The Relationship Between Facial Asymmetry and Nasal Septal Deviation

Internal structural analysis of the nasomaxillary complex in patients with skeletal class III asymmetry: A study on asymmetry patterns

OBJECTIVES

To investigate the internal structure of the nasomaxillary complex, including the maxillary sinus, nasal cavity and nasal septum according to the facial asymmetry pattern and to evaluate its correlation with external maxillomandibular asymmetry in Class III patients based on cone-beam computerized tomography (CBCT) images.

MATERIALS AND METHODS

Facial asymmetry was analysed in a total of 100 Class III patients aged 16 years or older using CBCT scans. Patients were categorized into subgroups based on asymmetry pattern. Measurements of the nasomaxillary complex were obtained from the CBCT scans, including the volume and width of the maxillary sinuses and nasal cavities on deviated and non-deviated sides, as well as the displacement of the nasal septum. Statistical analysis was performed to compare the internal nasomaxillary variables within and between groups, and regression analysis was conducted to evaluate the correlation between facial asymmetry and the internal nasomaxillary variables.

RESULTS

Group comparisons showed that there were no significant differences in the volume of the maxillary sinus and nasal cavity. However, the direction and extent of nasal septum deviation, as well as the width of the nasal cavity, varied depending on the maxillary asymmetry pattern. Regression analysis indicated a correlation between nasal septum deviation and the difference in maxillary height, while the difference in nasal cavity width was correlated with the difference in maxillary width.

CONCLUSION

A comprehensive evaluation of the internal nasal anatomy is vital for understanding the intricate relationship between nasal structure and maxillary growth.

Nasal Airway Volumes are More Asymmetric in Skeletally Mature Patients With Cleft lip and Palate Than Controls on 3-Dimensional Analysis

BACKGROUND

This study assesses nasal airway volumes in skeletally mature patients with CLP and healthy controls and examines the relationship among nasal volumes, cleft laterality, and facial asymmetry.

METHODS

Computed tomography images from patients with CLP and controls were analyzed using Mimics Version 23.0 (Materialise, Leuven, Belgium). Relationships among nasal airway volume, cleft laterality, and facial asymmetry were compared.

RESULTS

The 89 patients in this study included 66 (74%) CLP and 23 (17%) controls. Nasal airway volumes in CLP were more asymmetric than controls (26.8±17.5% vs. 17.2±14.4%; P=0.015). In UCLP, the smaller nasal airway was on the cleft side 81% of the time (P<0.001). Maximum airway stenosis was on the cleft side 79% of the time (P<0.001), and maximum stenosis was on the same side as the smaller airway 89% of the time (P<0.001). There was a mild linear relationship between nasal airway asymmetry and maximum stenosis (r=0.247, P=0.023). On 3-dimensional image reconstruction, the septum often bowed convexly into the cleft-sided nasal airway with a caudal deviation towards the noncleft side. Nasal airway asymmetry was not associated with facial midline asymmetry (P>0.05).

CONCLUSION

The nasal airway is more asymmetric in patients with cleft lip and palate compared with the general population, with the area of maximum stenosis usually occurring on the cleft-sided airway. In patients with unilateral cleft lip and palate, the septum often bows into the cleft side, reducing the size of that nasal airway. Nasal airway asymmetry did not correlate with facial asymmetry.

Influence of nasal septum deviation on fluctuating asymmetries of the nasomaxillary complex: A cross-sectional study

