In the analysis of the characteristics of a pleasant smile, a gummy smile has negative components, which most affect the esthetics of non-verbal communication. For this purpose a proposed classification based upon etiopathogenetic criteria as useful indications for a therapeutical approach is given. The nature of a high smile line can be: dento-gingival, connected to an abnormal dental eruption, which is revealed by a short clinic crown; muscular, caused by an hyperactivity of the elevator muscle of the upper lip; dento-alveolar (skeletal), due to an excessive protuberance or vertical growth of the jawbone (maxillary); lastly, a mixed nature, in the presence of more than one of the above described factors The diagnosis of gummy smile must be precocious and based, with reference to specific parameters, upon a careful analysis of the etiopathogenetic factors and the degree of seriousness of the alteration. A correct treatment plan must contemplate the possibility of an orthognatodontic, orthopedic and/or surgical therapeutic resolution considering the seriousness and complexity of the gums exposures (high smile line) in connection with the age of the subject.