Advancement of maxillary anterior segment by distraction osteogenesis for severe maxillary retrusion in cleft lip and palate

Background Maxillary anterior segmental distraction osteogenesis （MASDO） is a recently used method for correction of severe maxillary retrusion in cleft lip and palate （CLP） patients.In this article,we evaluated the feasibility of MASDO using rigid external distraction （RED） and rapid orthodontic tooth movement to correct severe maxillary retrusion in CLP patients.Methods Fourteen male and five female complete CLP patients between the ages of 18 and 22 years （mean age 19.7 years） at the time of distraction,with severe maxillary retrusion,were treated with the rigid external distraction （RED） device after maxillary anterior osteotomy.Rapid orthodontic tooth movement was started one week after the MASDO.Standard profile photographic,cephalometric films were obtained preoperatively and after therapy.Sella-nasion-point A （SNA） and Sella-nasion-point B （SNB） angles were measured to reflect changes in maxillary and mandibular position,and the distance between anterior nasal spine and posterior nasal spine （ANS-PNS） was measured to represent the maxillary dental arch length.Results The SNA angle increased from an average of 74.6° （range 73.0°-78.0°）,preoperatively,to 83.4° （range 78.6°-88.0°） after the RED was removed （P ＜0.01）.All cases of severe maxillary retrusion were improved.Nine patients＇ profiles became harmonious after therapy.One patient had a bimaxillary protrusion deformity and needed further surgery.The regenerate alveolar crest and edentulous space on both segments was almost completely eliminated after rapid orthodontic tooth movement.Conclusion MASDO with the RED system and rapid orthodontic tooth movement is a successful way of correcting severe maxillary retrusion in CLP patients.

Clinical Effect of Tip-Edge plus Appliance in Children with Angle Ⅱ1 Malocclusion

The effects of Tip-Edge plus appliance in the treatment of Angle Ⅱ1 malocclusion and the mechanism were investigated. Fifty-two Angle Ⅱ1 children, aged from 12.3-14.2 years, with mandibu- lar retrusion in permanent dentition were selected and treated with Tip-Edge plus appliance. Lateral cephalometric films taken before and after treatment were analyzed. The arithmetic mean and standard deviation were calculated for each variable. Paired t-test was performed to evaluate the significant treatment change. Results showed that the average treatment time was 16 months. Normal overjet and overbite were established with retroclination of upper incisors and proclination of lower incisors. U1-NA was decreased by 15.4° （P〈0.01）. ANB and Y axial angle were decreased significantly （P〈0.05） Soft tissue measurements showed that FCA and UL-E were decreased dramatically （P〈0.05）, and LL-E was increased significantly （P〈0.05）. Remarkable soft tissue change was noted after the treatment and convex facial profile changed to the straight profile. In conclusion, Tip-Edge plus technique can quickly and efficiently correct anterior bite and lateral outlook.

Maxillary Distraction Osteogenesis

Background: Distraction Osteogenesis is popular for long bones. And nowadays it has found its role in facial bone deficiency treatments. Purpose: We used our special designed Distractor for advancement of Maxillary deficiencies in cleft lip and palate patients. The purpose of this paper is to compare the treatment of hypoplastic, posteriorly retruded maxillary of cleft palate patients using distraction osteogenesis vs. Le fort I orthognathic surgery for length of advancement, stability and relapse, growth after distraction and soft tissue expansion and soft tissue profile changes. Meterial & Methods: In group A only Le fort I and surgical maxillary advancement sometimes with bone graft were done. In group B we used our special Distractor for Distraction Osteogenesis and advancement of the Maxillary bone. Demographic data, length of retrusion of maxilla, time length of treatment, length of advancement and relapse, SNA and SNB angles were measured and included in the study. The results were compared in each group before and after advancement and between both groups. The rate of distraction was 0.5 mm twice per day to achieve normal occlusion with 2 mm overcorrection more than calculated measures. The devices removed after 10 weeks as latency period. Results: The SNA increased at the end of distraction (p < 0.001), with no significant relapse indicating stability at 1 year after treatment. The total length of advancement in group A was 17 ± 4 mm and in group B was 20 ± 3 mm. The difference between before and after measurements in each group was significant (p = 0.002, p = 0.003 respectively). The mean length of relapse in group A was 3 ± 1 mm and in group B was 1 mm. Discussion: For the deformities and retrusions less than 7 - 8 mm, the Orthognatic surgery is the treatment of choice, however for more retrusions (>10 mm) we recommend Distraction Osteogenesis, and it preferred to start it soon in younger ages.

A novel skeletal anchorage for rigid external distractor

Aim: Maxillofacial surgery has always aimed to find alternative therapies to treat severe maxillary hypoplasia. Distraction osteogenesis of the midface has become the technique with the best functional and aesthetic results. Nevertheless, anchoring a distractor to the middle third of the face continues to involve complex planning. Plus, achieving the desired force vector can sometimes be cumbersome and uncomfortable. The aim of this study is to propose a novel skeletal anchorage technique for the rigid external distractor. Methods:Non-controlled, prospective study of 9 patients with severe midface hypoplasia who were treated with distraction osteogenesis using a rigid external distractor anchored to the infraorbital rims and the bilateral pyriform apertures. The activation phase started the first postoperative day at a rate of 1 mm per day. The consolidation period lasted 6 to 8 weeks. Results: Eight patients achieved the desired distraction objective (24.5 mm on average), with only 1 suffering a 5-mm relapse. None of the patients reported complications. Conclusion:Distraction osteogenesis of the midface by skeletal anchorage is an alternative method when treating patients with severe maxillary hypoplasia. It has significant advantages compared to traditional anchoring because it simplifies the procedure, diminishes the costs and complications.