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RECORDING OF MASTICATION ANGLES BY PLANAS’S LAWS Figure 3. The antero-posterior growth is the movement of mandible to the non-working side Figure 4. The gliding of the mandible to the working side causes transversal development Figure 5. Growth or expansion of the maxilla The gliding of the mandibular condyle and articular disc complex [2] during the diagono - transverse movement is the stimulant need for growth. What is essential for the mandible antero-posterior growth is the movement of the mandible to the non-working side (fig 3). The gliding of the mandible to the working side causes transversal development (fig 4.) determined by muscular contraction and occlusal contacts during mastication (the stimulants are perceived and transmitted thanks to a rich periodontal innervation). Petrovic’s [13] observations after sectioning the pterygoid muscle (on rats), certify that the mandible undergoes a “decrease in longitudinal development and a drop in the number of mitoses in the growth area”. The growth of the mandible is obtained using a system that amplifies the propulsion of the mandible. In conclusion, immobilizing or limiting the movements of the mandible can induce a significant diminution of the mandible size and the diminution of the mitoses number [3]. STOMA.EDUJ (2014) 1 (2) Maxillary growth, according to Planas[14, 15], depends on the friction force that appears in mastication between the dental articular facets of the superior and inferior teeth on the working side [10-15]. The result will be the growth or expansion of the maxilla in that zone together with the palatal vault and the floor of the nasal fossae (fig. 5). Thus, a circle is created in which the growth of the mandible determines the growth of the maxilla. To have physiological masticatory movements, we need to cause the diagonotransverse movements of the hemi-mandible to the non-working side and sufficiently intense dental contacts on the working side. Murphy [1] explained that the masticatory cycle evinces overlapping of the terminal points, irrespective of the mandible trajectory, which we have also underlined. In order to consider the masticatory function correct, it is necessary that the masticatory angles permit not only an easy lateral movement of the mandible, but also equal dental contacts. 89