Abstract
Background
Loss of permanent dentition is often of great concern to patients, apart from the aesthetic consequences in the anterior region of the mouth, such loss has no natural form of replacement.
Aim
To determine the pattern of tooth loss among patients attending the Dental Clinic at a Nigerian teaching hospital
Material and Methods
The case files of patients who attended the Dental Clinic of Aminu Kano Teaching Hospital, Kano between January and December 2012 with one or more missing tooth were retrospectively analyzed. The information collected included age, gender, educational level, residential area, missing tooth/teeth and reasons for the loss. The data were analyzed using SPSS version 13.0 (Chicago, Illinois). A p-value of less than 0.05 was considered significant.
Results
A total of 1100 missing teeth were recorded involving 960 patients within the period of one year. Males comprises 520(54.2%) and females 440(45.8%). The most predominant age group was the 21-30 years with a mean of 29.53 +12.41 years and this comprised 48.2% of the cases. Caries related extractions (65.6%) were the most common cause of tooth loss followed by periodontal disease in 13.1% of cases and symptomatic impacted tooth in 9.8%. Gender affects the etiology of tooth loss was significant with males having more tooth loss (X2=52.93, df=6, P=0.001). There was a significant association between age and the pattern of tooth loss with tooth loss due to periodontal diseases occurring in the older age groups (X2=1071.67, p=0.001).
Conclusion
Dental caries and periodontal diseases still remain the main causative factors for tooth loss in this environment, more common in men and rural dwellers.
Keywords: Tooth loss, Permanent teeth, Tooth extraction, Nigeria
Introduction
Dental caries and periodontal diseases have been reported as the predominant causes of tooth loss.1, 2, 3 Other documented causes include pericoronitis, trauma, orthodontic and prosthetic reasons as well as neoplasms.1,3 The causes of tooth mortality, especially those removed for therapeutic reasons by oral health care givers have been reported to have wide geographical and cultural variation across different populations.4While caries and its sequealae remain the major cause of tooth mortality in some countries5,6 periodontal disease is responsible for tooth loss in other countries.7 Oginni8 from southwest Nigeria identified dental caries and periodontal diseases, in that order, as the predominant causes of tooth loss. This was similar to the findings of Madukwe 9 from Benin City, South-South Nigeria.
Although dental caries and periodontal disease are the most common reasons for tooth pattern of tooth loss among populations.10 Studies have shown that subjects of low income and low education are more prone to be edentulous than those of higher socio-economic status. 10,11 A study on correlation between gender and reasons for tooth extraction showed more teeth loss in less educated rural male population.12
Data on the pattern of tooth loss in a population is important as it helps to provide necessary information such as treatment needs including appropriate preventive measures, level of oral health awareness, available oral health manpower and needed human and material resources. Although, Northern Nigeria is noted to be densely populated and has a high burden of illiteracy with its antecedent poor oral health awareness,13 no previous work on the pattern of tooth loss appears to have been carried out from the that part of the country. A review of the literature showed that majority of the studies on tooth loss have been from the South-Western and South-South Nigeria.1,8,9
This study aimed to determine the aetiology and pattern of loss of the permanent teeth among patients attending the dental and maxillofacial clinic of Aminu Kano Teaching Hospital, Kano, Nigeria over a period of one year has been carried out and the results compared with previous reports from Nigeria and other parts of the world.
Material and Methods
The case files of patients, who attended the Dental and Maxillofacial Clinic of the Aminu Kano Teaching Hospital, Kano between January and December 2012 with missing permanent tooth lost due to other causes other than neoplasms, were reviewed and retrospectively analyzed.
All cases of tooth loss were classified as being due to caries-related sequealae, periodontal disease, impacted teeth, trauma (road traffic accident, assault, fall) and orthodontic reasons. A tooth was considered missing due to caries if there was extraction in a tooth with a cavity.14 The criteria described by Ainamo et al 15 were modified and adopted for the diagnosis of tooth loss due to other reasons other than dental caries. Thus a tooth was lost due to periodontal diseases when there was gross mobility in the absence of trauma or neoplastic diseases prior to extraction. Impaction was the reason for extraction when a partially or fully impacted tooth was removed due to pain. Trauma was responsible for tooth loss when a non-carious tooth was avulsed or extracted due to falls, assault or road traffic accident. A tooth was lost due to orthodontic reasons when extraction was done because of crowding or during orthodontic treatment. The information collected included age, gender, educational level, residential area, missing tooth and reasons for loss. The data so obtained were analyzed using SPSS version 13.0 (Chicago, Illinois). Continuous variables were measured using mean and standard deviations, while categorical variables were presented as frequencies and percentages. A p value of less than 0.05 was considered significant.
