Novel Parameter in Pre-Surgical Orthodontic Preparation: A Retrospective Study on the Role of the Upper Incisor Position and a Morphological Evaluation of the Anterior Nasal Spine.

The position and inclination of the incisors play a crucial role in achieving optimal outcomes in orthodontic and orthognathic surgical treatment, given their impact on facial aesthetics. Background/objectives: Due to numerous distorting factors that affect the reliability of the ANB angle, the aim of the present work is to evaluate a more constant parameter over time, the anterior nasal spine (ANS), and explore whether aligning the incisal margin of the upper incisors with the anterior nasal spine could be a reliable indicator for achieving appropriate labial support in pre-surgical orthodontic preparation. Methods: From a pool of 500 cone beam computed tomography (CBCT) scans, 50 CBCT examinations displaying a Class 1 skeletal pattern (ANB = 2° ± 2°) with an intermediate (3.2-4 mm) or mixed (4-6 mm) sagittal maxillary position (MX), as determined by the 3D multiplanar total face approach (TFA), were selected and compared with CBCT examinations randomly chosen from the initial pool. Moreover, 12 landmarks were identified, and measurements were automatically obtained, using software, and recorded. Mean and standard deviation values were calculated for each sample. A comparison was made between the two samples, aligning the results with the morphological analysis of the anterior nasal spine and the sagittal position of the upper maxilla. Results: In Class 1 subjects, the distance between the incisal margin and the plane passed in relation to the anterior nasal spine should range between -1 mm and 1 mm, aligned with or slightly ahead of the anterior nasal spine or slightly ahead of this limit. Conclusions: The anterior nasal spine can serve as a reliable reference point for planning the position of the upper incisors, with excessive proclination or retroclination from this reference point deemed unacceptable.

The nasal spine suture: A novel approach for membrane stabilization.

BACKGROUND: Current evidence acknowledges guided bone regeneration (GBR) as a predictable therapeutic modality in the augmentation of a deficient alveolar ridge. Such deficiencies often reveal inadequate bone volume to support implant placement in a position amenable to prosthetic reconstruction. Additionally, an evolving body of literature demonstrates that membrane fixation may lead to improved clinical bone gain through positively influencing blood clot formation, stability, and the eventual osteogenic potential of the defect. Alternative benefits to membrane fixation, such as reduced graft displacement and reduction in wound micromotion, have also been cited as mechanisms for an increased regenerative response. METHODS AND RESULTS: The aim of this report was to present a case, including diagnosis, treatment, and follow-up for the reconstruction of a horizontal ridge deficiency. The patient's deficiency in ridge volume was found to be a developmental sequelae of lateral incisor agenesis, resulting in an underdeveloped midfacial region of the alveolar process subjacent to sites #7 and #10. The fixation protocol outlined in this report demonstrated adequate horizontal ridge augmentation to facilitate future prosthetic reconstruction with the use of implants. CONCLUSIONS: Numerous protocols have been established in an attempt to achieve effective barrier membrane stabilization for bone augmentation procedures. However, some techniques are poorly suited for the anatomically challenging region of the anterior maxilla. A case report describing the utilization of the anterior nasal spine for anchorage of a membrane-stabilizing suture may present a novel, safe, and effective technique for stabilizing the intended region of augmentation, as well as preventing graft migration beyond the membrane-maxilla interface. Key points Regarding guided bone regeneration (GBR) procedures, micromotion of the membrane or of the underlying particulate graft may negatively influence the volume of the augmented site. The ability to adequately stabilize the graft-membrane interface is recognized as a necessary prerequisite to predictably achieve optimal surgical outcomes. To the authors' knowledge, there is no clinical or scientific evidence regarding the use of the anterior nasal spine for membrane anchorage in maxillary GBR procedures, and thus a novel approach to membrane stabilization is introduced.

Evaluation of Optimal Insertion Sites and Angles for Orthodontic Mini-Implants at the Anterior Nasal Spine Region Based on Cone-Beam Computed Tomography.

