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Background: Midpalatal suture (MPS) maturation may be influenced by a range of parameters including age, gender, and vertical skeletal pattern. We therefore aimed to evaluate the effect of Frankfurt-mandibular angle (FMA), skeletal maturation, and age on the timing of MPS maturation. Methods: In this cross-sectional study, cone-beam computed tomography (CBCT) and lateral cephalograms were used to assess the MPS and cervical vertebral maturation (CVM) stage. A proportional odds logistic regression model was used to assess associations between age adjusted for gender and MPS maturation, and a regression analysis was performed to analyze the effect of vertical pattern on these associations. Results: A total of 201 patients (84 male and 117 female) with a mean age of 13.48 (SD 1.94) were included. With increasing age, the odds of belonging to a higher maturation stage increased (OR: 2.14; 95% CI 1.789; 2.567; P < 0.001); however, no association between FMA and MPS maturation was observed (OR: 1.01; 95% CI 0.964; 1.051; P = 0.76). A strong correlation between MPS maturation and CVM stage was not reported. Males had a higher probability of belonging to a lower MPS maturation stage (OR: 0.24; 95% CI 0.136; 0.415; P < 0.001). Conclusions: Based on this cross-sectional analysis, midpalatal sutural maturation classification is associated with chronological age and occurs later in males. Neither CVM staging nor variation in vertical skeletal proportions were useful predictors of midpalatal maturation stage. [ABSTRACT FROM AUTHOR]

The pterygoid implant is a feasible alternative for posterior dental rehabilitation without grafting; however, the ideal pterygoid implant placement continues to be debated. The aim of this study was to identify effective landmarks and establish valid guidelines to determine the ideal pterygoid implant placement. Cone beam computed tomography (CBCT) data of 100 severely atrophied maxillae requiring implant rehabilitation, obtained between January 2015 and December 2018, were included. The CBCT data were obtained in DICOM format from the radiographic database and imported into Nobel Clinician software (Nobel Biocare) for radiographic analysis. Virtual pterygoid implant placement was successful in 67 maxillae: a 13-mm virtual implant in four maxillae (6.0%), 15-mm in 52 maxillae (77.6%), and 18-mm in 11 maxillae (16.4%). For the virtual pterygoid implant, the mean implant angulation± standard deviation in the anteroposterior axis (sagittal view) was 45.08 ± 2.56° relative to the Frankfort plane. In the buccopalatal axis (coronal view), the mean implant angulation was 64.30 ± 4.99° relative to the Frankfort plane and the mean value for the shortest linear distance between the palatine canal and apical tip of the virtual implant was 3.91 ± 0.62 mm. A 15-mm pterygoid implant placed at 45° in the anteroposterior axis and 60° in the buccopalatal axis (relative to the Frankfort plane), is generally recommended in this Chinese patient population. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether the morphology of the temporomandibular joint (TMJ) is associated with chewing patterns while considering skeletal morphology, sex, age, and symptoms of temporomandibular disorder (TMD). A cross-sectional observational study of 102 TMJs of 80 patients (age 16–40 years) was performed using pretreatment records of cone-beam computed tomography imaging of the TMJ, mandibular kinesiographic records of gum chewing, lateral and posteroanterior cephalometric radiographs, patient history, and pretreatment questionnaires. To select appropriate TMJ measurements, linear regression analyses were performed using TMJ measurements as dependent variables and chewing patterns as the independent variable with adjustment for other covariates, including Nasion-B plane (SNB) angle, Frankfort-mandibular plane angle (FMA), amount of lateral mandibular shift, sex, age, and symptoms of TMD. In multiple linear regression models adjusted for other covariates, the length of the horizontal short axis of the condyle and radius of the condyle at 135° from the medial pole were significantly (p < 0.05) associated with the chewing patterns in the frontal plane on the working side. "Non-bilateral grinding" displayed a more rounded shape of the mandibular condyle. Conversely, "bilateral grinding" exhibited a flatter shape in the anteroposterior aspect. These findings suggest that the mandibular condyle morphology might be related to skeletal and masticatory function, including chewing patterns. [ABSTRACT FROM AUTHOR]

