scholarly journals Analysis of Three-Dimensional Morphological Differences in the Mandible between Skeletal Class I and Class II with CBCT Fixed-Point Measurement Method

Scanning ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qiang Dong ◽  
HaoYu Shi ◽  
Qi Jia ◽  
Yueyi Tian ◽  
Keqian Zhi ◽  
...  

This study was aimed at determining the three-dimensional differences in the mandible morphology between skeletal class I and II patients, at exploring the pathogenic mechanisms and morphological characteristics of skeletal class II, and at providing clinical references. The subjects were assigned to two groups according to the size of ANB angle: skeletal class I ( 2 ° < ANB   angle < 5 ° ) and skeletal class II ( 5 ° < ANB   angle < 8 ° ). After cone-beam computed tomography (CBCT) scanning, 31 landmarks and 25 measurement items were determined by In Vivo Dental 5.1 software (Anatomage, CA) for statistical analysis. The results were as follows: Co-Go, Go-Me, and CdM-CdD in skeletal class II cases were smaller than those in skeletal class I, and GoR-Me-GoL, GoR-Me-CoL, and, Ig-Men were larger than those in skeletal class I cases. In conclusion, there were significant differences in the three-dimensional morphology of the mandible between skeletal class I and class II patients. The vertical growth of the ramus, the horizontal growth of the mandibular body, and the condyle in skeletal class II patients were smaller than those in skeletal class I cases. In skeletal class II, the growth of the anterior part of the mandible in the vertical direction was larger than that in skeletal class I, and the shape of the mandible was more extended.

2021 ◽  
Author(s):  
Xueqin Zhang ◽  
Jianqing Deng ◽  
Zhaoxiang Wen ◽  
Zhengyuan Chen ◽  
Liyi Gan ◽  
...  

Abstract Background: To establish the three-dimensional facial soft tissue morphology of adolescent and adult females in the Guangdong ethnic group and to study the morphological characteristics of hyperdivergent skeletal class Ⅱ females in Guangdong compared with the characteristics of normal groups.Materials and Methods: The 3dMDface system was used to capture face scans of 160 patients, including 45 normal and 35 hyperdivergent skeletal class II adolescents (aged 11–14 years old) and 45 normal and 35 hyperdivergent skeletal class II adults (aged 18–30 years old). Thirty-two soft tissue landmarks were mapped, and 21 linear, 10 angular and 17 ratio measurements were obtained by 3dMDvultus analysis software. Data were assessed with a t-test of two independent samples between the normal adolescent and adult groups and between the normal and hyperdivergent skeletal class II groups.Results: The linear measurements of the Guangdong adult females were larger than those of the adolescents. However, the angular and ratio measurements had little difference. The vertical linear measurements were higher and the sagittal and transverse linear measurements were smaller in the hyperdivergent class II group (p<0.05). The soft tissue ANB angle, chin-lip angle, and mandibular angle were significantly larger and the soft tissue facial convexity angle and nasal convexity angle were significantly smaller in the hyperdivergent class II group (p<0.05). Additionally, there were significant differences in the ratio measurements between the hyperdivergent class II groups and the control groups (p<0.05).Conclusions: The three-dimensional facial morphology of Guangdong adolescent and adult females was acquired. The facial soft tissue measurements of the adults were higher in height, width and depth, suggesting that from the adolescent to adult period, facial soft tissue grows in three dimensions. However, the facial convexity and proportional relationships were similar, suggesting that the growth pattern remained the same. The three-dimensional facial soft tissue features of hyperdivergent skeletal class II were characterized by the terms “long, convex, and narrow”, which was similar to the hard tissue features of hyperdivergent skeletal class II seen in previous studies. Three-dimensional facial measurements can reflect intrinsic hard tissue characteristics.


2018 ◽  
Vol 89 (1) ◽  
pp. 93-101
Author(s):  
Fernando C. Brito ◽  
Daniel P. Brunetto ◽  
Matilde C. G. Nojima

ABSTRACT Objectives: To characterize upper airway volume and morphology in patients with different skeletal patterns of Class II malocclusion compared to Class I. Materials and Methods: A total of 197 individuals who had cone-beam computed tomography were allocated into groups according to ANB, SNA, and SNB angles (Class I, Class II maxillary protrusion, Class II mandibular retrusion), each subdivided into hypodivergent, normal, and hyperdivergent. Nasopharynx (NP), oropharynx (OP), and hypopharynx (HP) were assessed with three-dimensional image reconstruction software. Results: Intergroup comparison did not detect significant differences in volume and morphology of NP, OP, and HP. The males displayed larger OP and HP volume than the females. Positive correlations between age and NP, OP, HP volume and between craniocervical angle and OP and HP volume were observed. Linear regression analysis detected a tendency for OP and HP volume to increase as maxillary and mandibular length increased. Conclusions: Upper airway volume and morphology were similar in different skeletal patterns of Class II malocclusion. Actual upper and lower jaw lengths were more closely related to upper airway volume and morphology than the angles that reflected their position relative to the cranial base.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhuqing Wan ◽  
Steve Guofang Shen ◽  
Haijun Gui ◽  
Peng Zhang ◽  
Shunyao Shen

