Anatomical study of the maxillary sinus: which characteristics can influence its volume?

PURPOSE: To investigate whether there is a relationship between the volume of the maxillary sinus and individual parameters such as gender, side, posterior tooth absence, sinus membrane thickening, bony septa, vertical and sagittal skeletal patterns. METHODS: The tomographic volume of the maxillary sinus from 211 individuals (422 sides) was evaluated using Horos DICOM Viewer Software. Bony septa and sinus membrane thickening were classified as absent or present. At the same time, loss of one or more teeth in the posterior region of the maxilla (except for the third molars) was considered. The t test was applied to analyze maxillary sinus volume according to gender, age, side, posterior tooth absence, sinus membrane thickening and bony septa. A one-way analysis of variance (ANOVA) with Tukey's post-hoc test was applied to compare sagittal and vertical patterns. Pearson's correlation coefficient was also used to verify the association between maxillary sinus volume, age and skeletal patterns. RESULTS: Concerning the sagittal skeletal pattern, a statistically significant difference was observed between Classes II and III (p = 0.05) and it was confirmed by the Pearson's correlation coefficient (r = - 0.107/p = 0.029). No statistically significant differences were observed between the maxillary sinus volume according to gender (p = 0.06), side (p = 0.37), posterior tooth absence (p = 0.92), sinus membrane thickening (p = 0.47), bony septa (0.89) and vertical skeletal pattern (p = 0.67). No significant differences were observed with age (r = - 0.076/p = 0.109) and the vertical skeletal pattern (r = - 0.078/p = 0.108). CONCLUSION: Maxillary sinus volume was influenced by the sagittal skeletal pattern and was higher in Class III individuals.

Tomographic assessment of infrazygomatic crest bone depth for extra-alveolar miniscrew insertion in subjects with different vertical and sagittal skeletal patterns.

OBJECTIVE: To evaluate bone availability at the infrazygomatic crest for extra-alveolar bone miniscrew insertion in subjects with different vertical and sagittal skeletal patterns. SETTING AND SAMPLE POPULATION: Measurements of the infrazygomatic crest were performed on multislice computed tomography scans from 58 adults with different skeletal patterns. MATERIALS AND METHODS: Infrazygomatic crest bone depth was measured at 4, 5 and 6 mm from the cementoenamel junction (CEJ) of the maxillary first molar at three different angles (60°, 70° and 80°) in the first molar occlusal plane. The sagittal and vertical skeletal patterns were determined. Analysis of variance followed by Tukey's post hoc test was used (P ≤ .05). RESULTS: Bone depth was greater near the CEJ (8.7 ± 3.1 mm) and lower in the apical area (5.8 ± 2.7 mm). In Class II subjects, considering 6 mm from the CEJ, there was a significantly lower depth at the 80° angle (5.4 ± 2.5 mm) than at 60° (8.6 ± 3.5 mm; P = .007). In mesofacial subjects, considering 5 and 6 mm from the CEJ, bone depth was lower at 80° (5.7 ± 3.2 mm and 5.3 ± 2.5 mm) than at 60° considering 4 mm from the CEJ (P ≤ .019). CONCLUSION: Bone availability was lower at the apical level, especially in Class II and mesofacial subjects. Therefore, when the planned insertion site is located in the apical direction, it is recommended to choose shorter miniscrews (2.0 x 12mm) and a smaller insertion angle (60°) and/or to plan a miniscrew bone insertion deep enough to allow bicortical fixation.

Assessment of the mandibular buccal shelf for orthodontic anchorage: Influence of side, gender and skeletal patterns.

