The evolution into 3D maxillofacial planning concepts in orhtognatic surgery

Contains fulltext : 90819.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 11 juli 2011Promotores : Berge, S.J., Kuijpers-Jagtman, A.M. Co-promotor : Ettema, A.M.199 p

Trans-sinusal maxillary distraction for correction of midfacial hypoplasia: long-term clinical results.

Item does not contain fulltextMaxillary distraction osteogenesis is indicated in severe angle class III malocclusions, and severe maxillary hypoplasia among some cleft patients and other craniofacial deformities. Twenty patients, aged 8-48 years (mean 17.8+/-10.5 SD) with maxillary and midfacial hypoplasia were treated. The follow-up period was 13-65 months (mean 35+/-16.3 SD). A trans-sinusal maxillary distractor was placed intraorally at each side of the maxilla. The distraction vector was predicted using specialist software, and was transferred to the patients using stereolithographic models and individual templates. A (high) Le Fort I type osteotomy was performed. The amount of activation varied from 8 to 17.5 mm (mean 13.1+/-2.9 SD). Soft and hard tissue formation resulted in complete healing across the distraction gaps. The distractors are almost completely submerged, and can be left in place as long as necessary to avoid relapse. Wit's appraisal was used to measure the stability of the long-term distraction results. Results up to 5 years after distraction showed considerable maxillary advancement with long-term stability. Ongoing growth of the facial skeleton must be considered when distraction osteogenesis is chosen in growing patients

A qualitative study of children’s quality of life in the context of living with cleft lip and palate

Maryam Zeraatkar,1 Shabnam Ajami,2 Nasser Nadjmi,3 Seyad Aliakbar Faghihi,4 Ali Golkari1 1Oral and Dental Disease Research Center, Department of Dental Public Health, Shiraz University of Medical Sciences, Shiraz, Iran; 2Orthodontic Research Center, Department of Orthodontics, Shiraz University of Medical Sciences, Shiraz, Iran; 3Department of Cranio-Maxillofacial Surgery, Antwerp University Hospital, Antwerpen, Belgium; 4Clinical Educational Research Center, Shiraz University of Medical Sciences, Shiraz, Iran Background and objective: Quality-of-life measures have been expanded to help in assessing the physical and psychosocial effects of oral health. Although, in the case of children undergoing oral surgery, the oro-facial status is generally measured by studies, it is essential to carry out investigations into the level of quality of life (QoL) after surgery to assess the actual effect of these surgeries on children’s lives. Hence, our study is aimed at evaluating the QoL in these children. Methods: The study was performed using qualitative content analysis method. Eighteen caregivers of 4–6 year old children with a history of unilateral cleft lip and palate participated in in-depth interviews about the children’s experiences with different problems affecting their daily lives. The results were divided into codes, sub-categories and categories through an inductive process in which the researchers moved from the specific to the general. Result: A number of problems were identified, particularly insufficient functional and socio-emotional well-being including, difficulty in eating and speaking, dento-facial problems, shame, anxiety, insufficient peer interaction and dissatisfaction with their own appearance. Conclusion: The most critical problems derived from the participants’ experiences were insufficient functional and socio-emotional well-being that contributed to the reduced QoL among these children. Long term multidisciplinary interventional strategies such as psycho-social supportive programs are required to improve the QoL of these children. These interventions should be considered from the early stages of treatment, or even early stages of diagnosis. Keywords: children, cleft lip, cleft palate, quality of lif

Predicting soft tissue deformations for a maxillofacial surgery planning system: from computational strategies to a complete clinical validation.

Item does not contain fulltextIn the field of maxillofacial surgery, there is a huge demand from surgeons to be able to pre-operatively predict the new facial outlook after surgery. Besides the big interest for the surgeon during the planning, it is also an essential tool to improve the communication between the surgeon and his patient. In this work, we compare the usage of four different computational strategies to predict this new facial outlook. These four strategies are: a linear Finite Element Model (FEM), a non-linear Finite Element Model (NFEM), a Mass Spring Model (MSM) and a novel Mass Tensor Model (MTM). For true validation of these four models we acquired a data set of 10 patients who underwent maxillofacial surgery, including pre-operative and post-operative CT data. For all patient data we compared in a quantitative validation the predicted facial outlook, obtained with one of the four computational models, with post-operative image data. During this quantitative validation distance measurements between corresponding points of the predicted and the actual post-operative facial skin surface, are quantified and visualised in 3D. Our results show that the MTM and linear FEM predictions achieve the highest accuracy. For these models the average median distance measures only 0.60 mm and even the average 90% percentile stays below 1.5 mm. Furthermore, the MTM turned out to be the fastest model, with an average simulation time of only 10 s. Besides this quantitative validation, a qualitative validation study was carried out by eight maxillofacial surgeons, who scored the visualised predicted facial appearance by means of pre-defined statements. This study confirmed the positive results of the quantitative study, so we can conclude that fast and accurate predictions of the post-operative facial outcome are possible. Therefore, the usage of a maxillofacial soft tissue prediction system is relevant and suitable for daily clinical practice

