Journal of Plastic, Reconstructive & Aesthetic Surgery (2015) 68, 615e621
Nasal soft-tissue and vault deviation in unicoronal synostosis Isadora Silveira Camargos, Philipp Metzler, John Persing, Andre Alcon, Derek M. Steinbacher* Plastic and Reconstructive Surgery, Yale University School of Medicine, 330 Cedar St, BB 3rd Floor, New Haven, CT 06520, USA Received 8 July 2014; accepted 2 February 2015
KEYWORDS Nose; Nasal soft tissue; Inclination; Anterior plagiocephaly; Unicoronal synostosis; Three-dimensional morphometrics
Summary Background: Unicoronal synostosis (UCS) results in nasal root deviation toward the fused side of the face, resulting in an apparent nasal dorsal deviation to the non-fused side. The impact of the altered radix position on the osteocartilaginous vault and nasal soft tissue has not been analyzed. The purpose of this study is to morphometrically assess the nasal structure and deviation in UCS. We hypothesize the proximal etiology exerts an impact on the distal nasal form, compared to controls. Methods: Demographic data were tabulated and computed tomographic information recorded. Three-dimensional reconstruction was created and analyzed digitally (using Surgi Case). Morphometric landmarks were determined and used to perform measurements on the nasal soft tissue and osseous skull surface to evaluate nasal deviation within a midsaggital plane (MSP). Results: Forty three-dimensional CT scans of 20 UCS patients and 20 control subjects were analyzed. The deviation angle of the nose to the non-fused side was 6.6 2.9 in the bony layer. In the soft-tissue layer, the deviation angle of the nasal dorsum line to the non-fused side was 5.4 3.4 . The tip of the nose showed a significant deviation to the non-fused side (2.2 1.2 mm). Paired landmarks (alares, inferior lateral nostril bases) related to the MSP showed a greater distance on the non-fused side. Paired landmarks related to an intrinsic nasal midline (Nsup-ANS; tip-columella line (TCL)) did not show any significant differences. Conclusion: UCS confers osteocartilaginous and soft-tissue nasal deviation, with the distal nose toward the non-fused side. The nasal root inclination underpins this asymmetry across the midsaggital reference plane. However, the nose in isolation exhibits balanced sideeside proportions. ª 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Craniofacial Center, Yale University School of Medicine, Plastic and Craniomaxillofacial Surgery, 330 Cedar St, BB 3rd Floor, New Haven, CT 06520, USA. Tel.: þ1 (203) 785 4559; fax: þ1 (203) 785 7514. E-mail address: [email protected] (D.M. Steinbacher). http://dx.doi.org/10.1016/j.bjps.2015.02.015 1748-6815/ª 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
616
Introduction Unicoronal synostosis (UCS), from premature fusion of the coronal suture, results in anterior plagiocephaly with asymmetric craniofacial features. The ipsilateral forehead and supraorbital rim are depressed, with compensatory bossing of the opposite forehead and related orbital asymmetry. The nasal radix is also deviated toward the affected side and is pathognomonic of UCS.1e8 The fusion and twisting of the cranial base lead to asymmetry of the viscerocranium, including temporo-mandibular joint (TMJ), ear, and mandibular deviation with alteration in malar position.3,9,10,21 The nasal deformity, with the root toward the fused side and tip toward the non-fused side, is recognized but not adequately studied. Incorporation of the nasal radix in the reconstructive bandeau to improve this nasal deviation has been debated for some time. Despite the surgical technique, clinical experience reveals that some element of nasal deviation may persist, requiring rhinoplasty later on during life. To date, the relationship between the nasal osteocartilaginous framework and soft-tissue structures has not been assessed three-dimensionally using computed tomography (CT). The understanding of proximal fusion leading to nasal root deviation, which ultimately impacts downstream nasal anatomy, is important in order to follow the natural course of UCS and possibly better guide treatment. The purpose of this study is to morphometrically characterize the entire nasal deviation, including bony support and soft tissue, in untreated UCS infants. We hypothesize that the soft-tissue nasal deviation correlates with the underlying osteocartilaginous framework, which exhibits root deviation toward the fused side and tip deviation toward the unfused side.