OBJECTIVES: To evaluate bone height and thickness in the mandibular buccal shelf region and to compare differences between anatomical sites according to gender, side and vertical and sagittal skeletal patterns. SETTINGS AND SAMPLE POPULATION: Multislice computed tomography (MSCT) images of 94 subjects (51 females and 43 males) were previously obtained as part of preoperative planning for orthognathic surgery. METHODS: Measurements were performed in three different regions of the mandibular buccal shelf: mesially, towards the central groove and distally to the second molars. Bone thickness measurements were obtained perpendicularly 3, 5 and 7 mm below the bone crest towards the mandible outer cortex. Bone height was measured 3 mm away from the bone crest perpendicularly to the outer cortex of the base of mandible. RESULTS: There was an increase in bone thickness in the posterior and basal directions. The increase in bone thickness ranged from 1.8 to 7.1 mm. Greater bone height was found in the anterior direction. The increase in bone height ranged from 17.5 to 22.5 mm. Hypodivergent and Class III subjects showed significantly greater bone thickness (P < .05). Significantly greater bone height was found mesially to the second molar in Class III subjects compared with Class I subjects (P < .05) and in hyperdivergent males compared with hypodivergent males (P < .05). CONCLUSIONS: The region distal to the second molar is the most appropriate for the insertion of extra-alveolar mini-screws in terms of bone thickness. Hypodivergent and Class III subjects showed greater bone thickness in the mandibular buccal shelf region.

Efficacy of digital radiography for detecting a second mesiobuccal canal adjacent to unfilled or filled canals.

The aim of this study was to assess the diagnostic accuracy of digital periapical radiography for the detection of the second mesiobuccal (MB2) canal when the adjacent canals are unfilled or filled with gutta percha. Forty human maxillary first molars were selected, 20 of which had an MB2 canal. The presence or absence of the MB2 canal was confirmed using microcomputed tomography. Digital periapical radiographs of each tooth were obtained from 3 horizontal angles before and after the adjacent root canals were filled with gutta percha. Three experienced oral radiologists evaluated all images and indicated the presence or absence of the MB2 canal using a confidence scale of 5 points. To assess intraobserver and interobserver agreement, weighted kappa coefficients were calculated. The diagnostic test (sensitivity, specificity, and accuracy) and area under the receiver operating characteristic curve (Az) values were calculated and compared between groups (n = 40): radiographs of the first molars with unfilled adjacent canals and radiographs of the same teeth with filled adjacent canals. For all observers, intraobserver reproducibility ranged from substantial (0.70) to almost perfect (0.86), and interobserver reproducibility ranged from fair (0.39) to substantial (0.67). Similar values of specificity and Az for the detection of the MB2 canal were observed with unfilled and filled adjacent canals. The sensitivity and accuracy were slightly greater when the adjacent root canals were filled with gutta percha. Detection of the MB2 canal on digital periapical radiographs can be challenging even when obtained at varying horizontal angles, and the presence of gutta percha does not influence the detection.

Branch of the canalis sinuosus: a rare anatomical variation--a case report.

The canalis sinuosus (CS) is a neurovascular canal, a branch of the infraorbital canal through which the anterior superior alveolar nerve passes. There are no studies or case reports of anatomical variations related to this canal. A rare case of anatomical variation in the CS is reported that was detected by cone beam computed tomography done in a 47-year-old female as a pre-operative workup before dental implants. In this case, in the region slightly medial to tooth 23, a wide accessory branch from the CS was observed, running an intraosseous course in the inferior and posterior direction up to a foramen located in the hard palate, slightly medial in relation to tooth 23. The location of this branching, as well as its neurovascular component, is important for dental implant planning because of its proximity to the upper teeth. Identification of neurovascular bundles is fundamental to avoid complications for the patient.

Tomographic diagnosis of alveolar bone coverage impact in orthodontic planning: cross-sectional study.

INTRODUCTION: Alveolar bone coverage can be diagnosed through cone beam computed tomography (CBCT) and this information can prevent orthodontic tooth movement beyond the biological limit. OBJECTIVE: This study evaluated the impact of the bone coverage (BC) diagnosis by CBCT in the orthodontists' planning. METHODS: One hundred fifty-nine Brazilian orthodontists suggested treatment plans for six patients at two different times, using two sequential questionnaires. The first questionnaire consisted of extra and intra-oral photographs, one panoramic radiograph; one lateral cephalometric radiograph with Steiner and Tweed analysis, and the patient chief complaint. The second questionnaire included the same presentations of cases with tomographic images and the radiologist's report. The McNemar test assessed the difference between the first and the second treatment plans. RESULTS: In all six cases, most participants changed the treatment plan after evaluating the CBCT images and the radiologist's report (93.7% in case 5, 78.6% in case 4, 74.2% in case 3, 69.8% in case 6, 66% in case 2 and 61% in case 1; p≤0.01). CONCLUSION: The evaluation of bone coverage through CBCT images has a substantial impact on the orthodontic diagnosis and planning of the Brazilian orthodontists.

