Morphological interaction between the nasal septum and nasofacial skeleton during human ontogeny

Assessment of the prevalence of nasal deviation in patients requiring orthognathic surgery: association with maxillary, mandibular, or chin asymmetry

PURPOSE

Identifying nasal deviation in patients requiring orthognathic surgery is critical for developing an accurate treatment plan, particularly in the axial plane. This study aimed to evaluate the prevalence and degree of nasal and septal deviation in patients requiring orthognathic surgery, and to assess their relationship with maxillary, mandibular, and chin asymmetries, as well as dento-skeletal class.

MATERIAL AND METHODS

A retrospective study was conducted on patients who required orthognathic surgery between July 2020 and February 2021. Exclusion criteria included congenital craniofacial anomalies, history of mandibular condylar hyperplasia, or prior rhino-septoplasty procedures.

RESULTS

Of the 103 patients studied, 97.1% exhibited some degree of nasal deviation, and all presented with septal deviation. Nasal septum deviation correlated significantly with nasal tip deviation (r = 0.44, p < 0.001) and dorsum deviation (r = 0.41, p < 0.001). A combination of nasal, maxillary, mandibular, and chin deviations was present in 77.3%, 83.5%, and 88.3% of patients, respectively. Significant correlations were found between the directions of maxillary (r = 0.21, p = 0.032), mandibular (r = 0.25, p = 0.012), and chin deviations (r = 0.19, p = 0.050).

CONCLUSIONS

This study highlights that nasal and septal deviations are highly prevalent in patients requiring orthognathic surgery, and their accurate diagnosis is essential for successful orthognathic diagnosis and surgical planning. These findings support the inclusion of nasal assessments in the treatment plans for orthognathic surgery patients.

Correlation of maximal nasal septal deviation with deviation at the maxillary insertion

PURPOSE

It is unclear if septal deviation at the insertion points to the nasal cavity is associated with the overall septal deviation. This study aimed to assess septal deviation at the cribriform plate (CP) and maxillary crest (MC) using CT scans and to see if there was any correlation with overall septal deviation.

METHODS

All consecutive CT sinus scans between January 2020 and December 2021 were retrospectively reviewed. Patients were excluded if they had a history of head, nasal or facial trauma, or any previous nasal surgical procedure. Angles between the septum and MC and the septum and CP as well as maximal angle of septal deviation (MSD) were measured.

RESULTS

A total of 70 scans were included in the final analysis. The mean MSD was 8.14°. The mean septal deviation was 0.89° at the CP and 2.02° at the MC. The correlation coefficient between the deviation at the CP and MSD was 0.025 and between the deviation at the MC and MSD was 0.321.

CONCLUSION

Our data reveal a positive correlation between septal deviation at the floor of the nose and overall septal deviation; this was not observed at the septal deviation at the roof. This could be explained due to the inherent tilt in the cribriform plate or by earlier ossification and fixation of the septum during its development at its insertion to the roof, thereby allowing further growth and potential for deviation of the lower part of the septum and its insertion to the floor.

Correlation Analysis of Nasal Septum Deviation and Results of AI-Driven Automated 3D Cephalometric Analysis

The nasal septum is believed to play a crucial role in the development of the craniofacial skeleton. Nasal septum deviation (NSD) is a common condition, affecting 18-65% of individuals. This study aimed to assess the prevalence of NSD and its potential association with abnormalities detected through cephalometric analysis using artificial intelligence (AI) algorithms. The study included CT scans of 120 consecutive, post-traumatic patients aged 18-30. Cephalometric analysis was performed using an AI web-based software, CephX. The automatic analysis comprised all the available cephalometric analyses. NSD was assessed using two methods: maximum deviation from an ideal non-deviated septum and septal deviation angle (SDA). The concordance of repeated manual measurements and automatic analyses was assessed. Of the 120 cases, 90 met the inclusion criteria. The AI-based cephalometric analysis provided comprehensive reports with over 100 measurements. Only the hinge axis angle (HAA) and SDA showed significant (p = 0.039) negative correlations. The rest of the cephalometric analyses showed no correlation with the NSD indicators. The analysis of the agreement between repeated manual measurements and automatic analyses showed good-to-excellent concordance, except in the case of two angular measurements: LI-N-B and Pr-N-A. The CephX AI platform showed high repeatability in automatic cephalometric analyses, demonstrating the reliability of the AI model for most cephalometric analyses.

