Region and representation
The majority of participants came from Ghana and Nigeria, meaning that this data can only confidently relate to this portion of West-Africa. The sample population showed reasonable representation across the demographic variables, with skew in the categories place of birth, education & profession.
Given the small percentage of participants who had been born outside of their country of heritage, it can be assumed that the majority of those who now live abroad were first generation immigrants. Given the varied ages at the point of immigration, the impact of Western influence cannot be ascertained from this sample.
Prevalence
The prevalence of Maxillary Midline Diastemas was significantly higher in this study (42%) than it was in studies of the same population included in a recent literature review [21] (17–30%). It is also slightly higher than the highest figure previously reported in the literature reported by Mabiaku and Ibawoh [17] at 36%. Given the sampling method, participants who had a diastema may have been more likely to participate resulting in a sample bias.
Diastema width
The ideal diastema width in this study has been noted to be 0–2 mm for males and 0–3 mm for females, based upon the inflection point noted across all demographic variables. This supports the conclusions drawn from Ahiaku and Millar’s [21] literature review of 2–4 mm being the acceptable diastema width [9].
Beauty
Based on this study, it is apparent that MMDs are more acceptable in females than they are in males, regardless of their size, with females being more accepting of diastemas, with one participant commenting “A little diastema is desirable, even sexy, in a female smile, but less so in males.”
The majority of participants found MMDs attractive in general. This is further supported by the mean attractiveness ratings for each smile, particularly showing that male diastemas of 1 and 2 mm are more attractive than those of 0 mm.
Critique of methodology and suggestions
This study scored 20/22 on the Witt & Flores-Mir [22] criteria (Table 3). This criterion, in combination with a literature review [21], was used to design the study to ensure its validity.
Sampling
Improving the representativeness of the sample would improve the quality of this data. Using a stratified-random sample, would provide results which were more generalisable. Opportunistic sampling and word of mouth is likely to have led to clusters of participants, introducing bias. Although present, this bias appears to be minimal as the trend in perception appears to be reproduced across the demographic stratifications of the data.
Hosting the questionnaire on a web-based platform, although making it easier to manage for the researcher, is likely to have excluded some sectors of the population who are either online but suspicious of the internet, or not online at all. This would have contributed to the lower numbers of participants in some portions of the population like the elderly and those in lower socio-economic categories.
Smile simulations
In this study, smile simulations were created by adding to the width of the central incisor, which itself is a determinant of attractiveness. The smile simulations could have been created in a number of ways, as shown by Reis et al. [1] who showed both orthodontically managed spaces and spaces closed by restorative means. All the simulations were based on restorative management alone. It is possible that simulations with orthodontic management, rather than restorative management, would have affected the perception of some of the smiles as the height : width ratio of the tooth itself would remain un-affected.
A further study could create the smile menu simulating both techniques. In addition, creating a smile simulation for a male and female from each participant’s specific country of national heritage would generate more robust data given that overall facial features do vary in the region.
Finally, some participants commented that they found no problem with any of the smile simulations but were unable to indicate that they did not find any smiles un-attractive. Should this study be repeated, allowing participants to select such an option would be beneficial.