Rare anatomical variation related to the nasopalatine canal.

The nasopalatine canal is a relatively long narrow structure located in the midline of the maxilla that contains the nasopalatine nerve and terminal branch of the descending palatine artery. Anatomical variations related to this structure have been reported. This article aimed to report a case of a complete additional nasopalatine canal on a 53-year-old female patient who underwent an examination by cone beam computed tomography. On sagittal slices, it was possible to observe the presence of an additional canal anterior and superior to the nasopalatine canal, separated by a bony septum. Each canal extended from independent superior openings (located in the nasal cavity) to independent openings located in the remaining alveolar process of the anterior maxilla. Identification of individual anatomical variations, especially involving neurovascular structures, plays an important role in the successful outcomes of surgical procedures involving the anterior maxilla.

Surgical management of multiple myeloma in the mandible: a case report.

Multiple myeloma (MM), solitary bone plasmacytoma, and extramedullary plasmacytoma are different types of plasma cell neoplasia, which is a lymphoid neoplastic proliferation of ß-cells. While MM is most frequently seen in the vertebrae and long bones, 30% of MM cases are found in the jaws. This case report presents a 58-year-old man with mandibular swelling; his medical history indicated he had a fracture of the humerus 1 month earlier. Panoramic radiography revealed a radiolucent lesion in the mandibular posterior region. Biopsy was performed and the histopathological examination indicated plasmocytoma. However, given the patient's dental and medical history, and the presence of multiple osteolytic lesions, the final diagnosis was MM. The patient underwent chemotherapy for the MM. To treat the pathological fracture of the jaw, a hemimandibulectomy was followed by the installation of a reconstructive plate.

Extensive central ossifying fibroma of the maxilla: a case report.

Central ossifying fibroma (COF) is a benign osteogenic neoplasm, with fibrous tissue and calcifications similar to bone, which has the clinical presentation of an asymptomatic bulging. It is more common in the mandibular premolar and molar region, in the third and fourth decades of life, and in women more frequently than men. Surgical removal is the treatment of choice and additional reconstruction is essential due to the functional and esthetic problems faced by the patient. This article describes the surgical treatment and subsequent reconstruction in a 22-year-old man with COF and an expansile lesion of the anterior maxilla. Enucleation of the lesion was performed and porous high-density polyethylene biomaterial was used for reconstruction.

Correlation between maxillofacial radiographic features and systemic severity as sickle cell disease severity predictor.

This study was conducted to investigate the relationship among radiographic features observed on panoramic radiographs of sickle cell disease patients and analyze their relationship with history of systemic severity of the disease. Panoramic radiographs of 71 subjects with sickle cell disease were evaluated for the presence of the following radiographic bony alterations: radiopaque areas, increased spacing of bony trabeculae, horizontal arrangement of bony trabeculae and corticalization of mandibular canal. History of clinical systemic severity was assessed through direct questioning about the frequency of vaso-occlusive crisis, history of stroke, clinical jaundice, femur head necrosis, and leg ulceration. Chi-square or Fisher's exact test were applied in order to analyze possible associations between radiographic features and history of complications, with p < 0.05 significance level. Increased spacing of bony trabeculae was statistically associated with absence of corticalization of mandibular canal (p < 0.01) and horizontal arrangement of bony trabeculae (p = 0.04). Statistically significant associations were demonstrated between history of clinical jaundice and presence of increased spacing of bony trabeculae (p = 0.02) and between history of stroke and presence of horizontal arrangement of bony trabeculae (p = 0.04). Based on the results of the current study, maxillofacial radiographic features may be associated with clinical parameters of systemic complications in sickle cell disease patients. The relationship between radiographic features and history of complications associated with clinical severity of sickle cell disease has not been demonstrated in the literature. Acknowledgment of such possible association may help establish prognosis and influence clinical treatment of systemic and oral complications.

