Nasal Spine Research Articles

Nasomaxillary Expansion by Endoscopically-Assisted Surgical Expansion (EASE): An airway centric approach

The aim of this study was to analyze the skeletal, dental and airway changes with endoscopically assisted surgical expansion (EASE) to widen the nasomaxillary complex for the treatment of sleep apnea in adults. One hundred and five consecutive patients underwent EASE. Cone beam computed tomography (CBCT) was conducted preoperatively and within four weeks after the completion of the expansion process. Computational fluid dynamic (CFD) analysis was performed on 20 randomly selected patients to assess airway flow changes. One hundred patients (67 males) with the mean age of 35.0±13.5 years (17-64 years) had completed pre- and post-expansion imaging. Ninety-six patients (96%) had successful expansion defined as separation of the midpalatal suture at least 1 mm from anterior nasal spine (ANS) to posterior nasal spine (PNS). The nasal cavity expansion was 3.12±1.11 mm at ANS, 3.64±1.06 mm at first molar and 2.39±1.15 mm at PNS. The zygoma expansion was 2.17±1.11 mm. The ratio of dental expansion to skeletal expansion was 1.23:1 (3.83 mm:3.12 mm) at canine and 1.31:1 (4.77 mm:3.64 mm) at first molar. CFD airway simulation showed a dynamic change following expansion throughout the airway. The mean negative pressure improved in the nasal airway (from -395.5±721.0 to -32.7±19.2 Pa), nasopharyngal airway (from -394.2±719.4 to -33.6±18.5 Pa), oropharyngeal airway (from -405.9±710.8 to -39.4±19.3 Pa) and hypopharyngeal airway (from -422.6±704.9 to -55.1±33.7 Pa). The mean airflow velocity within the nasal airway decreased from 18.8±15.9 to 7.6±2.0 m/s and the oropharyngeal airway decreased from 4.2±2.9 to 3.2±1.2 m/s. The velocity did not change significantly in the nasopharyngeal and hypopharyngeal regions. EASE results in expansion of the midpalatal suture from the ANS to PNS with a nearly pure skeletal movement of minimal dental effect. The expansion of the nasomaxillary complex resulted in the widening of the nasal sidewall throughout the nasal cavity. The improved air flow dynamics was demonstrated by CFD simulation.

Update of the classification of midpalatal suture behaviour after surgically assisted rapid maxillary expansion using computed tomography

The aim of this study was to update the midpalatal suture classification after surgically assisted rapid maxillary expansion (SARME) using computed tomography (CT). Thirty-five patients with a transverse maxillary deficiency and unilateral or bilateral posterior crossbite underwent SARME with osteotomy of the pterygoid apophysis of the sphenoid. CT was performed before installation of the Hyrax expander appliance and after the final activation. Opening of the midpalatal suture was classified into three types: type I, total midpalatal suture opening from anterior nasal spine (ANS) to posterior nasal spine (PNS); type II, partial midpalatal suture opening from ANS to the transverse palatine suture, with partial or non-existent opening of the midpalatal suture posterior to the transverse palatine suture; type III, complete maxillary opening from ANS, but not of PNS, because a paramedian fracture completed the opening of the hard palate. Type I was observed in 42.8% of the patients, type II in 40%, and type III in 17.2%. Opening of the transverse palatine suture was found in all midpalatal suture opening patterns and was more frequent in type III, followed by type II and type I. CT was used to update the classification of midpalatal suture patterns, with the inclusion of type III: total opening of the hard palate due partly to opening of the midpalatal suture and partly to a paramedian fracture.

Simultaneous Le Fort III and Le Fort I Osteotomy: Surgical Outcomes and Clinical Parameters.

Simultaneous Le Fort III/I (LF III/I) osteotomies are often performed when a differential advancement of the upper and lower midface is needed. This study aims to evaluate midface position preoperative and 1 week postoperative in patients with severe midface hypoplasia. In addition, this study aims to compare the planned surgical movements to the actual postoperative movements. A retrospective review was conducted using cephalometry for patients treated with a simultaneous LF III/I osteotomy at a single institution. Osteotomies were performed during 1980-2018 on skeletally mature patients with a craniofacial syndrome, with clinical and radiographic follow-up available. Twelve patients met the inclusion criteria with a mean age of 20.2±6.4 years. Treatment resulted in statistically significant anterior movements related to Orbitale, anterior nasal spine, A Point, and the upper incisor tip, and inferior movements related to anterior nasal spine, A Point, upper and lower incisor tips, B point, and pogonion. Stability after 1 year showed only statistically significant changes at ANB. The predictable error for planned movements versus actual movements was greater in the vertical plane than the horizontal plane. A simultaneous LF III/I osteotomy significantly improved the midface position and occlusal relationship in syndromic patients with midface hypoplasia in a predictable manner. Further multicenter studies with larger sample sizes are needed to validate the conclusions.

