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Three-dimensional soft tissue changes associated with mandibular orthognathic surgery
72 associated with this surgical technique cannot be assessed accurately with cephalograms or photographs. The purpose of this study was to determinate the soft tissue changes of the posterior lower face and the mandibular angle in patients who underwent MC-BSSO. Sixty-four patients underwent bilateral sagittal split osteotomy procedures (BSSO) for treatment of their dentofacial deformity. Thirty of these patients (18 females and 12 males) received a MC-BSSO to address their transverse discrepancy. The mean surgical constriction in the lower 2nd molar region was 5.75±1.45 mm (range 3-9 mm). The patients were interviewed and three dimension surface images were taken preoperatively as well as 3, respectively 6 months after surgery. Facial soft tissue analysis was obtained with the 3dMD Face System that allowed identification of the chosen surface anatomic landmarks (anterior and posterior mandible and gonion) and superimposition of the scans with a minimal accuracy of 0.5 mm. The obtained measurements showed a statistically significant decrease in transverse width at the posterior level of the mandible and the gonion in patients receiving MC-BSSO compared to the group only receiving BSSO (p >0.001). No significant changes between the two groups were obtained at the anterior level of the mandible. The overall soft-tissue response to reduction of transverse width by MC-BSSO was approximately 66.5%. The interviews of the patients demonstrated no aesthetic disadvantages noticed by the patients concerning lower facial width at the posterior face or mandibular angle. In some patients receiving MC-BSSO the changes of the mandibular angle was clearly stated to be an even more favorable aesthetic result, compared to the presurgical situation. MC-BSSO is as previously reported a simple, sable, low cost and low morbidity surgical procedure with minimal soft tissue changes in the lower posterior face and mandibular angle.
[ - O - ' ~ - ] EVALUATION OF THE SOFT AND HARD TISSUE CHANGES AFTER BIMAXILLARY ANTERIOR SEGMENTAL OSTEOTOMY B. Rahsepar, K. Taban, H.R. Pakshir. Shiraz University of Medical
Sciences, Shiraz, Iran Facial changes of 76 adult Iranian, who underwent Wunderer segmental osteotomy on the maxilla and mandible, were analyzed with pre and post operative cephalograms and facial photos. Facial changes of 76 adult Iranian, who underwent Wunderer segmental osteotomy on the maxilla and mandible, were analyzed with pre and post operative cephalograms and facial photos. Significant facial changes were noted as follows: posterior movement of the upper and lower lip at a ratio 3:4 and 1:1 to the upper and lower incisors, the increase of the nasolabial angle, the decrease of the width and thickness of the lip, and accentuation of the labiomental fold. The nasal change could be kept as minimal as possible with Wunderer technique because of the palatal approach and not disturbing alar attachments. Wundere technique is a safe approach for Maxillary Protrusion.
[-0-'~'-~ CONSEQUENCES OF ORTHOGNATHIC SURGERY ON SOFT TISSUE PROFILE M. RLicker1, B. Bastian2, T. Binger3, W.J. Spitzer3. 1Clinic for Oral and Maxillofacial Surgery, Medical University Hannover, 30625 Hannover; 2Dep. of Orthodontics, University of Saarland, Homburg/Saar; 3Dep. of Oral and Maxillofacial Surgery, University of Saarland, 66421 Homburg/Saar, Germany Surgical treatment of maxillofacial dysgnathia results in changes of soft tissue profile. Since the achieved soft tissue profile is essential for patient's pleasure, we studied whether the orthognathic surgery results in a favourable facial esthetic. Maxillofacial dysgnathias were treated surgically either by monomaxillary procedures, in particular by mandibular set back (group 1, n = 18) and maxillary advancement (group 2, n = 17), respectively, or by bimaxillary osteotomy (group 3, n = 10). Using lateral cephalograms taken before and after orthognathic surgery, the soft tissue profile was analyzed according to the methods described by Ricketts and Steiner. After orthognathic surgery a neutral basal relation of jaws was found in group 1 (ANB: 0.5±2.3°), group 2 (ANB: 0.9±2.5 °) and group 3 (ANB: 0.7±2.3°). However, only in some patients the standard values of the Ricketts esthetic line (group 1: lower lip 39/ upper lip 28; group 2: 56/50; group 3: 30/30%patients) and the standard values of the Steiner line (39/59; 50/31; 20/0% patients) could be achieved, although the deviation of upper lip and lower lip from these analytic reference lines was frequently found reduced. After orthognathic surgery
Int. J. Oral Maxillofac. Surg. 2005; 34 (Supplement 1): $ 1 - $ 1 8 1 despite achievement of neutral basal relation of jaws the soft tissue profile was found frequently improved but rarely optimized. Our results that soft tissue profile was found insufficient after both monomaxillary and bimaxillary surgery indicates deviations of facial components not influenced by orthognathic surgery rather than occlusal limitation of jaw movements. Therefore, the request for a perfect soft tissue profile frequently requires additional plastic surgery.