Association between nasal septum deviation and transverse maxillary development: A retrospective cross-sectional study

INTRODUCTION

The few studies investigating the relationship between nasal septum deviation (NSD) and maxillary development, using different assessment methods and the age of subjects, reported contradicting results.

METHODS

The association between NSD and transverse maxillary parameters was analyzed using 141 preorthodontic full-skull cone-beam computed tomography scans (mean age, 27.4 ± 9.01 years). Six maxillary, 2 nasal, and 3 dentoalveolar landmarks were measured. The intraclass correlation coefficient was used to assess intrarater and interrater reliability. The correlation between NSD and transverse maxillary parameters was analyzed using the Pearson correlation coefficient. Each transverse maxillary parameter was compared among 3 groups of different degrees of severity using the analysis of variance test. Transverse maxillary parameters were also compared between the more and less deviated nasal septum sides using the independent t test.

RESULTS

A correlation between deviated septal width and palatal arch depth (r = 0.2, P <0.013) and significant differences in palatal arch depth (P <0.05) among 3 NSD severity groups classified with deviated septal width was noted. There was no correlation between septal deviated angle and transverse maxillary parameters and no significant difference for transverse maxillary parameters among the 3 groups of NSD severity classified by septal deviated angle. No significant difference in transverse maxillary parameters was found when comparing the more and the less deviated sides.

CONCLUSIONS

This study suggests that NSD can affect palatal vault morphology. The magnitude of NSD may be a factor associated with transverse maxillary growth disturbance.

The Effect of Trans-Sutural Distraction Osteogenesis on Nasal Bone, Nasal Septum, and Nasal Airway in the Treatment for Midfacial Hypoplasia in Growing Patients

The purposes of this study were to analyze the effect of trans-sutural distraction osteogenesis (TSDO) on nasal bone, nasal septum, and nasal airway in the treatment of midfacial hypoplasia. A total of 29 growing patients with midfacial hypoplasia who underwent TSDO by a single surgeon were enrolled. The 3-dimensional measurement of nasal bone and nasal septum changes was performed using computed tomography (CT) images obtained preoperatively (T0) and postoperatively (T1). One patient was selected to establish 3-dimensional finite element models to simulate the characteristics of nasal airflow field before and after traction. After traction, the nasal bone moved forward significantly ( P <0.01). The septal deviation angle was lower than that before traction (14.43±4.70 versus 16.86 ±4.59 degrees) ( P <0.01). The length of the anterior and posterior margin of the vomer increased by 21.4% ( P <0.01) and 27.6% ( P <0.01), respectively, after TSDO. The length of the posterior margin of the perpendicular plate of ethmoid increased ( P <0.05). The length of the posterior inferior and the posterior superior margin of the nasal septum cartilage increased ( P <0.01) after traction. The cross-sectional area of nasal airway on the deviated side of nasal septum increased by 23.0% after traction ( P <0.05). The analysis of nasal airflow field showed that the pressure and velocity of nasal airflow and the nasal resistance decreased. In conclusion, TSDO can promote the growth of the midface, especially nasal septum, and increase the nasal space. Furthermore, TSDO is conductive to improve nasal septum deviation and decrease nasal airway resistance.

Normal human craniofacial growth and development from 0 to 4 years

Knowledge of human craniofacial growth (increase in size) and development (change in shape) is important in the clinical treatment of a range of conditions that affects it. This study uses an extensive collection of clinical CT scans to investigate craniofacial growth and development over the first 48 months of life, detail how the cranium changes in form (size and shape) in each sex and how these changes are associated with the growth and development of various soft tissues such as the brain, eyes and tongue and the expansion of the nasal cavity. This is achieved through multivariate analyses of cranial form based on 3D landmarks and semi-landmarks and by analyses of linear dimensions, and cranial volumes. The results highlight accelerations and decelerations in cranial form changes throughout early childhood. They show that from 0 to 12 months, the cranium undergoes greater changes in form than from 12 to 48 months. However, in terms of the development of overall cranial shape, there is no significant sexual dimorphism in the age range considered in this study. In consequence a single model of human craniofacial growth and development is presented for future studies to examine the physio-mechanical interactions of the craniofacial growth.

