two hundred and ninety-four (249) teeth have been extracted in the oral surgery clinic. The sequence of the extracted teeth was designingly, the upper posterior as the most frequently extracted teeth (54.2%), followed by the lower posterior (47.7%), upper anterior (8.5%), and lower anterior presented the least common extracted tooth (3.9%).

Dental caries and periodontal disease were the most common causes for extraction, with one hundred twenty-six 126 teeth (82.4%) lost due to dental caries and eighteen 19 teeth (12.4%) removed due to periodontal disease, only (2%) were extracted for orthodontic treatment, while (3.3%) were third molars with different problems such caries, pericoronitis, or overeruption.

In the present population, tooth extraction for periodontal disease was significantly higher in unhealthy individuals with chronic diseases (such as diabetes and hypertension) (p=0.038). Regarding smoking, the results showed that there was an insignificant statistical difference between smokers and non-smokers patient as a cause of tooth extraction (Table 2).

Table 2. Medical status and smoking behavier in participant as a cause of tooth extraction

People with a history of previous teeth extractions showed a statistically significant difference in a patient with caries and periodontal disease (p=0.043). The patients with the previous extraction tend to extract repeatedly for the same reason, while a patient who came to the clinic for third molar extraction or orthodontic reasons presented once for the procedure (Table 3).

Table 3. History of previous extraction and tendency to extract again

DMFS and bone loss in the radiograph

The patient who lost their teeth due to periodontal disease suffered from bone loss. The results showed that the highest percentage for severe bone loss (62.5%) and (23.3%) had moderate bone loss, while patients who had their teeth extracted for caries scored 4 or remaining roots revealed moderate bone loss (76.7%), in addition, patients who came for teeth extraction for orthodontic reasons and third molar problems had intact bone (Table 4).

Table 4. Bone loss and DMFS for the extracted tooth

Factor associated with oral hygiene and number of mobile teeth

Oral care and brushing frequency revealed significant results at (P=0.049) as a cause of tooth extraction. People with orthodontic treatment, or referred for extraction of 3^rd molars were brushing twice/day. On the other hand, patients with multiple caries and periodontal problems were brushing mostly once a day. Most of the patients were not using floss regularly, which might explain the high incidence of caries and periodontal disease (P=0.05) (Table 5).

Table 5. Practice of participants toward brushing and floss using