Anatomical variations in the maxillary anterior region: a cone beam computed tomographic study of the canalis sinuosus and its accessory canals.

The objective of this study was to verify the frequency, diameter, and location of the canalis sinuosus (CS) and its accessory canals (ACs) using cone beam computed tomographic (CBCT) images and to correlate these findings with patient sex, age, and skeletal facial pattern. This observational retrospective study assessed the CBCT scans of 398 patients. The laterality, diameter, and location of the terminal portion of the canals were recorded. Linear measurements of the nasal cavity floor, buccal cortical bone, and alveolar ridge crest were also made. The χ2 and Fisher exact tests were used to verify the relationships between patient sex, age, and facial pattern and the presence of CS and ACs. The presence of CS and ACs was verified in 195 (48.99%) and 186 (46.73%) individuals, respectively, and showed no correlations with sex, age, or facial pattern. In 165 cases (84.61%), the CS emerged bilaterally. For ACs, most cases (n = 97; 52.14%) were unilateral. A total of 277 ACs were detected, and 161 (58.12%) of these were located in the palatal or incisive foramen region and 116 (41.88%) in the buccal region. Their terminal portions were located more frequently in the central incisor region (38.26%). The mean CS diameter was significantly larger in men than in women (P < 0.001). The linear measurements of the nasal cavity floor, buccal cortical bone, and alveolar ridge crest did not reveal statistically significant differences between the sexes. This knowledge is helpful for maxillary surgical planning to avoid damage to the neurovascular bundle and subsequent complications.

Accuracy of 3D virtual surgical planning for maxillary positioning and orientation in orthognathic surgery.

OBJECTIVE: This retrospective and observational study evaluated the accuracy of a 3D virtual surgical planning (VSP) for the maxillary positioning and orientation in patients undergoing bimaxillary orthognathic surgery, comparing the planned and postoperative outcomes. SETTING AND SAMPLE POPULATION: Seventy consecutive patients of both sexes, who were submitted to bimaxillary orthognathic surgery between 2015 and 2019 were included in our study. MATERIAL AND METHODS: The patients were evaluated by fusing preoperative planning and postoperative outcome using cone-beam computed tomography scan evaluation. Three-dimensional VSP and postoperative outcomes were compared by using three linear and three angular measurements. The main outcome interest was the difference between the VSP movement, and the surgical movement obtained. The success criterion adopted was a mean linear difference of <2 mm and a mean angular difference of <4°. RESULTS: Results were analysed using a linear mixed model with fixed and random effects, at α = .05. No significant statistical differences were found for linear and angular measurements between the planned and postsurgical outcomes (P > .05). All overlapping points presented values within the range considered clinically irrelevant (<2 mm; <1°). CONCLUSIONS: Three-dimensional VSP was executed with a high degree of accuracy. When comparing the planned and postsurgical outcomes, all overlapping points presented values within the range considered clinically irrelevant.

Imaginology Tridimensional Study of Temporomandibular Joint Osseous Components According to Sagittal Skeletal Relationship, Sex, and Age.

OBJECTIVE: To assess the temporomandibular joint (TMJ) osseous components morphology and the condyle position in patients with different sagittal skeletal relationships, sex, and age, using cone-beam computed tomography (CBCT). METHODS: The CBCT images of 180 asymptomatic patients (60 class I, 60 class II, and 60 class III) were assessed retrospectively. Groups were also divided according to age (<40 years, n = 90; ≥40 years, n = 90) and sex (male, n = 90; female, n = 90). Right- and left-sided TMJ spaces, articular eminence inclination (AEI) and height (AEH), thickness of the roof of the glenoid fossa (TRGF) and the anteroposterior position of the condyle in glenoid fossa were evaluated. Differences were tested using the analysis of variance, Tukey and t-tests (P < 0.05). RESULTS: For condylar position, no differences were found between sex and age groups, but spatial differences existed among skeletal classes. Significant differences were found between the right and left angular position in patients with malocclusion. Class II individuals presented lower anterior articular spaces. The condyle-glenoid fossa relationship presented a moderate correlation of bilaterality. The AEI and AEH were significant lower in class III individuals and class I patients presented the lowest values for TRGF. The values of AEH, TRGF and of all joint spaces of males were higher. In individuals over the age of 40 years, the AEI and AEH measurements were significant greater. CONCLUSION: Sagittal skeletal relationships have a significant effect on condyle position, AEI, and AEH. The eminence inclination and height and TRGF are influenced by sex and age.

