Perception of Maxillary Midline Diastemas in West African Smiles

A structured self-administered questionnaire was administered asking participants a series of questions about themselves, their experience of maxillary midline diastemas, and their opinions of 8 female and 8 male full-face photographs.

The 16 photographs represented simulated smiles with a 0-6mm diastema for each model. To obtain the simulated smiles informed consent was obtained from two models aged 25-35 known to one researcher were recruited. Both models had Ghanaian heritage (of at least 2 generations), had an existing diastema and had not undergone any orthodontic or cosmetic dental treatment to change the shape or the size of their teeth. Both models had however undertaken a course of tooth whitening. A suitable image of each model was taken using a DSLR camera and this image was altered to create the simulated smiles in Adobe Photoshop (version: Creative Cloud 2019). The images were first harmonised by creating dental symmetry across the midline, thus removing distracting features in each smile. This produced ‘male smile C’ (4mm) and ‘female smile D’ (3mm) as the harmonised images of each model’s existing smile. The central incisors were then edited to make the diastema smaller (by widening the central incisors) or larger (by narrowing the central incisors). No other parameters were adjusted in each image. Participants were asked to rate the desirability and attractiveness of the 16 smiles on a 5 point Likert a scale, with 1 representing a very attractive smile, 5 representing a very unattractive smile, and 3 representing an acceptable smile.

A combination of quantitative and qualitative data was collected. Within the questionnaire, the order in which the 16 images appeared was randomised for each participant.

The questionnaire was administered using the web-based tool TypeForm™ between 3rd March 2021 and 12th April 2021 at participants’ convenience on their own device. The study was based online, and as such participants were not included or excluded based upon their geographical location, enabling global participation. An opportunistic sampling method was used to contact potential participants via gatekeepers (community leaders and network members known to one researcher within the target population). Each participant was subsequently invited to share the link to the survey with any potential participants they knew. Participants in the questionnaire were all aged 18 or older and had heritage in West-Africa.