An important parameter in diagnostic analysis and treatment planning of different biological areas is facial symmetry, and several etiological factors have been attributed to skeletal facial asymmetry. Although causality cannot be determined, previous studies have reported a relationship between the anatomical deviation of the nasal septum and facial development. Diagnosis is critical for patients in growth stages due to the association between nasal septum deviation (NSD) and abnormal growth of the nasomaxillary complex. To understand this relationship, this study aimed to investigate the influence of nasal septum deviation on fluctuating asymmetries (FA) of the nasomaxillary complex at different stages of skeletal maturation. Another goal was to determine whether an association exists between the degrees of septal deviation severity and asymmetry of the nasomaxillary complex. This was a retrospective, cross-sectional observational study comprising 60 selected cone-beam computed tomography (CBCT) scans that were divided into four groups (n = 15) according to the degree of septal deviation and skeletal maturation: mild deviation (MD; <10°), moderate to severe deviation (MSD; ≥10°), early group (EG), and late group (LG). The angle and area of deviation were measured for the greatest NSD, and a geometric morphometric approach was used to evaluate the nasal septum (NS) shape. The morphology of the nasomaxillary complex and the presence of fluctuating asymmetries were evaluated using 23 two-dimensional landmarks on the nasomaxillary complex (nasal, lateral, and palatal regions) with Procrustes ANOVA and Mann-Whitney test. Additionally, Spearman's correlation and multivariate regression were used to correlate the NSD with asymmetries in these regions. No significant differences were observed in the Procrustes FA scores of the nasomaxillary complex between the MD-EG × MSD-EG and MD-LG × MSD-LG (p > 0.05). However, the results of the multivariate regression revealed more specific aspects of asymmetry (asymmetry component), there was a positive correlation between the NSD angle and the palatal regions (p = 0.035 and p = 0.047, middle and posterior, respectively), and the nasal septum shape and anterior palatal regions (p = 0.039). The nasal and lateral regions did not correlate with the NSD angle in the multivariate regression analysis (p > 0.05). The results of this study indicate that there were no significant differences in the fluctuating asymmetry of the nasomaxillary complex between the mild and moderate to severe nasal septum deviation groups, in both early and late skeletal maturation stages. However, a positive correlation was observed in the degree of nasal septum deviation angle and asymmetry components of the middle and posterior palatal regions, likewise between the nasal septum shape and asymmetry components of the anterior palatal region. The diagnosis of nasal septum deviation by both physicians and dentists is important, as a relationship was observed with fluctuating asymmetry component of the palatal region. This information can guide the decision of the treatment planning for these individuals, and should be considered, especially in cases of severe septum deviation, due to the great anatomical proximity of these structures.

Evaluation of the relationship between nasal septal deviation and development of facial asymmetry with anthropometric measurements depending on age

AIM

It was aimed to determine the change of facial asymmetry resulting from nasal septal deviation (SD) depending on age, gender, degree of deviation and the affected area besides the effect of SD on somatotype and craniofacial morphology.

MATERIALS AND METHODS

171 volunteers (90 males, 81 females), 27 individuals aged 9-13, 44 individuals aged 14-18, 44 individuals aged 19-23 and 56 individuals in control group participated in the study conducted in otorhinolaryngology polyclinic.11 photometric, 16 anthropometric measurements were taken from the participants.

RESULTS

SD affects facial asymmetry formation, although not statistically significant compared to healthy individuals asymmetry rates (p˃0.05). It was determined that the degree of SD affected asymmetry only between the ages of 14-18 (in adolescence) and the development of asymmetry in all SD patients was not statistically dependent on age and gender (p˃0.05). Photometric measurements demonstrated asymmetries in horizontally-extending parameters of 1/3 middle part of face. There was no statistically significant difference in the cranial anthropometric measurements of the upper and lower 1/3 of the face compared to the control group (p˃0.05). The order of the most asymmetrical parameters is Alare-Zygion, Alare-Subnasale, Cheilion-Gonion, Exocanthion-Cheilion, Midsagittal plane-Zygion, Zygion-Cheilion, Zygion-Gonion, Subalare-Cheilion, Glabella-Exocanthion. In all participants were determined that endomorph somatotype was dominant in female and mesomorph somatotype was dominant in male besides SD did not affect somatotype and somatotype did not alter with age.

CONCLUSION

The development of facial asymmetry due to SD is not affected by age and gender furthermore SD does not affect craniofacial asymmetry and somatotype.

The effect of anatomical variations of the sinonasal region on maxillary sinus volume and dimensions: a three-dimensional study

INTRODUCTION

Anatomical variations in the sinonasal region are remarkably common and these variations may have an impact on maxillary sinus development due to their close anatomical adjacency.

OBJECTIVE

The aim of this study was to investigate the effect of anatomical variations of the sinonasal region on the width, height, length, and volume of the maxillary sinus.

METHODS

Cone beam computed tomography records of 120 patients were evaluated. Nasal septum deviation angle was measured for each patient and patients were divided into three groups as mild, moderate, and severe. Sinonasal variations such as nasal septum deviation direction, septal spur, concha bullosa, uncinate process pneumatization, middle concha hypertrophy, inferior concha hypertrophy, paradoxical middle concha and presence of septa in the maxillary sinus were registered. Cone beam computed tomography images were transferred to the SimPlant software thus right and left maxillary sinus volumes and dimensions were measured separately.