I. Silveira Camargos et al. soft-tissue morphometric landmarks were determined by the investigators to be the most representative of the overall symmetry of the nose (Figures 1 and 2). A midsaggital plane (MSP) was drawn using the midpoint between the two anterior clinoid processes of the sphenoid bone and the bony nasion. This MSP was used for all bony and softtissue cephalometric measurements (Tables 1e3). A single observer performed all cephalometric measurements to maintain consistency throughout.
Data analysis Microsoft Excel (Version 14.0.0, Microsoft Office 2011, Microsoft; Redmond, WA, USA) and GraphPad Prism (Version 6, Windows; GraphPad Software) were used to perform statistical analysis. The distances and angles that were obtained with anthropometric measurements were analyzed using the unpaired two-sample t-test. Differences were considered significant at a value of p < 0.05. UCS was the primary predictor variable, while nasal symmetry and deviation indicated by the various cephalometric angles and distances were the primary outcomes of this study.
Results A total of 40 3D CT scans of 20 patients with UCS and 20 control subjects were analyzed. The ratio of males to
Materials and methods Patients This single-institution, retrospective study was performed using patients with nonsyndromic UCS. This study was approved by Yale University Institutional review board (Protocol number: HIC# 1101007932). The inclusion criteria included 20 consecutive infants with UCS who had CT of the head and neck prior to any surgical treatment for their condition. Patients who had UCS associated with a genetic syndrome or prior surgical treatments to address their craniofacial abnormalities were excluded from this study. A control group consisting of 20 consecutive healthy, agematched infants was also utilized. Inclusion criteria for the control cohort included healthy infants without any craniofacial abnormalities or intracranial pathologies who had head and neck CT imaging. Notably, control subjects received CT scans for a variety of reasons, including, but not limited to, trauma; however, craniofacial abnormalities were ruled out in all subjects prior to including them in the study.
Data collection The three-dimensional (3D) digitized images were analyzed using Surgi Case (Materialise, Leuven, Belgium). Bone and
Figure 1 Nasal soft-tissue landmarks for morphometric analysis in UCS patient.
Nasal soft-tissue and vault deviation in UCS
617
Figure 2 Osseous landmarks for morphometric analysis in same patient. Table 1
Landmarks for 3D nasal bone and soft-tissue deviation. Landmark
Bony points used:
Abbreviation Definition
Anterior clinoid process Nasion Rhinion Anterior nasal spine Nasal aperture of fusioned side Nasal aperture of non-fusioned side Soft.tissue points used: Glabella Endocanthions Nasion-soft tissue Pronasale Subnasale Alare on fusioned side Alare on non-fusioned Nostril base on fusioned side Nostril base on non-fusioned side Labaile superius
Table 2
females was 1:0.8 in the UCS group, with a mean of 5 months and about 65% experienced unilateral coronal suture fusion on the right side. The ratio of males to females in the control group was 1:1, with a mean of 6 months (Table 4). Results of anthropometric measurements were compared in both groups respectively (Tables 5 and 6). To measure the deviation of the bony architecture of the nose in patients with UCS, we measured the angle between the nasal aperture line (Nsup-ANS) and MSP. There was a statistically significant deviation of 6.6 2.9 in UCS patients whereas healthy control infants showed no statistically significant deviation (0.92 0.73 ; p Z 0.226) from the MSP using the same cephalometric landmarks. The distances between the widest lateral points of the nasal aperture (fNlat, nfNlat) and the MSP were also used to assess for any horizontal shift of the bony architecture of the nose in patients with UCS. The distance between the lateral-most points of the nasal aperture and the MSP on the fused side (6 0.9) was consistently shorter than the same distance on the contralateral, non-fused side of the face (9.7 1.5). Interestingly, the distances between the widest lateral points of the nasal aperture (fNlat, nfNlat) and the nasal aperture line did not show a significant (p Z 0.3244) difference between the fused (8.2 1) and the non-fused (8.6 1.2) side, suggesting that the entire bony nasal structure is shifted symmetrically from the midline toward the non-fused side of the face. Similar measurements were recorded using the softtissue layer to identify any correlation with the bony aberrations measured above. In patients with UCS, the tip of
Cl1, Cl2 N Nsup ANS fNlat nfNlat G Ec1, Ec2 Ns Prn Sn fA nfA fAb nfAb Ls
Apex of anterior processus clinoidei Midpoint of endocanthioneendocanthion distance Most caudal point of internasal suture Midpoint of inferior nasal aperture border Most lateral point of nasal aperture e Most anteriorly projected point of the forehead Medial corner of the eye Midpoint of the frontonasal suture Most protruded point of the apex nasi Midpoint of the columella base Most lateral point of the alar contour Most inferolateral point of the nostril Midpoint of the upper vermillion border
Reference lines and planes for anthropometric measurements.