Properties of the Nasal Cartilage, from Development to Adulthood: A Scoping Review

OBJECTIVE

Nasal septum cartilage is a hyaline cartilage that provides structural support to the nasal cavity and midface. Currently, information on its cellular and mechanical properties is widely dispersed and has often been inferred from studies conducted on other cartilage types such as the knee. A detailed understanding of nasal cartilage properties is important for several biological, clinical, and engineering disciplines. The objectives of this scoping review are to (1) consolidate actual existing knowledge on nasal cartilage properties and (2) identify gaps of knowledge and research questions requiring future investigations.

DESIGN

This scoping review incorporated articles identified using PROSPERO, Cochrane Library (CDSR and Central), WOS BIOSIS, WOS Core Collection, and ProQuest Dissertations and Theses Global databases. Following the screening process, 86 articles were considered. Articles were categorized into three groups: growth, extracellular matrix, and mechanical properties.

RESULTS

Most articles investigated growth properties followed by extracellular matrix and mechanical properties. NSC cartilage is not uniform. Nasal cartilage growth varies with age and location. Similarly, extracellular matrix composition and mechanical properties are location-specific within the NSC. Moreover, most articles included in the review investigate these properties in isolation and only very few articles demonstrate the interrelationship between multiple cartilage properties.

CONCLUSIONS

This scoping review presents a first comprehensive description of research on NSC properties with a focus on NSC growth, extracellular matrix and mechanical properties. It additionally identifies the needs (1) to understand how these various cartilage properties intersect and (2) for more granular, standardized assessment protocols to describe NSC.

Effect of septal deviation on nasomaxillary shape: A geometric morphometric study

Nasal cavities in their primitive stage communicate with the oral cavity until the 8th week of intrauterine life where the posterior palate initiates its development. Hence, starting from the initial growth phases, a significant connection lays between the nasal structures and the maxillary bone and witnessing key functional roles, among which the respiration. Proper nasal breathing has been proven to be a crucial factor for the maturity of the craniofacial complex, and obstruction of the respiratory airway due to nasal septum deviation can generate clinically significant reduction of the nasal airflow. This situation will imply irreversible repercussions that hinders the harmonious development of the craniofacial complex. In order to understand such potential impacts of septal deviation, our first objective was to materialize the relation between septum deviation, and both nasal cavity and maxillary structures. For the second objective, we used Procrustes analysis to assess the shape variation of these two anatomical regions, the bivariate plots of Principal Components to evaluate their shape space, and a two-block Partial Least Square (PLS) to explore their covariation. We analysed, in this cross-sectional study, 62 posteroanterior cephalometric radiographs of adult subjects from both sexes (23 males, 39 females; mean age 25.3 years) collected from the database of the Department of Orthodontics at Lebanese University. Landmarks were plotted and variables were calculated and divided into nasal septum, nasal cavity and maxillary ones. The sample was further divided into two groups based on septal deviation severity (a septal deviation is considered minor if <6). The results suggested that nasal septum deviation was correlated to reduced nasal cavity area and a reduced maxillary area. Moreover, the comparison of the two groups concluded that the difference between all variables was statistically significant with higher scores in the minor septal deviation group. These findings were corroborated with the shape analysis where the mean centroid size of nasal cavity and that of the maxilla in the group of reduced septal deviation were significantly greater than those of the group with increased angle of deviation. Results of PLS analysis concluded to a strong covariation between nasal septum and nasomaxillary complex. These conclusions support the early septoplasty in growing patients as a solution to redirect the normal course of growth and re-establish a good function of the nasomaxillary complex.