Results
A total of 1,100 missing teeth were recorded from 960 patients within the period of study. Males were 520(54.2%) and females 440(45.8%) and the ages ranged from 10 to 78 years with a mean of 29.53 +12.41 years. The most predominant age group was the 21-30 years bracket which constituted 48.2% of the cases, followed by the 31- 40 years bracket constituting 20.2% and the 11-20 years bracket with (16.2%). Table 1 shows the anatomical distribution of missing teeth. The lower first and third molars were the most frequently missing teeth, accounting for 14.3% and 12.6% respectively. This was followed by the upper first molar (10.9%).
Table 1: Anatomical distribution of missing teeth.
| Tooth | Frequency | Percentage |
| Upper central incisor | 78.0 | 7.1 |
| Upper lateral incisor | 32.0 | 2.9 |
| Upper canine | 24.0 | 2.2 |
| Upper first premolar | 33.0 | 3.0 |
| Upper second premolar | 59.0 | 5.4 |
| Upper first molar | 120.0 | 10.9 |
| Upper second molar | 94.0 | 8.5 |
| Upper third molar | 89.0 | 8.1 |
| Lower central incisor | 39.0 | 3.5 |
| Lower lateral incisor | 32.0 | 2.9 |
| Lower canine | 28.0 | 2.5 |
| Lower first premolar | 40.0 | 3.6 |
| Lower second premolar | 50.0 | 4.0 |
| Lower first molar | 157.0 | 14.3 |
| Lower second molar | 86.0 | 7.8 |
| Lower third molar | 139.0 | 12.6 |
| Total | 1,100.0 | 100.0 |
Dental caries and its sequealae were the most common causes of tooth loss and accounted for about 65.6% of cases. Other causes included periodontal disease (13.1%), symptomatic impacted lower third molars (9.8%) and trauma (9.2%) which was represented by road traffic accidents (4.7%), assault (1.7%) and falls (2.8%). Table 2 shows the causes of tooth loss in relation to gender. Gender distribution of aetiology of tooth loss was significant (X2=52.93, df=6, P=0.001). A total of 19 patients (1.7%) constituting of male gender only had tooth loss following assault (Table 2).
Table 2: Causes of tooth loss with relation to gender.
| Gender | Caries | Perio | Impaction | RTA | Assault | Orth | Falls | Total |
| Female | 378 | 55 | 32 | 0 | 15 | 17 | 8 | 505 |
| P value | 0.88 | 0.25 | 0.50 | 0.02* | <0.00** | <0.00** | 0.50 | |
| Male | 344 | 89 | 76 | 52 | 4 | 7 | 23 | 595 |
| P value | 0.119 | 0.142 | 0.301 | 0.851 | 0.612 | 0.462 | ||
| Total | 722 | 144 | 108 | 52 | 19 | 24 | 31 | 1100 |
| (X2=52.93, df=6, P=0.001) | ||||||||
| Perio=Periodontal disease; Ortho=Orthodontic treatment. * P<0.05;**P<0.0001 | ||||||||
The distribution of tooth loss with respect to age is presented in Table 3. The 3rd decade was seen to record the highest number of teeth lost (n = 484; 44%), followed by the 4th and 2nd decades with loss accounting for (n=489; 44.5 %) and (n=228; 20.7 %) respectively. The age group recording the least loss of teeth was those who are over 70 years. Overall, there was a significant association between age and the pattern of tooth loss (X2=1071.67, p=0.001).
Table 3: Causes of tooth loss with respect to age groups.
| Age | Caries | Perio | RTA | Impaction | Falls | Assault | Ortho | Total |
| ≤10 | 3 | 1 | 2 | 0 | 19 | 0 | 0 | 25 |
| P value | 0.99 | 1.00 | 1.00 | 1.00 | <0.00* | 1.00 | 1.00 | |
| 11-20 | 101 | 10 | 14 | 21 | 12 | 10 | 14 | 182 |
| P value | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 0.99 | 0.98 | |
| 21-30 | 387 | 22 | 19 | 54 | 0 | 3 | 4 | 489 |
| P value | 0.99 | 0.96 | 1.00 | 1.00 | 0.99 | 1.00 | 1.00 | |
| 31-40 | 157 | 24 | 13 | 28 | 0 | 3 | 3 | 228 |
| P value | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | |
| 41-50 | 55 | 49 | 4 | 5 | 0 | 3 | 3 | 119 |
| P value | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | |
| 51-60 | 13 | 27 | 0 | 0 | 0 | 0 | 0 | 40 |
| P value | 1.00 | 1.00 | <0.00* | 1.00 | 1.00 | 1.00 | 1.00 | |
| 61-70 | 6 | 9 | 0 | 0 | 0 | 0 | 0 | 15 |
| P value | 1.00 | 0.98 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | |
| > 70 | 0 | 2 | 0 | 0 | 0 | 0 | 0 | 2 |
| P value | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | |
| Total | 722 | 144 | 52 | 108 | 31 | 19 | 24 | 1100 |
| X2=1071.67, p=0.001; Orthod. =Orthodontic; Perio=Periodontal diseases; RTA = Road traffic accident.P<0.00*= 0.00001 | ||||||||
Table 4 shows causes of tooth loss with respect to educational level. There were more tooth loss among those with tertiary (n=385; %) and secondary schools (n=344; %) as the highest form of education than among those with lesser qualifications Table 4), and dental caries was the main aetiological factors in these groups.