Accuracy of linear measurements in cone beam computed tomography with different voxel sizes.

OBJECTIVE: To evaluate the accuracy of linear measurements on dry mandible specimens using cone beam computed tomography (CBCT) images acquired with different voxel sizes. METHODOLOGY: Eight human dry mandibles were submitted to CBCT examination, using the i-CAT (Imaging Sciences, Inc. Hatfield, PA) device and four protocols with different voxel sizes. Tomographic slices with a more central view of the markers, placed on six sites on each mandible, were selected to perform measurements. Values obtained from direct measurements on the dry mandible after sectioning them on the preestablished sites were compared with measurements from the tomographic images and the measurement error. RESULTS: There was no statistical difference between the measurement error of the protocols (P = 0.606). The mean value of the difference between the values obtained in the images and the dry mandible was smaller than 1 mm for all the protocols. CONCLUSION: The accuracy of vertical and horizontal measurements, using CBCT (i-CAT) for the four protocols, was shown to be comparable with the measurements performed on the dry mandible.

Canalis sinuosus: a rare anatomical variation.

The infraorbital canal issues a small branch on its lateral face close to its midpoint to allow passage of the anterior superior alveolar nerve. This small canal, sometimes called the canalis sinuosus, runs forward and downward to the inferior wall of the orbit, lateral to the infraorbital canal and medially bent to the anterior wall of the maxillary sinus, passing below the infraorbital foramen. Anatomical variations in the maxilla are rarely described in the literature and, in most cases, are related to the nasopalatine canal. This article describes a rare anatomical variation of the presence of a bilateral accessory canal extending from the nasal cavity lateral wall to an accessory foramen located on the hard palate, adjacent to the maxillary lateral incisor observed in cone beam computed tomography (CBCT) images. This case is an anatomical variation of the anterior superior alveolar nerve (canalis sinuosus). Identification of individual anatomical variations, especially on CBCT, may help the surgeon to avoid injuries to nerves during implant placement.

Risk assessment of inferior alveolar neurovascular bundle by multidetector computed tomography in extractions of third molars.

PURPOSE: This study aimed to assess the reliability of multidetector computed tomography (MDCT) in determining the surgical risk of the inferior alveolar neurovascular bundle in extractions of third molars. METHODS: The sample comprised thirty-three individuals (63 third molars) who underwent preoperative evaluation by MDCT before extraction of impacted mandibular third molars. MDCT was used to determine the relationship between the roots of the third molars and the mandibular canal, and the course of the mandibular canal. Inferior alveolar nerve (IAN) exposure and the presence of hemorrhage were analyzed after removal of the teeth. IAN neurosensory deficit was recorded after 7 days. Clinical and MDCT findings were compared using Fisher's exact test (P < 0.05). RESULTS: There was a statistically significant association between IAN exposure and the tomographic relationship between the roots of third molars and the mandibular canal (P = 0.015). Conventionally, all cases of IAN neurosensory deficit and hemorrhage occurred when the roots of the third molar presented in an at-risk relationship with the mandibular canal, however, this association was not statistically significant (P > 0.05). A statistically significant association was found between the lingual course of the mandibular canal and IAN exposure (P = 0.03). CONCLUSIONS: MDCT is an effective tool for determination of the surgical risk to the inferior alveolar neurovascular bundle in extraction of mandibular third molars.

Assessment of the relationship between tooth inclination and gingival and alveolar bone dimensions using computed tomography of the maxillary anterior teeth: a cross-sectional study.