Nasal cavity structural anomalies in children and adolescents at high risk of sleep-disordered breathing: An exploratory cone-beam computed tomography study

INTRODUCTION

In this study, we investigated the presence of structural anomalies in the nasal cavity (deviated nasal septum [DNS] and turbinate hypertrophy [TH]) in patients at high risk or not of sleep-disordered breathing (SDB).

METHODS

A retrospective study considering available cone-beam computed tomography scans of 99 patients was conducted. Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif) was used to process the craniofacial scans. A pediatric sleep questionnaire (PSQ) was used to suggest a high risk of SDB. Subjective and objective assessments of DNS and TH were considered.

RESULTS

Good to excellent intrareliability and interreliability were attained. The prevalence of a PSQ score suggestive of a high risk of SDB in this sample was 59%. The prevalence of subjective DNS and TH assessment was 64% and 70%, respectively. In contrast, on the basis of objective assessments, 27% of patients presented with DNS and 25% with TH. Cross-tabulation of DNS and TH with PSQ score indicated a statistically significant association between subjective DNS and subjective TH and subjective TH and positive PSQ. A positive correlation between age and subjective and objective DNS assessments was also observed.

CONCLUSIONS

Older patients are more likely to present with DNS. Only the presence of subjectively determined TH in patients is associated with a high risk for SDB. The study reveals that assessment of DNS and TH using cone-beam computed tomography imaging is not likely suitable to strongly suggest patients at high risk for SDB. DNS subjective assessments were capable of identifying less than 5% of deviation.

The role of the nasal region in craniofacial growth: An investigation using path analysis

This study focuses on the role of the nasal region and its interactions with adjacent facial elements during early ontogeny. A series of linear measurements, areas and volumes were extracted from a collection of 227 medical CT-scans of children from 0 to 6 years of age. These measurements describe aspects of the form of the orbit, maxilla, peri-alveolar (subnasal) region, nasal area, eye, oral region, masseter, and temporal muscles. Hypothesized interactions were then examined using path analysis. Two paths were designed: the first to investigate potential interactions in, and relative contributions of the nasal derivatives and adjacent regions to overall facial growth and development; the second path sees the addition of facial soft tissue measurements and aims to assess their effects on skeletal components, and on overall facial growth and development. The results of the first path indicate a large contribution of the nasal and subnasal regions to facial development. This indicates that the nasal septum and the developing dentition provide an important but variable contribution to facial ontogeny during early years. This result is confirmed in the second path, where the soft tissue elements were added to the diagram. Results of the second path indicate that the soft tissues contribute only locally to the development of some skeletal elements of the face. This indicates that the contribution of skeletal components has a more direct effect on facial height than soft tissue matrices, however there are complex interactions between soft tissues and skeletal elements throughout ontogeny.

The Expanding Role of Geometric Morphometrics in Craniofacial Surgery

INTRODUCTION

Geometric morphometrics (GM) is an advanced landmark-based quantitative method used to study biological shape and form. Historically, GM has been limited to non-biomedical fields such as comparative biology; however, this technique confers advantages over traditional cephalometric methods, warranting a review of current applications of GM to human craniofacial disorders.

METHODS

The RISmed package was used to extract metadata associated with PubMed publications referencing GM analysis techniques in craniofacial and reconstructive surgery. PubMed search terms included "geometric AND morphometric AND craniofacial;" and "geometric AND morphometric AND reconstructive surgery." Duplicate search results were eliminated.

RESULTS

Search yielded 139 studies between 2005 and 2020, of which 27 met inclusion criteria. Human craniofacial studies constituted 2% of all queried GM studies. Among these, cleft lip and palate were the most commonly studied craniofacial conditions (7 studies, 26%), followed by sagittal craniosynostosis (4 studies, 15%). Seventeen studies (63%) used GM to assess skeletal structures, seven studies (26%) examined both skeletal and soft tissues, and three studies (11%) analyzed soft tissues only. Eleven studies (40.1%) employed a GM approach to evaluate postoperative changes in craniofacial morphology. Two studies (7%) systematically compared GM analysis with conventional shape measurements.