BACKGROUND: To infer the optimal angulation and height level of mini-implant insertion in the anterior nasal spine (ANS) region from alveolar bone depth (BD) and labial cortical bone thickness (CBT) through cone-beam computed tomography (CBCT), the influences of sex, age, and growth pattern on BD, CBT, and the starting point of the ANS were examined. MATERIAL AND METHODS: BD and CBT were measured on CBCT median sagittal images at specific angles (0, 15, 30, 45, and 60 degrees) to simulate the angulation of insertion. The height level of the first axial image with obvious bone ridge was recorded as the start of ANS. RESULTS: The average height of ANS start was 9.42 mm from the alveolar bone crest between the central incisors. The variations in height level and insertion angle combined, or either of them individually, significantly influenced BD and CBT, demonstrating overall decreasing trends (p < 0.001). BD was not influenced by sex, age, or growth pattern (p > 0.05). However, CBT was found to be correlated with sex and growth pattern, while the height level of ANS start was associated only with growth pattern, particularly in hypodivergent patients (p < 0.05). CONCLUSION: The recommended insertion height level is 14-16 mm from the alveolar bone crest and the recommended angulation is 30-45°. An innovative inequity in the relationship between a certain height level and the insertion angulation is proposed.

Cone-Beam Computerized Tomography Evaluation of the Relationship between Orthodontic Vertical Direction Parameters and the Distance from the Apex of the Upper Central Tooth to the Nasal Floor and Anterior Nasal Spine.

The aim of this study was to examine the relationship between the vertical cephalometric values and the distance from the apex tip of the upper central tooth (U1A) to the anterior nasal spine (ANS) and nasal floor (NF) using cone-beam computerized tomography (CBCT). One hundred and twenty-two patients who applied to the Department of Orthodontics between January 2011 and June 2019 were included. The distances between the U1A and the NF and ANS were measured using CBCT. Statistical significance was considered as p < 0.05. Of the 122 individuals, 73.8% (n = 90) were female and 26.2% (n = 32) were male, with a mean age of 22.8 ± 3.3 years. A statistically significant moderate positive correlation was found between the mean NF-U1A values and the N-Me, ANS-Me, ANS-Gn, S-Go, and N-ANS measurements (p < 0.01). A statistically significant positive correlation was found between the mean ANS-U1A values and the Ar-Go-Me, total posterior angles, N-Me, SN/GoGn and Y-axis angle, ANS-Me, and ANS-Gn measurements (p < 0.01). The distance from the U1A to the ANS and NF was related to the orthodontic vertical direction parameters. The ANS-U1A and NF-U1A distances can serve as reference points for identifying the orthodontic vertical growth pattern from CBCT scans.

Metric evaluation of the anterior nasal spine to estimate sex and population group in South African individuals.

INTRODUCTION: The anterior nasal spine is a pointed, midline projection of the maxilla. This bony structure dictates the overlying soft tissues providing the phenotypic features of the nose and upper lip and determines the differences in the mid-face morphology. Little data is available on the metric features of the Anterior nasal spine (ANS). This study aimed to perform metric evaluations of the ANS of white and black South African males and females to ascertain if morphological variations exist and if the differences are viable for the use in sex and population identification. MATERIALS AND METHODS: The sample included 100 CBCT images for each population and sex group. Linear and angular measurements of the ANS were recorded in both the sagittal and axial planes. RESULTS: Classification decision trees (pruned) were fitted to ascertain the relationship between population group, sex and the ANS measurements including and excluding age. For population group, all the ANS measurements were statistically significant for females but in males, all the ANS measurements were significant when performed individually. However, when fitted to the classification tree, Sagittal 2 did not show any statistical significance. When considering sex, only 2 of the ANS measurements (Sagittal 2 and Axial 1) were found to be significant. The results did not differ significantly when comparing the decision trees including and excluding age. CONCLUSIONS: White South African individuals presented with a longer ANS that produced a more acute angle whereas black South African individuals presented with a shorter ANS and a more obtuse angle. Additionally, males presented with a longer ANS compared to females. ANS measurements were found to be more relevant for population discernment than for sex.

