Orthodontic expander comprising a left frame (Tl) and a right frame (T2), wherein said left frame (Tl) and right frame (T2) respectively comprise a left body (1) and a right body (2) provided with means for their anchorage to the teeth of a dental arch, wherein said bodies (1.2) have through holes (10) oriented in an expansion direction (d), wherein said frames (Tl, T2) are slidingly mounted along said expansion direction (d) by means of guides (4) inserted in said holes (10) of said bodies (1.2), wherein the distance (h) between the said bodies (1, 2) is adjusted by means of a screw (5) screwed into the body (2) of one of said frames, wherein said screw (5) has an operating head (51) positioned between said bodies (1.2), and wherein elastic means (M) are positioned and acting between said frames (Tl, T2) and can be activated or reactivated by acting on said screw (5) which compresses them to activate or reactivate them when desired. The elastic means (M) comprise a plurality of elastic plates (6) with a curvilinear profile (P) oriented transversely with respect to said expansion direction (d).La présente invention concerne un expandeur orthodontique comprenant une cadre gauche (T1) et un cadre droit (T2), lesdits cadre gauche (T1) et cadre droit (T2) comprennent respectivement un corps gauche (1) et un corps droit (2) pourvu de moyens pour leur ancrage aux dents dune arcade dentaire, lesdits corps (1, 2) ayant des trous de passage (10) orientés dans une direction dexpansion (d), lesdits cadres (T1, T2) étant montés de façon coulissante le long de ladite direction dexpansion (d) au moyen de guides (4) insérés dans lesdits trous (10) desdits corps (1, 2), la distance (h) entre lesdits corps (1, 2) étant ajustée au moyen dune vis (5) vissée dans le corps (2) dun desdits cadres, ladite vis (5) ayant une tête opérationnelle (51) positionnée entre lesdits corps (1, 2), et des moyens élastiques (M) étant positionnés et agissant entre lesdits cadres (T1, T2) et peut être a
