scholarly journals Evaluation of horizontal condylar angle in malocclusions with mandibular lateral displacement using cone-beam computed tomography

2021 ◽  
Author(s):  
Roberto L. Velásquez ◽  
Jorge C. Coro ◽  
José M. Bustillo ◽  
Sadao Sato

ABSTRACT Objectives To evaluate the horizontal condylar angle (HCA) in mandibular lateral displacement (MLD). Materials and Method s: HCA in MLD malocclusions were examined using cone-beam computed tomography data in subjects with MLD and control subjects. Results HCA in joints of control patients and contralateral side joints of MLD patients were not significantly different. The mean HCA on the shifted side was larger than on the contralateral side (P < .001) in the different HCA groups. HCA was significantly larger on the shifted side than on the contralateral side in skeletal Class I, Class II, and Class III groups (P < .001). Conclusions (1) There was no statistically significant difference between HCA in control patients and on the contralateral side in MLD patients. (2) HCA was significantly larger on the shifted side than on the contralateral side. (3) HCA on the shifted side and the contralateral side in MLD Class I, Class II, and Class III are significantly different.

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Mohammad Zandi ◽  
Abbas Shokri ◽  
Vahid Mollabashi ◽  
Zahed Eghdami ◽  
Payam Amini

Objetive: This study aimed to compare the anatomical characteristics of the mandible in patients with skeletal class I, II and class III disorders using cone beam computed tomography (CBCT). Material and Methods: CBCT scans of patients between 17 to 40 years taken with NewTom 3G CBCT system with 12-inch field of view (FOV) were selected from the archive. Lateral cephalograms were obtained from CBCT scans of patients, and type of skeletal malocclusion was determined (Class I, II or III). All CBCT scans were evaluated in the sagittal, coronal and axial planes using the N.N.T viewer software. Results: The ramus height and distance from the mandibular foramen to the sigmoid notch in class II patients were significantly different from those in skeletal class I (P < 0.005). Distance from the mandibular canal to the anterior border of ramus in class III individuals was significantly different from that in skeletal class I individuals (P < .005). Conclusion: Length of the body of mandible in skeletal class I was significantly different from that in skeletal class II and III patients. Also, ramus height in skeletal class I was significantly different from that in skeletal class II patients. CBCT had high efficacy for accurate identification of anatomical landmarks.   Keywords Prognathism; Retrognathism; Mandible; Anatomy; Cone beam computed tomography.


2011 ◽  
Vol 82 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Ahmet Yagci ◽  
İlknur Veli ◽  
Tancan Uysal ◽  
Faruk Izzet Ucar ◽  
Törün Ozer ◽  
...  

Abstract Objective: To test the null hypothesis that the presence of dehiscence and fenestration was not different among patients with skeletal Class I, II, and III malocclusions. Materials and Methods: In this retrospective study, a total of 123 cone-beam computed tomography (CBCT) images were obtained with an iCAT scanner (Imaging Sciences International, Hatfield, Pa). Patients with normal vertical patterns were classified according to dental malocclusion and ANB angle. Class I comprised 41 patients—21 girls and 20 boys (mean age, 22.4 ± 4.5 years); Class II comprised 42 patients—22 girls and 20 boys (mean age, 21.5 ± 4.2 years); and Class III comprised 40 subjects—22 girls and 18 boys (mean age, 22.1 ± 4.5 years). A total of 3444 teeth were evaluated. Analysis of variance and Tukey's test were used for statistical comparisons at the P &lt; .05 level. Results: Statistical analysis indicated that the Class II group had a greater prevalence of fenestration than the other groups (P &lt; .001). No difference was found in the prevalence of dehiscence among the three groups. Although fenestration had greater prevalence in the maxilla, more dehiscence was found in the mandible for all groups. In Class I, alveolar defects (dehiscence, fenestration) were matched relatively in both jaws. Furthermore, Class II and Class III subjects had more alveolar defects (41.11% and 45.02%, respectively) in the mandible. Dehiscences were seen with greater frequency in the mandibular incisors of all groups. Conclusion: The null hypothesis was rejected. Significant differences in the presence of fenestration were found among subjects with skeletal Class I, Class II, and Class III malocclusions. Fenestrations had greater prevalence in the maxilla, but more dehiscences were found in the mandible.


Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 541
Author(s):  
Xiao-Chuan Fan ◽  
Lin-Sha Ma ◽  
Li Chen ◽  
Diwakar Singh ◽  
Xiaohui Rausch-Fan ◽  
...  

(1) Background—The aim of the present study was to evaluate the correlation between the temporomandibular joint (TMJ) osseous morphology of normal skeletal pattern individuals with different dental malocclusions by using cone-beam computed tomography (CBCT). (2) Methods—The CBCT images of bilateral TMJs in 67 subjects with skeletal class I and average mandibular angle (26 males and 41 females, age range 20–49 years) were evaluated in this study. The subjects were divided into class I, class II division 1, and class II division 2 according to the molar relationship and retroclination of the maxillary incisors. Angular and linear measurements of TMJ were evaluated and the differences between the groups were statistically analyzed. (3) Results—Intragroup comparisons showed statistical differences for articular eminence inclination, the width of the glenoid fossa, the ratio of the width of the glenoid fossa to the depth of the glenoid fossa, the condylar angle, and the intercondylar angle between the malocclusion groups. The measurements of the glenoid fossa shape showed no significant difference between the left and right sides. Females showed more differences in the morphological parameters of TMJ between the three malocclusion groups than the males. (4) Conclusion—The present study revealed differences in the TMJ osseous morphology between dental class I and class II malocclusions in the normal skeletal pattern.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wener Chen ◽  
HungEn Mou ◽  
Yufen Qian ◽  
Liwen Qian

