Facial esthetics can be divided into three sections: microesthetics which includes the concept of ideal tooth shapes, dimensions, proportions and associated gingival contours, miniesthetics which includes the relationships between teeth and lips, and macroesthetics which refers to different facial features.
Microesthetics (dental appearance):
Central incisor proportion: the width to height ratio is approximate 80% with the width dimension varies from 8.37-9.3mm while the height dimension varies from 10.4-11.2mm
The size of the front teeth should become progressively smaller as we proceed toward the back of the mouth in the ratio of 1.6 to 1.0 to 0.6 called The Golden Proportion.
Gingival Zenith: for ideal appearance, the contour of the gingiva over the maxillary central incisors and canines is a half-ecllipse, with the zenith distal to the midline of the tooth. The maxillary lateral incisor, in contrast, has a gingival contour of a half-circle, with the zenith at the mid-line of the tooth
The Smile Arc: the smile arc is the contour of the incisal edges of the maxillary anterior teeth relative to the curvature of the lower lip. The contour of these teeth should match that of the lower lip.
Connector s and Embrasures: connectors are the contact area of adjacent teeth. The normal connector height is greatest between central incisors, and diminishes from the centrals to the posterior teeth, moving apically in a progression from the central incisors to the premolars and molars. The embrasures are the triangular spaces incisal and gingival to the contact areas. It is narrow between central incisors, asymmetric between lateral and central incisor, and large between the lateral incisor and canine. The incisor embrasures increase from maxillary central incisor to canine.
Gingival Heights, Shape, and contour: the gingival margins of the central incisors and canines are at the same levels while the gingival margins of the lateral incisors are approximately 1.5mm lower than that of the centrals
Buccal Corridor: spaces between the buccal surfaces of the maxillary posterior teeth and the cheek. In full smile, the buccal corridor is almost filled with teeth.