Lines and planes
Abbreviation
Definition
Midsaggital plane Nasal bone line Nasal aperture line Nasal dorsum line Tip-columella line
MSP NBL Nsup-ANS Ns-Prn TCL
Midsaggital plane through C1, C2 and bony nasion N Line that connects bony nasion and superior point of nasal aperture Line between rhinion and anterior nasal spine Line that connects soft-tissue nasion and tip of the nose Line between tip of the nose and subnasal
618 Table 3
I. Silveira Camargos et al. Anthropometric measurements: distances and angles in 3D nasal bone and soft-tissue deviation.
Definition
Abbreviation
Distance between NsuperioreMidplane MSP Angle between nasal bone line-MSP Angle between nasal aperture length line-MSP Distance between Nlat on non-fusioned side-MSP Distance between Nlat on fusioned side-MSP Distance between Nlat on non-fusioned nasal aperture length line Distance between Nlat on fusioned nasal aperture length line Distance between PrneMSP Angle between nasal dorsum length line-MSP Distance between A on non-fusioned side-MSP Distance between A on fusioned-MSP Distance between A on non-fusioned and tip-columella line Distance between A on fusioned and tip-columella line Distance between Ab on non-fusioned and tip-columella line Distance between Ab on fusioned and tip-columella line Distance between SneMSP Distance between LseMSP
NMP AngBMP AngMP NlatMP NlatMP0 NlatA NlatA0 PrMP AngDMP AMP AMP0 ACL ACL0 AbCL AbCL0 SMP LMP
the nose was found to deviate toward the non-fused side of the face (2.2 1.2 ) compared to control patients. Similarly, in patients with UCS, the nasal dorsum line (Ns-Prn) deviated farther from the MSP (5.4 3.4 ) toward the nonfused side of the case in contrast to control patients, which showed no overall deviation toward the left or right. The distances between MSP and the ala on the fused and nonfused side were also used to assess the horizontal shift of the soft tissue of the nose similar to the bony measurements made above. Again, the distances on the fused side of the face was consistently shorter than the non-fused side in patients with UCS, indicating that the whole soft tissue of the nose is shifted from the midline toward the non-fused side of the face. Furthermore, the distance between the MSP and the most inferolateral points of the nostril bases (Ab) on the fused side (7.1 1.5) was shorter than the same distance measured on the non-fused side (12.4 1.9). The midpoint of the columellar base (Sn) and the midpoint of the upper vermillion border (Ls) both showed a significant (p < 0.001) deviation from MSP toward the non-fused side. The nasal soft-tissue measurements of control patients did not show a predilection for either side of the face (Figure 3).
Table 4
Demographic information.