Surgical Treatment of Synovial Chondromatosis in the Inferior Compartment of the Temporomandibular Joint With Articular Disc Involvement.

The authors report an unusual case of painful synovial chondromatosis originated in the inferior compartment of the temporomandibular joint (TMJ) with articular disc involvement in a 56-year-old woman with complaint of severe pain in the right preauricular region. Magnetic resonance images showed advanced destruction of the right articular disc anteriorly displaced, condylar erosion, and distinct nodules within an extremely expanded inferior joint compartment with large amount of fluid, as well as a large TMJ effusion. A scintigraphy showed elevated bone uptake in the right TMJ, demonstrating intense bone remodeling activity in the region. After a right internal maxillary artery embolization, the patient underwent open surgery. The intraoperative procedures, including articular disc removal, condylar remodeling, and replacement of the articular disc, are described in detail. Synovial chondromatosis of the TMJ is a rare disease, especially when it affects the inferior compartment and the articular disc. Initial diagnosis is challenging and imaging techniques (magnetic resonance imaging and scintigraphy) play an important role in identifying signs, making accurate diagnosis, and offering additional information not available with conventional imaging, such as TMJ inflammation or remodeling. In these patients, open surgery may be considered a definitive treatment, since the postoperative recurrence rate is very low.

Le Fort I osteotomy for the removal of a rare unicystic ameloblastoma lesion in the maxillary sinus.

The unicystic ameloblastoma (UA) presents the clinical and radiographic characteristics of a maxillary cyst, making early diagnosis difficult. A 30-year-old man had an extensive, asymptomatic lesion in the right maxillary sinus. Radiographic examinations demonstrated a retained tooth in association with a lesion. Histopathologic examination revealed the presence of UA with intraluminal and mural infiltration and a follicular pattern. Le Fort I access was chosen for enucleation of the lesion and curettage of the site, which were followed by cryotherapy. The treatment provided adequate intraoperative visibility, enabled the preservation of the surrounding bone, and eliminated postoperative complications. Follow-up over 5 years demonstrated no recurrence.

Uprighting Bilateral Impacted Mandibular Permanent Second Molars with the Brass Wire Technique: A Case Report.

UNLABELLED: Revalence of impaction of mandibular permanent second molars is between 0.06 and 2.3 percent. In order to reduce treatment time and complications associated with tooth impaction, intervention should take place once the problem is detected. The usual treatment options consists of surgical exposure, luxation of the impacted tooth, extraction of adjacent third molar, orthodontic treatment, and uprighting with brass wires or mini-screws. AIM: The present paper reports a case of bilateral impaction of mandibular permanent second molars ' (MM2s) treated with extraction of the mandibular third molars (MM3s) and surgical-orthodontic uprighting with the brass wire technique. METHOD: The MM3s were removed, and the impacted MM2s were surgically exposed. Brass wire was placed apicaly to the mesial of the MM2 from the lingual tissue out toward the buccal. The lingual end of the wire was bent over the area of contact and twisted with the buccal end Monthly wire tightening gradually moved the MM2s distally and towards the occlusal plane. RESULTS: Uprighting was achieved in 4-5 months, with discrete pain caused by activation of the wire. CONCLUSION: This technique proved to be a simple, low-cost, and quick treatment option for uprighting impacted mandibular permanent second molars.

The relation between persistent foramen tympanicum and degenerative bone alterations in temporomandibular joint region.