The position of the maxillary central incisors (MCIs) is an important factor in treatment planning since it is related to esthetics and physiological function. This study aimed to evaluate maxillofacial morphology related to the proximity of the MCI to the incisive canal (IC) using cone-beam computed tomography (CBCT). In 157 patients, the distance between the MCI and IC was measured using CBCT images, and the maxillofacial morphology was measured using cephalograms. The relationship between age, sex, and cephalometric analysis was subsequently investigated using stepwise multiple regression analysis, with the distance between the MCI root apex and IC as the objective variable, and age, sex, and cephalometric variables as explanatory variables. The results demonstrated significant associations between the distance separating point A and the pterygomaxillary fissure projected on the palatal plane (B = 0.092, p < 0.01), the maxillary central incisal edge to the Frankfort horizontal plane (B = −0.058, p < 0.01), and the mandibular plane (B = −0.036, p = 0.031). Age and sex showed no association with the distance between the IC and MCI. Particular attention should be paid to the proximity of the tooth root to the IC in patients with short anteroposterior diameters of the maxilla and an anterior labial tilt of the dolichofacial type. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to identify the variation of bi-dimensional cephalometric measurements following real head rotation. Material and methods: Thirty cone beam–computed tomography (CBCT) head films were oriented according to three axes: horizontal Frankfort plane, transverse bi-orbital plane, and Opisthion-Nasion median plane. Axial rotation of 2°, 4°, 6°, and 8° from the Odontoïdale point were performed. Horizontal and vertical linear and angular measurements were studied on lateral cephalograms derived from each rotation T0, T2, T4, T6, and T8. A paired t-test was applied to compare the measurements between T0 and each rotational angle. Results: Of the 18 measurements, 55% showed statistically significant differences (P < 0.05) and 22% showed clinically significant differences, mostly at T6 and T8. Horizontal linear measurements Ba-A and N-Ba decreased, and vertical linear measurement G-Sn increased gradually, as the angle of head rotation increased. Angular measurements studied did not vary. Conclusions: Head malpositions during X-ray acquisition should be avoided and rotated lateral CBCT cephalograms should be corrected and recentered to prevent any variation in linear measurements. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to systematically explore the inclination of the lower central incisor and symphysis in alveolar bone in severe skeletal class III patients. Materials and methods: A total of 198 severe skeletal class III patients (ANB ≤ -4°) who underwent combined orthodontic and orthognathic treatment were divided into three groups based on the mandibular plane angle (MP-SN). Pretreatment lateral cephalograms were analysed and compared among the three groups. We also assessed cone-beam computed tomography (CBCT) images of 11 samples to investigate the reliability of the cephalometric analysis. Results: ANOVA showed no statistically significant differences in the angle between the long axis of the mandibular symphysis and the long axis of the lower central incisor (MIA) among the low-angle, normal-angle and high-angle groups (P > 0.05), while significant differences were found in the angle between the axis of the lower incisor and the mandibular plane (IMPA) among the three groups (P < 0.001). The mean IMPA decreased with increasing MP-SN in the 198 patients. The mean MIA in the low-angle and normal-angle groups was 3.70° and 3.52°, respectively, while the value (2.33°) was smaller in the high-angle group. Paired-samples t test showed no statistically significant differences between the cephalometric and CBCT measurements of the MP-SN, the angle between the mandibular plane and the Frankfort plane (FH-MP) and the MIA (P > 0.05). Conclusions: In severe skeletal class III patients, the long axis of the lower central incisor was highly consistent with the long axis of the mandibular symphysis, which was more obvious in the high-angle subjects. The MIA reflects the physiological inclination of the lower central incisor better than the IMPA. [ABSTRACT FROM AUTHOR]

Objectives: To compare the maxillary sinus volume between both sides in adult patients with upper occlusal canting (>2 mm cant) and a control group (≤2 mm cant) using cone‐beam computed tomography scans. Materials and methods: This retrospective study included a total of 84 scans (42 scans per group) according to predetermined selection criteria. OnDemand 3‐D™ software was used for volumetric and linear measurements of the maxillary sinus. Maxillary occlusal canting was determined at the level of the maxillary first molars. It was defined as the vertical difference between right and left sides relative to the Frankfort horizontal plane. Non‐parametric tests were applied. Results: The median difference in the maxillary sinus volume between the sides was statistically significant between the control and cant groups (P < 0.001). Also, the median difference in the maxillary sinus craniocaudal height and apex sinus distance between the sides was statistically significant between the control and cant groups (P < 0.05 and P < 0.001, respectively). Conclusion: In adult patients, maxillary occlusal canting of more than 2 mm was associated with asymmetric maxillary sinus volumes. In the cant group, maxillary first molars on the canted‐down side were in close proximity to the sinus floor, which suggests a limited leeway for molar intrusion. [ABSTRACT FROM AUTHOR]

