Nasal Profile Changes Following Anterior Maxillary Segmental Osteotomy: A Lateral Cephalometric Study

Purpose

Orthognathic surgery in reference to the maxilla attempts to correct underlying skeletal deformities and improve function. Consequently it has the potential to significantly alter the central esthetic unit of the face, the nasolabial region. In order to evaluate the nasal morphological changes which would result following anterior maxillary segmental osteotomy (superior and posterior repositioning); four angles namely, nasolabial, nasal tip projection, columellar labial and supra tip break angle were evaluated.

Method and materials

In ten selected subjects who have undergone anterior maxillary segmental osteotomy with superior and posterior repositioning, pre (T1) and post operative (T2) lateral cephalometric parameters pertaining to the four angles were analysed using Wilcoxon signed rank test.

Results

A significant increase in nasolabial angle and mild changes in nasal tip projection, columellar labial angle and supra tip break angle were observed.

Conclusion

The results of this study emphasize the need for the pre surgical evaluation of nasal morphology in every individual planned for anterior maxillary segmental osteotomy.

     

成年女性上颌前突术后颜面部软组织侧貌改变的研究

目的:探讨上颌前份节段性骨切开术矫治上颌前突畸形软组织侧貌改变,说明其稳定性。方法:对26例上颌前份节段性骨切开成年女性患者术前、术后1个月内及术后1年后的X线头影测量进行对比研究,并进行统计学分析。结果:1)术后软组织侧貌改变:上中切牙切缘点Is平均后移(6.1±2.7)mm(P<0.01),上唇突点Ls平均后移(4.6±1.6)mm(P<0.01),鼻唇角Cm-Sn-Ls平均增加(6.8±5.6)°(P<0.01),上下唇间隙Stm s-Stm i平均缩小(4.5±3.5)mm(P<0.01),露齿程度Is-Stm s平均减小(2.1±2.2)mm(P<0.05),上唇突度减小,上唇厚度、长度及软组织面型角G-Sn-Pgss无显著改变(P<0.05)。2)术后1年颜面软组织侧貌改变的稳定性;与手术后早期相比,在水平方向上,所有指标复发率均超过10%。在垂直方向上,各项指标复发率均在10%以内。结论:上颌前份节段性骨切开矫正上颌前突,患者颜面软组织侧貌的改善明显,效果稳定。     

Achieving the Prediction Results by Visualized Treatment Objective Following Anterior Maxillary Segmental Osteotomy. A Retrospective Study

This study used the manual visualized treatment objectives (VTO) as a tool to evaluate the predictive value of the computer-assisted VTO. Presurgical cephalometric tracing predictions generated by oral and maxillofacial surgeons and computer-assisted VTOs were compared with the postsurgical outcome as seen on lateral cephalometric tracings. Ten measurements of the predicted and actual postsurgical hard tissue landmarks were compared statistically. A paired Student’s t test showed that in nine of ten measurements, there were no statistically significant differences in the mean values of manual VTO (MVTO). Statistically significant differences were found in one of the four linear measurements (cant of upper lip P − 0.0001). For computer assisted (CAVTO) Student’s t test showed that in nine of ten measurements, there were no statistically significant differences in the mean values. Statistically significant differences were found in one of the four linear measurements (nasolabial angle, P  − 0.0001). From these data, it appears that both VTOs demonstrated good predictive comparative outcome, and are equally predictive, but CAVTO is precise.     

Profile Changes Following Maxillary Impaction and Autorotation of the Mandible

OBJECTIVE: The aim of this study was the evaluation and prediction of profile changes after Le Fort I osteotomy including maxillary impaction and subsequent autorotation of the mandible. MATERIALS AND METHODS: A group of 42 patients (32 female, 10 male) underwent a Le Fort I osteotomy with posterior impaction after preoperative orthodontic treatment. No surgical intervention in the mandible was performed. Pre- and postoperative lateral cephalograms of each patient were analyzed in two steps using the Wilcoxon and Mann-Whitney U test. All patients were evaluated for vertical and sagittal skeletal and soft tissue changes. These results led to further classification into three groups according to the type and extent of maxillary impaction. These groups included parallel impaction, posterior impaction with additional anterior subsidence, and posterior impaction only. RESULTS: The results of the first evaluation step revealed that the chin had advanced on average by 79%, while the lower face was shortened by as much as 70% in the pogonion point. However, the second evaluation showed that the type and extent of maxillary impaction led to significant changes in these parameters. Parallel maxillary impaction resulted in 100%, posterior impaction in 80% and posterior impaction with anterior subsidence in 50% advancement of the mandible in the pogonion point in relation to the distance covered during impaction. CONCLUSION: This study showed that the change in the facial profile caused by autorotation of the mandible after Le Fort I osteotomy and maxillary impaction can be predicted in relation to the dimensions of maxillary impaction.     