Number of subjects Sex Male Female Age (mo) Mean Median Side Right Left
UCS
Control group
20
20
11 (55%) 9 (45%)
10 (50%) 10 (50%)
5.3 5
6.4 6
65% 35%
The overall symmetry of the soft tissue of the nose was evaluated by comparing the distances from the tipcolumella line (TCL) to the alares. No statistically significant difference could be found between the fused (14.7 1.3) and the non-fused (14.6 1.5) side of the face in patients with UCS and control patients. Likewise, no difference could be found comparing the distances between TCL and the most inferolateral points of the right and left nostril bases (Table 5), suggesting that the soft tissue of the nose in patients with UCS exhibits symmetrical growth but the entire structure is shifted from the midline.
Discussion UCS confers significant forehead and facial asymmetries. On the fused side, a more open palpebral fissure, retruded supraorbital rim and forehead, and facial and ear asymmetries are most frequently reported.5,9,10 The nasal root is “pulled” toward the affected side, with resultant nasal deviation to the opposite side.6,11,12 This radix deviation is important for the diagnosis of UCS, and different classification schemes have been devised based on the nasal deformity and deviation.13,14 Additionally, treatment strategies, such as the incorporation of this most proximal aspect of the nose into the bandeau and closing wedge with pyramid shift, have been described as possibly helping to ameliorate the nasal deviation.7,10 In any case, several studies have used a variety of methods to measure the soft tissue or bony structure of the nose in patients with UCS; however, there is a paucity of literature examining the morphology of both the soft tissue and bony structure using more accurate 3D CT reconstructions. We used anthropometric points and reference planes to elucidate the differences in nasal hard and soft-tissue vaults in UCS versus control patients. Bony nasal deviation in UCS patients revealed consistent deviation toward the non-fused side of 6.6 between the nasal bone line (nasionerhinion) and the MSP. The soft-tissue deviation was
Nasal soft-tissue and vault deviation in UCS Table 5
619
Comparison of measurements in UCS group.
Measurements (mm, )
Distance between NsuperiorMidplane MSP Angle between Nsup-ANS and MSP Distance between fNlat/nfNlat and MSP Distance between fNlat/nfNlat and Nsup-ANS Distance between Prn and MSP Angle between Ns-Prn and MSP Distance between fA/nfA and MSP Distance between fAb/nfAb and MSP Distance between fA/nfA and TCL Distance between fAb/nfAb and TCL Distance between Sn-MSP Distance between Ls-MSP
UCS Fused
Non-fused
e e
0.8 6.6 9.7 8.6 2.2 5.4 13.9 12.4 14.6 10 2.8 4
6 8.2 e e 12 7.1 14.7 10.2 e e
0.9 1
2,4 1.5 1.3 1.1
even greater at 5.4 . Additionally, paired bony landmarks (fNlat, nfNlat) indicating the widest lateral borders of the nasal aperture showed a consistent deviation toward the non-fused side of the face. This was also found to be true using soft-tissue measurements. Interestingly, symmetrical distances were found between paired bony and soft-tissue landmarks in relation to the nasal aperture line (Nsup-ANS). However, comparing the soft-tissue TCL with the nasal aperture line on the bone window showed a persistent asymmetry, independent from other deviations, suggesting that the inferior cartilaginous framework of the nose itself is symmetrical, but as a whole is shifted from the MSP to the non-fused side of the face. This deviation results from alterations of the pyramidal bone and maxilla that were subjectively classified in previous studies.10,12,13,15 Nasal root and tip deviation were first noted in early studies examining the effects of various surgical approaches to UCS.9,12,13,15,16 These studies simply note the presence of preoperative nasal deviation, but they fail to objectively quantify the nasal deviation before and after surgery. Alternatively, Meara et al. measured the nasal soft-tissue deformities pre- and postoperatively in patients with unilateral coronal synostosis who received frontoorbital advancement surgery.7 They found that preoperatively the nasal dorsum was angled at 9.2 toward the Table 6
0.5 2.9 1.5 1.2 1.2 3.4 3.2 1.9 1.5 1 1.4 1.9
D difference between means
p-Value