Objective: The study investigated the preoperative anatomical variables that affect the outcome of surgical correction in patients with Class III facial asymmetry. Methods: The study recruited 37 consecutive patients with facial asymmetry who had 2-jaw orthognathic surgery. They were divided into two groups based on the surgical outcome: symmetrical (S group) or asymmetrical (A group), according to the asymmetry index. The CBCT images were obtained before surgery (T0) and after debond (T1). The 3D dentofacial measurements were compared between groups S and A by the Mann–Whitney test. Spearman correlation analysis was performed to examine the relationship of all dentoskeletal variables in T0 with the facial symmetry outcome. Results: Significant between-group differences were observed in preoperative time, including maxillary anterior occlusal canting, maxillary posterior occlusal canting, the gonion–Frankfort horizontal plane (FHP) distance, the mandibular ramus axis–FHP distances, and sagittal and transverse of condyle position. Conclusions: For patients with severe skeletal Class III asymmetry, preoperative anatomical variables, particularly preoperative "roll" and "yaw" discrepancies and anatomical limitations of the mandible, should be considered for favorable asymmetry correction. Based on the anatomic variables that affect the outcomes of facial asymmetry correction, prognosis and treatment limitation could be predicted before treatment. [ABSTRACT FROM AUTHOR]

Objective: This retrospective study aimed to analyse the anatomical dimensions of the pterygomaxillary region, installation angulations of pterygoid implants and bone density in the pterygoid pillar region by cone beam computed tomography (CBCT) examinations used in planning dental rehabilitation with implant‐supported prostheses in patients with atrophic jaws. Materials and Methods: We analysed 360 CBCTs of patients with atrophic jaws using Xoran® software v.3.1.62 (Xoran Technologies). In addition, the angulation of virtual implants installed in the pterygomaxillary region was analysed in relation to the Frankfurt plan, as well as the length required for the installation of implants in this region. Results: The implant length installed in the pterygoid pillar varied between 13 and 20 mm, with an average of 16.17 mm (SD 2.16 mm). The pterygoid implant angulation on the latero‐lateral axis (frontal view) averaged 78.71° (SD. 3.58°) and 73.50° (SD 3.49°) in the anteroposterior direction (sagittal view). Bone density was found to be significantly higher in the pterygoid pillar region compared the maxillary tuberosity region (p < 0.05); the region of the tuberosity and pterygoid pillar had an average density value of 132.9 (SD 230.24) and 513.91 (SD 291.63) respectively. Conclusion: According to the results of this study, a pterygoid implant with a minimum length of 13 mm should be used in the pterygomaxillary region to reach the pterygoid bone pillar. [ABSTRACT FROM AUTHOR]

Aim: To assess the upper airway (UA) morphology in patients with pycnodysostosis with a 3D analysis, compare results with normative data and investigate the correlation of the total volume (TV) with other UA morphology variables. Materials and methods: Cone beam computed tomography (CBCT) images of eight Danish patients with pycnodysostosis (4 males and 4 females with a mean age of 31.8 years, SD: 16.3 years) were analyzed using Mimics® (Materialise®) and compared with a sex‐ and age‐matched control group (6 males and 8 females with a mean age of 33.6 years, SD: 18.6 years). Results: The distance from the tip of the epiglottis (E) to the Frankfurt horizontal plane (Fp) was significantly shorter in the pycnodysostosis group (P <.042). Regarding the cross‐sectional measurements, at the 'maximum constriction' (P <.005), the 'upper airway limit' (P <.001) and the 'lower airway limit' (P <.035) cross‐sections were significantly smaller in the pycnodysostosis group. The volumes 'nasopharynx' (P <.002) and 'total airway' (TV) (P <.01) were also significantly smaller. Conclusion: Patients with pycnodysostosis have a reduced total airway as well as nasopharyngeal volume compared with matched controls. Additionally, they have a reduced cross‐sectional area in the upper and lower borders of the UA, and the area of maximum constriction is also reduced. These factors might explain the high prevalence of obstructive sleep apnoea in pycnodysostosis. Total airway is positively correlated with total length and cross‐sections at all levels including the maximum constriction area as well as the anteroposterior dimension at the upper and lower airway borders. [ABSTRACT FROM AUTHOR]

