# Speech Disorders in Dysgnathic Adult Patients in the Field of Severity of Primary Dysfunction
## 4 Discussion
[25] suggested that the reason could be skeletal abnormalities and suggests patients' rehabilitation using myofunctional therapy after the surgical treatment. The patients with class II usually have better motor abilities in the orofacial region than class III. It is easier to use muscles to create some compensations than to force the skeleton. Chewing activates several muscles in cranio- and orofacial regions, and because of their constant activity class II patients had less evident pronunciation disorders. The patients with unilateral chewing more often present disorders in pronouncing palatal and dental sounds; however, patients with class III, especially progenia, presented distortions in bilabial sound due to the inability to seal the lips. The lack of lips seal was also observed during chewing, which justifies why total visual assessment in our study is low. Chewing and biting patterns are closely connected with motor skills which are fundamental for pronunciation. In addition to chewing, it was proved that patients with lateral biting patterns had difficulties in pronunciation palatal_PL and dental phonemes. In Polish, palatal_PL phonemes are medio-alveolar sounds, meaning that the tongue must be placed correctly, and the mandible has to present good kinematics. [PERSON] et al. [26] stated that during normal chewing, the mandible deviates laterally towards the bolus side and then medially during closure. In the reverse sequence, the mandible first deviates medially and then laterally, thus ensuring an overlap of opposing dental occlusal surfaces. They also add that reverse chewing cycles show an abnormal, narrow pattern characterised by smaller lateral displacement, a crossover of the opening and closing pattern, the mandible's slow velocity, and altered coordination of the masseter muscles. As this state becomes habitual for a patient affected by malocclusion, it may influence oral motor control and tongue movements crucial for proper articulation of alveolar, palatal_PL and dental phonemes. It has to be added that such observations may be a tool for the detection of primary function disorders which may require a myofunctional treatment after surgical correction. That is a justification for orthognathic speech therapy present in the field of maxillofacial surgery and widely recognised dentistry. The presented method of calculating severity of primary dysfunction showed to be an interesting and helpful tool for diagnosing disorders in the stomatognathic system. Moreover, the lack of proper elevating movements creates compensation mechanisms for pronunciation of palatal, dental and alveolar phonemes as well as provokes extra muscles activity. All phonemes require exact elevation of the tongue and its placement over the hard palate and the alveolar ridge. [PERSON] et al. [21] conducted research on tongue-palatal contact changes in patients with skeletal mandibular prongathism after sagittal split ramus osteotomy and found that whole total of palate tongue. To summarise, the conducted study accompanied by a literature review reveals that primary functions such as breathing, swallowing, chewing and biting are usually distorted in patients affected by malocclusion in class II and class III and impair articulation of speech intelligibility. Maxillofacial surgery can successfully correct both. Considering the functions, stomatognathic surgery corrects the skeleton and provides new and often better possibilities for oral motor control and due to that leads to pronunciation improvement. It is crucial to establish criteria for diagnosing primary function dysfunction and speech before surgery. Such actions may help early diagnosing the possibility of relapse in some malocclusions, such as the open bite. Moreover, it is crucial for orthodontists, maxillofacial surgeons and speech-language pathologists to cooperate as only by interdisciplinary treatment it is possible to accomplish all the goals both for the patients and for the medical team.