OBJECTIVE: The present study aimed to investigate the relationship between tooth inclination and gingival and bone dimensions in maxillary anterior teeth. METHODS: This cross-sectional study included cone-beam computed tomography (CBCT) images of 160 maxillary anterior teeth (30 individuals). Tooth inclination, gingival and bone thickness, and distances from cementoenamel junction to alveolar bone crest and gingival margin were measured in the labial surface. The correlations were analyzed using Pearson and partial correlation tests (p≤0.05). RESULTS: In the central incisors, tooth inclination was positively and significantly related to apical bone thickness (R = 0.34, p= 0.001). In the canines, tooth inclination was negatively and significantly related to cervical bone thickness (R = - 0.34, p= 0.01) and positively associated to apical bone thickness (R = 0.36, p= 0.01) and to gingival margin-cementoenamel junction distance (R = 0.31, p= 0.03). In the lateral incisors, tooth inclination was not associated with gingival or bone dimensions. CONCLUSIONS: In the central incisors, the greater the labial tooth inclination, the greater is the apical bone thickness. In the canines, the greater the labial tooth inclination, the smallest is the cervical bone thickness, the greater is the apical bone thickness, and the greater is the gingival margin. Gingival and bone dimensions should be assessed when planning orthodontic treatment involving buccal movement of central incisors and canines.

Comparison of digital image displays performance in the detection of artificial internal root resorptions lesions.

OBJECTIVE: To compare the diagnostic efficacy of different devices for visualizing digital images in detecting simulated internal root resorption (IRR). METHODS: 26 uniradicular human teeth were sectioned along its long axis and randomly divided into two groups. Then, they were submerged in hydrochloric acid (HCl) P.A 37% at different times to make two types of defects: Type 1 (2 hours), and type 2 (3 hours). Digital periapical radiographs were acquired in three moments: before section, after section and after immersion in acid. The images were evaluated on three different devices: 27-inch iMac Desktop, 8-inch Android Tablet, and 5.5-inch iPhone 8 Plus using a 5-point scale. RESULTS: The sensitivity and accuracy values were higher with the use of the Android Tablet, for both types of defects. For the values of the area under ROC curve, higher results were observed with the Android Tablet and lower results with the iMac, showing a significant difference (p < 0.05) when comparing the use of the iMac with the Android Tablet and iPhone 8, for type 1 defects. When comparing the different devices, in the evaluation of images of type 2 defects, the values showed no statistical difference, regardless of the device evaluated (p > 0.05). CONCLUSIONS: The size of the lesion interferes with the detection capacity in the image. However, the use of portable devices does not impair the diagnosis of IRR, regardless of size and the dental practioners may use different devices/display, under optimal viewing conditions, to detect IRR lesions, without jeopardizing the diagnostic ability.

Computer tomographic differential diagnosis of ameloblastoma and odontogenic keratocyst: classification using a convolutional neural network.

OBJECTIVE: To analyse the automatic classification performance of a convolutional neural network (CNN), Google Inception v3, using tomographic images of odontogenic keratocysts (OKCs) and ameloblastomas (AMs). METHODS: For construction of the database, we selected axial multidetector CT images from patients with confirmed AM (n = 22) and OKC (n = 18) based on a conclusive histopathological report. The images (n = 350) were segmented manually and data augmentation algorithms were applied, totalling 2500 images. The k-fold × five cross-validation method (k = 2) was used to estimate the accuracy of the CNN model. RESULTS: The accuracy and standard deviation (%) of cross-validation for the five iterations performed were 90.16 ± 0.95, 91.37 ± 0.57, 91.62 ± 0.19, 92.48 ± 0.16 and 91.21 ± 0.87, respectively. A higher error rate was observed for the classification of AM images. CONCLUSION: This study demonstrated a high classification accuracy of Google Inception v3 for tomographic images of OKCs and AMs. However, AMs images presented the higher error rate.

Tomographic evaluation of infrazygomatic crest for orthodontic anchorage in different vertical and sagittal skeletal patterns.

