Our teeth are important for chewing, smiling and speaking and our quality of life: biologically, psychologically and socially will decrease by the loss of these teeth so we need to keep our permanent teeth as long as possible and extraction of permanent teeth should be considered the last option for dental treatment . The number of extracted teeth can be used as an indicator of socioeconomic and oral hygiene level . There are some reasons that have been given for permanent tooth extraction, including the presence of caries, periodontal disease, orthodontic treatment, trauma, prosthetic procedures, impacted teeth, failed dental treatment, prosthetic indications and other reasons  - . Thus, understanding the patterns and the causes for tooth loss is essential for oral health outcomes and disease prevention. Numerous cross-sectional studies have investigated for the reasons of tooth loss in different countries and areas. Generally speaking, in many studies, Dental caries followed by periodontal disease caused the majority of tooth extraction. With age consideration, dental caries and its sequels are the most frequent cause of tooth loss in young people, whereas periodontal disease is the main reason of tooth loss in middle-aged and elderly people      .
Orthodontic reason is the principal reason in people younger than 20 years old    - . Amongst these studies the only study that has investigated for the reasons of permanent tooth extraction in Afghanistan is the one that performed in Mazar-e-Sharif, located in the north of Afghanistan . Populations with low socioeconomic level have demonstrated higher prevalence and extent of tooth mortality, which increases with aging   .
Tooth loss decreased in developed countries in the last years   . This reduction of tooth extraction may be resulting from preventive programs and higher accessibility of the oral health care  . Some studies revealed the prevalence of dental caries in females more than males and more periodontal disease in males than in females   . Amongst various tooth types, third molars or molars generally were the most frequently extracted ones        and the main reason were dental caries whereas extracting of anterior teeth mostly resulting from periodontal diseases     . Unfortunately, not enough data are available on this topic in Afghanistan and related information is strongly needed. By identifying the main causes and predictors for tooth loss, it may be possible to limit future extractions and highlight the crucial role of prevention. Therefore, the purpose of this paper was to investigate the reasons for extraction of permanent teeth, its correlations to several aspects such as age and gender and the best predictors for dental caries in Kabul.
The study protocol is in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans.
The present study involved two major centers for dental treatment in Kabul, the capital city of Afghanistan, including the clinics of Dr. Naseer Ahmad Nazhand and Watan hospital. The selection of these two centers was based on their location, and the numbers of patients who could be recruited into the study. Dentists cooperated this study were the instructors from the faculty of dentistry of Khatam al-Nabieen University. Patients aged between 10 - 60 years who came with toothache and after physical examination and X-ray photos the final decision for their treatment was tooth extraction, were included in this study.
The reasons for tooth extraction in questionnaire were assigned as: dental caries, periodontal disease, eruption problems, trauma, orthodontics, maxillary or mandibular fracture, patient request and other reason. Other data requested for each extraction included patient age, gender, type of tooth removed, and the reason for extraction, treatment before extraction, satisfaction with the extraction process and any problem during extraction. The design of the questionnaire and its validity and reliability were tested and modified during a one-month pilot study before the main study. Data were collected over a 6-month period (April-September 2019) and analyzed descriptively using Statistical Package for Social Sciences version 17 software.
The survey questionnaire, collecting data of reasons and patterns of tooth extractions in 100 patients (64 males and 36 females) was analyzed over a 6-month period at two dental clinics in Kabul city. The numbers and percentages of teeth extracted during this period are shown according to sex and age group in Table 1 and Figure 1. Table 1 shows that the number of teeth extracted was different for the different age groups in both sex and young people aged between 20 - 29 years old had the highest percentage of extraction. Periodontal disease (39%) followed by caries (20%) was the most common reason for tooth extraction. Trauma was found the third most common reason for the tooth extraction (15%). Other reasons for teeth extraction can be verified as follows: eruption problems (8%), orthodontics (5%), patient request (3%), fracture (1%) and other reasons (9%) (Table 2 and Figure 2).
