Dolanmaz, Karaman, Gurel, Kalayci, Kucukkolbasi, Usumez techniques currently applied to surgically correct ternal devices allow multi-dimensional control. mandibular deformities. Although randomized External devices, however, are very conspicuous clinical trials are lacking, some support was found and are more likely to cause traction scars than in the literature for distraction osteogenesis hav- internal devices. Although intra-oral distractors ing advantages over BSSO in the surgical treat- are known to have some advantages (i.e. no fa- ment of low and normal mandibular plane angle cial scar, better tolerance by the patient), they are patients needing greater advancement (greater only unidirectional and require a subsequent sur- than 7 mm). In all other mandibular retrognathia gical procedure for their removal.33 We observed patients the treatment outcomes of distraction os- ulcerative lesions around the distractor pins par- teogenesis and BSSO seemed to be comparable.28 ticularly during the consolidation period and post- Differential growth and conventional orthognathic operative facial scar in patient 1. Our experience procedures become more difficult and less pre- leads us to think that the placement of intra-oral dictable when correcting severe mandibular de- distractors in desired locations is associated with ficiencies requiring lengthening of the mandible the experience of the surgeon. For this reason, the more than 8–10 mm.29 The primary advantage surgical procedure for the placement of intra-oral claimed in connection with distraction osteogen- distractors took longer than that for extra-oral esis is that it allows major reshaping of the facial distractors. bones without bone grafts or jaw wiring. It is be- The nature of distraction osteogenesis is well lieved that distraction osteogenesis may be safer suited for stretching of the pterygomasseteric than other methods of facial reconstruction, since sling, which is not easily overcome by conven- it can involve less blood loss and a lower risk of in- tional procedures. Pterygoid muscle usually does fection.30 Moreover, reports on patients with cleft not adapt to the elongation of ramus. However, palate have suggested that maxillary advance- during distraction osteogenesis, active histiogen- ments achieved by distraction are more stable esis occurs in different tissues including gingiva, than the advancements achieved with orthogna- blood vessels, ligaments, cartilage, muscles and thic surgery.31,32 nerves. These adaptive changes in the soft tissues The specially fabricated hardware used for decrease the relapse risk and allow the treatment the distraction process can be internal or exter- of severe facial deformities.34,35 Although we ob- nal. Advantages of external devices include ease served a significant increase in ramus height on of placement and removal. In addition, some ex- the affected side in patients 4 and 5. We did not Table 2. Results of lateral cephalometric analysis. Patients 1 2 3 Stages PreT PoT FU PreT PoT FU PreT PoT FU SNA (deg) 75.5 76 76 84 84 84 77.5 78 78 SNB (deg) 67 73 73 76 80 80 69 75 74 ANB (deg) 8.5 3 3 8 4 4 8.5 3 4 Corpus length, Me-Go (mm) 53 65 65 72 87 87 65.5 83 83 Ramus height, Go-Ar, Go-Co* (mm) 39 42 42 56 56 56 36 36 36 Gonial angle (PRP-MP) (deg) 121 154 153 111 113 113 133 125 128 Horizontal overjet (mm) 17.5 5 5 18 4 4.5 13 3 4 Convexity angle (Gl-Sn-Pg) (deg) 147.5 155 155 144 159 159 154 163.5 162 PreT 78 74 4 65 L 49 R 75 129 12 165 4 PoT 78 75 3 70 L 59 R 75 124 4 170 FU 78 75 3 70 L 59 R 75 124 5 170 PreT 75 63 12 55 L 80 R 60 118.5 9 142.5 5 PoT 76 70 6 61 L 80 R 71 131 3.8 156 FU 76 70 6 61 L 80 R 71 131 4 155 * Patients with laterognathia Deg: Degree; PreT: Pre-treatment; PoT: Post-treatment; FU: Follow-up; L: Left ramus; R: Right ramus. October 2009 - Vol.3 339 European Journal of Dentistry