Assessment of the accuracy of cephalometric prediction tracings in patients subjected to orthognathic surgery in the mandible

Admin Dental Press

Edition V15N04 | Year 2010 | Editorial Article | Pages 117 to 123

Thallita Pereira Queiroz , Jéssica Lemos Gulinelli , Francisley Ávila Souza , Liliane Scheidegger Da Silva Zanetti , Osvaldo Magro Filho , Idelmo Rangel Garcia Júnior , Eduardo Hochuli Vieira

Objective: The purpose of this study was to assess the accuracy of cephalometric prediction tracings—performed for orthognathic surgery—by means of the cephalometric analysis of preoperative and seven-day postoperative tracings, in patients subjected to correction of mandibular deformities. Methods: The lateral cephalograms of 17 patients who had been submitted to mandibular orthognathic surgery, three years earlier, were used. Cephalometric tracings were performed in the preoperative and seven-day postoperative periods and the following landmarks were traced: condyle (Co), pogonion (Pog), gonial (Go), menton (Me), B (B) and incisor (I). The analysis was based on the difference obtained by superimposing preoperative, prediction and postoperative tracings. The landmarks were projected onto a Cartesian plane for measuring distances between points in millimeters. The data were statistically analyzed using the paired Student t test (Į = 0.05). Results: A statistically significant mean difference was observed between the planned change and the change effectively achieved in the postoperative cephalometric tracings for points Pog (p = 0.014) and I (p = 0.008) on the horizontal axis. No statistically significant difference was found for the aforementioned cephalometric points on the vertical axis (p > 0.05). Conclusions: Cephalometric prediction tracings contributed to the preoperative evaluation of the patients and consequently to treatment optimization. However, they was not entirely reliable in these cases due to a slight underestimation of horizontal skeletal changes. These changes should be considered in planning and postoperative follow-up of patients subjected to orthognathic surgery in the mandible.

Surgery, Cephalometry, Mandible,

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