Evaluation of optimal anterior-posterior position of upper incisors through ANS point: a retrospective study on a Chinese sample.

OBJECTIVES: This study was designed to determine the optimal anterior-posterior (AP) position of upper incisors through Anterior Nasal Spine (ANS) point. MATERIALS AND METHODS: Lateral cephalometric radiographic images of 690 patients were collected and divided into a derivation group and a validation group, and the former were subdivided into a proper AP position (PAP) group and an improper AP position (iPAP) group. The distance from facia-axis (FA) point of upper incisors to the line perpendicular to Frankfort horizontal (FH) plane through ANS (FA-ANS) was measured, and the relationship between FA-ANS and several cephalometric indices were studied through Pearson correlation analysis. Receiver operating characteristic (ROC) curves for different clinical indices were analyzed to evaluate the diagnostic efficiency of optimal AP position of upper incisors. RESULTS: The average value of FA-ANS in PAP group was 0.57±1.99, which was significantly different from FA-ANS in iPAP group. Cephalometric indices such as U1-NA, U1-SN, AB-NPo, UL-TVL, Wits, and ANB were found to be correlated with FA-ANS. The receiver operating characteristic (ROC) curves represented a greater diagnostic efficiency of FA-ANS compared with other clinical indices. CONCLUSIONS: ANS point, as a stable skeletal landmark, could be used to access an optimal AP position of upper incisors, providing aids to clinical diagnosis and treatment goal determination for clinical practice. CLINICAL RELEVANCE: A new index FA-ANS, together with other traditional indices, could help determine the optimal position of upper incisors and provide a personalized therapeutic plan.

Open Reduction of an Isolated Anterior Nasal Spine Fracture: A Case Report and Review of the Literature.

A 14-year-old girl had a midfacial trauma event caused by hitting against an opening door and experienced discomfort and swelling of the columella and upper lip. Physical examination revealed mild tenderness on light palpation without any discomfort with upper lip movement. A computed tomography scan of the maxillofacial bones with three-dimensional reconstruction showed a fracture of the anterior nasal spine with obvious leftward displacement, mild-deviation of the caudal aspect of the nasal septum, and no sign of nasal bone fracture. Open reduction and internal fixation was performed with regard to aesthetic and functional concerns, including nasal septum deviation. The postoperative course was uneventful, and healing proceeded normally without complications. Herein, we emphasize the importance of differential diagnosis of isolated anterior nasal spine fractures in patients with midfacial trauma and clinicians' strategic decision-making in treatment modalities.

Anatomical landmarks for localisation of the anterior ethmoidal artery: a combined radiological and cadaveric (endoscopic) study.

PURPOSE: The anterior ethmoidal artery is a major surgical landmark that is susceptible to iatrogenic injury during surgery of the anterior ethmoidal sinus, frontal sinus, and skull base. The present study aimed to define the location of the anterior ethmoidal artery in relation to specific anatomical landmarks using radiological imaging and endoscopic dissection. METHODS: Eighty-six anterior ethmoidal arteries were assessed using computed tomography scans (bilateral analyses) and forty anterior ethmoidal arteries were assessed using cadaveric specimens (bilateral analyses). The skull base, anterior nasal spine, anterior axilla of the middle turbinate, and nasal axilla were morphometrically analysed to determine their reliability as anterior ethmoidal artery landmarks. RESULTS: Distances to the skull base, anterior nasal spine, and nasal axilla displayed statistically significant differences between sexes and sides (p < 0.05). All landmarks demonstrated excellent reliability as anatomical landmarks for the localisation of the anterior ethmoidal artery, radiologically and endoscopically (ICC values ranged from 0.94 to 0.99). CONCLUSION: The middle turbinate axilla was the most reliable landmark, due to the lack of statistically significant differences according to sex and laterality, and the high inter-rater agreement between measurements. Anatomical knowledge of variations and relationships observed in the present study can be applied to surgeries of the anterior ethmoidal sinus, frontal sinus, and skull base to improve localisation of the anterior ethmoidal artery, preoperatively and intraoperatively, and avoid iatrogenic injury of the vessel.