Introduction: The success of prosthodontic procedures can be accurately determined by the exact replication of the patient's condylar path using a semi-adjustable articulator. It allows the clinician to determine the morphology of the occlusal surfaces in relation to the condylar pathway during mandibular movements. If condylar guidance is not exactly registered, it might result in occlusal interferences during movements of the mandible and lengthen chairside adjustment time, which is inconvenient for the patient and dentist. Materials and methods: A total of 20 dentulous patients from 20 to 30 years of age group attending the department of prosthodontics at Sibar institute of dental sciences were selected for the study. Alu wax and jet bite were used to obtain the protrusive interocclusal record (PIR). Protrusive records were then used to program the semi-adjustable articulator to obtain HCGA values on both sides. Using the same protrusive records CBCT radiograph was taken. Radiographic images were traced on tracing paper and HCGA values were measured using Frankfort's horizontal reference line (the line connecting porion and orbitale) and the mean curvature line (most-superior and most-inferior points of the curvatures) on both sides using a protractor. The data were analyzed by paired sample t-tests and Pearson's correlation tests. Results: There was no significant difference between the right and left sides in the clinical and radiographic methods using Alu wax PIR. In the clinical method utilizing jet bite PIR, the right side had significantly higher HCGA values than on the left side. On CBCT, no such differences were found. Conclusion: CBCT horizontal condylar guidance angle values were higher than those obtained using the clinical method by using both records. Values obtained from both the methods, i.e., protrusive interocclusal record and cone-beam computed tomography, were compared and correlated. [ABSTRACT FROM AUTHOR]

Linear measurements taken from bony landmarks are often utilised in facial approximation (FA) to estimate and plan the placement of overlying soft tissue features. This process similarly guides craniofacial superimposition (CFS) practices. Knowledge of how hard and soft tissue features spatially relate around the mouth region is, however, limited. Geometric morphometric techniques have thus been used to investigate size and shape variation in dentition-to-lip mouth morphology in a South African population. Twenty landmarks (twelve dentition, eight lips) were digitised, using cone-beam CT images of the anterior craniofacial complex in a Frankfurt/Frankfort position, for 147 individuals aged between 20 and 75 years. Principal Component Analysis and Canonical Variate Analysis established that much shape variation exists. A two-way ANOVA identified significant (p < 0.0001) population and sex variation with mouth shape. Black individuals presented with thicker lips, with the oral fissure aligning closely to the dental occlusion. Oral fissure position for white individuals corresponded to the inferior one-quarter (females) or one-sixth (males) of the maxillary central incisor crowns. Males presented larger dimensions than females, but females had a greater lip-to-teeth height ratio than their male counterparts. A pooled within-group regression analysis assessed the effect of age on the dentition and lips and found that it had a significant (p < 0.0001) impact on mouth shape. Ageing was associated with a reduced lip and teeth height, increased mouth width, and a lowered oral fissure and cheilion placement. The generated mean shape data, with metric guides, offer a visual and numerical guide that builds on existing FA and CFS standards, enhancing our understanding of hard and soft tissue relationships. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to assess craniofacial dimensions in obstructive sleep apnea (OSA) patients treated with a mandibular advancement device (MAD) and to identify anatomic influences on OSA severity and MAD therapy outcomes. Materials and methods: Twenty patients with OSA were prospectively treated with MAD. Clinical, cone-beam computed tomography, and polysomnography exams were performed before treatment and 4–6 months after achieving the MAD therapeutic position. Polysomnographic exams and three-dimensional maxillary, mandibular, and upper airway (UA) measurements were evaluated. Pearson's correlation and t-tests were applied. Results: Before MAD treatment, the transverse width measured at the frontomaxillary suture and the angle between the mandibular ramus and Frankfurt horizontal were statistically correlated with apnea and the hypopnea index (AHI), while the gonial angle was correlated with therapeutic protrusion. After MAD treatment, all patients showed a significant AHI reduction and an improvement in minimum oxyhemoglobin saturation. The UA total volume, superior and inferior oropharynx volume, and area were statistically correlated with MAD therapeutic protrusion. The UA total area showed a statistical correlation with the improvement in AHI, and the superior oropharynx volume and area increased significantly. Conclusions: The transversal frontomaxillary suture width and the mandibular ramus facial angle may influence OSA severity. The gonial angle, volume, and area of all UA regions may indicate the amount of protrusion needed for successful MAD treatment. Clinical relevance: The craniofacial characteristics reported as important factors for OSA severity and MAD treatment outcomes impact therapy planning for OSA patients, considering individual anatomic characteristics, prognosis, and cost benefits. [ABSTRACT FROM AUTHOR]

