scholarly journals Evaluation of the position and morphology of tongue and hyoid bone in skeletal Class II malocclusion based on 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 ◽  
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 ◽  
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.


Author(s):  
PAN JIANG ◽  
YUXING BAI ◽  
FEI HU ◽  
XUEYANG ZHANG ◽  
QUN YANG ◽  
...  

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 [Formula: see text] 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.


2019 ◽  
Vol 48 (2) ◽  
pp. 030006051989238
Author(s):  
Min Lin ◽  
Yifei Xu ◽  
Hao Wu ◽  
Haixia Zhang ◽  
Shuang Wang ◽  
...  

Objective This study was performed to evaluate the position and morphology of the temporomandibular joint in female patients with skeletal class II malocclusion and to investigate the association between temporomandibular joint disorders and facial types using cone-beam computed tomography. Methods A lateral cephalogram was taken to determine the skeletal class of each participant. Sixty female patients aged 16 to 28 years were divided into high-angle, low-angle, and control groups. The shape of the condyle–fossa was measured and assessed on cone-beam computed tomography images of the 120 temporomandibular joints. Results Some condylar shape measurements displayed statistically significant differences among the groups. No significant differences were found in the length of the condyle, width of the glenoid fossa, or height of the articular eminence among the three groups. The posterior condylar position was more frequently observed in the low-angle group, whereas the anterior condylar position was more prevalent in the high-angle group. Conclusion The present study revealed differences in the condyle–fossa morphology and position in female patients with skeletal class II malocclusion with different vertical facial types.


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 12 (3) ◽  
pp. 230-233
Author(s):  
Piyush Gupta ◽  
Nivedita Sahoo ◽  
Kavuda Nagarjuna Prasad ◽  
MS Rami Reddy ◽  
Saranya Sreedhar ◽  
...  

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