{'fraction_non_alphanumeric': 0.053983228511530396, 'fraction_numerical': 0.020440251572327043, 'mean_word_length': 5.363333333333333, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Prevalence of tooth forms and their gender correlation

OBJECTIVE
This study evaluated different tooth shapes from female and male genders, matching them with the firstly proposed pure basic forms, and proposed different hybrid shapes; it also evaluated the percentage of correct gender identification of lay people, dentists and dental students.


MATERIALS AND METHODS
Standardized digital photos were taken from 460 people and analyzed by 3 experts regarding genders and tooth forms: pure basic forms-oval (O), triangular (T), square (S) and rectangular (R); and combined hybrid forms-oval-rectangular (OR), triangular-rectangular (TR), triangular-oval (TO), square-oval with flat lateral incisors (SOF), and square-oval with scalloped lateral incisors (SOS). Then, correct gender identification (%) was evaluated among lay people, dentists and dental students (n = 10).


RESULTS
Pure forms showed less prevalence in the population studied (O:6.52%; S:3.48%; T:3.26%; R:2.39%) than hybrid ones (TO:20.87%; SOS:20.65%; OR:19.57%; SOF:16.96%;TR: 6.30%). Tooth gender selection among different evaluators was not significantly different (≈50% correct answers).


CONCLUSIONS
No correspondence exists between tooth shapes and patient genders. Pre-standardized pure tooth forms appeared less than hybrid ones, while the most frequently found in the population studied were TO, SOS, and OR forms, disregarding genders.


CLINICAL SIGNIFICANCE
Esthetic perception is an increasingly important criterion critical to satisfy patients. The correlation of reported tooth shapes with specific genders was not reliably observed in natural smiles. Tooth shapes should be selected according to the wishes of the patient rather than by previously believed gender specific tooth shapes. Pure basic tooth forms should be complemented with the addition of combination forms to more accurately portray forms found in nature.