CONCLUSION

The ability to study shape while controlling for variability in structure size and imaging technique make GM a promising tool for understanding growth patterns in complex craniofacial diseases. Furthermore, GM overcomes many limitations of traditional cephalometric techniques, and hence may claim an expanded role in the study of human craniofacial disorders in clinical and research settings.

Analysis of inferior nasal turbinate width and concha bullosa in subjects with nasal septum deviation: a cone beam tomography study

Background

In individuals with nasal septal deviation (NSD), compensatory hypertrophy of the nasal turbinates occurs as a protective mechanism of the nasal passage from dry and cold air. NSD associated nasal turbinate hypertrophy is usually recurrent, requiring repetitive imaging. Therefore, a multiplanar imaging modality with a low radiation dose is best suited for long-term follow-up of this condition. This study aimed to evaluate the association of width of inferior turbinates and presence of concha bullosa with the degree of NSD using Cone beam computed tomography (CT).

Methods

The CBCT scans of 100 patients with NSD were selected as per convenience sampling and were evaluated by two maxillofacial radiologists. The width of the non-hypertrophied inferior turbinate (NHT) on the convex side of the NSD, and hypertrophic inferior turbinates (HT) on the concave side of the NSD were measured at three locations. The septal deviation angle (SDA) and the presence of concha bullosa (CB) were determined.

Results

A significant difference was observed in the anterior, middle, posterior, and mean widths between HT and NHT (p < 0.001). There was a significant difference in the widths of the HT and NHT among different types of NSD. A strong positive correlation (r = 0.71, p < 0.001) was found between SDA and the mean width of the HT. Age (P = 0.71) and gender (P = 0.65) had no significant difference among different types of NSD. Regression analysis revealed that the presence of CB (p = 0.01) and middle width of the HT (p < 0.001) are significant predictors of SDA and type of NSD.

Conclusion

The results of the present study reveal that the middle width of the HT and the presence of CB influence the degree of NSD. The present study results recommend the use of CBCT as a substitutive low radiation dose imaging modality for evaluation of NSD, CB, and associated inferior turbinate hypertrophy.

Histological and molecular characterization of the growing nasal septum in mice

The nasal septum is a cartilaginous structure that serves as a pacemaker for the development of the midface. The septum is a hyaline cartilage which is surrounded by a perichondrium and epithelium. It remains cartilaginous anteriorly, but posteriorly it undergoes endochondral ossification to form the perpendicular plate of the ethmoid. Understanding of hyaline cartilage differentiation stems predominantly from investigations of growth plate cartilage. It is currently unclear if the morphological and molecular properties of the differentiating nasal septum align with what is known from the growth plate. In this study, we describe growth, molecular, and cellular characteristics of the nasal septum with reference to hyaline cartilage differentiation. The nasal septum grows asynchronous across its length with phases of rapid growth interrupted by more stagnant growth. Growth appears to be driven predominantly by acquisition of chondrocyte hypertrophy. Similarly, cellular differentiation is asynchronous, and differentiation observed in the anterior part precedes posterior differentiation. Overall, the nasal septum is structurally and molecularly heterogeneous. Early and extensive chondrocyte hypertrophy but no ossification is observed in the anterior septum. Onset of hypertrophic chondrocyte differentiation coincided with collagen fiber deposition along the perichondrium. Sox9, Col2, Col10, Mmp13, Sp7, and Runx2 expression was heterogeneous and did not always follow the expected pattern established from chondrocyte differentiation in the growth plate. The presence of hypertrophic chondrocytes expressing bone-related proteins early on in regions where the nasal septum does not ossify displays incongruities with current understanding of hyaline cartilage differentiation. Runx2, Collagen II, Collagen X, and Sp7 commonly used to mark distinct stages of chondrocyte maturation and early bone formation show wider expression than expected and do not align with expected cellular characteristics. Thus, the hyaline cartilage of the nasal septum is quite distinct from growth plate hyaline cartilage, and caution should be taken before assigning cartilage properties to less well-defined cartilage structures using these commonly used markers. Beyond the structural description of the nasal cartilage, this study also provides important information for cartilage tissue engineering when using nasal septal cartilage for tissue regeneration.