Bilateral Inverted Mesiodens: A Rare Case Evaluated by Cone-Beam Computed Tomography.

Mesiodens is the most commonly occurring supernumerary tooth between the two maxillary central incisors. Mesiodens can be inverted, impacted, or placed buccally or palatally between the two maxillary central incisors. It mostly occurs unilaterally and rarely occurs bilaterally. We describe a rare occurrence of such a bilateral inverted mesiodens extended near the anterior nasal spine, evaluated by cone-beam computed tomography.

CT Diagnosis of the Fracture of Anterior Nasal Spine.

OBJECTIVE: To study anterior nasal spine fractures, including the incidence, missed diagnosis rates, and relationship with shapes using computed tomography (CT). METHODS: Two hundred cases of axial CT images performed for maxillofacial trauma were reviewed. The incidence, correct, and missed diagnosis rates of anterior nasal spine fractures were studied. The relationship between the fracture and the shape of the anterior nasal spine was also analyzed. RESULTS: The rate of anterior nasal spine fractures was 22.00% (44 of 200). The diagnostic accuracy was 4.55% (2 of 44) and the missed diagnosis rate was 95.45% (42 of 44). The fracture rates of the double rod, single rod, triangle, and irregular anterior nasal spine were 33.85% (22 of 65), 32.26% (10 of 31), 12.24% (12 of 98), and 0.00% (0 of 6), respectively. The double and single rod types of anterior nasal spine were most likely to be fractured than the type of triangle (χ2 = 11.05, 6.67, P < .0167). No fracture was found in the irregular type of anterior nasal spine. CONCLUSION: Anterior nasal spine fractures are not rare and the high missed diagnostic rate results from unfamiliarity with the structure. Double and single rod types of anterior nasal spines are easy to fracture. Bony reconstruction and thin thickness of CT images are necessary for diagnosis.

Anterior Nasal Spine Relocation for Caudal Septal Deviation: A Case Series and Discussion of Common Scenarios.

BACKGROUND: Deviation of the anterior nasal spine (ANS) is a common cause of caudal nasal septal deviation. In our experience, relocation of the deviated ANS is a useful technique in the correction of the caudal septal deviation. OBJECTIVES: To describe our experience with the ANS relocation technique in isolation and in combination with other techniques for correction of caudal septal deviation. METHODS: A retrospective chart review was performed on cases of ANS relocation. RESULTS: A total of 378 patients underwent ANS relocation over 4 years. Complete straightening of the septum occurred in 312 cases (82.5%), and significant improvement with mild remnant deviation occurred in 66 cases (17.5%). No patients had severe remnant deviation. None of the patients requested for revision surgery. A total of 351 patients (92.9%) experienced significant subjective improvement in bilateral nasal airflow, while 27 patients (7.1%) experienced mild improvement in bilateral nasal airflow. None of the patients had worsened airflow after surgery. CONCLUSION: The ANS relocation technique is a useful and effective technique which can be used in isolation or in combination of other techniques for the correction of caudal septal deviation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Nasal soft tissue changes after two different approaches for surgically assisted rapid maxillary expansion.

The aim of the study was to evaluate the nasal soft tissue changes in patients who underwent surgically assisted rapid maxillary expansion (SARME) using two different surgical approaches. Thirty-two patients were included in the study, and divided into two groups according to the type of surgical approach: in group A (n=17), SARME performed with standard Le Fort I circumvestibular approach with alar base cinch and anterior nasal spine (ANS) exposure; and in group B (n=15) operations were performed with the same standard Le Fort I circumvestibular approach with only alar base cinch. Measurements of height and width of the philtrum, nasal and subnasal width, and columella width were taken from three-dimensional facial images obtained before surgery (T1), after the distraction phase (T2) and 6 months postoperatively (T3). The mean maxillary expansion was 7.3±0.7mm for group A and 7.5±1.5mm for group B, without any significant difference between groups (P=0.59). Both groups presented an increase in all vaules in T2 and T3. The approach used in group A resulted in smaller changes in the columella width. The results of the present study show that there is no need for intraoperative releasing of the soft tissues around the anterior nasal spine during SARME if columella width is sufficient. However, further randomized studies based on large patient groups are needed before final conclusions on this topic can be reached.