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THREE-DIMENSIONAL SOFT TISSUE CHANGES ASSOCIATED WITH MANDIBULAR ORTHOGNATHIC SURGERY
R.E. Alcalde, Z. Lowe, D. Joondeph, T. Wallen, D. Bloomquist.
University of Washington Department of Oral and Maxillofacial Surgery & Department of Orthodontics, USA To determine the soft tissue changes associated with bilateral sagittal split osteotomy (BSSO) of the mandible, performed with or without a midline osteotomy (MC) Twenty-eight patients were included in this study, after meeting strict inclusion criteria. Thirteen underwent a BSSO with an MC to address transverse discrepancy, while the other fifteen patients only had a BSSO. Twenty-four BSSO procedures were advancements and the rest were setbacks. Pre and post surgical images of the patients' faces were obtained using the 3DMD photo imager, which allowed for the superimposition and manipulation of the 3D data with an accuracy of 0.5 mm. The pre and post surgical images were overlaid, anatomical landmarks identified, and the soft tissue measured for changes. Statistically significant changes in the transverse direction at the mandibular body and gonial angle were measured when a BSSO was combined with MC. In MC patients, the transverse skeletal to soft tissue ratio in the posterior mandible was 1:0.67. Soft tissue changes induced by mandibular advancement and setback were most prominent in the facial midline in 38% of the cases. The skeletal to soft tissue ratio in the anterior and posterior (A-P) direction ranged from 1:0.43 to 1:0.75. In BSSO advancement, the vertical height of the mandible remained relatively constant while the mentolabial fold moved downward following the clockwise rotation associated with mandibular advancement. This study demonstrated that the soft tissue changes occur at a higher degree outside the facial midline, which is where most of the lateral cephalometric measurements are made. 3D analysis of soft tissue changes, using the 3dMD imager allows accurate facial analysis of the A-P, vertical, and transverse changes induced by orthognathic surgery.
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PRESENTATION AND VALIDATION OF A VOXEL-BASED THREE-DIMENSIONAL (3-D) HARD AND SOFT TISSUE CEPHALOMETRIC ANALYSIS
G.R.J. Swennen, E Schutyser, E.-L. Barth, A. Lemaitre, C. Malevez, A. De Mey. 1Dept of Plastic Surgery, University Hospital Brugmann
(ULB), Brussels, Belgium; 2Medical Image Computing (Radiology ESAT/PSI), Faculties of Medicine and Engineering, University Hospital, Gasthuisberg, Leuven, Belgium The purpose of this study is to present and validate a new voxel-based three-dimensional (3-D) hard and soft tissue cephalometric analysis. The CT- data (DICOM 3.0 files) of 20 control patients with normal skeletal relationships were used for this study. To investigate accuracy and reliability of 3-D cephalometry (MaxilimTM, version 1.3.0) a total of 36 angular, 78 linear measurements and 164 (54 horizontal, 54 vertical and 54 transversal) orthogonal measurements were performed on each patient twice by each of two investigators. The intra-observer measurement error was less then 0.85 degrees for angular measurements and less then 0.78 mm, 0.88 mm, 0.76 mm and 0.84 mm for linear, horizontal, vertical and transversal orthogonal measurements, respectively. The inter-observer measurement error was less as 1.03 degrees for angular measurements and less then 0.84 mm, 0.78 mm, 0.86 mm and 1.26 mm for linear, horizontal, vertical and transversal orthogonal measurements, respectively. Squared correlation coefficients showed a high intra-observer and inter-observer reliability. The presented threedimensional cephalometric hard tissue analysis showed to be accurate and reliable and therefore presents a useful tool for objective evaluation of voxel-based virtual planning and surgery.in the future.