OBJECTIVES: The aim of this study was to evaluate, using cone-beam computed tomography (CBCT), the relationship of persistent foramen tympanicum (PFT) with degenerative changes in the temporomandibular joint (TMJ) and the presence of pneumatized glenoid fossae and articular eminences. METHOD: Two experienced oral and maxillofacial radiologists evaluated 510 CBCT scans, from which 94 patients were divided into two groups: G1-patients with PFT and G2-control group. The location of the PFT, presence, or absence of degenerative TMJ changes and morphology were evaluated. Similarly, all images were evaluated for the presence of pneumatized articular eminence and glenoid fossa. The Chi-square test and Fisher's Exact test were used for the categorical variables. A multinomial logistic regression model was performed for subgroup analysis. To assess the estimation-chance occurrence of TMJ alterations the Odds Ratio analysis was used. RESULTS: Statistically significant results were found for erosion, planning, and subchondral cyst. Regarding TMJ morphology, significant results were found for: round, flat, and others. Moreover, it was possible to observe that patients who had the PFT were approximately 48 times more likely to manifest TMJ alterations and approximately 3 times more likely to manifest articular eminence pneumatization. CONCLUSION: Since individuals who have FTP have a greater chance of having TMJ and PEA changes, it is important for the dental radiologist to be aware of these signs in CBCT scans for a correct diagnosis. TRIAL REGISTRATION NUMBER: CAAE: 34328214.3.0000.0104 (11/30/2014).

Assessment of temporomandibular joint bone changes associated with anterior disc displacement: An MRI cross-sectional study.

OBJECTIVE: This cross-sectional study aimed to evaluate the presence of bone changes on magnetic resonance imaging (MRI) scans of patients with temporomandibular joint (TMJ) anterior disc displacement (ADD) with reduction (ADDWR) and without reduction (ADDWoR). METHODS: TMJ-MRI scans were screened for the presence of ADD. 285 scans presented ADD, being further divided into ADDWR (n = 188) and ADDWoR (n = 97). Bone changes on the mandibular condyle and articular eminence were also assessed and computed. The chi-square test compared the association of these bone changes with the presence of ADDWR and ADDWoR, with a significance level of 5 %. Also, the prevalence ratio (PR) was calculated. RESULTS: In the mandibular condyle, subchondral cyst (p = 0.035, PR = 1.08) and bone edema (p = 0.044, PR = 2.40), more prevalent on ADDWR, and generalized sclerosis (p = 0.015, PR = 1.04), more prevalent on ADDWoR, presented significant association with ADD. On the articular eminence, generalized sclerosis (p = 0.015, PR = 1.04) and articular surface flattening (p = 0.003, PR = 1.19) presented significant association with ADD, both more prevalent on ADDWoR. CONCLUSION: Bone changes are usual findings in TMJ with ADD diagnosis. The real influence of ADD is not fully clear, although clinicians should be aware of patients with this condition, to provide an early diagnosis and improve patient´s prognosis.

Three-dimensional evaluation of mandibular condyle and coronoid process according to sex, age, and skeletal deformities.

OBJECTIVE: To correlate the volume of the mandibular condyle (MC) and the coronoid process (CP) with sex, age, and skeletal deformities. METHODS: The structures were visualized through semi-automatic segmentation of the 3D model and complemented with manual segmentation, using the ITK-SNAP 3.0 software. Mann-Whitney, Kruskal-Wallis, and the Dunn test were performed (p < 0.05). RESULTS: The MC volume showed statistical differences between sex and skeletal deformities. Men and Class III patients showed higher values. CP volume was not influenced by age or skeletal deformities. However, statistical differences were found between sex, with higher values for men. CONCLUSION: MC volume was influenced by sex and skeletal deformities, while CP was influenced only by sex. Women have smaller volumes for these structures. Age is not correlated with the volume of MC and CP. The highest and lowest values of condylar volume were found for Class III and II individuals, respectively.

Correlation between the presence of the median perforating canal in adults with sex, age and skeletal facial patterns: A cross-sectional study.