A novel and cost-effective technique for securing the nasal septum to the anterior nasal spine in septoplasty and/or rhinoplasty surgery.

Septoplasties and septorhinoplasties are common procedures in otolaryngology, aimed at addressing septal and/or bony pyramidal deflections to improve functional and cosmetic outcomes. The nasal septum as well as regulating air flow provides structural support to the nasal tip. The attachment of the nasal septum to the anterior nasal spine must be structurally resilient to prevent saddling or tip ptosis. This can be achieved by direct attachment with absorbable suture material to the periosteum of the anterior nasal spine or a drill fitted with 0.6 mm diamond tip burr (Ultrabur, Invotec International), to create channel through which the nasal spine can be secured to the anterior nasal spine. We describe a novel, and cost-effective alternative utilising a blunt fill needle and simple absorbable suture. A blunt fill needle (Sol-Millenium®, cost £0.03 per unit) is passed through to form a securing channel. The neoseptum is then secured using a figure-of-eight suture. Our novel technique enables the nasal septum to be secured to the anterior nasal spine in a cost effective and efficient manner.

A study of correlation between posterior palatal seal width and soft palatal angulation with palatal contour.

CONTEXT: The spatial relationship of posterior palatal seal (PPS) width and vibrating lines varies among individuals. Such variability could be related to contour of the palate. AIMS: The study was carried out to evaluate the relationship between PPS width of the patient intra-orally and cephalometric tracing of the same patient. Second part of the study was formulated to determine whether the anterior and posterior vibrating lines can be distinguished as two separate lines by different observers. MATERIALS AND METHODS: A lateral cephalogram was made to trace the hard and soft palatal contour, and the angle of the palatal contour was measured with the v-ceph program. Correlation analysis was conducted to examine the relationship between the distance from anterior to posterior vibrating lines and the angle of the palatal contour at the junction of the hard and soft palate. STATISTICAL ANALYSIS USED: The data were analyzed using the Karl Pearson Correlation test. RESULTS: Correlation of the angle of the palatal contour to PPS width, showed perfectly positive value; whereas, correlation of angle between anterior nasal spine-posterior nasal spine (ANS-PNS) and PNS-Uvula (U) to PPS width showed partially positive value. CONCLUSION: The correlation of angle between hard tissue and soft tissue to PPS width, and the angle between ANS-PNS and PNS-U to PPS width, increases with an increase in PPS width.

The anterior maxilla as a potential source of bone grafts: a morphometric cone beam computed tomography analysis of different anatomical areas.

The aim of this research was to use cone beam computed tomography (CBCT) to analyze the volume, density, and morphology of the bone available in the anterior region of the maxilla, in order to investigate its potential as a source of bone grafts. Three independent zones were evaluated: the palatine process of the maxilla (PPM), anterior nasal spine (ANS), and subnasal bone (SN). The latter was analyzed bilaterally (SNR, SNL). One hundred CBCT scans were evaluated. The morphometric analysis comprised volumetric and subsequent automatic density calculations, as well as linear measurements. Potential correlations among these parameters, including demographic characteristics, were investigated. The study comprised 52 women and 48 men (mean age 49.6±14.5 years). The calculated bone volume averaged 2.41±0.72cm(3) for PPM, 0.46±0.16cm(3) for ANS, 0.58±0.2cm(3) for SNR, and 0.57±0.21cm(3) for SNL. The anterior region of the maxilla can provide a considerable amount of bone volume from different anatomical zones and should be regarded as a potential donor site for the regeneration of maxillary atrophic bones. Further investigation is required before these findings can be applied in the routine clinical setting.

Predicting the limits of the endoscopic endonasal approach in children: a radiological anatomical study.