Does Clockwise Rotation of Maxillomandibular Complex Using Surgery-First Approach to Correct Mandibular Prognathism Affect Surgical Movement and Stability?

Orthognathic surgery (OGS) using the surgery-first approach (SFA) can decrease treatment time and increase patient satisfaction. Clockwise rotation (CWR) of the maxillomandibular complex to correct mandibular prognathism leads to optimized functional, aesthetic, and stable outcomes. This study examined the combined effect of SFA and CWR of the maxillomandibular complex to correct mandibular prognathism by comparing the surgical movement before (T0) and immediately after OGS (T1) and the stability between T1 and 12 months after OGS (T2). This prospective cohort study enrolled patients with skeletal Class III malocclusion who underwent SFA involving Le Fort I osteotomy and bilateral sagittal split osteotomy, with or without genioplasty. Based on the occlusal plane (OP) change at T0-T1, the patients were divided into CWR (OP>4°) and control (C) groups (OP≤4°). The predictor variable was OP change at T0-T1. The primary outcome variable was the stability of pogonion (Pog) at T1-T2. The covariates included demographic factors, cephalometric measurements (anterior facial height, posterior facial height, OP, mandibular plane angle, incisor mandibular plane angle, overjet, and overbite), and 3-dimensional landmark displacement (anterior nasal spine, A-point, upper central incisor, upper first molar, lower central incisor, lower first molar, Pog, gonion, and condylion). An independent t-test was used to compare between these 2 groups when appropriate. The level of significance was set at P<.05. The sample included 28 patients (17 females) in the C group and 36 (24 females) in the CWR group; the mean ages were 23.89±3.35 and 24.08±4.02years, respectively. For the surgical movement at T0-T1, the CWR group showed an association with vertical movement of the maxilla at posterior nasal spine (P=.005), anterior nasal spine (P<.001), and A-point (P<.001) and horizontal backward movement of the mandible at B-point (P<.001), Pog (P<.001), and gonion (P=.042). At T1-T2, all landmarks remained stable without clinically significant difference between the 2 groups. Surgical movement in the CWR group could vertically displace the maxilla and setback mandible more than that in the C group. Postoperative skeletal stability remained the same between the 2 groups at 1year after OGS.

Accuracy of Maxillary Positioning During Orthognathic Surgery: A Comparison of Web-based 3-Dimensional Virtual Surgical Planning and Actual Outcomes.

To determine the accuracy of planned maxillary positioning by virtual surgery by comparing planned and actual postoperative outcomes. Twenty patients who underwent 2-jaw orthognathic surgery performed by a single surgeon from May 2017 to December 2020 were the subjects of this retrospective study. The coordinates of reference points in horizontal, sagittal, and coronal planes as determined by virtual surgery were compared with those of actual surgical outcomes. The reference points used were as follows: #16 mesiobuccal cusp tip (#16), #26 mesiobuccal cusp tip (#26), and #11 mesial tip (U1); anterior nasal spine; and posterior nasal spine. Three-dimensional linear distances between the reference point on which virtual surgery was performed and the reference point after the actual operation was calculated. Of the 20 patients, there were 11 males and 9 females of average age 20.65±2.41 years. Three-dimensional printed wafers had high accuracy with a maximum difference of 0.3mm. No significant difference was observed in horizontal or coronal planes for any reference point, but a significant difference was observed in the sagittal plane. However, positional differences between planned and actual reference points were all <1mm. Virtual surgical planning and 3-dimensional printed wafer achieved excellent maxillary positioning accuracies after orthognathic surgery.

Facial asymmetry in children with either unilateral lambdoid craniosynostosis or positional posterior plagiocephaly.