Nasal soft-tissue and vault deviation in unicoronal synostosis Isadora Silveira Camargos, Philipp Metzler, John Persing, Andre Alcon, Derek M. Steinbacher* Plastic and Reconstructive Surgery, Yale University School of Medicine, 330 Cedar St, BB 3rd Floor, New Haven, CT 06520, USA Received 8 July 2014; accepted 2 February 2015
KEYWORDS Nose; Nasal soft tissue; Inclination; Anterior plagiocephaly; Unicoronal synostosis; Three-dimensional morphometrics
Summary Background: Unicoronal synostosis (UCS) results in nasal root deviation toward the fused side of the face, resulting in an apparent nasal dorsal deviation to the non-fused side. The impact of the altered radix position on the osteocartilaginous vault and nasal soft tissue has not been analyzed. The purpose of this study is to morphometrically assess the nasal structure and deviation in UCS. We hypothesize the proximal etiology exerts an impact on the distal nasal form, compared to controls. Methods: Demographic data were tabulated and computed tomographic information recorded. Three-dimensional reconstruction was created and analyzed digitally (using Surgi Case). Morphometric landmarks were determined and used to perform measurements on the nasal soft tissue and osseous skull surface to evaluate nasal deviation within a midsaggital plane (MSP). Results: Forty three-dimensional CT scans of 20 UCS patients and 20 control subjects were analyzed. The deviation angle of the nose to the non-fused side was 6.6 2.9 in the bony layer. In the soft-tissue layer, the deviation angle of the nasal dorsum line to the non-fused side was 5.4 3.4 . The tip of the nose showed a significant deviation to the non-fused side (2.2 1.2 mm). Paired landmarks (alares, inferior lateral nostril bases) related to the MSP showed a greater distance on the non-fused side. Paired landmarks related to an intrinsic nasal midline (Nsup-ANS; tip-columella line (TCL)) did not show any significant differences. Conclusion: UCS confers osteocartilaginous and soft-tissue nasal deviation, with the distal nose toward the non-fused side. The nasal root inclination underpins this asymmetry across the midsaggital reference plane. However, the nose in isolation exhibits balanced sideeside proportions. ª 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Craniofacial Center, Yale University School of Medicine, Plastic and Craniomaxillofacial Surgery, 330 Cedar St, BB 3rd Floor, New Haven, CT 06520, USA. Tel.: þ1 (203) 785 4559; fax: þ1 (203) 785 7514. E-mail address: [email protected] (D.M. Steinbacher). http://dx.doi.org/10.1016/j.bjps.2015.02.015 1748-6815/ª 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
616
Introduction Unicoronal synostosis (UCS), from premature fusion of the coronal suture, results in anterior plagiocephaly with asymmetric craniofacial features. The ipsilateral forehead and supraorbital rim are depressed, with compensatory bossing of the opposite forehead and related orbital asymmetry. The nasal radix is also deviated toward the affected side and is pathognomonic of UCS.1e8 The fusion and twisting of the cranial base lead to asymmetry of the viscerocranium, including temporo-mandibular joint (TMJ), ear, and mandibular deviation with alteration in malar position.3,9,10,21 The nasal deformity, with the root toward the fused side and tip toward the non-fused side, is recognized but not adequately studied. Incorporation of the nasal radix in the reconstructive bandeau to improve this nasal deviation has been debated for some time. Despite the surgical technique, clinical experience reveals that some element of nasal deviation may persist, requiring rhinoplasty later on during life. To date, the relationship between the nasal osteocartilaginous framework and soft-tissue structures has not been assessed three-dimensionally using computed tomography (CT). The understanding of proximal fusion leading to nasal root deviation, which ultimately impacts downstream nasal anatomy, is important in order to follow the natural course of UCS and possibly better guide treatment. The purpose of this study is to morphometrically characterize the entire nasal deviation, including bony support and soft tissue, in untreated UCS infants. We hypothesize that the soft-tissue nasal deviation correlates with the underlying osteocartilaginous framework, which exhibits root deviation toward the fused side and tip deviation toward the unfused side.