Table 1. Numbers of extracted teeth according to sex and age.
Figure 1. Number of tooth extraction according to age. The highest number of tooth extraction is seen in 20 - 29 years old (46%), including 18% females and 28% males.
Table 2. Numbers and percentages of tooth extractions according to reason.
Figure 2. Number of tooth extraction according to reason. Periodontal disease is the most common reason for tooth extraction (39%), including 13% females and 26% males and fracture is the least one (1%).
Regarding the tooth types, maxillary and mandibular first molars were removed most frequently (31%), followed by second molar (23%) and second premolar (14%), and canine and central incisor removal was the least frequent (3%) (Table 3 and Figure 3). Data in Table 4 reveals that 29% of patients have treated their teeth before extraction and RCT (Root Canal Treatment) (19%) is the most common previous treatment. Findings of current study showed that people who have higher educational level (doctors, engineers, teachers and government employees) lose their teeth less (14%) than people having no or incomplete education (Table 5).
Table 3. Prevalence (%) of extractions by type of teeth.
Figure 3. Prevalence of extraction by type of teeth. First molar is the most prevalent extracted tooth (31%), following by second molar (23%).Central incisor and canine are the least prevalent one.
Table 4. Prevalence and type of treatment before extraction.
Table 5. Numbers and percentages of tooth extractions according to occupation.
To our knowledge, the present study reveals the first available detailed information on the reasons for tooth extraction in Kabul.
The results of this survey indicated that in Kabul, Afghanistan, periodontal disease followed by dental caries were the leading reason for extraction. The finding that periodontal disease was the Main cause of tooth extraction is in agreement with the Studies in Canada   and Jordan . Some studies in Japan , Italy  and Singapore  showed that both caries and periodontal disease have the same level of importance for tooth loss. The findings of this study revealed that tooth loss has an opposite relationship with education level. Other studies support this relationship in which tooth loss was associated with an incomplete or low level of education       and unfortunately a high percentage of tooth loss is seen among university students in the current study. Data like this about tooth loss in developing countries is important due to evaluate the dental health status in young people and may be used as baseline data for future dental health planning.
This study, like many other surveys clarified that the molars are the most prevalent missing teeth  . In the present study, extraction of molar teeth, especially first molars, accounted for 67% of all extractions, followed by extractions of premolars and anterior teeth. Our finding is in line with other study in Saudi Arabia  and also with previous surveys that have demonstrated that the first molars were the most commonly extracted teeth in Brazilian youth   .
Finding of current study showed higher prevalence of tooth mortality in men (64%) than in women (36%) which is in contrast with findings of Barbato et al. in Brazil . Youth aged 20 - 29 years has the highest rate of tooth loss in west of Kabul (46%) and it is an alarm for those who is responsible for public health to have a logical plan for developing oral hygiene, for example systemic fluoridation like water or salt fluoridation or licensed dental hygienists to educate students or people in the community. Educating students at school play a key role in promoting oral health in some Asian countries like Malaysia . Some other countries like Thailand have portable dental clinics to serve school children . Nutritional status among school children can be affected by poor oral health .
Not all people have regular dental checkups, which are very important to diagnose caries at an early stage in order to prevent extensive dental treatment and decrease tooth extraction. Besides, it is an urgent need to have some programs of screening for periodontal disease which is the most common reason of tooth loss in this study. Further studies are needed to carry out in other provinces and also other parts of Kabul in order to use their results in planning for promoting dental health in Afghanistan. However, this study had some limitations such as people who didn’t know their exact ages and the small number of centers selected for this study in comparison with several dental clinics available in the west of Kabul which were not reliable or cooperative.
The results of this survey indicated that periodontal disease and caries were the principal reasons for tooth extraction in the west of Kabul. First molar is the most frequent extracted tooth and tooth loss has an opposite relationship with education level. A high percentage of tooth loss is seen among young people, in conclusion, educating and preventive programs need to be implemented in order to reduce tooth loss for the common reasons discussed here.
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