Two-stage palatoplasty using a modified Furlow procedure

Item does not contain fulltextA two-stage palatal repair using a modification of Furlow palatoplasty is presented. The authors investigate the speech outcome, fistula formation and maxillary growth. In a prospective, successive cohort study, 40 nonsyndromic patients with wide cleft palate were operated on between March 2001 and June 2006 by a single surgeon. 10 patients in the first cohort underwent a Furlow palatoplasty (control group). In 30 patients in the second cohort a unilateral myomucosal cheek flap was used in combination with a modified Furlow palatoplasty (study group). The hard palate was closed in both groups 9-12 months later. The Bzoch speech quality score was superior in the study group, and the hypernasality was significantly reduced in the study group. Overall fistula formation was 0%. At the time of hard palate reconstruction palatal cleft width was significantly reduced. Relative short-term follow up of maxillary growth was excellent. There were no postoperative haematomas, infections, or episodes of airway obstruction. This technique is particularly encouraging, because of better speech outcome, absence of raw surfaces on the soft palate, no fistula formation, and good maxillary growth. Further follow-up is necessary to determine the long-term effects on facial development

Conversion and Cosmological Confluence: Nahua-Christian Art of the 16th century

Scholarships & Prizes Office. University of Sydne

Trans-sinusoidal maxillary distraction in three cleft patients.

Contains fulltext : 49821.pdf (publisher's version ) (Closed access)The trans-sinusoidal maxillary distractor (TS-MD) was used to achieve maxillary advancement in three patients with repaired cleft lip and palate. After preoperative computer-aided planning of the distraction vectors, each TS-MD was bent on a stereolithographic model of the maxilla of the patient. The devices were intraoperatively positioned using a methyl-methacrylate template. After standard Le Fort I osteotomy the devices were intraorally activated. After distraction the devices remained in situ for 3 months as rigid internal fixation of the maxilla. All patients were successfully distracted according to protocol. Maxillary advancement was 12, 8 and 11 mm. In two patients, additional maxillary widening of 6 and 8 mm was achieved by choosing divergent distraction vectors. After distraction a clockwise rotation of the maxilla was observed in two patients. There was no relapse during the 3 months of consolidation and 12-month follow-up. The TS-MD allows not only distraction but also rigid internal fixation after distraction. It was easy to apply but difficult to remove. Owing to preoperative 3D planning of the distraction vectors, the results were predictable, but clockwise rotation of the maxilla during distraction should be considered in planning. The distractor did not interfere with function or social activities during distraction and retention periods. After removal it left no extraoral scars

Virtual occlusion in planning orthognathic surgical procedures.

Item does not contain fulltextAccurate preoperative planning is mandatory for orthognathic surgery. One of the most important aims of this planning process is obtaining good postoperative dental occlusion. Recently, 3D image-based planning systems have been introduced that enable a surgeon to define different osteotomy planes preoperatively and to assess the result of moving different bone fragments in a 3D virtual environment, even for soft tissue simulation of the face. Although the use of these systems is becoming more accepted in orthognathic surgery, few solutions have been proposed for determining optimal occlusion in the 3D planning process. In this study, a 3D virtual occlusion tool is presented that calculates a realistic interaction between upper and lower dentitions. It enables the surgeon to obtain an optimal and physically possible occlusion easily. A validation study, including 11 patient data sets, demonstrates that the differences between manually and virtually defined occlusions are small, therefore the presented system can be used in clinical practice.1 mei 201

Cephalometric evaluation of maxillary advancement with an internal distractor in an adult boxer dog

OBJECTIVE: The aim of the study was to evaluate cephalometrically the effects of distraction of the maxilla over a 1-year period by means of an internal distractor applied in a boxer dog. DESIGN: Internal distractors were placed bilaterally in the internal cavity of the maxillary sinus of a 2-year-old boxer dog after a Le Fort I osteotomy. Distraction was started 5 days after surgery and activations were continued for 14 days at a rate of 1 mm/day. Standardized lateral cephalograms were taken with an extemal source of 90 kV, 60 mS immediately pre-surgery, at day 1 after the start of the distraction (dp) and at day 5 dp, day 7 dp, day 10 dp, day 14 dp (end of distraction), at 14 days of consolidation period (cp), at 28 days cp and at 56 days cp (removal of the distractors). One year after the removal of the distractor, a final lateral cephalogram was taken. Cephalometric analysis was performed and superimpositions were used for the evaluation of the sagittal position of the maxilla. RESULTS: The linear measurements, as well as the superimposition showed evidence for a significantly advanced position of the maxilla, which was stable 1 year after removal of the distractor. CONCLUSION: The application of the internal maxillary distractor in a boxer dog resulted in a sagittal advancement of the midface that was still present after 1 year.status: publishe