Maternal Folic Acid Deficiency Is Associated to Developing Nasal and Palate Malformations in Mice

Craniofacial development requires extremely fine-tuned developmental coordination of multiple specialized tissues. It has been evidenced that a folate deficiency (vitamin B9), or its synthetic form, folic acid (FA), in maternal diet could trigger multiple craniofacial malformations as oral clefts, tongue, or mandible abnormalities. In this study, a folic acid-deficient (FAD) diet was administered to eight-week-old C57/BL/6J female mouse for 2-16 weeks. The head symmetry, palate and nasal region were studied in 24 control and 260 experimental fetuses. Our results showed a significant reduction in the mean number of fetuses per litter according to maternal weeks on FAD diet (p < 0.01). Fetuses were affected by cleft palate (3.8%) as well as other severe congenital abnormalities, for the first time related to maternal FAD diet, as head asymmetries (4.6%), high arched palate (3.5%), nasal septum malformed (7.3%), nasopharynx duct shape (15%), and cilia and epithelium abnormalities (11.2% and 5.8%). Dysmorphologies of the nasal region were the most frequent, appearing at just four weeks following a maternal FAD diet. This is the first time that nasal region development is experimentally related to this vitamin deficiency. In conclusion, our report offers novel discoveries about the importance of maternal folate intake on midface craniofacial development of the embryos. Moreover, the longer the deficit lasts, the more serious the consequent effects appear to be.

Evaluation of the Midface by Statistical Shape Modeling

PURPOSE

The aim of this investigation was to generate a statistical shape model (SSM) of the midface and evaluate symmetry, gender aspects, and bone thickness.

METHODS

About 102 computed tomography scans were analyzed to create the SSM. This included segmentation, landmark attribution, and Procrustes and principal component analysis. Afterward, symmetry and gender differences were visualized by registration and color coding. Bone thickness was calculated by measuring the distance between outer and inner surfaces.

RESULTS

Symmetry was high in all models. The male model showed a more prominent forehead, nasal bones, and larger bizygomatic width. Bone thickness resembled the concept of vertical and horizontal maxillary pillars and buttresses.

CONCLUSIONS

SSM can be used to analyze midface morphology and help in virtual surgery planning. Calculation of bone thickness could also be a useful tool in surgical planning and biomechanics.

Ontogeny of the human maxilla: a study of intra-population variability combining surface bone histology and geometric morphometrics

Bone modeling is the process by which bone grows in size and models its shape via the cellular activities of the osteoblasts and osteoclasts that respectively form and remove bone. The patterns of expression of these two activities, visible on bone surfaces, are poorly understood during facial ontogeny in Homo sapiens; this is due mainly to small sample sizes and a lack of quantitative data. Furthermore, how microscopic activities are related to the development of morphological features, like the uniquely human-canine fossa, has been rarely explored. We developed novel techniques for quantifying and visualizing variability in bone modeling patterns and applied these methods to the human maxilla to better understand its development at the micro- and macroscopic levels. We used a cross-sectional ontogenetic series of 47 skulls of known calendar age, ranging from birth to 12 years, from a population of European ancestry. Surface histology was employed to record and quantify formation and resorption on the maxilla, and digital maps representing each individual's bone modeling patterns were created. Semilandmark geometric morphometric (GM) methods and multivariate statistics were used to analyze facial growth. Our results demonstrate that surface histology and GM methods give complementary results, and can be used as an integrative approach in ontogenetic studies. The bone modeling patterns specific to our sample are expressed early in ontogeny, and fairly constant through time. Bone resorption varies in the size of its fields, but not in location. Consequently, absence of bone resorption in extinct species with small sample sizes should be interpreted with caution. At the macroscopic level, maxillary growth is predominant in the top half of the bone where bone formation is mostly present. Our results suggest that maxillary growth in humans is highly constrained from early stages in ontogeny, and morphological changes are likely driven by changes in osteoblastic and osteoclastic rates of expression rather than differences in the bone modeling patterns (i.e. changes in location of formation and resorption). Finally, the results of the micro- and macroscopic analyses suggest that the development of the canine fossa results from a combination of bone resorption and bone growth in the surrounding region.