Assessment of the Smile Characteristics in Different Dentoalveolar Malocclusion Cases

Abstract

Objectives: This study was designed to assess the smile characteristics in different dentoalveolar malocclusion cases, by standardized photographic analysis. Subjects and methods: A sample of 132 subjects with age range from 18 to 24 years. The study groups were designed according to Angles Classification in to 4 groups. Standardized extraoral photographs at rest position, social smile, maximum smile and profile were taken for each subject. Smile analysis was done by identifying certain measurements digitally via software. Results: The upper and lower lip length showed significant change. The mouth width increased during smiling significantly. The smile area showed no significant different in social smile between all groups. The buccal corridors area showed significant increase. The incisal show had significant difference among all groups in social smile. The smile arch depth showed no significant difference in social smile among all groups. The gingival exposure significantly increased during maximum smile. Conclusions: Control group showed moderate smile Class I with bimaxillary protrusion, spacing and openbite subgroups showed high smile. Class I with crowding and deepbite subgroups showed low smile. Class II Division 1 group showed high smile while Division 2 showed moderate smile. Class III group showed low smile.

Analysis of Different Vertical and Horizontal Smile Characteristics

“…While the lowest values when smiling were observed in subjects with class II malocclusion. These results were consistent with other studies showing that class III subjects had the highest lower lip height values [29], [30], and [31]. Reduced height of the lower third of the face is associated with a vertical maxillary deficit and a deep bite with retrognathism of the mandible.…”

“…In the current study, the largest vertical display of upper central incisors was observed during social smile in untreated and treated individuals with class I malocclusion, which is consistent with the study by Abdarazik et al and the smallest in class III malocclusion [29]. In the study by Salehi et al a significantly greater display of central incisors was observed in patients with class II malocclusion compared to those with class III malocclusion [35].…”

“…During a posed smile, the highest height of the upper lips is observed in patients with class I malocclusion. This result is consistent with several studies [29], [30], and [31]. However, it is contrary to other studies that reported that the height of the upper lip in class II malocclusion is higher compared to class I malocclusion [17], [32].…”

Assessment of Aesthetic Smile Components in Patients With Skeletal Class II Vertical and Horizontal Growth Patterns Compared to Class I Cases

“…To achieve uniformity of shape in orthodontic treatments, it is necessary to assess the inherent features of the smile. This requires identifying the elements and circumstances that influence these traits [ 3 ].…”

“…Numerous writers have distinguished between various sorts of smiles; one writer distinguished between two fundamental forms of smiles: Put on a grin (the social grin): it's a deliberate, relaxed, motionless facial expression with only mildly contracted muscles. This is the smile that people usually use to say hello [ 3 ]. A person who consistently and voluntarily smiles in social situations is said to be wearing a social smile.…”