Introduction: Due to the close anatomic relationship between paranasal structures and NLC, the morphometric measure of the nasolacrimal canal (NLC) could be affected by the osteomeatal complex (OMC) anatomical variations. The present study aimed to assess the effect of OMC variations on the NLC morphometric features using cone-beam computed tomography (CBCT). Materials and Methods: This cross-sectional study consisted of CBCT images of 150 subjects in the case group with at least one OMC variation and 40 cases in the control group without any OMC variation within the age range of 18-50 years. The presence of the OMC variations, including agger nasi, nasal septum deviation, concha bullosa, Haller cells, paradoxical middle turbinate, and pneumatization of the uncinate process, was evaluated in each patient. The NLC morphometric measurements were performed and compared between the case and control groups. Results: The middle anteroposterior diameter and middle sectional area of NCL were significantly higher in patients with OMC variations, as compared to that in the control group. The NLC volume was significantly higher in patients with agger nasi, nasal septum deviation, concha bullosa, and pneumatization of the uncinate process, as compared to that in the control group. Nonetheless, no significant difference in NLC angulation with the nasal floor or Frankfurt horizontal plane was observed in the presence of each OMC variation. Conclusions: As evidenced by the obtained results, a higher volume of the canal was revealed in the presence of some of the OMC variations. Therefore, it can be suggested that OMC variations cannot be a predisposing factor in cases with primary acquired nasolacrimal duct obstruction. [ABSTRACT FROM AUTHOR]

The purpose of this preliminary study was to evaluate the diagnostic accuracy of the combined use of 2 cone-beam computed tomographic (CBCT) volumes obtained with the tooth of interest positioned at different orientations in the detection of vertical root fracture (VRF). Thirty single-rooted teeth were divided into 2 main groups (n = 15): control and with VRF. The teeth were individually placed in a phantom composed of a human skull and mandible, which was CBCT scanned in 2 spatial orientations: conventional (with the Frankfurt plane parallel to the floor) and angled acquisition (tilted 90° backward). Also, each tooth was scanned with gutta-percha, a metal post, and without any intracanal material. Three oral radiologists individually evaluated the images resulting from conventional acquisition and verified the presence or absence of VRF (conventional CBCT assessment), setting a score on a 5-point scale. Subsequently, the observers evaluated both images resulting from the conventional and angled acquisitions (combined CBCT assessment). The diagnostic values of the conventional and combined assessments were compared using 2-way analysis of variance with the post hoc Tukey test. The significance level was set at 5% (α = 0.05). The combined CBCT assessment showed higher accuracy and sensitivity in the VRF diagnosis of teeth filled with gutta-percha (P <.05). In teeth with a metal post, all diagnostic values were higher in the combined CBCT assessment (P <.05). This preliminary study suggests that the CBCT-based diagnosis of VRF in teeth with intracanal material was improved when the assessment combines images obtained at 2 orientations. [ABSTRACT FROM AUTHOR]

Great variation has been found in sagittal condylar inclination (SCI) values among individuals with different skeletal structures. Therefore, average value articulators cannot fully represent the physiological characteristics of the mandible, or reproduce its sagittal movements. The purpose of this study was to measure the SCI value of skeletal Class II patients by two different three-dimensional assessments, and to evaluate the correlation and consistency between the two methods. A total of 23 patients (aged 15–65 years) diagnosed with skeletal Class II malocclusion were recruited from the Stomatological Center of Shunde Hospital, Southern Medical University. Subjects were divided into three groups based on different A point–nasion–B point angle (ANB), and angle between the upper central incisor and Frankfort horizontal plane (U1-FH). Bilateral SCI values were measured using computer-aided diagnosis axiography (CADIAX) and cone-beam computed tomography (CBCT). Statistical analysis showed that the SCI value measured by CADIAX was significantly higher than that measured by CBCT. Significant differences were found among different ANB and U1-FH groups, and the average value of the 6 ∘ < ANB ≤ 8 ∘ group was the highest. Our findings indicate that the measurement of SCI by CADIAX cannot be replaced by CBCT, and it is recommended that personalized measurements of SCI values in skeletal class II patients be carried out. Individual SCI measurement can help coordinate the physiological characteristics of patients in dental treatment, benefit the health of temporomandibular joint and improve the long-term outcome. Our results suggest that the SCI values obtained by CBCT is different from the real SCI values of patients, and we will look for a simpler and more accurate clinical method to measure SCI value in future research. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the morphometric and morphological features of zygomatic arch on cone beam computed tomography (CBCT) images and evaluate the usability of zygomatic arch instead of Frankfort horizontal plane. Methods: In this retrospective study, CBCT images of 130 adults (mean age: 38.43±16.20 years, 60 males, 70 females) were analyzed with Planmeca Romexis Viewer program. Approval was received from the Clinical Research Ethics Committee (2023/317). The length, angle, height of zygomatic arch, angle between line passing through superior border of zygomatic arch and Frankfort horizontal plane, distance between jugale and inferior border of zygomatic arch, jugale angle were measured. Typing was made according to the shape of zygomatic arch. Statistical analyses were performed with SPSS 22.0 package program. Results: A statistically significant difference was found between genders in length of zygomatic arch and jugale angle (p<0.001 and p=0.037, respectively). In zygomatic arch angle, the left side (134.53±6.69°) had statistically higher values than the right side (129.78±8.06°) (p<0.001). Zygomatic arch types were 29.6% flat, 40.4% curved and 30% wavy. There was no statistically significant difference in angle between line passing through superior border of zygomatic arch and Frankfort horizontal plane between the sides and between genders. Conclusion: Considering morphometric variables related to zygomatic arch length and jugale angle, the significant difference between genders may contribute to clinical or forensic medical evaluations. The line passing through superior border of zygomatic arch can be used as an alternative to Frankfort horizontal plane as a reference line in clinical applications and anthropological studies. [ABSTRACT FROM AUTHOR]