INTRODUCTION: The aim of the present study was to evaluate the presence of the median perforating canal (MPC) and its morphometric measurements in Cone Beam CT (CBCT) scans of adult patients, correlating the findings with sex, age and skeletal facial patterns. MATERIAL AND METHODS: 717 CBCT scans were selected from a Brazilian population and the presence of the MPC was recorded. MPC diameter was measured in three points: lingual, medial and buccal. To determine the correlation between MPC presence and sex, age and ANB angle classifications the Chi-square test was performed. MPC diameters were related to sex, age and skeletal discrepancies using Mann-Whitney U and Kruskal-Wallis tests. The level of significance adopted was 5%. RESULTS: Of the 717 CBCT scans analyzed, the MPC was present in 181 patients (25.24%), 279 (38.91%) men and 438 (61.09%) women. The mean age was 37.91 (±14.46) years old, ranging from 18 to 88 years old. There were no differences in the presence of MPC between women and men (p = 0.85), between skeletal discrepancies (p = 0.09) and age groups (p = 0.94). Regarding the MPC diameter, statistical difference was found only for the medial diameter between sexes (p = 0.04), with the highest values in men. CONCLUSION: The MPC was detected in 25.24% of the studied population, with significant differences only for its medial diameter in men.

Evaluation of ortogonblender software bone movement tools in bimaxillary orthognatic surgeries performed in dolphin software.

The aim of this observational, longitudinal and retrospective study was to evaluate the fidelity of virtual surgical planning (VSP) performed on Dolphin Imaging & Management Solutions® 11.95 software on hard tissues, using the tools of the open-source software OrtogOnBlender - Blender3D. For this, linear, angular and 7-point anatomical measurements of the skeletal profile were used, and the discrepancies between the VSP and the result after bimaxillary orthognathic surgery were calculated. Pre- and postoperative cone beam CT (CBCT) scans of 43 consecutive patients with class II and III skeletal deformities were evaluated and the results of the VSP were compared to the 1-month postoperative results. All overlapping points presented values within the range considered clinically irrelevant (< 2 mm and < 4°) and differences were not significant (p > 0.05). The comparison of anatomical points showed lower values (≤ 2.11 mm) in point A of class II. For hard tissues, the comparison between VSP and 1-month postoperative tomography demonstrated the faithful results of virtual planning using this software.

Accuracy of three-dimensional soft tissue profile prediction in orthognathic surgery.

PURPOSE: To evaluate the accuracy of three-dimensional (3D) soft tissue prediction in bimaxillary orthognathic surgery. METHODS: Cone-beam computed tomographs of 88 patients with class II (n = 46) and class III (n = 42) malocclusions, who underwent bimaxillary orthognathic surgery, were included in this retrospective study. 3D soft tissue prediction and postoperative outcome were compared by using ten landmarks of facial soft tissues. Patients' sex and age were also assessed. Results were analyzed using a mixed model methodology (p < 0.05). RESULTS: The success criterion adopted was a mean discrepancy of < 2 mm. Most mandibular landmarks indicated a tendency for underprediction with a downward direction in class II patients, with some values > 2 mm. In class III, there was overprediction with a downward direction for the mandibular landmarks, with values < 2 mm. More accurate results were found in female and older patients. CONCLUSIONS: 3D surgical planning showed clinically acceptable results for predicting soft tissues in patients undergoing bimaxillary orthognathic surgery, with more accurate results for class III patients. Although some differences were found when age and sex were interacted, a consistent association between these variables could not be stated. These results support the clinician, as accuracy can provide a strong guide to the surgeon when planning surgical orthodontic treatment.

Impact of orthognathic surgery on the prevalence of dehiscence in Class II and Class III surgical-orthodontic patients.

OBJECTIVES: The objectives were to evaluate and compare the presence of bone dehiscence before and after orthognathic surgery. MATERIALS AND METHODS: In this retrospective study, 90 cone-beam computed tomography (CBCT) scans from 45 patients were evaluated. Class II (n = 23) and Class III (n = 22) orthodontic patients who were being prepared for orthognathic surgery were measured. CBCT scans were obtained about 30 days prior to (T0) and 6 months after (T1) double jaw orthognathic surgery. The distance between the cemento-enamel junction (CEJ) and the alveolar bone crest was assessed at the buccal and lingual surfaces of all teeth, on both sides and arches, except for the second premolars and the second and third molars. A total of 1332 sites were measured for Class II (644) and Class III (688) patients. The software used was OsiriX (version 3.3 32-bit). Data were compared with Wilcoxon and McNemar tests at the 5% level. RESULTS: Bone dehiscence before surgery was present in 26% and 15% of the Class II and III groups, respectively. The presence of dehiscence increased to 31% in the Class II and 20% in the Class III patients after surgery (P < .05). CONCLUSIONS: The prevalence of dehiscence increased slightly in Class II and Class III surgical-orthodontic patients after orthognathic surgery. Temporary vascular supply reduction and oral hygiene difficulties may explain these results; however, more studies are needed.