RESULTS

There was a negative and statistically significant relationship between age and left maxillary sinus width (p = 0.015). The relationships between gender and maxillary sinus volumes and dimensions were statistically significant (p < 0.05). Although there were significant relationships between the nasal septum deviation severity, middle concha hypertrophy, inferior concha hypertrophy, paradoxical middle concha, and presence of septa and maxillary sinus dimensions; there was no significant relationship between septal spur, nasal septum deviation direction, concha bullosa, uncinate process pneumatization, and maxillary sinus dimensions. No statistically significant relationship could be determined between maxillary sinus volume and anatomical variations of the sinonasal region.

CONCLUSION

According to our findings, while certain the variations were found to affect the sinus dimensions; none of the variations was found to be related to the maxillary sinus volume.

Nasal Floor Asymmetry Is Associated With Nasal Obstruction

PURPOSE

The role of morphologic characteristics of the nasal cavity in nasal obstruction is not yet sufficiently understood. The aim of this study was to determine which morphometric parameters of the nasal cavity severely impair nasal breathing and when.

PATIENTS AND METHODS

In a hospital-based, computed tomography-morphometric cross-sectional study, we evaluated computed tomography coronal scans of patients with known nasal obstruction scheduled to undergo functional nasal surgical procedures (cases) and trauma patients without facial involvement or known nasal obstruction (controls). The primary predictor variable was case versus control. In both groups, we measured and compared the piriform aperture width; nasal floor canting; piriform aperture vertical height, height-width ratio, and total cross-sectional area; height difference between the right and left nasal floors; and nasal septal thickness; as well as age and gender differences. Metric data means, standard deviations, and 95% confidence intervals were calculated and analyzed.

RESULTS

The sample was composed of 60 patients evenly divided between cases and controls. Of these, 30 were men. The average age of the cases and controls was 27.4 ± 7.8 years and 38.5 ± 18.6 years, respectively (P < .001). The differences in piriform aperture width were not statistically significant between cases and controls (23.3 ± 1.9 mm and 23.8 ± 1.7 mm, respectively; P > .2). In contrast, we noted statistically significant differences between cases and controls in nasal floor canting (5.4° ± 4.6° and 1.8° ± 1.5°, respectively; P < .001) and height difference between the right and left nasal floors (1.8 ± 1.2 mm and 1.0 ± 0.7 mm, respectively; P = .002).

CONCLUSIONS

Nasal floor canting of 3° or greater and a height difference between the right and left nasal floors of 1.5 mm or greater may contribute to the etiology of clinically relevant nasal obstruction. A piriform aperture width of 22 mm or less may be considered narrow. Future studies can determine when and how exactly to surgically address a clinically relevant narrow piriform aperture and nasal floor canting.

Horizontal change of philtrum after orthognathic surgery in patients with facial asymmetry

Background

Soft tissue asymmetry such as lip canting or deviation of the philtrum is an important influencing factor for unbalanced facial appearance. Lip canting could be improved by the correction of the occlusal canting or positional change of the mentum. Although there are many studies about changes of lip canting, however, postoperative changes of philtrum deviation have not been yet reported. In this study, we investigate the positional change of the philtrum after orthognathic surgery and influencing factors.

Methods

Positional change of the philtrum was evaluated in 41 patients with facial asymmetry who underwent bimaxillary surgery, in relation to other anatomical soft tissue landmarks using a frontal clinical photo. The surgical movement of the maxillary and mandibular dental midline and canting were measured in postero-anterior cephalogram before and 1 day after surgery. The same procedure was repeated in patients with more than 1.5 mm perioperative change of the mandibular dental midline after bimaxillary surgery.

Results

Maxillary dental midline shifting and canting correction did not have a significant correlation with lateral movement of the philtrum midline. However, the mandibular shift had a statistically significant correlation with a lateral movement of the philtrum (p < 0.05) as well as other linear parameters and angle values.

Conclusion

The horizontal change of the philtrum is influenced by lateral mandibular movement in patients with facial asymmetry, rather than maxillary lateral movement.

Hard- and soft-tissue symmetry comparison in patients with Class III malocclusion

OBJECTIVE

Our aim was to describe hard- and soft-tissue asymmetry in people who have a skeletal Class III malocclusion, and to compare with those without asymmetry. We also performed a regional analysis of a possible correlation between facial soft- and hard-tissue asymmetries.