In unilateral lambdoid craniosynostosis (ULC), the posteriorly situated lambdoid suture of the cranial vault fuses prematurely. Positional posterior plagiocephaly (PPP) causes flattening of the posterior side of the head, either through external forces or through underlying differences in brain development. Both conditions cause occipital flattening of the head, but the aetiology is different. Eight ULC children were compared with 16 sex- and age-matched PPP children. 3D computer tomography scans of all 24 children were analysed with Dolphin imaging software. The location and symmetry of the temporomandibular joint (Co), and the symmetry of the maxillary anterior nasal spine (ANS) and the mandibular symphysis (Pgn) were analysed. Furthermore, the mandibular bone (Co-Pgn) length, corpus length, ramus height, positional changes in the external acoustic meatus (PoL) and the distance from the orbital margin to the articular fossa were measured. In all eight ULC children, the Co was anteriorly displaced on the affected side compared with the unaffected side. In all ULC and PPP children, the ANS, which is considered the bony maxillary midpoint, was shifted towards the affected side. In all ULC children, the mandibular bone (Co-Pgn) was shorter on the affected side. The PoL was antero-inferiorly positioned in all ULC children on the affected side compared with the unaffected side. Our results show that both types of posterior plagiocephaly are associated with an asymmetric position of the Co and asymmetry of the mandible and maxilla. Facial asymmetry was more frequently seen in ULC than PPP children.

Nasomaxillary Expansion by Endoscopically-Assisted Surgical Expansion (EASE): An airway centric approach

The aim of this study was to analyze the skeletal, dental and airway changes with endoscopically assisted surgical expansion (EASE) to widen the nasomaxillary complex for the treatment of sleep apnea in adults. One hundred and five consecutive patients underwent EASE. Cone beam computed tomography (CBCT) was conducted preoperatively and within four weeks after the completion of the expansion process. Computational fluid dynamic (CFD) analysis was performed on 20 randomly selected patients to assess airway flow changes. One hundred patients (67 males) with the mean age of 35.0±13.5 years (17-64 years) had completed pre- and post-expansion imaging. Ninety-six patients (96%) had successful expansion defined as separation of the midpalatal suture at least 1 mm from anterior nasal spine (ANS) to posterior nasal spine (PNS). The nasal cavity expansion was 3.12±1.11 mm at ANS, 3.64±1.06 mm at first molar and 2.39±1.15 mm at PNS. The zygoma expansion was 2.17±1.11 mm. The ratio of dental expansion to skeletal expansion was 1.23:1 (3.83 mm:3.12 mm) at canine and 1.31:1 (4.77 mm:3.64 mm) at first molar. CFD airway simulation showed a dynamic change following expansion throughout the airway. The mean negative pressure improved in the nasal airway (from -395.5±721.0 to -32.7±19.2 Pa), nasopharyngal airway (from -394.2±719.4 to -33.6±18.5 Pa), oropharyngeal airway (from -405.9±710.8 to -39.4±19.3 Pa) and hypopharyngeal airway (from -422.6±704.9 to -55.1±33.7 Pa). The mean airflow velocity within the nasal airway decreased from 18.8±15.9 to 7.6±2.0 m/s and the oropharyngeal airway decreased from 4.2±2.9 to 3.2±1.2 m/s. The velocity did not change significantly in the nasopharyngeal and hypopharyngeal regions. EASE results in expansion of the midpalatal suture from the ANS to PNS with a nearly pure skeletal movement of minimal dental effect. The expansion of the nasomaxillary complex resulted in the widening of the nasal sidewall throughout the nasal cavity. The improved air flow dynamics was demonstrated by CFD simulation.

Surgical Accuracy of 3D Virtual Surgery and CAD/CAM-Assisted Orthognathic Surgery for Skeletal Class III Patients.