[ - O - ' ~ - ] EVALUATION OF THE SOFT AND HARD TISSUE CHANGES AFTER BIMAXILLARY ANTERIOR SEGMENTAL OSTEOTOMY B. Rahsepar, K. Taban, H.R. Pakshir. Shiraz University of Medical
Sciences, Shiraz, Iran Facial changes of 76 adult Iranian, who underwent Wunderer segmental osteotomy on the maxilla and mandible, were analyzed with pre and post operative cephalograms and facial photos. Facial changes of 76 adult Iranian, who underwent Wunderer segmental osteotomy on the maxilla and mandible, were analyzed with pre and post operative cephalograms and facial photos. Significant facial changes were noted as follows: posterior movement of the upper and lower lip at a ratio 3:4 and 1:1 to the upper and lower incisors, the increase of the nasolabial angle, the decrease of the width and thickness of the lip, and accentuation of the labiomental fold. The nasal change could be kept as minimal as possible with Wunderer technique because of the palatal approach and not disturbing alar attachments. Wundere technique is a safe approach for Maxillary Protrusion.
[-0-'~'-~ CONSEQUENCES OF ORTHOGNATHIC SURGERY ON SOFT TISSUE PROFILE M. RLicker1, B. Bastian2, T. Binger3, W.J. Spitzer3. 1Clinic for Oral and Maxillofacial Surgery, Medical University Hannover, 30625 Hannover; 2Dep. of Orthodontics, University of Saarland, Homburg/Saar; 3Dep. of Oral and Maxillofacial Surgery, University of Saarland, 66421 Homburg/Saar, Germany Surgical treatment of maxillofacial dysgnathia results in changes of soft tissue profile. Since the achieved soft tissue profile is essential for patient's pleasure, we studied whether the orthognathic surgery results in a favourable facial esthetic. Maxillofacial dysgnathias were treated surgically either by monomaxillary procedures, in particular by mandibular set back (group 1, n = 18) and maxillary advancement (group 2, n = 17), respectively, or by bimaxillary osteotomy (group 3, n = 10). Using lateral cephalograms taken before and after orthognathic surgery, the soft tissue profile was analyzed according to the methods described by Ricketts and Steiner. After orthognathic surgery a neutral basal relation of jaws was found in group 1 (ANB: 0.5±2.3°), group 2 (ANB: 0.9±2.5 °) and group 3 (ANB: 0.7±2.3°). However, only in some patients the standard values of the Ricketts esthetic line (group 1: lower lip 39/ upper lip 28; group 2: 56/50; group 3: 30/30%patients) and the standard values of the Steiner line (39/59; 50/31; 20/0% patients) could be achieved, although the deviation of upper lip and lower lip from these analytic reference lines was frequently found reduced. After orthognathic surgery
Int. J. Oral Maxillofac. Surg. 2005; 34 (Supplement 1): $ 1 - $ 1 8 1 despite achievement of neutral basal relation of jaws the soft tissue profile was found frequently improved but rarely optimized. Our results that soft tissue profile was found insufficient after both monomaxillary and bimaxillary surgery indicates deviations of facial components not influenced by orthognathic surgery rather than occlusal limitation of jaw movements. Therefore, the request for a perfect soft tissue profile frequently requires additional plastic surgery.