BACKGROUND: Analysis of the anatomy of the region during preoperative planning is very important in order to minimize the risks of undesired movements in the supporting teeth or even damage to important structures such as the maxillary sinus. To the best of our knowledge, no study evaluated the relationship of these skeletal patterns with the anatomy of the infrazygomatic crest. The aim of this study was to evaluate the tomographic measurements of the infrazygomatic crest for placement of temporary anchorage devices in individuals with different vertical and sagittal skeletal patterns. MATERIAL AND METHODS: The measurements were analyzed in three regions in the crest of 67 patients above the maxillary first molar: A slice in the long axis of the mesiobuccal root, a slice passing through the center of the furcation area of the tooth, and another slice in the long axis of the distobuccal root. In each of these slices five measurements of the thickness of the infrazygomatic crest were performed, with a difference of 1 mm between them. The sagittal skeletal pattern was determined by the ANB angle and the vertical skeletal pattern by the SN.GoGn angle. RESULTS: The bone thickness of the crest tended to decrease gradually in the apical direction. There was no difference between different vertical and sagittal skeletal patterns. CONCLUSIONS: The individual parameters did not have significant influence in the thickness of the infrazygomatic crest. Key words:Tomography, X-Ray Computed, orthodontics, mini-implant, infrazygomatic crest, maxilla.

Assessment of fractal dimension and panoramic radiomorphometric indices in women with celiac disease.

OBJECTIVES: To assess the panoramic radiomorphometric indices and fractal dimension in women with celiac disease. METHODS: The sample consisted of 20 women with celiac disease and 20 healthy women (control group). The mandibular cortical index classification, panoramic mandibular index, mental index, and fractal dimension were evaluated on panoramic radiographs. One-way ANOVA with post hoc Tukey test was used for comparison of the linear measurements and fractal dimension between the celiac and control groups, adopting a significance level of 5% RESULTS: There was no significant difference in panoramic radiomorphometric indices or fractal dimension between the celiac and control groups. CONCLUSIONS: Panoramic radiomorphometric indices and fractal dimension revealed no significant bone changes in women with celiac disease.

Does the presence of maxillary central incisor edge asymmetry influence the perception of dentofacial esthetics in video analysis?

OBJECTIVE: To investigate the influence of incisal edge asymmetry of the maxillary central incisors on dentofacial esthetics among orthodontists, prosthodontists, and laypersons using video analysis. MATERIALS AND METHODS: Full-face films of a 52-year-old afro-descendant woman displaying various levels of incisal wear in the esthetic zone were captured. An acrylic resin mockup was made of the maxillary anterior region, enabling the reproduction of an attractive smile and restoring tooth wear. Four different levels of incisal asymmetry between the upper central incisors in 0.5 mm increments were prepared from this mockup. A film was made for each level of asymmetry (0.5, 1.0, 1.5, and 2.0) and one with no asymmetry, with the patient repeating a sentence, totaling five films. After a pilot study and sample calculation, the films were evaluated by 138 examiners: 46 orthodontists, 46 laypeople, and 46 prosthodontists. Each examiner evaluated the dentofacial esthetics of each film using visual analog scales. Data collected were statistically analyzed. RESULTS: Highest scores were awarded to the film with no asymmetry between upper centrals and the one with 0.5 mm of asymmetry. The asymmetries of 1.5 mm and 2.0 mm had the lowest scores from all three groups. CONCLUSIONS: The results of this video analysis indicate that asymmetries equal to or greater than 1.0 mm between the upper central incisors edges jeopardize dentofacial esthetics.

Assessing bone thickness in the infrazygomatic crest area aiming the orthodontic miniplates positioning: a tomographic study.

INTRODUCTION:: Due to the increasing use of miniplates for anchorage purposes in orthodontics, it is very important to know more about infrazigomatic crest anatomy (thickness), in adult patients. OBJECTIVES:: Evaluate the infrazygomatic crest region thickness, in adult (male and female) patients. METHODS:: Cone-beam computerized tomography (CBCT) images from 40 patients were used to assess cross-sectional measurements of the infrazygomatic crest region. Measurement 1 considered thickness 2 mm above the distobuccal root of the permanent maxillary first molar, while measurement 2 was taken 2 mm above the first measurement. RESULTS:: The mean thickness of the infrazygomatic crest in males was 3.55 mm for measurement 1 and 2.84 mm for measurement 2, while in females these were 2.37 mm and 2.24 mm, respectively. CONCLUSION:: The authors concluded that the overall mean thickness of the infrazygomatic crest was 2.49 mm with respect to measurement 1, and 2.29 mm for measurement 2, with no statistically significant differences between gender.