Orthognathic surgery is an effective surgical method to achieve functionality and facial esthetics for mandibular prognathism. If surgery is performed with a conventional method, errors may occur in the surgical preparation process and the surgical procedures, and there is a limitation in that the accuracy of surgery is determined according to the surgeon's experience and tactual sense. However, with the recent development of three-dimensional (3D) virtual planning and CAD/CAM technology, more 3D and predictable surgical planning and more accurate and time-saving surgery have become possible. The purpose of this study is to evaluate the surgical accuracy of 3D Virtual Surgery, CAD/CAM-Assisted Orthognathic surgery for Skeletal Class III Patients. The study included 18 patients who had undergone orthognathic surgery for skeletal class III malocclusion from January 2020 to December 2021. To evaluate the accuracy of the virtual planning, 3D facial cone-beam computed tomography taken immediately after surgery (T1) and virtual surgery data (Tv) were superimposed in each patient. Landmarks were set on each of the maxillary segment, mandibular distal segment, and left and right mandibular proximal segment, and the difference between T1 and Tv was compared 3D on the x , y , and z -axis. (ΔT: T1-Tv). As a result, the average distance between Tv and T1 at each landmark, all landmarks except for the posterior nasal spine of the maxillary segment showed <1mm. In particular, the differences across the x and z -axis were very small, while the difference across the y -axis tend to be large. The comparison of the position of each segment in virtual surgery and actual surgery was as follows. It can be seen that all segments were located slightly downward, and the medial pole of the mandibular proximal segment was located posterolateral and the lateral pole was located anteromedial after the actual surgery compared with the virtual planning. It means that the proximal segment was slightly rotated, but the difference was within 1mm, so it can be considered that the surgery was accurate. Base on this study, orthognathic surgery using 3D virtual surgery planning and CAD/CAM technologies was very accurate. By applying these cutting-edge technologies to clinical practice, it was possible not only to increase the predictability of surgery but also to improve the convenience of surgery. Therefore, it is thought that it will be important for clinicians to make continuous efforts to applicate cutting-edge technologies to be developed in the future to patient diagnosis and surgery.

Anatomical Study of Domain Rescue of Palatal Length in Patients With a Wide Cleft Palate: Buccal Flap Reconstruction in Primary Palatoplasty.

This study characterizes the potential loss of velar length in patients with a wide cleft and rescue of this loss of domain by local flap reconstruction, providing anatomic evidence in support of primary lengthening of the soft palate during palatoplasty. A retrospective review was conducted of all patients with a cleft palate at least 10mm in width, who underwent primary palatoplasty with a buccal flap prior to 18 months of age over a 2-year period. All patients underwent primary palatoplasty with horizontal transection of the nasal mucosa, which was performed after nasal mucosa repair, but prior to muscular reconstruction. The resulting palatal lengthening was measured and the mucosal defect was reconstructed with a buccal flap. Of the 22 patients included, 3 (13.6%) had a history of Pierre Robin sequence, and 5 (22.7%) had an associated syndrome. No patients had a Veau I cleft, 7 (31.8%) had a Veau II, 12 (54.5%) had a Veau III, and 3 had (13.6%) a Veau IV cleft. All patients had a right buccal flap during primary palatoplasty. The mean cleft width at the posterior nasal spine was 10.6 ± 2.82mm, and mean lengthening of the velum after horizontal transection of the nasal mucosa closure was 10.5 ± 2.23mm. There were 2 (9.1%) fistulas, 1 (4.5%) wound dehiscence, 1 (4.5%) 30-day readmission, and no bleeding complications. Patients with a wide cleft palate have a potential loss of 1cm velar length. The buccal flap can rescue the loss of domain in palatal length, and potentially improve palatal excursion.

A Simple Clinical Application for Locating the Anterior Ethmoidal Artery Using the Anterior Ethmoidal Foramen and the Anterior Nasal Spine

The anatomy and variations of the anterior ethmoidal artery (AEA) are clinically relevant. The anterior ethmoidal foramen (AEF) can be used to locate the initial site of the AEA, and the anterior nasal spine (ANS) is a constant bony marker in the anterior nasal atrium. However, there is no relevant research on AEF and ANS targeting the AEA. Hence, this study aimed to accurately locate the AEA through AEF and ANS using computed tomography. A total of 120 (240 sides) sinus computed tomography scans were retrospectively selected and studied. The AEA was classified into grades I, Ⅱ, and Ⅲ group based on the relationship between the AEA and the skull base. The distance between AEF and ANS and the angle between AEF-ANS and the axial plane were measured. The average distance from AEF to ANS was 58.26±3.64mm, and the corresponding angle was 60.05±5.93 degrees. The AEF-ANS distances and angles were negatively correlated with age. Moreover, the distances from AEF to ANS were significantly increased in the grade Ⅲ group compared with the grade Ⅱ group. The measurements obtained in this study add anatomic knowledge that can serve as a better intraoperative localization method of the AEA, which can help surgeons avoid relative complications during endoscopic sinus surgery.

X-Ray Cephalometric Analysis of the Effects of Angle Class II and III Malocclusion on the Upper Airway Width and Hyoid Position between Parents and Children of Uygur Nationality.