外科矫治上颌前突畸形颜面软组织侧貌改变及其预测的研究

对１５例上颌前部骨切开后退术患者的手术前后Ｘ线头影测量进行研究,结果显示软组织鼻底点Ｓｎ,上唇凹点Ａ＇分别以上齿槽座点Ａ的３７％和６３％向后移动,上唇突点Ｌｓ以上中切牙切缘点Ｉｓ的７５％向后移动。同时还分析求得了施行该术式后软硬组织变化的相关关系和回归方程。     

Soft Tissue Changes in Cleft Lip and Palate Patients: Anterior Maxillary Distraction versus Conventional Le-Fort I Osteotomy

The purpose of the study was to compare the soft tissue changes after maxillary advancement in patients with maxillary deficiency associated with cleft lip and palate (CLP) by two approaches—anterior maxillary distraction (AMD) and advancement LeFort I osteotomy (ALO). Twenty patients with maxillary hypoplasia associated with cleft lip and palate who had undergone either LeFort I osteotomy or distraction osteogenesis with maxillary advancement were included in this study. Lateral cephalogram taken at various intervals of time were used to evaluate soft tissue and hard tissue changes over time. In both groups, vertical as well as horizontal changes in pronasale was well observed. A substantial increase in nasal parameters was noted in case of AMD group in comparison to ALO. Though maxillary advancement was evident in both the groups, a significant and consistent change was observed in AMD. Significant vertical and horizontal changes were seen with respect to subnasale and labrale superius in AMD group. Soft tissue as well as hard tissue relapse was greater in ALO group than AMD group. Significant soft tissue and hard tissue changes were clearly observed in both the groups, but the treatment results were more consistent in cases treated with AMD. Hence AMD could be considered as a better treatment of choice in cases of maxillary hypoplasia associated with cleft lip and palate.     

Factors Influencing the Accuracy of Cephalometric Prediction of Soft Tissue Profile Changes Following Orthognathic Surgery

The cephalometric prediction of orthognathic treatment outcome is an important part of the surgical planning and the process of informed consent. The orthodontic and surgical changes must be described accurately prior to treatment in order to assess the treatment’s feasibility, to optimize case management and to increase patient’s understanding and acceptance of the recommended treatment. The aim of the present article was to investigate on the factors that could influence the accuracy of cephalometric prediction in planning orthognathic surgery. Review of the literature revealed that, besides factors directly related to the prediction method and its use, there exist a considerable number of factors which could affect significantly the accuracy of soft tissue response. These factors could be biological ones such as relapse, centre of mandibular rotation and individual variation in response to treatment and others such as gender, race, pre-operative soft tissue thickness and data bases for mean ratios of soft to hard tissue movement changes. Some of the factors affecting the accuracy of prediction of soft tissue response following orthognathic surgery are inevitable and there are others, difficult to control and predict. However, patients should be informed that predictions are only a guide, may not represent the actual result of the surgical outcome, and as such they should be implemented.     

Hard and Soft Tissue Changes Following Maxillary Distraction Osteogenesis and Mandibular Setback with Bilateral Sagittal Split Osteotomy

Aims of this Study

(1) To highlight the role of intraoral submerged device in distraction osteogenesis (DO) of patients requiring two jaw surgeries for the correction of severe developmental maxillary hypoplasia (MH) and mandibular prognathism (MP) (2) To analyse the hard and soft tissue changes following maxillary DO and mandibular setback with bilateral sagittal split osteotomy (BSSO) in patients with severe MH and MP requiring two jaw surgeries.

Materials and Methods

During the period Jan 2004 to Dec 2006, five patients with severe developmental MH along with MP were treated. In 1st stage maxillary distraction was done. Distraction started on 6th postoperative day, 1 mm distraction was carried out for 10–15 days on either side. Serial radiographs were taken immediate postoperative period for baseline comparison, post-distraction and at the end of distraction. After a period of 3–4 months of distraction 2nd stage was done. In 2nd stage, mandibular setback was done with BSSO and distractors were removed under general anesthesia. Radiographs were taken immediately and at 4 months post-operatively. Cephalometric tracings were carried out preoperatively, post DO and finally after mandibular setback with BSSO.