Comparison of limited- and large-volume cone-beam computed tomography using a small voxel size for detecting isthmuses in mandibular molars.

PURPOSE: This study was performed to compare the ability of limited- and large-volume cone-beam computed tomography (CBCT) to display isthmuses in the apical root canals of mandibular molars. MATERIALS AND METHODS: Forty human mandibular first molars with isthmuses in the apical 3 mm of mesial roots were scanned by micro-computed tomography (micro-CT), and their thickness, area, and length were recorded. The samples were examined using 2 CBCT systems, using the smallest voxels and field of view available for each device. The Mann-Whitney, Friedman, and Dunn multiple comparison tests were performed (α=0.05). RESULTS: The 3D Accuitomo 170 and i-Cat devices detected 77.5% and 75.0% of isthmuses, respectively (P>0.05). For length measurements, there were significant differences between micro-CT and both 3D Accuitomo 170 and i-Cat (P<0.05). CONCLUSION: Both CBCT systems performed similarly and did not detect isthmuses in the apical third in some cases. CBCT still does not equal the performance of micro-CT in isthmus detection, but it is nonetheless a valuable tool in endodontic practice.

A comparative study of the accuracy between two computer-aided surgical simulation methods in virtual surgical planning.

OBJECTIVE: The aim of this retrospective and observational study was to compare the accuracy of two different virtual surgical planning (VSP) protocols, namely, the CASS method and the modified CASS method. MATERIALS AND METHODS: The patients underwent bimaxillary orthognathic surgery, planned using either the CASS method or the modified CASS method. Linear and angular discrepancies between the VSP outcome and postoperative outcome for both groups were compared for maxilla, mandible, and chin segments. Aside from the comparison between both groups, additional criteria were used to determine the accuracy of the protocol based on a linear and angular difference between planned and actual outcomes of less than 2 mm and 4°, respectively. The intergroup comparisons were performed by one-way ANOVA, with the level of significance set at 5%. RESULTS: A total of 21 patients, of both genders, were assigned into group I (n = 11), planned with the CASS method, and group II (n = 10), planned with the modified CASS method. Both the CASS and modified CASS methods presented similar accuracy with regard to linear differences for the maxilla, mandible, and chin segments, except for ΔX for the mandibular segment, where the modified CASS method showed slightly better accuracy. However, there was a statistically significant difference with regard to angular differences in the chin segment, with the CASS method shown to be the more accurate. Aside from Δpitch for the chin segment, no linear or angular differences exceeded 2 mm or 4°. CONCLUSION: Although statistically significant differences were found with regard to angular measurements in the chin segment, the accuracy of the modified CASS method for virtual planning can be considered as clinically equivalent, with a performance comparable to that of the CASS method.

Correlation between joint effusion and morphology of the articular disc within the temporomandibular joint as viewed in the sagittal plane in patients with chronic disc displacement with reduction: A retrospective analytical study from magnetic resonance imaging.

Objective: To evaluate the presence of joint effusion and morphology of the articular disc (AD) viewed in the sagittal plane in patients with disc displacement with reduction (DDWR) and to correlate the results with clinical findings.Methods: The sample consisted of 116 patients with DDWR who were evaluated clinically and with magnetic resonance imaging. The AD's morphology was assessed from the sagittal view with the mouth both open and closed. The statistical analysis demonstrated a significance level of 5%.Results: With a mean age of 35 years, 79 patients (68.10%) showed joint effusion, and the female gender was most prevalent (p < 0.05). The results showed a relationship between joint effusion and DDWR in both sides (p < 0.05).Conclusion: Clinically, the present study can infer that DDWR is associated with joint effusion, and females are the most affected. It can be suggested that the pain may be associated with joint effusion.

