Patients with congenitally missing maxillary lateral incisors may seek treatment from an orthodontist for several reasons; unpleasant smile, dental arch disharmony, and midline deviations are among the most frequent complaints. Orthodontists and prosthodontists have raised important questions about the esthetics, occlusion, periodontal health, and psychological conditions noted in these patients. The decision to open lateral incisor spaces for prosthetics or close spaces by mesial movement of the canines requires a careful diagnosis and comprehensive multidisciplinary treatment planning. The purpose of this article is to present a diagnostic protocol to assist in the decision-making process, while analyzing patients with absent maxillary lateral incisors. The basis for a sound diagnosis and an effective treatment plan resides in careful consideration of the facial and dental characteristics of each patient. All information gathered during the clinical examination should be added to data obtained with other diagnostic tools, such as cephalometric analysis and orthodontic waxups, to achieve the treatment option that best suits the patient's expectations.