METHODS

This retrospective study was performed with the use of the computed tomographic scans of 60 subjects. The skeletal Class III subjects were categorized into 2 subgroups: soft-tissue menton deviation ≤4 mm (n = 20) versus >4 mm (n = 20). The Class III groups were compared with a Class I symmetry group (n = 20). Hard and soft tissues were segmented into different morphologic areas and deviation calculated. Pearson correlation coefficients were obtained, and 1-way analysis of variance was conducted for statistical analysis.

RESULTS

The highest deviation in the hard tissues of the Class III asymmetry group was in the corpus region (5.55 ± 3.05 mm), with the second highest in the angulus region (4.70 ± 2.43 mm). The highest average deviation in the soft tissues was seen in the lower cheek (7.04 ± 3.46 mm). In the different study groups, the amounts of asymmetry measured in anatomic structures on the mandible were found to be highly correlated between neighboring structures.

CONCLUSIONS

Clinically and statistically significant differences were found in the anatomic regions located in the middle and lower thirds of the face. There was a medium or high correlation between condyle, coronoid process, ramus, and angulus regions. A low level of correlation was observed between middle face and mandibular asymmetries in hard-tissue upper cheek and lower cheek regions were correlated with different mandibular regions.

Bony/Cartilaginous Mismatch: A Radiologic Investigation into the Cause of Tension Nose Deformity

BACKGROUND

Tension nose deformity is believed to be caused by an "oversized" septal quadrangular cartilage. Prior studies have shown that quadrangular cartilage size is relatively consistent in populations. The authors hypothesize that the tension nose deformity is actually caused by an external extrusion of a normal sized septal cartilage from an undersized bony septal encasement.

METHODS

A retrospective case-control study of sagittal computed tomographic scans was conducted, measuring the perimeter and surface area of the quadrangular cartilage and bony septal aperture in tension nose cases and controls. Statistical analysis was performed.

RESULTS

Of 23 patients enrolled in the study, 12 patients were sorted into the tension nose group, and 11 patients were considered controls. Both groups had similar perimeter and surface area of their quadrangular cartilage, without statistical difference between the two groups. However, the tension nose group had a statistically significant reduction in bony septal aperture perimeter compared with controls (p < 0.01) and a larger externally extruded septum compared with their internal septal size. They also had a substantially higher rate of septal deviation than controls.

CONCLUSIONS

The results of this study suggest that a mismatch between a small bony septal aperture and a normal sized septal quadrangular cartilage may be responsible for caudal, upper lip, and dorsal fullness seen with the tension nose deformity caused by external extrusion of cartilage. Septal deviation may co-occur as a buckling phenomenon in a limited bony space. Surgical strategies to match the entire quadrangular cartilage size to the bony framework are suggested.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Nasal Deviation in Patients With Asymmetric Mandibular Prognathism

PURPOSE

This study was aimed to evaluate the nasal deviation in patients with asymmetric mandibular prognathism.

MATERIALS AND METHODS

Thirty-five patients with skeletal class III malocclusion were included in the study. Significant mandibular asymmetry of >4 mm menton deviation in three-dimensional (3D) reformatted cone beam computed tomography images was defined as asymmetry group (n = 20). Patients without mandibular asymmetry served as control group (n = 15). The mandibular asymmetry was evaluated pre- and postoperatively.

RESULTS

Nasal tip was significantly shifted to the deviated side of the mandible (short side) in the asymmetry group, as compared to the control group (1.5 ± 0.9 degree, P < 0.01). Alar base angle (ABA) was significantly narrower in nondeviated side (long side) than in the deviated side in asymmetry group. However, control group showed no bilateral difference in ABA. Correction of deviated mandibular prognathism by isolated mandibular surgery resulted in change in the ABA but not the columella base position or nasal asymmetry. ABA on nondeviated side significantly decreased in proportion to the amount of transverse menton movement by surgery (r = -0.560, P < 0.01).

CONCLUSION

Our results showed that mandibular chin deviation was accompanied by nasal deviation. Isolated mandibular surgery can potentially influence the alar base position on the contralateral side of deviation but not the nasal tip asymmetry. Therefore, clinicians should inform patients preoperatively of the fundamental limitation of mandibular surgery in cases with preexisting nasal asymmetry.