I. Silveira Camargos et al. soft-tissue morphometric landmarks were determined by the investigators to be the most representative of the overall symmetry of the nose (Figures 1 and 2). A midsaggital plane (MSP) was drawn using the midpoint between the two anterior clinoid processes of the sphenoid bone and the bony nasion. This MSP was used for all bony and softtissue cephalometric measurements (Tables 1e3). A single observer performed all cephalometric measurements to maintain consistency throughout.
Data analysis Microsoft Excel (Version 14.0.0, Microsoft Office 2011, Microsoft; Redmond, WA, USA) and GraphPad Prism (Version 6, Windows; GraphPad Software) were used to perform statistical analysis. The distances and angles that were obtained with anthropometric measurements were analyzed using the unpaired two-sample t-test. Differences were considered significant at a value of p < 0.05. UCS was the primary predictor variable, while nasal symmetry and deviation indicated by the various cephalometric angles and distances were the primary outcomes of this study.
Results A total of 40 3D CT scans of 20 patients with UCS and 20 control subjects were analyzed. The ratio of males to
Materials and methods Patients This single-institution, retrospective study was performed using patients with nonsyndromic UCS. This study was approved by Yale University Institutional review board (Protocol number: HIC# 1101007932). The inclusion criteria included 20 consecutive infants with UCS who had CT of the head and neck prior to any surgical treatment for their condition. Patients who had UCS associated with a genetic syndrome or prior surgical treatments to address their craniofacial abnormalities were excluded from this study. A control group consisting of 20 consecutive healthy, agematched infants was also utilized. Inclusion criteria for the control cohort included healthy infants without any craniofacial abnormalities or intracranial pathologies who had head and neck CT imaging. Notably, control subjects received CT scans for a variety of reasons, including, but not limited to, trauma; however, craniofacial abnormalities were ruled out in all subjects prior to including them in the study.
Data collection The three-dimensional (3D) digitized images were analyzed using Surgi Case (Materialise, Leuven, Belgium). Bone and
Figure 1 Nasal soft-tissue landmarks for morphometric analysis in UCS patient.
Nasal soft-tissue and vault deviation in UCS
617
Figure 2 Osseous landmarks for morphometric analysis in same patient. Table 1
Landmarks for 3D nasal bone and soft-tissue deviation. Landmark
Bony points used:
Abbreviation Definition
Anterior clinoid process Nasion Rhinion Anterior nasal spine Nasal aperture of fusioned side Nasal aperture of non-fusioned side Soft.tissue points used: Glabella Endocanthions Nasion-soft tissue Pronasale Subnasale Alare on fusioned side Alare on non-fusioned Nostril base on fusioned side Nostril base on non-fusioned side Labaile superius
Table 2
females was 1:0.8 in the UCS group, with a mean of 5 months and about 65% experienced unilateral coronal suture fusion on the right side. The ratio of males to females in the control group was 1:1, with a mean of 6 months (Table 4). Results of anthropometric measurements were compared in both groups respectively (Tables 5 and 6). To measure the deviation of the bony architecture of the nose in patients with UCS, we measured the angle between the nasal aperture line (Nsup-ANS) and MSP. There was a statistically significant deviation of 6.6 2.9 in UCS patients whereas healthy control infants showed no statistically significant deviation (0.92 0.73 ; p Z 0.226) from the MSP using the same cephalometric landmarks. The distances between the widest lateral points of the nasal aperture (fNlat, nfNlat) and the MSP were also used to assess for any horizontal shift of the bony architecture of the nose in patients with UCS. The distance between the lateral-most points of the nasal aperture and the MSP on the fused side (6 0.9) was consistently shorter than the same distance on the contralateral, non-fused side of the face (9.7 1.5). Interestingly, the distances between the widest lateral points of the nasal aperture (fNlat, nfNlat) and the nasal aperture line did not show a significant (p Z 0.3244) difference between the fused (8.2 1) and the non-fused (8.6 1.2) side, suggesting that the entire bony nasal structure is shifted symmetrically from the midline toward the non-fused side of the face. Similar measurements were recorded using the softtissue layer to identify any correlation with the bony aberrations measured above. In patients with UCS, the tip of
Cl1, Cl2 N Nsup ANS fNlat nfNlat G Ec1, Ec2 Ns Prn Sn fA nfA fAb nfAb Ls
Apex of anterior processus clinoidei Midpoint of endocanthioneendocanthion distance Most caudal point of internasal suture Midpoint of inferior nasal aperture border Most lateral point of nasal aperture e Most anteriorly projected point of the forehead Medial corner of the eye Midpoint of the frontonasal suture Most protruded point of the apex nasi Midpoint of the columella base Most lateral point of the alar contour Most inferolateral point of the nostril Midpoint of the upper vermillion border
Reference lines and planes for anthropometric measurements.