Objective The objective of this paper is to analyze the effect of angle class II and III malocclusion on the sagittal diameter of the upper airway between parents and children of Uygur nationality and to compare the degree of influence. Methods 29 Uygur adolescents with malocclusion and their fathers (mothers) were selected as our subjects via X-ray cephalometric radiograph to analyze the difference between the upper airway sagittal dimension and normal occlusion and compare the influence of malocclusion on the upper airway between parents and children. Results Compared with normal group, the vertical distance from the hyoid point to orbital-ear plane (H-FH) and vertical distance from hyoid point to the mandibular plane (H-MP) in angle class II malocclusion elevated signally, while the vertical distance from hyoid point to anterior cervical plane (H-VL), PNS-UPW, H-FH, and H-MP decreased significantly; compared with normal group: the distance between the posterior nasal spine and the upper pharynx wall (PNS-UPW), H-FH, and H-MP in angle class III malocclusion visually reduced, while PAS, and horizontal distance from the hyoid point and center point of sella turcica to orbital-ear foot (H-S), increased markedly. The impact of class II malocclusion on parents' U-MPM was greater than their children. Conclusion The oropharyngeal space of upper airway becomes smaller and hyoid shifts downwards due to class II malocclusion. Class III malocclusion results in decreased nasopharyngeal gap with hyoid to shift upward. The influence of class II malocclusion on the upper pharyngeal tract of parents was greater than their children.

Cone-beam CT evaluation of the effect of indirect anchorage of mini-screw assisted clear aligner on molar distalization

Objective: To evaluate the effect of indirect anchorage with mini-screw assisted clear aligner on molar distalization. Methods: Twenty-six adult patients [12 males and 14 females, aged 19 to 31 years, mean age (26.4±4.2) years], who were treated in the Department of Orthodontics, the Affiliated Stomatological Hospital of Nanchang University between January 2018 and September 2021, were included. All the patients were treated with clear aligner and mini-screw indirect anchorage to distalize maxillary molars. In the stage of molar distalization, the mini-implants were implanted between the buccal roots of the maxillary first molar and the second premolar, and rigidly connected to the maxillary second premolar as anchorage reenforcement. Until the first molar had distally moved to the designated position, the mini-implants were transferred to the buccal area between the first and the second molars and similar device was connected to the first molar. Cone-beam CT (CBCT) images were taken before the treatment (T0), at the maxillary first molar distally moved to the designated position (T1), and at the anterior teeth alignment finished (T2). The CBCT data were imported into Mimics 20.0 software for three-dimensional reconstruction. After correcting the head position, each reference point was determined in the multi-plane reconstruction view. The bilateral porion, the right orbitale, the nasion, and the anterior nasal spine were selected as reference points to construct the three-dimensional space coordinate system. The positions of the first molar, the second premolar, and the incisor were analyzed three-dimensionally. The three-dimensional position changes of maxillary first molars and maxillary second premolars during the stages of T0-T1, T1-T2, T0-T2, and the mesiodistal and vertical position changes of maxillary central incisors were analyzed. The statistical analysis was carried out using a one-way repeated measures ANOVA. Results: There was a significant difference in the sagittal position changes of the root and cusp of the maxillary central incisors among three time points (F=24.84, P<0.001; F=27.66, P=0.001), but no difference was observed between T0 and T1 (P>0.05). There was a significant difference in lingual retraction of the maxillary central incisor root [(2.17±0.42) mm] and cusp [(1.81±0.28) mm] between T1 and T2 (P<0.05). A significant difference was noted in the sagittal position changes of the root and crown of the maxillary second premolars among three time points (F=17.16, P=0.001; F=57.99, P<0.001). However, no statistical difference was detected between T0 and T1 (P>0.05) and the difference in maxillary second premolar distalization [root (1.95±0.42) mm, cusp (2.53±0.33) mm] was observed between T1 and T2 (P<0.05). There was a statistically significant difference in the sagittal position changes of the root and the crown of the maxillary first molar among three time points (F=9.37, P=0.002; F=140.26, P<0.001). The difference in the maxillary first molar distalization [crown (3.51±0.30) mm, root (1.98±0.25) mm] between T0 and T1 was significant (P<0.05). However, no significant difference in the sagittal position of the maxillary first molars was observed between T1 and T2 (P>0.05). There was a statistically significant difference in the vertical position of the center point of the root in maxillary first molar among three time points (F=59.06, P<0.001), while (2.28±0.24) mm of intrusion between T0 and T1 was exhibited (P<0.05). However, no significant difference was found in the vertical position of the maxillary first molars between T1 and T2 (P>0.05). There was no significant difference in other measurements among three time points (P>0.05). Conclusions: The effect of indirect anchorage with mini-screw-assisted clear aligner on molar distalization was positive.

