ANALYSIS OF THE RADIOGRAPHIC PROJECTION OF CRANIOFACIAL STRUCTURES
The analysis of the radiographic projection of craniofacial structures is an essential step in the diagnosis and treatment planning of dentofacial deformities. Since the first application of radiography to dentistry, several cephalometric analysis have been proposed for the study of size and shape of hard and soft tissue structures, as well as for their reciprocal arrangement (Merow and Broadbent, 1990).11 In cephalometric studies one of the most widely used measurements of antero-posterior jaw relationship are the angles SNA, SNB, and the difference between them, ANB. SNA is a measure of maxillary prognathism or retrognathia (i.e. projection of the maxilla beyond or behind the cranial base), and SNB a measure of the mandibular position. The jaw relationship may be described as being orthognathic when the SNA or SNB values lie within normal ranges (Dietrich 1970). Besides, there are many ways of assessing vertical skeletal proportions are mandibular planes angle with many different references′ lines that is the cranial base, maxillary plan and occlusal plane. mandibular plane angle to the Sella-Nasion (SN) plane, the average value 32 extremely high lead to vertical growers or low lead to horizontal growing face (hypodivergent growth pattern) , Frankfort mandibular plane angle (FMPA), the average angle is 28 ± 4° excessively high is suggestive of grater vertical growth of the mandible (hyperdivergent facial patterns) and occlusal plan angle S-N plan angle the average value is 14 excessively increased lead to long face or vertical growing individual or it may be decreased in horizontal growing or vertical upward growth. As a result of the measurements we will determine whether the patient is hyperdivergent or hypodivergent. The analysis of the radiographic projection of craniofacial structures is an essential step in the diagnosis and treatment planning of dentofacial deformities. Since the first application of radiography to dentistry, several cephalometric analysis have been proposed for the study of size and shape of hard and soft tissue structures, as well as for their reciprocal arrangement (Merow and Broadbent, 1990).11 In cephalometric studies one of the most widely used measurements of antero-posterior jaw relationship are the angles SNA, SNB, and the difference between them, ANB. SNA is a measure of maxillary prognathism or retrognathia (i.e. projection of the maxilla beyond or behind the cranial base), and SNB a measure of the mandibular position. The jaw relationship may be described as being orthognathic when the SNA or SNB values lie within normal ranges (Dietrich 1970). Besides, there are many ways of assessing vertical skeletal proportions are mandibular planes angle with many different references′ lines that is the cranial base, maxillary plan and occlusal plane. mandibular plane angle to the Sella-Nasion (SN) plane, the average value 32 extremely high lead to vertical growers or low lead to horizontal growing face (hypodivergent growth pattern) , Frankfort mandibular plane angle (FMPA), the average angle is 28 ± 4° excessively high is suggestive of grater vertical growth of the mandible (hyperdivergent facial patterns) and occlusal plan angle S-N plan angle the average value is 14 excessively increased lead to long face or vertical growing individual or it may be decreased in horizontal growing or vertical upward growth. As a result of the measurements we will determine whether the patient is hyperdivergent or hypodivergent.