OBJECT The endoscopic endonasal approach (EEA) has been established as an alternative approach to craniovertebral junction (CVJ) pathology in adults. The authors have previously described the nasoaxial line (NAxL) as an accurate predictor of the lower limit of the EEA to the CVJ in adults. The surgical anatomy limiting the EEA to the pediatric CVJ has not been well studied. Furthermore, predicting the lower limit of the EEA in various pediatric age groups is important in surgical planning. To better understand the anatomy affecting the EEA to the CVJ, the authors examined the skull base anatomy relevant to the EEA in children of different age groups and used the NAxL to predict the EEA lower limit in children. METHODS Axial brain CT scans of 39 children with normal skull base anatomy were reconstructed sagittally. Children were divided into 4 groups according to age: 3-6, 7-10, 11-14, and 15-18 years old. The intersection of the NAxL with the odontoid process of C-2 was described for each group. Analyses of variance were used to estimate the effect of age, sex, interaction between age and sex on different anatomical parameters relevant to the endonasal corridor (including the length of the hard palate [HPLe]), dimensions of choana and piriform aperture, and the length of the NAxL to C-2. The effect of the HPLe on the working distance of NAxL to the odontoid was also estimated using analysis of covariance, controlling for age, sex, and their interaction. RESULTS The NAxL extended to the odontoid process in 38 of the 39 children. Among the 39 children, the NAxL intersected the upper third of the odontoid process in 25 while intersecting the middle third in the remaining 13 children. The measurements of the inferior limits did not differ with age, varying between 9 and 11 mm below the hard palate line at the ventral surface of C-2. Significant increases in the size of the piriform aperture and choana and the HPLe were observed after age 10. The HPLe predicted the length of the NAxL (p < 0.0001). CONCLUSIONS The caudal limit of the EEA extends as far as the middle third of the odontoid process in children, as predicted by the NAxL. The most prominent increase in the size of the choana and piriform aperture occurs after age 10. The HPLe is a significant predictor of the working distance to C-2. Utilizing the NAxL preoperatively may help in planning the EEA to the CVJ in children.

THE ANATOMY OF THE BONY PART OF THE HUMAN EXTERNAL NOSE IN THE CHINESE / 解剖学报

The bony part of the external nose was observed and measured in 150 Chinese adult skulls (male 100, female 50), The results are as follows.1. The nasion consists of the upper end of the nasal bone and the nasal part of the frontal bone. It is the anterior wall of the frontonasal canal. The average thickness of this wall is 8.08?0.11 mm.2. Features of the nasal bone: 144 cases (288 sides, 96.00％) are oblong and 4 cases (8 sides, 2.67％) are triangular in shape, in 2 cases (4 sides, 1.33％) the right sides are oblong and the left sides are triangular in shape. The length, width and thickness of the nasal bone were measured.3. The frontal process of the maxilla, according to the feature and clinical importance of the topographical characteristics, can be divided into upper, middle and lower portions. (1) The upper portion is a somewhat flat bony process, its anterior surface is flat and posterior surface is rough, which related to the ethmoid cell closely. The average width and thickness of this portion are 8.45?0.06mm and 5.72?0.09mm respectively. (2) The middle portion is the surgical area of the nasolacrimal fistulation. The average width of the part anterior to the anterior lacrimal crest (nasal part) is 6.77?0.05mm; and the average width of the part posterior to the crest (lacrimal part) is 4.97?0.04mm. The average thickness of the middle point of the anterior lacrimal crest is 4.68?0.08mm. (3) The lower portion is the transitional area of the frontal process and the corpus of the maxilla. It is a three-facet pyramid with an obtuse sulcus on its anterior lateral surface the nasofacial sulcus, which is the landmark between the external nose and face. The average width from the lower end of the nasomaxillary suture to the bottom of the sulcus is 8.16?0.04mm. The average thickness is 1.70?0.02mm.4. The margin of the piriform aperture: (a) The upper part of the margin formed by the lower border of the nasal bone, the upper border of the upper lateral cartilage of the nose digs behind it and joins each other by a syndesmosis; (b) the width of the lateral part of this margin was measured from the free border of the margin to the anterior end of the inferior turbinate, the average width is 2.62?0.07mm; (c) the lower margin of the piriform aperture and the anterior nasal spine, according to the anthropological classification, were observed and their clinical significance were discussed.