Retrospective Evaluation of the Prevalence of Diastema among an Adult Population ()
1. Introduction
One of the main reasons patients are addressing the dentist is the improving facial aesthetics. Face symmetry is considered an importance factor for facial aesthetics. Midline synchronization is considered an essential criterion for achieving harmony for facial esthetics.
A diastema is spacing or a gap in between the proximal surfaces of two adjacent teeth of 0.5 mm or more; spacing of upper or lower central incisors is frequently known as midline diastema [1]. Although commonly associated with maxillary midline diastema, such a spacing may occur between any two adjacent teeth. Most children will develop diastema during the process of normal development, and in many cases, treatment is not indicated [2]. However, maxillary midline diastemas of more than 2 mm are unlikely to close spontaneously and remain in the adult dentition [3]. Most adult patients consider a diastema, especially a maxillary midline diastema, to be unappealing [4]. Studies have shown that people consider those with diastema to be less intelligent, less beautiful, and of a lower social class [5]. Diastema may be brought about by several factors. Familial factors [4], abnormal size, shape, or number of teeth, periodontal defects, fibrous frenum defects, and muscular defects of the tongue [6] are all possible etiologies associated with the formation of diastema. Diastema formation has proven to be a truly multifactorial anomaly [7] [8]. Several studies support the concept of a possible genetic predisposition for the maxillary midline diastema [4] [7] [9] [10]. Genetics or family tree is considered the leading risk factor for the relapse of any orthodontic treatment of midline diastema; the other important factor is the size of the diastema [11].
Some studies concluded that maxillary midline diastema familial incidence was one of significant factors associated with the prevalence of maxillary midline diastema [7] [11]. In 2003, Gass et al. suggested that the midline diastema is inherited by an autosomal dominant mode of inheritance [10]. Diastema prevalence has been estimated between 3.7% [12] to 36.8% [13]. There was a variation of the acceptable maxillary to mandibular midline deviation, 1 - 2 mm deviation was considered to be acceptable while 2 - 4 mm was less esthetic or less acceptable, and 4 mm of deviation is considered as unaccepted [14] [15] [16]. The frequency of its occurrence and negative perceptions, it is clear that diastema is a concern for patients and practitioners. In 2007, Bernabe and Flores-Mir concluded that among young adults the maxillary anterior diastema had the most negative impact on self-perceived dental appearance [17].
Many techniques have been demonstrated to attempt to close diastema [18]. The aim of our study was to determine the prevalence of diastema in specific social demographics in our patient population at UNLV.
2. Methods
2.1. Patient Sample
The present retrospective study was approved by University of Nevada, Las Vegas, Biomedical Institutional Review Board and was given the status of exempt [IRB No. 1489457-1]. The data collection methods were inspired by a previous study where the data were collected from patients records in axiUm by using their clinical notes [19]. The search was conducted in the axiUmTM to find all patients at UNLV, SDM clinics presenting with diastema. The search contained the keywords of “diastema” or “midline diastema” to identify the patients presenting with diastema at UNLV SDM clinic. All patient identifiers were removed from the collected data. Our search resulted in 4859 entries. 2248 duplicate responses were removed from the search results. Inclusion criteria for the selected patients consisted of patients 12 years of age and older and were patients at the UNLV SDM clinic from 1/1/2014-9/30/2019. Only patients over 12 were included in this study because children under 12 will commonly have mixed and primary dentition. This mixed or primary dentition often contains natural diastema to make room for the larger permanent teeth as they erupt. 12 years old was chosen as the age cutoff for our inclusion criteria because most permanent teeth should have erupted by this age. Patients who did not report a race/ethnicity on the forms were listed as “mixed/unknown”.
2.2. Data Collection
Excel 2019 (Microsoft Corporation) was used to collect and organize data. Patient charts and exam notes were reviewed to collect data on age, sex, ethnicity, and diastema location. Size of diastema was also obtained through clinical photos, radiographs, and exam notes. This information was separated and organized into Excel. Demographic information and clinical data was evaluated as follows. Age was determined as being the age of the patient at the time of patient selection from the axiUmTM record base. Sex and age of the patient was listed on axiUmTM as filled out by the patient during screening. Ethnicity was also listed on axiUmTM as filled out by the patient during screening. Categories for patient ethnicity were divided into Caucasian, African American, Hispanic, Asian, and mixed/unknown. Diastema location was categorized based on tooth number and arch. Lastly, size of diastema was determined and then recorded into the Excel sheet. To determine diastema size, clinical photos and radiographs were measured. Each diastema was then separated into 3 categories. Diastemas 1 - 1.9 mm were considered mild, 2 mm were moderate, and above 2 mm were considered severe.
