The Surgical - Orthodontic Correction of Mandibular Prognathism in Skeletal Class III Malocclusion - การผ่าตัด - การจัดฟัน เพื่อแก้ไขขากรรไกรล่างยื่นในการสบฟันผิดปรกติชนิดโครงสร้าง class III

Abstract

                     Mandibular prognathism is defined as the lower jaw projecting too far forward so that the foreteeth pass those of the upper jaw.  Generally, the functional occlusal relationship and balanced facial harmony cannot be obtained by surgical or orthodontic treatment alone.  Its success depends on careful conjoint, supplementary diagnostic, and treatment plans.  Set back of the mandible to correct mandibular prognathism is a well-known procedure.  The most frequently used technique is the sagittal-split ramus osteotomy.

                      A 28-year-old Thai woman with skeletal class III malocclusion and asymmetrical mandibular prognathism was treated by combined surgical-orthodontic management during April 2002 - January 2004.  The orthodontic treatment relocated and compensated of malposition teeth and skeletal deformity was eliminated by the surgical treatment; bilateral sagittal-split ramus osteotomy with rigid internal fixation via bone screws.  The resulting profile was still concave due to excessive chin contour but occlusal improvement was satisfactory.  One year later the bone screws were surgical removed (2005).  The right lower border of the excessive chin contour were ground at the same time.  Long-term observation showed relative stability.

Key words:  surgical, orthodontic correction, mandibular prognathism, class III malocclusion