Eruption is the continuous process of movement of a tooth from its developmental location inside the jaw to its functional location in the mouth. Impaired tooth eruption, where this process is disturbed, is common in dental practice. It may manifest either as delayed or complete absence of eruption. This article reviews the local and systemic conditions under which IITE has been reported to occur. The terminology related to disturbances in tooth eruption is also reviewed and clarified. A diagnostic algorithm is proposed to aid the clinician in the diagnosis and treatment planning of IITE. The sequential and timely eruption of teeth is critical to the timing of treatment and the selection of an orthodontic treatment modality. This review addresses the need for a more in-depth understanding of the underlying pathophysiology of IITE and gives the clinician a methodology to approach its diagnosis and treatment.