scholarly journals Anatomical characteristics of mandibular bone in skeletal Class I, II and III patients by using cone beam computed tomography images in an iranian population

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.

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 ◽  
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 &lt; .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 &lt; .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.


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.


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.


2016 ◽  
Vol 87 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Luela Aranitasi ◽  
Beatriz Tarazona ◽  
Natalia Zamora ◽  
Jose Luis Gandía ◽  
Vanessa Paredes

ABSTRACT Objectives: To quantify the prevalence of cervical vertebrae anomalies and to analyze any association between them and skeletal malocclusions or head posture positions in the same study. Materials and Methods: Two hundred forty patients who were attending the Department of Orthodontics of the University of Valencia for orthodontic treatment were selected and divided into three groups: skeletal Class I (control group, 0° &lt;ANB &lt; 4°), Class II (ANB ≥ 4°), and Class III (ANB ≤ 0°) according to ANB Steiner angle. The morphology of the first five cervical vertebrae was analyzed with cone beam computed tomography to identify any anomalies. Intra- and interobserver error methods were calculated. Results: Dehiscence and fusion of one unit (both 23.3%) and partial cleft (11.7%) were the most frequent anomalies, while occipitalization was the least common (3.3%). Dehiscence anomaly was observed when the control group was compared with Classes II and III and partial cleft anomaly when Class I was compared with Class III. Furthermore, NSBa and ss-N-sm/ANB angles were associated with partial cleft anomaly, while NSL/NL angle and extended head posture were associated with fusion anomaly. Conclusions: Fusion, dehiscence, and partial cleft were the most frequent cervical vertebrae anomalies. Dehiscence and partial cleft were found to present statistically significant differences between Class I and Classes II and III. Cervical vertebrae anomalies and head posture were associated with fusion.


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