## 4 Discussion  
Class-III dentofacial deformities are intermaximillary skeletal gaps treated by Orthographic surgery [8]. In 1980, [PERSON], [PERSON], and white conducted a study concerning the surgical treatment in such cases and showed how determining a surgical treatment plan (mandibular setback or maxillary advancement or a combination of the two) is based on the analysis of facial cephalometric radiographs, model analysis, and the patient's complaint [13]. In 2009, [PERSON] showed the importance of orthodontic treatment before the surgical procedure for de-compensation and after the surgical procedure for achieving optimal occlusion [10]. Patients with Skeletal Class- III usually present a narrow maxilla; as part of presurgical treatment, the patients undergo treatment with SARPE (surgically assisted rapid palatal expansion) [14]. In [PERSON]'s study in 2016, the authors show the importance of calculating the angle of the incisors relative to jaw bases for planning Presurgical Operations (PSOs) according to the obtained values. In 2016, [PERSON] maintained that, in cases where the Proclination of upper incisors is large, the extraction of premolars should be considered to achieve enough space for the correction of the incisor proclination and for decompensation of the maxillary teeth. [PERSON] 2000 shows that orthodontists need to be aware of the potential restriction and that an accurate analysis of the cephalometric radiograph is required to plan a proper course of treatment [9; 15]. However, the condition in the mandible is different: In most prognathic cases, no extraction of mandibular teeth is performed, and de-compensation can be achieved without extractions [16]. The mandibular incisors are usually in a lingual position and the purpose of de-compensation, in this case, is to return them to a more buccal position [15; 16]. Therefore, cephalometric measurements are essential for correctly diagnosing and planning a combined ortho-surgical treatment. An accurate diagnosis of the angles of the incisors is part of the modus operandi on which the entire planning process of combined therapy of maxillofacial deformities is based [1; 9]. In 2013, [PERSON] emphasized the importance of planning surgeries and making decisions regarding the extraction of premolars. He showed that the values obtained through calculating angles in the cephalometric radiograph are essential parameters for making such decisions [17]. Naturally, miscalculating these angles may lead to an incorrect decision. The more severe the deformity and the more radical the action needed, the less accurate the values obtained in the cephalometric analysis regarding incisor angles. [PERSON] 1993 raises a question concerning the reason for this error. He hypothesizes that the longitudinal axis of the root of the upper incisor is not always the same as the axis of the crown according to the cephalometric analysis; therefore, there is an angle between the crown and the root; this angle is larger than the more lingually inclined the crown is, and the angle between the crown-root to the upper incisor is larger in the Class-III set of relations, a fact that causes great difficulty in identifying the appropriate longitudinal axis of the upper incisor. This conclusion has implications concerning the accuracy of the model on which the entire process of planning a combined treatment for maxillofacial deformities is based and may result in inaccurate overtreatment [18]. To examine the accuracy of the model on which the entire planning process is based, ten physicians were provided 100 cephalometric radiographs (1000 measurements for each one of the parameters) to obtain a statistically significant index concerning the accuracy of measurement in Class-I compared to Class-III.