Table 4: Causes of tooth loss with respect to level of education.
| Aetiology | Caries | Perio | Impaction | RTA | Assault | Ortho | Falls | Total |
| None | 35 | 46 | 13 | 14 | 6 | 1 | 8 | 123 |
| P value | 0.117 | <0.00** | 1.00 | 0.91 | 0.98 | 1.00 | 0.97 | |
| Primary | 60 | 34 | 11 | 10 | 3 | 10 | 9 | 137 |
| P value | 0.93 | 0.71 | 1.00 | 0.99 | 1.00 | 0.57 | 0.99 | |
| Secondary | 262 | 20 | 38 | 10 | 1 | 6 | 7 | 344 |
| P value | 0.99 | 0.74 | 1.00 | 0.99 | 0.99 | 1.00 | 1.00 | |
| Tertiary | 325 | 14 | 34 | 7 | 0 | 5 | 2 | 385 |
| P value | 0.27 | 0.10 | 1.00 | 0.99 | 0.99 | 1.00 | 0.98 | |
| Arabic | 111 | 7 | 30 | 35 | 25 | 4 | 3 | 7 |
| P value | 0.00* | 0.92 | 0.00* | 0.00* | 1.00 | 1.00 | 0.99 | |
| Total | 722 | 144 | 108 | 52 | 19 | 24 | 31 | |
| X=406.78; df=24; P=0.00001; Perio=Periodontal disease; Ortho=Orthodontic Treatment; * P<0.05;**P<0.0001 | ||||||||
Table 5 shows the distribution of reasons for tooth loss in relation to urban and rural dwellers. There was a significant relationship between area of residence and reasons for tooth loss (X2=53.14; df=6; P=0.0001). Dental caries and its sequealae was the main reason for tooth loss in urban dwellers (OR=2.1; 95% CI=1.58-2.76) while periodontal disease was responsible for majority of tooth loss in rural dwellers (OR=0.28; 95% CI=0.19-0.41).
Table 5: Causes of tooth loss among rural and urban dwellers.
| Aetiology | Caries | Perio | Impaction | RTA | Assault | Ortho | Falls | Total |
| Rural | 219 | 87 | 43 | 22 | 6 | 4 | 16 | 39 |
| P value | 0.34 | 0.0006** | 0.99 | 0.99 | 0.99 | 0.84 | 0.89 | |
| Urban | 503 | 57 | 65 | 30 | 13 | 20 | 15 | 703 |
| P value | 0.69 | 0.04 | 0.99 | 0.99 | 0.99 | 0.95 | 0.97 | |
| Total | 722 | 144 | 108 | 52 | 19 | 24 | 31 | 1100 |
| X2=53.14; df=6; P=0.0001 | ||||||||
| Perio=Periodontal disease; Ortho=Orthodontic Treatment; * P<0.05;**P<0.0001 | ||||||||
The result of a multivariate analysis for the causes of tooth loss is presented in Table 6.The multivariate analysis helped determine which of the aetiological factors actually affected the incidence of tooth loss. All the causative factors were significant except for gender.
Table 6: Multivariate analysis of factors that affected tooth loss.
| Variable | Coefficient (β) | SE | t | 95% CI | P value |
| Intercept | -2.215 | 0.116 | -19.087 | -2.443,-1.988 | 0.000* |
| Age | 1.120 | 0.119 | 58.818 | 1.082,1.157 | 0.000* |
| Gender | 0.025 | 0.052 | 0.484 | -0.078,0.128 | 0.628 |
| Education | -0.219 | 0.020 | -11.196 | 0.181,-0.042 | 0.000* |
| Residence | 0.569 | 0.056 | 10.157 | 0.678,0.022 | 0.000* |
| *Significant at P<0.05 | |||||
Discussion
The present study evaluated the pattern and causes of tooth loss among patients attending a tertiary health institution in Northwestern Nigeria. Males were observed to have more missing teeth than females and this tended to contrast the results of previous studies that found more tooth loss in females. 16, 17, 18 The reason generally adduced for the higher frequency of tooth loss among females was that they tended to consume more refined carbohydrates than males. The other reason may be explained in terms of their dental seeking behavior and thus the probability of having dental extractions may be higher than that of males who may be less concerned with health-related issues.19 Our study was conducted in a predominantly Muslim community where women were usually restrained from outdoor activities owing to their ethno-religious beliefs. While this same factor partly explains the male dominance as a result of tooth loss due to road traffic accident the other components of trauma-induced tooth loss (assault and falls) may be due to the inherent nature of the male gender to engage in outdoor physical and contact-sporting activities which often result in falls.1,8, 20In addition, assaults and violence tendencies have frequently been reported among males.20 Although, the result of this study tends to favour male predominance, the result of multivariate analysis of the predictors for tooth loss however showed that gender does not play a significant role; its influence being strongly modified by the other variables (CI=-0.078, 0.128; P=0.628).