Lines and planes
Abbreviation
Definition
Midsaggital plane Nasal bone line Nasal aperture line Nasal dorsum line Tip-columella line
MSP NBL Nsup-ANS Ns-Prn TCL
Midsaggital plane through C1, C2 and bony nasion N Line that connects bony nasion and superior point of nasal aperture Line between rhinion and anterior nasal spine Line that connects soft-tissue nasion and tip of the nose Line between tip of the nose and subnasal
618 Table 3
I. Silveira Camargos et al. Anthropometric measurements: distances and angles in 3D nasal bone and soft-tissue deviation.
Definition
Abbreviation
Distance between NsuperioreMidplane MSP Angle between nasal bone line-MSP Angle between nasal aperture length line-MSP Distance between Nlat on non-fusioned side-MSP Distance between Nlat on fusioned side-MSP Distance between Nlat on non-fusioned nasal aperture length line Distance between Nlat on fusioned nasal aperture length line Distance between PrneMSP Angle between nasal dorsum length line-MSP Distance between A on non-fusioned side-MSP Distance between A on fusioned-MSP Distance between A on non-fusioned and tip-columella line Distance between A on fusioned and tip-columella line Distance between Ab on non-fusioned and tip-columella line Distance between Ab on fusioned and tip-columella line Distance between SneMSP Distance between LseMSP
NMP AngBMP AngMP NlatMP NlatMP0 NlatA NlatA0 PrMP AngDMP AMP AMP0 ACL ACL0 AbCL AbCL0 SMP LMP
the nose was found to deviate toward the non-fused side of the face (2.2 1.2 ) compared to control patients. Similarly, in patients with UCS, the nasal dorsum line (Ns-Prn) deviated farther from the MSP (5.4 3.4 ) toward the nonfused side of the case in contrast to control patients, which showed no overall deviation toward the left or right. The distances between MSP and the ala on the fused and nonfused side were also used to assess the horizontal shift of the soft tissue of the nose similar to the bony measurements made above. Again, the distances on the fused side of the face was consistently shorter than the non-fused side in patients with UCS, indicating that the whole soft tissue of the nose is shifted from the midline toward the non-fused side of the face. Furthermore, the distance between the MSP and the most inferolateral points of the nostril bases (Ab) on the fused side (7.1 1.5) was shorter than the same distance measured on the non-fused side (12.4 1.9). The midpoint of the columellar base (Sn) and the midpoint of the upper vermillion border (Ls) both showed a significant (p < 0.001) deviation from MSP toward the non-fused side. The nasal soft-tissue measurements of control patients did not show a predilection for either side of the face (Figure 3).
Table 4
Demographic information.
