Abstract : Smile design refers to the many scientific and artistic principles that considered collectively can create a beautiful smile. These principles are established through data collected from patients, diagnostic models, dental research, scientific measurements, and basic artistic concepts of beauty. From the patient’s perspective, beauty measures that individual’s perception of beauty as noted in the saying: ‘‘Beauty is in the eye of the beholder.’’ That perception of beauty may also be influenced by cultural, ethnic, or racial concepts of beauty and may vary from the standards established in the North American dental community. When planning treatment for esthetic cases, smile design cannot be isolated from a comprehensive approach to patient care. Achieving a successful, healthy, and functional result requires an understanding of the interrelationship among all the supporting oral structures, including the muscles, bones, joints, gingival tissues, and occlusion. Gaining this understanding requires collecting all the data necessary to properly evaluate all the structures of the oral complex. The face, lips, gingival tissues, and teeth must all be examined, evaluated, and their overall appearance must be taken into consideration in order to create the perfect smile. The symmetry and harmony of the facial and dental characteristics are necessary for such a perfect smile. The teeth's location, color, and form all play a role in the equation. The importance of understanding that the anterior teeth play a crucial part in the patient's dental health and that form always follows function cannot be overstated. When assessing and arranging esthetic situations, a thorough approach may help patients have the smile that best complements their entire facial look and offers the added advantage of improved dental health. The objective of this article is to review and discuss criterion adopted by dental literature to technically analyze the smile, such as dental midline, smile line, dental exposure, negative space, dental proportion, and symmetry.