Mandibular first and third molar teeth as well as maxillary first molar teeth were noted to be the most frequently missing teeth in our study. A reason adduced for this is often related to the age the first molar in the mouth being one of the first permanent tooth to erupt. Our results were similar to previous studies from Nigeria and other parts of the world.1,18,21 Extraction of mandibular third molars is also often related to its impaction and the attendant morbidity. In contrast, extractions of the molars and premolars are often due to caries or its sequaelae, while that of the anteriors, especially the incisors are as a result of trauma.3,6,8
Dental caries normally progress from simple cavitation with little or no pain, to reversible pulpitis, irreversible pulpitis and apical periodontitis. At the latter stages, the tooth is characterized by throbbing and excruciating pain which often interferes with patients’ sleep the treatment option is usually a root canal therapy (RCT) or extraction. High levels of caries related tooth loss were seen in the present study and with a much higher prevalence than previous reports from Nigeria 1,8, 17This corroborates a previous report that alluded to a rising trend in the incidence of dental caries in Nigeria.1 On the other hand, our findings may just be a reflection of the lack of dental health awareness in the Northern Nigerian states with a consequent high prevalence of dental caries 13 while recent reports from the western world show a gradual reduction in the prevalence of dental caries.2, 22, 23
Periodontal diseases was the second most common cause of tooth loss in our findings and its occurrence was observed to be higher in males which is in keeping with reports from other workers. 1, 8, 15 ,19 Studies have shown a strong association between smoking and periodontal disease.24, 25 The second to fifth decades recorded the highest number of tooth loss with more caries-related extractions in the second to fourth decades while extractions due to periodontal diseases were frequently observed among subjects in the fifth and sixth decades. In contrast to the findings of previous studies2,4, 8, 18 that tooth loss due to dental caries or its sequaelae occur more in adolescents and young adults, our findings differed in that caries-related extractions occurred uniformly across all the age group with no significant differences. Tooth loss secondary to periodontal disease was seen more in older population and lends credence to earlier reports from different part of the world that found a rising frequency of periodontal disease with age.2, 4,8, 24The results of our study also support the findings that trauma related causes like falls were predominantly seen among children aged 10 years and below.20 The observed age distribution for victims who lost their teeth either in isolation or as a part of more severe maxillofacial trauma arising from road traffic crashes (second to fourth decades of life), is in tandem with reported demographic characteristics of road traffic accident patients.19,26
Our finding that people of high educational attainment experienced significantly more tooth loss through dental caries and its sequealae than their less educated counterpart supports previously documented reports.18, 27A high level of education is strongly correlated with high socioeconomic status and more educated individuals are also thought to have more regular visits to the dentists. Displaying an inverse relationship, low education status was significantly associated with tooth loss as a result of periodontal disease. More educated people and especially because of their social status, have better awareness about oral health care practices and are more likely to engage in regular scaling and polishing and other preventive measures than those of low educational level.27
Tooth loss has also been reported to vary from one part of the world to another and within the same country; it differs from rural and urban dwellers. Recent surveys have shown higher frequency of tooth loss among adults in the industrialized countries than among their counterparts in developing countries, where access to dental care is limited.22In this study the pattern of tooth loss differs significantly between urban and rural dwellers. While tooth loss secondary to dental caries was twice as much among urban populace than their rural counterpart, the reverse was true for tooth loss due to periodontal disease. This supports published reports of similar studies in the literature. People living in rural areas are believed to have less access to dental services than urban dwellers which leads to accumulation of tooth extraction demands among rural populace. Urban dwellers are assumed to be people of higher socio-economic status have easier access to dental care than their poor rural counterparts.19, 28
Conclusions
Dental caries and periodontal diseases still remain the main causative factors for tooth loss in this environment, more common in men and rural dwellers.
Footnotes
Competing Interests: The authors have declared that no competing interests exist.
Grant support: None
References
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