Introduction: Transverse discrepancies of the maxilla is one of the most prevalent skeletal problems. Due to the drawbacks of conventional RPE and invasive surgical expansion, alternative methods were developed, such as Mini Implant-supported rapid maxillary expanders (MARPE). Many studies reported by Haas, Davis and Kronman, Akkaya et al. regarding the maxillary response after MARPE on the sagittal dimensions were inconclusive. Aim: The aim of this study was to analyze the sagittal effects on the maxilla after Mini Implant assisted rapid palatal expansion (MARPE) in adolescents. Materials and methods: Pre-treatment CBCT images (T1) were taken as a standard initial record for all patients and post-treatment CBCT (T2) was taken three months in retention after expansion with MARPE. The parameters SNA angle, Frankfort horizontal plane to NA angle, A-N perpendicular in mm, ANS - PNS (in mm) were measured and calculated for evaluation of the sagittal maxillary changes. Comparisons were then made between the two treatment groups at T1, T2 and T2 - T1. Results: A positive increase was seen from pretreatment to post-treatment in both angular and linear measurements showing the significant sagittal skeletal change. Conclusion: The study found a statistically significant forward displacement of maxilla after transverse skeletal expansion in adolescent patients with transverse problems achieved through MARPE. [ABSTRACT FROM AUTHOR]

Objectives. This study aimed to assess the buccolingual inclination of canine and first and second molar teeth and the curve of Wilson in different sagittal skeletal patterns in untreated adults using cone-beam computed tomography (CBCT). Materials and Methods. Sixty-six CBCT scans of adults (mean age: 28.74 ± 5.25 years) were evaluated in this cross-sectional study. The images were standardized using the Frankfurt horizontal plane and the interorbital line. The sagittal skeletal pattern was determined using the ANB angle and Wits appraisal. Inclination angles were measured by NNT Viewer and Mimics software. The curve of Wilson was measured by connecting the tips of mesiobuccal and mesiolingual cusps of maxillary first and second molars along the buccal groove and measuring the formed angle. Data were analyzed using ANOVA. Results. The intraobserver agreement was 0.969. The mean inclination of maxillary first and second molars in class I and III patients was significantly higher than that in class II patients P < 0.05 . The mean inclination of mandibular first and second molars in class II patients was significantly higher than that in class I and III patients P < 0.05 . The difference in inclination of maxillary and mandibular canine teeth was not significant P > 0.05 . The mean curve of Wilson in second molars of class II patients was significantly higher than that in class I patients P < 0.05 . Conclusion. In different sagittal skeletal patterns, a compensatory relationship exists between the opposing teeth, which, along with the standards of crowns, can be used to determine the appropriate position of teeth in dental arch. [ABSTRACT FROM AUTHOR]

Objectives: To test the validity of a novel protocol for 3D sagittal jaw discrepancy assessment (skeletal class determination) through comparison with common 2D indexes by the use of reduced FOV (10 × 10) CBCT which shows at least from the Frankfurt plane to the B point vertically, and from the most anterior between A and B point to Po point horizontally. Methods: A sample of CBCT scans of 109 adult patients (46 females; 63 males; mean age 30 years ± 11.6) equally distributed between I, II and III class was selected. Skeletal class was evaluated with specific software using the distance of A and B point's projection (AF-BF) on FHp (Frankfurt horizontal plane) and compared to 2D common indexes (ANB and Witts appraisal). The validity and reliability of the aforementioned analyses were determined using intra-class correlation coefficients, quadratic weighted Cohen's K and sensitivity. Result: A selected range of values of 2.5 ± 2.5 AF-BF showed a solid correlation with the ANB angle (r = 0.846, K = 0.838, p < 0.001) and moderate with Wits appraisal (r = 0.723, K = 0.720, p < 0.001). Conclusions: AF-BF showed high reliability in skeletal class determination on reduced FOV CBCT without the use of S and N cephalometric landmarks. Key Points: • Reduced FOV CT allows skeletal class determination for orthodontic purposes. • A new 3D-reduced FOV cephalometry is proposed. • AF-BF is a reliable alternative to ANB. [ABSTRACT FROM AUTHOR]