~--~
THREE-DIMENSIONAL SOFT TISSUE CHANGES ASSOCIATED WITH MANDIBULAR ORTHOGNATHIC SURGERY
R.E. Alcalde, Z. Lowe, D. Joondeph, T. Wallen, D. Bloomquist.
University of Washington Department of Oral and Maxillofacial Surgery & Department of Orthodontics, USA To determine the soft tissue changes associated with bilateral sagittal split osteotomy (BSSO) of the mandible, performed with or without a midline osteotomy (MC) Twenty-eight patients were included in this study, after meeting strict inclusion criteria. Thirteen underwent a BSSO with an MC to address transverse discrepancy, while the other fifteen patients only had a BSSO. Twenty-four BSSO procedures were advancements and the rest were setbacks. Pre and post surgical images of the patients' faces were obtained using the 3DMD photo imager, which allowed for the superimposition and manipulation of the 3D data with an accuracy of 0.5 mm. The pre and post surgical images were overlaid, anatomical landmarks identified, and the soft tissue measured for changes. Statistically significant changes in the transverse direction at the mandibular body and gonial angle were measured when a BSSO was combined with MC. In MC patients, the transverse skeletal to soft tissue ratio in the posterior mandible was 1:0.67. Soft tissue changes induced by mandibular advancement and setback were most prominent in the facial midline in 38% of the cases. The skeletal to soft tissue ratio in the anterior and posterior (A-P) direction ranged from 1:0.43 to 1:0.75. In BSSO advancement, the vertical height of the mandible remained relatively constant while the mentolabial fold moved downward following the clockwise rotation associated with mandibular advancement. This study demonstrated that the soft tissue changes occur at a higher degree outside the facial midline, which is where most of the lateral cephalometric measurements are made. 3D analysis of soft tissue changes, using the 3dMD imager allows accurate facial analysis of the A-P, vertical, and transverse changes induced by orthognathic surgery.
~--~
PRESENTATION AND VALIDATION OF A VOXEL-BASED THREE-DIMENSIONAL (3-D) HARD AND SOFT TISSUE CEPHALOMETRIC ANALYSIS
G.R.J. Swennen, E Schutyser, E.-L. Barth, A. Lemaitre, C. Malevez, A. De Mey. 1Dept of Plastic Surgery, University Hospital Brugmann
(ULB), Brussels, Belgium; 2Medical Image Computing (Radiology ESAT/PSI), Faculties of Medicine and Engineering, University Hospital, Gasthuisberg, Leuven, Belgium The purpose of this study is to present and validate a new voxel-based three-dimensional (3-D) hard and soft tissue cephalometric analysis. The CT- data (DICOM 3.0 files) of 20 control patients with normal skeletal relationships were used for this study. To investigate accuracy and reliability of 3-D cephalometry (MaxilimTM, version 1.3.0) a total of 36 angular, 78 linear measurements and 164 (54 horizontal, 54 vertical and 54 transversal) orthogonal measurements were performed on each patient twice by each of two investigators. The intra-observer measurement error was less then 0.85 degrees for angular measurements and less then 0.78 mm, 0.88 mm, 0.76 mm and 0.84 mm for linear, horizontal, vertical and transversal orthogonal measurements, respectively. The inter-observer measurement error was less as 1.03 degrees for angular measurements and less then 0.84 mm, 0.78 mm, 0.86 mm and 1.26 mm for linear, horizontal, vertical and transversal orthogonal measurements, respectively. Squared correlation coefficients showed a high intra-observer and inter-observer reliability. The presented threedimensional cephalometric hard tissue analysis showed to be accurate and reliable and therefore presents a useful tool for objective evaluation of voxel-based virtual planning and surgery.in the future.