Nasal Spine of the Frontal Bone: A Consistent Landmark for Safe Outside-In Frontal Drill-Out.

Outside-in frontal drill out entails drilling the frontal sinus floor in the midline before identifying and dissecting the frontal recesses. It is a more direct approach, especially in revision surgery or cases with challenging anatomy. The aim of this study was to highlight the anatomical and surgical concepts for easy and safe outside-in frontal drill out by a preclinical anatomic study on cadaveric heads. In addition, to review our experience with this approach over a 5-year period for challenging frontal sinus pathologies. The study included 2 sectors; a preclinical study, in which 5 cadaveric heads were dissected and studied to identify and standardize the anatomical landmarks of this approach. This was followed by a clinical case series which included 22 patients with challenging frontal sinus pathologies that were treated with this proposed approach. We concluded from the anatomic study that the nasal spine of the frontal bone (NSFB) and its anatomical orientation in relation to the nasal branch of the anterior ethmoidal artery (NBAEA) is a consistent landmark that enables the surgeon to identify the correct coronal trajectory of drilling to avoid injury of the cribriform and the skull base. The clinical case series included 22 patients that were successfully treated with the proposed approach. No intraoperative nor postoperative complications were reported in this study. Long-term follow-up showed that the frontal neo-ostium was patent in all cases (n = 22). Outside-in frontal drill-out is a safe and easy approach; especially in challenging frontal sinus pathologies; using the NSFB and its anatomical coronal orientation to the NBAEA as a consistent landmark, anterior to the skull base. This approach offers early, safe, and direct bone removal without the need for initial identification and dissection of the frontal recess.

Endonasal access to the lateral poststyloid space: Far lateral extension of an endoscopic endonasal corridor

The styloid process constitutes the posterolateral boundary for an endonasal exposure of the infratemporal fossa. This study aims to explore the feasibility of a far‐lateral extension to the lateral poststyloid space via an endonasal corridor. An endonasal dissection was performed on six cadaveric specimens (12 sides). Following an endoscopic endonasal access to the parapharyngeal space, the styloid process and the tympanic portion of the temporal bone were removed to reveal the jugular bulb and the extratemporal facial nerve. Distances from the anterior nasal spine to the relevant landmarks were measured using a surgical navigation device. Through an endonasal corridor, only the anteroinferior aspect of the jugular bulb was exposed. Conversely, the extratemporal facial nerve could be sufficiently exposed, and the deep temporal nerve could be transposed to the stylomastoid foramen. The average horizontal distances from the nasal spine to the posterior tract of V3, styloid process, and facial nerve were 79.33 ± 3.41, 97.10 ± 4.74, and 104.77 ± 4.42 mm, respectively. Access to the lateral poststyloid space via an endonasal corridor is feasible, potentially providing an alternative approach to address select lesions extending to this region. The deep temporal nerve has a similar diameter to that of the facial nerve; thus, providing potential reinnervation of the facial nerve.

Does the Rigid External Distraction Device Alter Maxillary Pitch in Cleft Maxillary Distraction?

The rigid external distraction (RED) device is reported to have the ability to three-dimensionally reposition the maxilla. The purpose of this study is to assess the ability of RED to intentionally alter the maxillary pitch. Retrospective cohort study. Institutional practice. A retrospective chart review was completed over the past 12 years and a total of 50 patients met the inclusion criteria. Cephalometric changes and alteration in palatal plane angle. Cephalometric analysis of standardized landmarks was completed on calibrated, standardized lateral cephalograms. Pre-distraction and post-consolidation variables were compared via a two-tailed paired t-test. The mean age at surgery of 12.2 ± 3.2 years. Through distraction osteogenesis (DO), the maxilla was moved anteriorly with a mean distraction distance of 8.4 ± 4.8 mm. The mean change in the angles sella-nasion-A-point angle (SNA), sella-nasion-B-point angle (SNB), and A-point-nasion-B-point angle (ANB) were 10.2 ± 4.8, 0.9 ± 2.7, and 9.3 ± 4.1, respectively. The mean change in the palatal plane angle was −4.4 ± 3.7. The mean change in the vertical position of the anterior nasal spine (ANS) and posterior nasal spine (PNS) in relation to the Frankfort horizontal (FH) were −2.0 ± 4.1 mm and 1.7 ± 3.8 mm, respectively. This study documents short-term findings of RED in a large cleft lip and palate (CLP) population. Despite positioning of distraction eyelets superior to the theoretical center of resistance, a counterclockwise (CCW) rotation of the palatal plane occurred. This suggests that adjunctive methods of vector control should be considered if clockwise (CW) rotation of the palatal plane is intended with the RED device.