The aim of this study is to evaluate through computed tomography differences in cortical plate thickness of condyle in patients with a different facial vertical skeletal pattern. The final sample of this retrospective study included CBCT exams of 60 adult subjects (mean age 33.2 ± 5.6), selected from the digital archive of a private practice. The subjects were assigned to 3 different groups according to the values of the Frankfurt-mandibular plane angle: hyper-, normo-, and hypodivergent groups. The volume rendering of the mandible was obtained and three condylar points were marked on it: median pole, lateral pole and the most cranial point. For each considered reference point, the minimum distance between external and internal cortical surface was measured, obtaining three different outcomes: condylar cortical bone thickness of median pole (CCBToMP), lateral pole (CCBToLP) and cranial pole (CCBToCP). The measurements were executed by means of Mimics software by the same expert operator in specific scan views. The cortical bone thickness of hyperdivergent patients was found to be statistically thicker than normodivergent patients and hypodivergent patients. Cortical bone thickness of normodivergent patients was found thicker than hypodivergent patients. All the differences were statistically significant (p < 0.05). The Pearson correlation coefficient showed a statistically significant correlation (p < 0.001) between the Frankfurt-mandibular plane angle and the evaluated cortical bone thickness outcomes. Facial biotype characteristics that define vertical facial skeletal pattern affect the cortical bone thickness of mandibular condyle. [ABSTRACT FROM AUTHOR]

Objectives: To assess the effect of virtual surgical planning (VSP) on the accuracy of condylar seating in surgical cases involving Bilateral Sagittal Split Osteotomy (BSSO). An additional aim was to quantify differences between actual surgical outcome and planned virtual outcome.Setting and Sample Population: A private practice in Charlotte North Carolina. Twenty-five consecutively operated subjects prepared with VSP and twenty consecutively subjects operated with conventional surgery planning were enrolled.Material and Methods: Cone beam computed tomography (CBCT) scans were obtained before surgery (T1) and post-surgery after splint removal (T2). The T1 and T2 CBCTs were superimposed on the anterior cranial base using voxel-based registration. Three dimensional (3D) models were built and oriented to a 3D Frankfurt horizontal. Displacement of corresponding condylar landmarks was measured.Results: No significant difference was found between the VSP and conventional group in the magnitude of translation or rotation of the condyles following surgery. VSP surgical outcomes differed significantly from predicted positions at all landmarks. Virtual surgical planning does not prevent changes to condylar position as a result of surgery. Actual surgical results differed significantly from VSP-predicted outcomes.Conclusions: Virtual surgical planning did not reduce the changes to condylar position and angulation that resulted from conventionally planned orthognathic surgery. [ABSTRACT FROM AUTHOR]

Abstract Superimposition of radiographic imaging is used to evaluate patient growth and the effects of surgical and/or orthodontic treatment. The purpose of this study was to compare the outcomes of superimposition between two-dimensional (2D) and three-dimensional (3D) superimpositions. 2D lateral cephalograms were generated from the initial and final cone beam computed tomography scans (CBCT) of 18 patients and superimposed. Both 3D CBCT and 2D CBCT generated lateral cephalograms were oriented to the Frankfort horizontal plane and superimposed according to the American Board of Orthodontics recommendations. Changes in landmark position were quantified from the resulting superimposition outcomes via linear measurements made with Dolphin software. Differences between the two methods were analyzed using paired t -tests. Measurements were repeated twice for 10 randomly selected scans to assess reliability by intra-class correlation coefficient (ICC) analysis. Intra-examiner reliability was high for all measurements (ICC > 0.84). Agreement between 2D and 3D superimposition outcomes, as measured by P -values, was low for ANS (P = 0.026), B-point (P < 0.001), ST Upper lip (P = 0.019), U1 tip (P = 0.010), and U1 apex (P = 0.026). 2D measurements were significantly higher than 3D measurements for ANS, B-point, ST Upper lip, U1 tip, and U1 apex. Findings indicated that both methods of superimposition (2D and 3D) are highly reliable. Statistical differences between 2D and 3D superimposition outcomes were below the threshold of clinical significance. [ABSTRACT FROM AUTHOR]