Number of subjects Sex Male Female Age (mo) Mean Median Side Right Left
UCS
Control group
20
20
11 (55%) 9 (45%)
10 (50%) 10 (50%)
5.3 5
6.4 6
65% 35%
The overall symmetry of the soft tissue of the nose was evaluated by comparing the distances from the tipcolumella line (TCL) to the alares. No statistically significant difference could be found between the fused (14.7 1.3) and the non-fused (14.6 1.5) side of the face in patients with UCS and control patients. Likewise, no difference could be found comparing the distances between TCL and the most inferolateral points of the right and left nostril bases (Table 5), suggesting that the soft tissue of the nose in patients with UCS exhibits symmetrical growth but the entire structure is shifted from the midline.
Discussion UCS confers significant forehead and facial asymmetries. On the fused side, a more open palpebral fissure, retruded supraorbital rim and forehead, and facial and ear asymmetries are most frequently reported.5,9,10 The nasal root is “pulled” toward the affected side, with resultant nasal deviation to the opposite side.6,11,12 This radix deviation is important for the diagnosis of UCS, and different classification schemes have been devised based on the nasal deformity and deviation.13,14 Additionally, treatment strategies, such as the incorporation of this most proximal aspect of the nose into the bandeau and closing wedge with pyramid shift, have been described as possibly helping to ameliorate the nasal deviation.7,10 In any case, several studies have used a variety of methods to measure the soft tissue or bony structure of the nose in patients with UCS; however, there is a paucity of literature examining the morphology of both the soft tissue and bony structure using more accurate 3D CT reconstructions. We used anthropometric points and reference planes to elucidate the differences in nasal hard and soft-tissue vaults in UCS versus control patients. Bony nasal deviation in UCS patients revealed consistent deviation toward the non-fused side of 6.6 between the nasal bone line (nasionerhinion) and the MSP. The soft-tissue deviation was
Nasal soft-tissue and vault deviation in UCS Table 5
619
Comparison of measurements in UCS group.
Measurements (mm, )
Distance between NsuperiorMidplane MSP Angle between Nsup-ANS and MSP Distance between fNlat/nfNlat and MSP Distance between fNlat/nfNlat and Nsup-ANS Distance between Prn and MSP Angle between Ns-Prn and MSP Distance between fA/nfA and MSP Distance between fAb/nfAb and MSP Distance between fA/nfA and TCL Distance between fAb/nfAb and TCL Distance between Sn-MSP Distance between Ls-MSP
UCS Fused
Non-fused
e e
0.8 6.6 9.7 8.6 2.2 5.4 13.9 12.4 14.6 10 2.8 4
6 8.2 e e 12 7.1 14.7 10.2 e e
0.9 1
2,4 1.5 1.3 1.1
even greater at 5.4 . Additionally, paired bony landmarks (fNlat, nfNlat) indicating the widest lateral borders of the nasal aperture showed a consistent deviation toward the non-fused side of the face. This was also found to be true using soft-tissue measurements. Interestingly, symmetrical distances were found between paired bony and soft-tissue landmarks in relation to the nasal aperture line (Nsup-ANS). However, comparing the soft-tissue TCL with the nasal aperture line on the bone window showed a persistent asymmetry, independent from other deviations, suggesting that the inferior cartilaginous framework of the nose itself is symmetrical, but as a whole is shifted from the MSP to the non-fused side of the face. This deviation results from alterations of the pyramidal bone and maxilla that were subjectively classified in previous studies.10,12,13,15 Nasal root and tip deviation were first noted in early studies examining the effects of various surgical approaches to UCS.9,12,13,15,16 These studies simply note the presence of preoperative nasal deviation, but they fail to objectively quantify the nasal deviation before and after surgery. Alternatively, Meara et al. measured the nasal soft-tissue deformities pre- and postoperatively in patients with unilateral coronal synostosis who received frontoorbital advancement surgery.7 They found that preoperatively the nasal dorsum was angled at 9.2 toward the Table 6
0.5 2.9 1.5 1.2 1.2 3.4 3.2 1.9 1.5 1 1.4 1.9
D difference between means
p-Value
