The morphology and physiology of odonto-periodontal units, muscles, temporomandibular joints, maxillary bones, ligaments are in a constant balance, even if all these components are subject to continuous transformation. Affecting a systemic element will attract imbalances to other levels, and the therapeutic solution will require knowledge and understanding of the ensemble. A complete dental exam must allow identification of all factors responsible or likely to cause imbalance in the stomatognat system. The maxillary compression is an abnormality characterized by a transversal developmental deficiency in the upper jaw and / or the mandibular, showing morpho-functional changes that denote a complex disruption in the development of the dento-maxillary apparatus. The common modification of all the fractured cases is the insufficient development in a transversal sense, dental arcades (mono - or bimaxilar), along with facial and maxillary bone changes, disturbances of inter - maxillary or occlusion blocking, functional deficits and disturbances. The strictly mandibular compression situation is very rare and addresses cases by affecting growth at the condylian level. The study includes 27 cases with jaw compression and benefited from orthognat surgery in the Maxillofacial Surgery Clinic between 2015 - 2018. If untreated, the abnormality determines the appearance of many cavities especially in the front teeth, difficulty in performing dental hygiene will lead to chronic marginal periodontitis, the occurrence of abnormal contact between teeth with joint pain, decreased chewing field. The jaw compression is revealed by multiple facial and oral signs, as well as by functional changes. Orthognatic surgery is the only effective treatment for many patients in jaw compression.