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The article entitled "Three-Dimensional Mandibular and Upper Airway Analysis in Patients with Sleep Apnea Treated with Mandibular Advancement Device" presents a study conducted with 20 patients with sleep apnea treated with a mandibular advancement device (MAD). The objective of the study was to evaluate the mandibular anatomy and upper airway (UA) using cone-beam computed tomography (CBCT) and to assess the anatomical influences of the mandible on the severity of sleep apnea and the outcomes of MAD treatment. The results showed that the angle formed between the mandibular ramus and the Frankfurt Plane (RMPF) was correlated with the apnea-hypopnea index (AHI), while the gonial angle (GA) was related to therapeutic protrusion (TP). Additionally, there was a significant reduction in AHI and improvement in minimum oxyhemoglobin saturation after MAD treatment. The volume and area of the UA were also correlated with MAD TP. It is concluded that RMPF influences the severity of sleep apnea and that GA, volume, and area of the UA are important for the success of MAD therapy. [Extracted from the article]

The purpose of this study was to evaluate midpalatal bone density (BD) by using cone-beam computed tomography (CBCT) according to gender, age, and vertical and horizontal skeletal patterns. CBCT images from 126 subjects (64 females and 62 males) were reoriented and analyzed in order to attain BD values at the midpalatal suture. Four age groups were used for classification (adolescence, 10 ≤ early < 14 years, 14 ≤ middle ≤ 17 years, and 17 < late ≤ 21 years; adult > 21 years). Vertical skeletal pattern categories were differentiated by the Frankfort horizontal line to mandibular plane angle (hypodivergent < 22°, 22° ≤ normovergent ≤ 28°, and 28° < hyperdivergent). Horizontal skeletal pattern differentiation was defined by ANB angle (Class III < 0°, 0° ≤ Class I ≤ 4°, and 4° < Class II). Females showed significantly higher BD than males (p < 0.001). As age increased, BD increased significantly (p < 0.001). There were no significant differences between vertical skeletal patterns. Class II showed significantly less BD than Class III (p < 0.05). With this information, clinicians can better understand BD trends of the midpalatal suture and, thus, better understand our patient's anatomy and potential hurdles in successful treatment. [ABSTRACT FROM AUTHOR]

Functional appliances are widely used for promoting mandibular growth by utilizing a construction bite position. We aimed to measure the mechanical load generated by movement of functional appliances and determine the factors influencing this load. Thirteen patients aged 8–12 years were selected for the study, and the load was measured using a previously developed measurement device. To investigate the factors affecting the load, the temporomandibular joint morphology and muscles related to the mandible were examined using cone-beam computed tomography. The standard regression coefficients of the factors affecting the load per millimeter of movement distance were 0.64 and 0.66 for (a) the inclination of the articular eminence and (b) the angle between occlusal plane and posterior temporalis, respectively. Measurement of the occlusal plane to the posterior temporalis and the inclination of the articular eminence were significantly different (p < 0.05). The angle of inclination of the articular eminence emerged as a strong influencing factor. Similarly, the influence of measurements from the occlusal plane to the posterior temporalis was considerable since the posterior temporalis muscle is the most active when the mandible is extended forward. We also found a possible relationship between the occlusal force and load at the construction bite position. To our knowledge, this is the first study to determine the actual load associated with the angle of the temporalis muscle to the occlusal plane, inclination angle of the articular eminence, angle between the occlusal plane and the Frankfort plane, and the angle between the geniohyoid muscle and the occlusal plane. Therefore, mechanical considerations need to be more accurate to facilitate safe orthodontic treatment. [ABSTRACT FROM AUTHOR]

Objective: Le Fort I osteotomy is one of the most preferred osteotomy for maxillary orthographic surgery. Posterior part of Le Fort I osteotomy consists of disjunction the pterygomaxillary junction. Variations of pterygomaxillary junction can lead to complications and therefore should be evaluated pre-operatively. The aim of this study is to evaluate pterygomaxillary junction using cone beam computed tomography. Methods: Total of 150 pterygomaxillary junction from 75 patients was evaluated retrospectively. Patients were grouped accourding to their maxillomandibular relationship as Class I, Class II or Class III. Head position orientation was applied on coronal section with using frontozygomatic sutures and Frankfurt horizontal plane on sagittal section. Pterygomaxillary junction was evaluated at axial section which is 3 mm superior to nasal floor. Results: 11 measurements made for each side from cone beam computed tomography. These measurements are; Anterior length from palatinal canal (A), Posterior measurements from palatinal canal (B), Length of pterygoid plates (C), Depth of palatial canal (D), Diameter of palatial canal (E), Posterior length of maxilla (F), Length of lateral pterygoid plate (G), Length of medial pterygoid plate (H), Depth of lateral pterygoid plate (I), Depth of pterygomaxillary junction (J) and Angle of pterygomaxillar junction (K) These measurements are compared between genders and according to right and left sides. Conclusion: Evaluation of pterygomaxillary junction preoperatively can be helpful for avoiding complications due to variations of pterygomaxillary area. [ABSTRACT FROM AUTHOR]