Results

The mean horizontal movement of maxilla was 11.4 mm at ANS and 9.6 mm at A point. Upper incisor edge was advanced by 8.8 mms. SNA increased by 8.4° and SNB decreased by 4.6°. Nasal projection advanced by 4°. Nasolabial angle normalized in all patients, mean change achieved was 10.8°. Upper lip moved forward by 5.4 mm. Lower lip moved backward by 5.4 mm. Mandible positioned backward by 4 mm at B point. No vertical change occurred in the position of A, ANS and upper incisor edges. Mean increase in skeletal angle of convexity was 26.4°. Concave profile was significantly changed to convex in all patients.

Conclusion

Maxillary DO and mandibular setback with BSSO was associated with improved facial balance and esthetics.

     

Effect of Alveolar Segmental Sandwich Osteotomy on Alveolar Height: A Preliminary Study

Purpose

Bone loss following extraction is maximum in horizontal dimension. Height is also reduced which is pronounced on the buccal aspect. Various surgical procedures are available to correct the bone volume viz. GBR, onlay bone grafting, alveolar distraction and sandwich osteotomy. Sandwich osteotomy has been found to increase the vertical alveolar bone height successfully.

Objectives

The objective of the study was to assess the effect of alveolar segmental sandwich osteotomy on alveolar height and crestal width.

Materials and Methodology

A prospective study was undertaken from December 2012 to August 2014. Seven patients with 12 implant sites with a mean age of 36 years were recruited. All seven patients with 12 implant sites underwent alveolar segmental sandwich osteotomy and interpositional bone grafting. Alveolar bone height was assessed radiographically preoperatively, immediate post-op, and at 3 months post-op. Alveolar bone width was assessed radiographically preoperatively and at 3 months post-op. Statistical significance was inferred at p < 0.05.

Results

The mean vertical augmentation at immediate post-op was 6.58 mm (p = 0.001). The vertical augmentation that was achieved 3 months post-op was a mean of 3.75 mm which was statistically significant (p = 0.004). The change in alveolar height from immediate post-op to 3 month post-op was a mean 1.69 mm. The mean change in alveolar crestal width at 3 months was a mean of ?0.29 mm (p = 0.57).

Conclusion

Sandwich osteotomy can be used as an alternative technique to increase alveolar bone height prior to implant placement. Moderate alveolar deficiency can be predictably corrected by this technique.

     

Stability Following Combined Orthodontic-surgical Treatment for Skeletal Anterior Open Bite – a Cephalometric 15-Year Follow-up Study

OBJECTIVE: The aim of the present study was to evaluate the long-term skeletal and dento-alveolar stability 15 years after combined orthodontic and surgical correction of skeletal anterior open bite. PATIENTS AND METHODS: Ten (8 female, 2 male) anterior openbite patients who had undergone orthodontic treatment in combination with bimaxillary surgery at Hanover Medical School were examined. Each patient had undergone Le Fort I osteotomy combined with bilateral sagittal split osteotomy (BSSO); osteosynthesis with plates and screws was carried out in the maxilla, and wire-osteosynthesis in the mandible. Cephalometric records of these patients were examined immediately before the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), medium-term after surgery, averaging 1.5 years (T4), and long-term after surgery, averaging 15 years (T5). Hasund cephalometric analysis was performed for which skeletal and dental cephalometric measurements had been taken. RESULTS: Moderate skeletal relapse was observed 15 years after surgery. Overbite remained quite stable 15 years after surgery, which is mainly due to the upper and lower incisors' eruption over the long-term period. CONCLUSION: Treatment of skeletal open bite via Le Fort I and bilateral sagittal split osteotomy appears to be a clinically successful procedure providing stable results.     

前段截骨牵引治疗唇腭裂继发上颌骨发育不足

目的 :利用颅外支架外固定牵引技术,采用上颌骨前段截骨牵引的方式治疗唇腭裂继发上颌骨重度发育不足患者,探讨手术效果并进行术后稳定性的评价。方法:选取唇腭裂术后继发上颌骨重度发育不足患者15例,采用上颌骨前段截骨,颅外支架外固定式牵引器进行术后牵引,通过头影测量分析,评价其术后效果及长期稳定性。利用SPSS 13.0软件包对数据进行方差分析。结果 :所有患者均顺利完成上颌骨前段截骨及颅外支架的固定,术后进行牵引,无明显并发症发生,面型及咬合关系显著改善,牵引成骨后上颌骨凸度、前牙覆盖、上颌骨长度和高度等显著增加(P<0.05),术后无明显复发(P>0.05)。而腭咽腔的深度、软腭长度无明显改变,语音功能未受明显影响。结论:上颌骨前段截骨配合颅骨外支架牵引能够显著增加上颌骨长度,同时避免了对腭咽闭合功能的损伤,降低了术后复发的风险,是一种理想的矫治唇腭裂继发上颌骨发育不足的方法。