How does bimaxillary orthognathic surgery change dimensions of maxillary sinuses and pharyngeal airway space?

OBJECTIVES: To assess changes in the maxillary sinus (MS) and pharyngeal airway space (PAS) after bimaxillary orthognathic surgery using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The CBCT scans of 48 patients were divided into two groups: group 1: maxillary advancement and mandibular setback (n = 24); group 2: maxillomandibular advancement (n = 24). The CBCTs were acquired 1 to 2 months preoperatively and 6 to 8 months postoperatively. A kappa test was used to determine intra- and interexaminer agreement. Area, volume, and linear measurements of MSs and PASs obtained before and after surgery were compared using a mixed model (P < .05). RESULTS: All variables of the MS showed significant postsurgical reductions in both groups, except the MS length, which showed a significant increase in group 2. Volume and minimum axial area of PAS showed statistically significant postsurgical increases in both groups (P < .05). CONCLUSIONS: Despite the reduction in the MS and the increase in the PAS, results indicated that the airway was not negatively affected after maxillomandibular advancement and maxillary advancement with mandibular setback.

Limitation of diagnostic value of cone-beam CT in detecting apical root isthmuses.

INTRODUCTION: Isthmuses are reported as common anatomic complexities in teeth often associated with failures in endodontic treatment. They should be considered before starting treatment and a preoperative computed tomography scan (CT) may demonstrate these complexities. OBJECTIVE: To assess the diagnostic value of the highest resolution settings of a cone-beam CT (CBCT) system in identifying and measuring apical isthmuses, using micro-CT as reference. METHODOLOGY: After micro-CT scanning, 40 humans' lower first molars with isthmuses in the apical-3 mm of mesial roots were scanned by the highest resolution settings of the New Generation i-Cat ® CBCT equipment. Two blinded observers recorded the detection of isthmuses in CBCT scans. The lengths of isthmuses were compared between micro-CT and CBCT to assess the diagnostic value of CBCT. Quantitative data for sensitivity were represented as percentages (95% confidence interval). The Bland-Altman method was used to assess differences between gold standard lengths (micro-CT) and CBCT lengths. RESULTS: BCT demonstrated 30 positive findings, representing sensitivity for isthmus identification of 75% (95% CI=0.4114-1.1364). Differences between the lengths in micro-CT (1.99±0.40 mm) and CBCT (1.53±0.41 mm) were significant (p<0.0001). CONCLUSION: The CBCT device used presented limited diagnostic value in the identification and measurement of apical isthmuses in the mesial roots of lower molars. In some cases, the actual anatomy of the apical root canal may not be completely delineated in this type of CBCT system, even using the highest resolution settings.

Cone beam computed tomography study of osteoarthritic alterations in the osseous components of temporomandibular joints in asymptomatic patients according to skeletal pattern, gender, and age.

OBJECTIVE: The aim of this study was to evaluate the prevalence of osteoarthritic alterations in the osseous components of the temporomandibular joint (TMJ) in asymptomatic patients with different skeletal patterns, gender, and age groups with cone beam computed tomography (CBCT) images. STUDY DESIGN: CBCT images of 213 asymptomatic patients were assessed for the presence of any degenerative changes in the condyle and fossa/eminence complex. Each TMJ was evaluated separately and was classified as normal, indeterminate for osteoarthritis, or affected by osteoarthritis. Differences were tested by using the χ2 and Fisher's exact tests (P < .05). RESULTS: In total, 52.3% of the joints presented some visible alteration in the osseous components. Abnormalities were detected in 32.6% of the condyles and 31.5% of the articular fossae/eminences, and flattening was the most prevalent alteration in all classes. There was no statistically significant difference in the prevalence of alterations in either the condyle or the articular fossa/eminence among the skeletal groups for the entire sample or for the gender and age subsets. CONCLUSIONS: There are no differences in degenerative TMJ changes in patients with or without skeletal jaw discrepancies. No differences were found when gender and age were considered.