2.3. Statistical Analyses
Excel 2019 (Microsoft Corporation) was used to analyze demographic and clinical data. A chi-square test was performed to compare gender and ethnicity compiled from axiUmTM to Clark county population. Each gender and ethnicity’s proportion of the patient sample was compared to the respective gender and ethnicity’s proportion of Clark County Population. The frequency of each diastema size and their location was calculated as well via Excel. The significance level considered was 5 per cent. All statistical analyses were performed using Statistical software GraphPad.
3. Results
Results showed that 1182 patients’ records were identified to have one of the search keywords. The socio-demographic data in Table 1 indicated that females have a higher prevalence of diastema (56.7%). Regarding age, 31.5% of the patients were between 12 - 19 years old. Ethnicity frequency calculations indicated that diastema was more among the Hispanic population (35%), followed by Caucasians (25%) and the African Americans population were 17% (Table 1). Most diastema cases were in the maxillary arch (80.69%), followed by cases with diastema in both the maxillary and mandibular arch (13.49%). Most patients presented with mild diastema (60%), followed by moderate (28.7%), and then severe (11.3%) (Figure 1). The chi-square analysis showed that these ethnicity results were statistically significant (p < 0.0001). Figure 2 shows some cases of different sizes of diastema.
4. Discussion
Diastemas are frequently considered as esthetic or malocclusion problems. Once defined their etiology, different treatments can be achieved. When analyzing the present findings, results showed that the prevalence of diastema was higher in females and is of statistical significance; this comes into disagreement with the previous study, which showed a high percentage of males with diastema [20]. Diastema presence can be predicted by ethnicity. Earlier studies showed that the prevalence of maxillary midline diastema was greater in African populations than among Caucasians or Asian [21]. Another research reported that a maxillary midline diastema (MMD) occurrence among African Americans is more
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Table 1. Socio-demographic characteristics of the patients.
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Figure 1. Distribution of diastema according their esthetic threshold were mild diastema (1 - 2 mm), moderate (2 mm) and severe (above 2 mm).
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Figure 2. Examples of some diastema cases; (a) Mild; (b) Moderate; and (c) Severe.
than twice as in the whites or Hispanics population [22].
The present investigation provides data that indicates that diastema is more prevalent in certain population groups, and revealed a significant difference where the hispanic population represented 35% of the patients’ population with diastema. The present results disagree with previous findings, which indicated that the prevalence of diastema, when examined by race-ethnicity, was high among African America compared to Mexican Americans and non-Hispanic whites [20] [21].
Some cultural influences considered midline diastema as an attractive dental feature that enhance their personality and beauty; Akinboboye in 2015, revealed that most Nigerian ethnic groups considered 2 to 3 mm diastema as esthetic pleasing feature [23]; while others consider it a dental problem that requires orthodontic or restorative intervention [1] [24] [25] [26] [27].
Few studies reported the presence of diastema in both arch diastema; the reported percentage was 6.3% [28]; the present investigation showed that 13.49% of the cases presented with diastema in both arches.
Facial esthetic is considered an essential factor in determining all patients’ social interactions and quality of life. To achieve a satisfactory dental esthetic, it is necessary to decide the underlying cause for the midline diastema. One of the limitations of the present study was the investigation of the presence of any family tree for the diastema case. Further research is needed to understand how ethnicity contributes to determining whether a person has diastema. Genetic studies could evaluate the lack of or presence of a gene that contributes to diastema formation. Further research may determine if diastema formation is determined during embryological development, during adolescence, or from periodontal condition.
5. Conclusion
Within the limitations of the present investigation, there was a significant relation between the presence of diastema and ethnicity. The most common type and site of diastema was mild diastema in the maxillary arch only followed by moderate diastema in both arches.
Clinical Relevance
Treatment planning for diastema early in patients of certain social demographics may help avoid esthetics concerns later in life.
Authors’ Contributions
KC, TA and NHA planned and performed the study; KC and NHA performed literature review. KC, NHA drafted the manuscript, KC carried out the statistical analyses and interpretation of data. TA and NHA critically revised the manuscript for intellectual content. All the authors have read and approved the final manuscript.
Ethics Approval
This study was approved by the University of Nevada, Las Vegas, Biomedical Institutional Review Board and was given the status of exempt [IRB no. 1489457-1].
Competing Interests
The authors declare no competing interest.
Cousineau, K., Al Talib, T. and Hassan, N.A. (2022) Retrospective Evaluation of the Prevalence of Diastema among an Adult Population. Open Journal of Stomatology, 12, 175-182. https://doi.org/10.4236/ojst.2022.126017
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