Assessment of Dentofacial Characteristics in Individuals with Different Midfacial Skeletal Morphologies

Abstract Introduction An orthodontist's primary objective is to diagnose and describe the characteristics of any particular malocclusion. It has been reported that when the anteroposterior dimension of the maxilla is either reduced or increased, the measured dentoalveolar and skeletal parameters gets affected in other dimensions also. Aim This study aims to assess and compare the dentofacial characteristics in individuals with different skeletal morphology (normal, retrognathic, and prognathic maxilla). Materials and Methods A total of 194 individuals in the age group of 18 to 32 years were grouped as group I (34 males, 33 females) with normal maxilla, group II (30 males, 32 females) with retrognathic maxilla, and group III (34 males, 31 females) with prognathic maxilla. The measurements of N-A and anterior nasal spine to posterior nasal spine were the basis for selecting the individuals. The dentoalveolar characteristics were assessed using 17 lateral cephalometric and 08 posteroanterior (P-A) cephalometric parameters. Results The data of the study when analyzed statistically using sample “t” test (p &lt; 0.05), revealed significant differences between the genders within the groups. All 08 characteristics measured in the P-A cephalogram showed had significant differences. Pairwise comparison between the groups was performed using the Tukey post hoc test (p &lt; 0.05) and significant differences in various dentoalveolar characteristics were observed between the groups. Conclusion Dentoalveolar and facial parameters showed a significant degree of sexual dimorphism associated with maxillary morphology in all three groups of individuals. The majority of the parameters showed male dominance, and the differences were statistically significant. Statistically significant differences were observed in dentofacial characteristics in individuals with different skeletal morphologies

Comparison of polysomnographic and cephalometric parameters based on positional and rapid eye movement sleep dependency in obstructive sleep apnea

The aim of this study is to investigate the differences in polysomnographic and cephalometric features according to positional and rapid eye movement (REM) sleep dependencies in obstructive sleep apnea patients. Standard polysomnography and cephalometric analyses were performed on 133 OSA patients. The subjects were categorized into positional and non-positional, and REM-related and not-REM-related OSA groups according to positional and REM sleep dependency on severity of sleep apnea. Polysomnographic and cephalometric parameters were compared between groups. Positional and REM-related OSA patients showed significantly lower non-supine apnea–hypopnea index (AHI), non-REM (NREM) AHI and overall AHI and higher NREM oxygen saturation (SpO2) and mean SpO2 compared to non-positional and not-REM-related OSA patients, respectively. Cephalometric features between positional and non-positional OSA patients did not show any significant differences. However, REM-related OSA patients showed significantly larger inferior oral airway space and shorter perpendicular distance between mandibular plane and anterior hyoid bone and the distance between uvula and posterior nasal spine, and narrower maximum width of soft palate than not-REM-related OSA patients. Positional and REM-related OSA patients have lower severity of sleep apnea, suggesting the possibility of lower collapsibility of the upper airway. REM sleep dependency was associated with anatomical factors, while positional dependency did not show such a tendency.

