Evaluation of skeletal changes in mandibular ramus height, corpus length, and mandibular angle changes following twin block appliance therapy using cone-beam computed tomography: A clinical prospective study

2021 ◽  
Vol 12 (3) ◽  
pp. 115
Author(s):  
VGanesh Shetty ◽  
KNillan Shetty
Author(s):  
Christian Reis Lemes ◽  
Carolina Fernandes Tozzi ◽  
Saulo Gribel ◽  
Bruno Frazão Gribel ◽  
Giovana Cherubini Venezian ◽  
...  

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.


2019 ◽  
Vol 13 (1) ◽  
pp. 544-550
Author(s):  
Silvan Correa ◽  
Rogério H. Lopes Motta ◽  
Milena B. Fellipe Silva ◽  
Sidney R. Figueroba ◽  
Francisco C. Groppo ◽  
...  

Purpose: The mandibular foramen, located on the internal surface of the mandibular ramus, is an important anatomical landmark for the success during the inferior alveolar nerve block. This cross-sectional retrospective study aimed to evaluate the location of the mandibular foramen through Cone-Beam Computed Tomography (CBCT) in different facial shapes. Materials and Methods: The determination of the location of the mandibular foramen was performed using CBCT of mesocephalic, dolichocephalic and brachycephalic patients (n=40 each). The ramus width (W), the distance from the mandibular foramen to the deepest point of the anterior border of the mandibular ramus (D), the distance from the mandibular foramen to the lowest point of the mandibular notch (V) and the distance from the inferior border of the mandible to the lowest point in of the mandibular border (R), as well as the ratios W/D and V/R, were measured. ANCOVA, two-way ANOVA and Chi-square tests were used to analyze the variation among the facial shapes. Results: The ramus width (W) was greater (p<0.0001) in the brachycephalic (28.4±0.5 mm) than in both mesocephalic (26.8±0.36 mm) and dolichocephalic (25.5±0.39 mm) patients. D (p=0.0433) and R (p=0.0072) were also greater in the brachycephalic (17.7±0.36 mm; 43.4±0.75 mm, respectively) than dolichocephalic (16.5±0.3 mm; 40.3±0.63 mm, respectively), but both did not differ from mesocephalic (17.3±0.36 mm; 41.8±0.66 mm, respectively) patients. The other measurements (V, W/D and R/V) did not significantly differ among facial shapes. Conclusion: The localization of the mandibular foramen was, in the horizontal direction, more posterior in the brachycephalic patients and, in the vertical direction, higher in the dolichocephalic patients, when compared to the other groups analyzed. Thus, the anatomic data found in this study may help dentists to increase the success of the inferior alveolar nerve block and prevent surgical complications.


2010 ◽  
Vol 35 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Kiyoshi Tai ◽  
Jae Hyun Park

Objective: The purpose of this research was to use cone-beam computed tomography (CBCT) images to evaluate dental and skeletal changes in upper and lower jaws after treatment with Schwarz appliances.Materials and Methods: 28 patients with Angle Class I molar relationships and crowding were randomly divided into two groups – 14 non-expanded and 14 expanded patients. 3D-Rugle CBCT software was used to measure various reference points before treatment (T0) and during the retention period of approximately 9 months after 6 to 12 month expansion (T1). Cephalometric and cast measurements were used to evaluate treatment in both groups. To test whether there were any significant differences between the control and treatment groups at T0 and T1, the Mann-Whitney U-test was used. Results: The dental arch (including tooth root apices) had expanded in the upper and lower jaws. Alveolar bone expansion of up to 2 mm apical to the cementoenamel junction (CEJ) was detected. The midpalatal sutures were separated in some cases and subsequent expansion was observed at the inner surface of the nasal cavity at the inferior turbinates. However,no significant (P &gt; 0.05) difference was observed in the inter-width of the mandibular bodies, zygomatic bones, nasal cavity in the middle turbinate region, condylar heads, or antegonial notches. In mandibular and maxillary cast measurements, arch crowding and arch perimeter showed statistically significant changes in the expansion group. The mandibular width values demonstrated no significant changes as measured from a point 2 mm apical to the CEJ, whereas the maxillary width values demonstrated significant changes as measured from a point 2 mm apical to the CEJ. Conclusions: This study indicates that the Schwarz appliance primarily affects the dento-alveolar complex, while it has little effect on either the mandibular bodies, any associated structures including the maxillary midpalatal suture and the inter-width of the nasal cavity in the middle turbinate region. In addition, the center of rotation of the mandibular and maxillary first molar was observed apical to the root apex.


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