Bruxism is defined as a parafunctional crunching or grinding of teeth. Etiology is unclear, but today there are more causal factors. The psychological stress of the child is considered among the primary factors. Since the respondents are minors, there is a lack of information on bruxism in children due to the complications of conducting research. The methods used in the diagnosis of bruxism can vary. They include expertly constructed questionnaires and interviews intended for children and parents, as well as clinical examination and, possibly, electromyogram or polysomnography during sleep. The consequences of bruxism are numerous and more difficult according to the chronicity and strength of bruxism. Consequences can be tooth wear, necrosis, tooth fractures, periodontal injuries and increased tooth mobility, premature resorption of primary tooth, and early eruption of permanent successor. The fatigue of the masticatory muscles manifests as pain and headache, and in the temporomandibular joint there is clicking and pain while opening the mouth. Biofeedback therapy is used in daily bruxism therapy. Night bruxism is usually controlled by a therapeutic splint that protects the teeth and joints from further damaging effects of bruxism activity. Less popular therapy methods are psychotherapy, physiotherapy, and in heavier cases medications. If some systemic illness causes bruxism, treatment of this condition will also solve bruxism.