Comparison Between Cephalometric Measurements Derived from Cone Beam Computed Tomography and Lateral Cephalogram

Objective: To compare the mean craniofacial linear and angular measurements derived from cone beam computed tomography synthesized lateral cephalogram and those obtained from conventional cephalogram.&#x0D; Study Design: Comparative cross-sectional study.&#x0D; Place and Duration of Study: Armed Forces Institute of Dentistry (AFID), Rawalpindi Pakistan, from Feb 2017 to Nov 2018.&#x0D; Methodology: Sample size was 32. Following linear measurements were evaluated; anterior facial height, right side and left side of mandibular length, nasal spine length, Upper and lower incisors to A-Pog distance. These measurements were obtained by both means i.e., conventional cephalogram and cone beam computed tomography synthesized cephalogram. Each of the measurement were taken twice by the single operator with a difference of two weeks.&#x0D; Results: No significant difference was found among measurements obtained through lateral head film cephalograph and cone beam synthesized cephalograph except for mandibular length (for which p=0.04).&#x0D; Conclusions: Cone beam computed tomography synthesized lateral cephalogram can be suggested as a substitute to conventional lateral cephalogram. Especially in conditions when cone beam computed tomography is already required for treatment planning thus reducing supplementary x- ray exposure and expenditure of an additional x-ray.

Persistent pediatric obstructive sleep apnea treated with skeletally anchored transpalatal distraction

The aim of this study was to evaluate the impact of nasomaxillary expansion using skeletally anchored transpalatal distraction (TPD) in children without transverse maxillary deficiency that were previously treated by rapid palatal expansion (RPE). Twenty-nine consecutive children were treated by TPD. Twenty-five children, aged 10-16 years completed pre- and post-operative clinical evaluations, questionnaires (OSA-18), cone beam computed tomography (CBCT), and polysomnography (PSG). The pre- and post-operative CBCT data were used to reconstruct the 3-dimensional shape of the upper airway. Two measures of airflow function (pressure and velocity) were simulated by using computational fluid dynamics (CFD) at four different airway segments (nasal, nasopharyngeal, oropharyngeal and hypopharyngeal). Twenty-three patients (92%) experienced improvement based on PSG. The apnea hypopnea index (AHI) improved from 6.72 ± 4.34 to 3.59 ± 5.11 (p<0.001) events per hour. Clinical symptoms based on OSA-18 scores were improved in all patients. Twenty-five patients (100%) had successful expansion defined as separation of the midpalatal suture at least 1mm from anterior nasal spine (ANS) to posterior nasal spine (PNS). The nasal sidewall widening was 2.59 ± 1,54 mm at canine, 2.91 ± 1,23 mm at first molar and 2.30 ± 1,29 mm at PNS. The ratio of dental expansion to nasal expansion was 1.12:1 (2.90mm:2.59mm) at canine and 1.37:1 (3.98mm:2.91mm) at first molar. The nasal airflow pressure reduced by 76% (-275.73 to -67.28 Pa) and the nasal airflow velocity reduced by over 50% (18.60 to 8.56 m/s). Nasomaxillary expansion by skeletally anchored TPD improves OSA in children without transverse maxillary deficiency that were previously treated by RPE. A nearly parallel anterior-posterior opening of the mid-palatal suture achieves enlargement of the entire nasal passage with improvement of the airflow characteristics in the nasal and pharyngeal airway. The improved airflow characteristic is significantly correlated with the improved polysomnographic findings, thus demonstrating that nasomaxillary expansion in previously expanded patients is a viable treatment option.

Anatomical Patterns of the Nasopalatine Canal and Incisive Foramen in an African Setting: A Cross-Sectional Study.

Study Design: Descriptive cross-sectional. Objective: To determine the morphology and morphometry of the nasopalatine canal (NPC) and incisive foramen (IF) in an African population. Methods: Measurements of the NPC and the IF were carried out on 150 Cone-Beam computed tomography (CBCT) scans. The maxillary bone thickness anterior to the NPC was measured at 3 levels. Independent t-test and Chi-square test were performed to determine the presence of sexual dimorphism. Results: The presence of one Stenson's foramen was most prevalent. The mean length of NPC was 13.21 ± 3.25mm with significantly longer canals in males. The most prevalent shape of NPC was cylindrical in sagittal view and a single canal in coronal view. The mean angulation of NPC was 118.42° to the horizontal plane. The average dimensions of the IF were 3.53mm and 3.07mm in the anteroposterior and mediolateral diameter, respectively, while the most common shape was round. The anterior maxillary bone was thicker in males and generally reduced in thickness from the anterior nasal spine superiorly towards the alveolar crest inferiorly. Conclusion: This study highlights the anatomical characteristics of the NPC and IF, with significant sexual dimorphism observed regarding the number of Stenson's foramina, length of NPC, shapes of the NPC and IF, as well as alveolar bone thickness anterior to NPC.