| ObjectiveIn recent years, it has been demonstrated that improvement of nasaldeformity is possible, and a presurgical interdisciplinary approach canlead to fewer surgeries and better outcomes. In the present study, weattempted to establish a new method of CAD-NAM (CAD nasal alveolarmolding) based on reverse engineering technique. A set of applianceswas designed based on a computer-aided reverse engineering systemand fabricated with rapid prototyping technique. The aim of surgicaltreatment of UCLP patients is to correct the affected side to restore thesymmetry of the upper lip. Most studies involving the quantitativeassessment of facial asymmetry have been performed on2Dreproductions of soft tissue morphology. Unfortunately, such methodsproject a complex3D structure onto a2D plane, thus causing one of thefacial dimensions, usually facial depth, to be lost. Correct evaluation offacial asymmetry should involve all three spatial planes simultaneously.The aim of this study was to utilize a new3D imaging system to establishthe3D facial characteristics of the adolescents with UCLP.Patients and methods1. A maxillary impression was taken by an orthodontist aided by asurgeon at the first examination. The cast data was acquired by a3Dlaser scanner. The digital geometrical3D model was judged throughapplying the Rapidform XOR3software. The CAD-NAM procedure wasdivided into several steps.2. The digital geometrical data was exported to print a scale model with arapid prototyping system when the treatment design was formulated. Aseries of appliances were then created according to these scale models.The patients’ parents were required to change one step of the applianceseach week. After3or4weeks, a nasal stent was added to the appliance,and the phase of active nasal cartilage molding began. 3.20patients (16boys,6girls, mean age15.81days) with completeUCLP were recruited for this study as the treatment group.20patients(15boys,5girls, mean age123.27days) with complete UCLP who did nothave any presurgical orthopedic treatment were selected as the controlgroup. We adopted a3D laser scanning device to obtain objective andquantifiable data of the physical characteristics of the cleft maxilla ininfants with UCLP. All parameters were measured by the RapidformXOR3software. For all measurements, computer-aided descriptivestatistical analysis was performed with SPSS15.0. Differences in allvariables pre-and post-CAD-NAM were tested for the treatment group bythe paired-samples t test. Before the lip repair surgery, the differencesbetween the treatment group and control group were compared with theindependent samples t test.4.20patients (12males,8females, mean age of11.82years) withcomplete UCLP were recruited for this study as the cases group.20healthy adolescents (10males,10females, mean age of12.00years) withideal facial asymmetry and profile were collected as the control group. Afacial stereo photogrammetry was taken by an orthodontist aided by asoftware engineer at the first examination using the Axis Three’s3DSimulation Platform.5. The digital facial soft tissue3D models were measured and analyzedusing the Rapidform XOR3software. For all measurements,computer-aided descriptive statistical analysis was performed usingSPSS15.0. Differences in all variables between the two groups weretested using the independent samples t test. In each group the variablesin nostril, alare and upper lip region were analyzed by the Pearsoncorrelation coefficient.6. The facial distance map was assessed and the facial asymmetry of theUCLP patient was evaluated by the Geomagic Qualify11.0software.Results1. The paired-samples t test analysis of the variables pre-and postCAD-NAM showed CAD-NAM therapy significantly reduced the alveolarcleft gap and arch length. The midline of the upper denture wascorrected. However, in the CAD-NAM group, the alveolar height wasdecreased post treatment2. The independent samples t test results between the CAD-NAM groupand the control group showed significant difference in cleft lip width and labial frenum deviation. In the sagittal dimensions, significant differencewas found in the dental length. In the vertical dimensions, significantdifference was found in the alveolar height in the incisor and bilateralcanine region.3. Significant difference was found in the nostril, the alar wing, thecolumella and the philtrum region between the UCLP patients and thecontrol group.4. The facial distance map assessment showed that the facial asymmetryof patients with UCLP focused on the alar wing, columella, upper lip andchin region.Conclusions1. CAD-NAM can produce a reliable and quantifiable analysis of palatevolume and shape in UCLP infants. This study suggests a trend towardmorphological improvement in maxillary alveolar of UCLP infantstreated with CAD-NAM.2. The CAD-NAM effectively reduced the cleft gap, corrected the maxillamidline, and improved the sagittal length of the maxilla.3. The alveolar height decreased significantly after the treatment, whichindicated that the traction force of the appliance may have obstructiveeffects on the vertical growth of the alveolar bone. Future studies arerecommended on the long-term effectiveness of CAD-NAM therapy ininfants’ alveolar and facial measurements4. The3D stereo photogrammetry technique is a suitable method ofcapturing the U LP patients’ face soft tissue in three-dimension. Most ofthe nasolabial measurements and the distance map assessment showedmore asymmetry in subjects with clefts than in controls. After primarylip repair surgery in patients with UCLP the asymmetry in the nasal andlip area still exists as compared to non-cleft controls.5. The Axis Threes3D Simulation Platform could deliver precise,interactive3D simulation experience to show patients possible outcomesof cosmetic facial procedures. Its simulation software is intuitive,straightforward, and easy to navigate and address a wide range of facialsoft tissue evaluation. |
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