Abstract Background The aim of the study was to analyze the morphology and position of the tongue and hyoid bone in skeletal Class II patients with different vertical growth patterns by cone beam computed tomography in comparison to skeletal Class I patients. Methods Ninety subjects with malocclusion were divided into skeletal Class II and Class I groups by ANB angles. Based on different vertical growth patterns, subjects in each group were divided into 3 subgroups: high-angle group (MP-FH ≥ 32.0°), average-angle group (22.0° ≤ MP-FH < 32°) and low-angle group (MP-FH < 22°). The position and morphology of the tongue and hyoid bone were evaluated in the cone beam computed tomography images. The independent Student’s t‐test was used to compare the position and morphology of the tongue and hyoid bone between skeletal Class I and Class II groups. One-way analysis of variance (ANOVA) was used to compare the measurement indexes of different vertical facial patterns in each group. Results Patients in skeletal Class II group had lower tongue posture, and the tongue body was smaller than that of those in the Class I group (P < 0.05). The position of the hyoid bone was lower in the skeletal Class II group than in Class I group (P < 0.05). The tongue length and H-Me in the skeletal Class I group with a low angle were significantly larger than those with an average angle and high angle (P < 0.05). There was no significant difference in the position or morphology of the tongue and hyoid bone in the skeletal Class II group with different vertical facial patterns (P > 0.05). Conclusion Patients with skeletal Class II malocclusion have lower tongue posture, a smaller tongue body, and greater occurrence of posterior inferior hyoid bone position than skeletal Class I patients. The length of the mandibular body in skeletal Class I patients with a horizontal growth type is longer. The position and morphology of the tongue and hyoid bone were not greatly affected by vertical facial development in skeletal Class II patients.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Weiting Chen ◽  
Kaili Zhang ◽  
Dongxu Liu

Abstract Background Maxillary skeletal expanders (MSE) is effective for the treatment of maxillary transverse deformity. The purpose of the study was to analyse the palatal bone thickness in the of MSE implantation in patients with skeletal class III malocclusion. Methods A total of 80 adult patients (40 males, 40 females) with an average angle before treatment were divided into two groups, the skeletal class III malocclusion group and the skeletal I malocclusion group, based on sagittal facial type. Each group consisted of 40 patients, with a male to female ratio of 1:1. A cone-beam computed tomography scanner was employed to obtain DICOM data for all patients. The palatal bone thickness was measured at 45 sites with MIMICS 21.0 software, and SPSS 22.0 software was employed for statistical analysis. The bone thickness at different regions of the palate in the same group was analysed with one-way repeated measures ANOVA. Fisher’s least significant difference-t method was used for the comparison of pairs, and independent sample t test was employed to determine the significance of differences in the bone thickness at the same sites between the two groups. Results Palatal bone thickness was greater in the middle region of the midline area (P < 0.01), while the thickness in the middle and lateral areas in both groups was generally lower (P < 0.001). The bone in the anterior, middle, and posterior regions of the two groups became increasingly thin from the middle area toward the parapalatine region. The palatal bone was significantly thinner in the area 9.0 mm before the transverse palatine suture in the midline area, 9.0 mm before and after the transverse palatine suture in the middle area, and 9.0 mm after the transverse palatine suture in the lateral area. Conclusion The palatal bone was thinner in patients with class III malocclusion than in patients with class I malocclusion, with significant differences in some areas. The differences in bone thickness should be considered when MSE miniscrews are implanted. The anterior and middle palatal areas are safer for the implantation of miniscrews, while the thinness of the posterior palatal bone increases the risk of the miniscrews falling off and perforating.


2016 ◽  
Vol 17 (7) ◽  
pp. 542-548 ◽  
Author(s):  
Mohammad Y Hajeer ◽  
Mowaffak A Ajaj ◽  
Heba M Jazmati

ABSTRACT Introduction Few studies utilized cone beam computed tomography (CBCT) to evaluate soft tissue dimensions in malocclusion patients. The aim of this study was to analyze the three-dimensional (3D) soft tissue relationships of adult patients according to their gender and skeletal sagittal class using CBCT. Materials and methods The study sample consisted of 96 CBCT images of patients of both genders; aged 18 to 25 years with a normal vertical skeletal pattern. Patients were segregated into three groups according to their skeletal sagittal class: Class I (2 < ANB < 4), class II (ANB > 4), and class III (ANB < 2). The soft tissue measurements were analyzed in both the sagittal views and frontal volumetric rendered views using 3D-OnDemand software. Results In males, the measurements (U1-stom, nasal width, mouth width) were greater in class I than in class II group. Lower lip thickness was greater in class I than in class III group (p < 0.05). In females, both labiomental fold thickness and upper lip height measurements showed greater mean values in class II than in class I group. In contrast, lower lip height was greater in class I than in class III group. Ls-Pr, U1-stom, and face width at Cheilion revealed greater values in class III patients than in class II patients. On the other hand, the lower lip thickness, upper lip height, and lower lip height measurements showed greater values in class II than in class III group (p < 0.05). Soft tissue thicknesses and measurements were greater in males than in females. However, statistically significant differences between the two sexes were not detected for all of the variables measured in each skeletal class. Conclusion The current study indicates the presence of differences in soft tissue thicknesses and facial soft tissue dimensions among skeletal classes and between the two sexes. Clinical significance Cone beam computed tomography imaging is a very valuable tool to analyze 3D soft tissue characteristics of patients with different skeletal patterns of malocclusion. How to cite this article Jazmati HM, Ajaj MA, Hajeer MY. Assessment of Facial Soft Tissue Dimensions in Adult Patients with Different Sagittal Skeletal Classes using Cone beam Computed Tomography. J Contemp Dent Pract 2016;17(7):542-548.


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