Abstract The aim of this study is to evaluate the postsurgical stability of skeletal class II patients after performing a counter-clockwise rotational (CCWR) procedure for the maxilla-mandibular complex (MMC) by using a novel Three-dimensional (3D) Position-Posture(P-P) measuring method. Twenty-five patients (5 males and 20 females) were included in this study. The postoperative CT scans of the skull were taken before surgery(T0), 3–7 days (T1), 3 months (T2), and 6 months (T3) after surgery. Specific anatomic landmarks were chosen to determine the position of the segments, while three equally perpendicular planes were created to describe their posture. The results show that the linear relapse of maxillary landmarks during the follow-up were acceptable (≤0.5 mm). The relapse of maxillary pitch plane at 6-months follow-up is 1.52°, which is acceptable. There was a significant pitch plane relapse of the mandibular-body segment with an average of 1.86° between T1 and T2 models, 3.28° between T1 and T3 models. There was no significant difference between roll and yaw planes during the follow-up. We therefore conclude that the P-P method could be used to accurately analyze the postsurgical stability of skeletal class II orthognathic surgery cases. For CCWR procedures, it was also shown that the there is a tendency for recurrence most specially on the body of the mandible.


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 17 (4) ◽  
pp. 817-825
Author(s):  
Frédéric Rafflenbeul ◽  
Hadrien Bonomi-Dunoyer ◽  
Thibaut Siebert ◽  
Yves Bolender

2018 ◽  
Vol 89 (3) ◽  
pp. 505-517. ◽  
Author(s):  
Tung Nguyen ◽  
Eui Seon Baek ◽  
Soonshin Hwang ◽  
Kyung-Ho Kim ◽  
Chooryung J. Chung

ABSTRACT This report illustrates the successful nonsurgical and nonprosthetic camouflage treatment of a skeletal Class II open bite malocclusion combined with missing mandibular first molars bilaterally. In the mandible, the second and third molars were uprighted and protracted, substituting for the missing first molars. In the maxilla, anterior bodily retraction and full-arch intrusion were achieved following premolar and second molar extraction, which also induced autorotation of the mandible. The treatment outcome and prognosis were confirmed with three-dimensional superimposition techniques, along with long-term stability.


2015 ◽  
Vol 86 (2) ◽  
pp. 292-305 ◽  
Author(s):  
Sherif A. Elkordy ◽  
Amr M. Abouelezz ◽  
Mona M. Salah Fayed ◽  
Khaled H. Attia ◽  
Ramy Abdul Rahman Ishaq ◽  
...  

ABSTRACT Objective:  To detect three-dimensionally the effects of using mini-implant anchorage with the Forsus Fatigue Resistant Device (FFRD). Materials and Methods:  The sample comprised 43 skeletal Class II females with deficient mandibles. They were randomly allocated into three groups: 16 patients (13.25 ± 1.12 years) received FFRD alone (Forsus group), 15 subjects (13.07 ± 1.41 years) received FFRD and mini-implants (FMI group), and 12 subjects (12.71 ± 1.44 years) were in the untreated control group. Three-dimensional analyses of cone beam computed tomographic images were completed, and the data were statistically analyzed. Results:  Class I relationship and overjet correction were achieved in 88% of the cases. None of the two treatment groups showed significant mandibular skeletal effects. In the FMI group, significant headgear effect, decrease in maxillary width, and increase in the lower facial height were noted. In the FMI group, retroclination of maxillary incisors and distalization of maxillary molars were significantly higher. Proclination and intrusion of mandibular incisors were significantly greater in the Forsus group. Conclusions:  FFRD resulted in Class II correction mainly through dentoalveolar effects and with minimal skeletal effects. Utilization of mini-implant anchorage effectively reduced the unfavorable proclination and intrusion of mandibular incisors but did not produce additional skeletal effects.


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.


2016 ◽  
Vol 1 (1) ◽  
pp. 27
Author(s):  
Setiarini Widiarsanti ◽  
Darmawan Sutantyo ◽  
Pinandi Sri Pudyani

Perawatan ortodontik interseptif efektif untuk mengurangi keparahan maloklusi disertai dengan kebiasaan buruk. Pemilihan waktu perawatan sangat penting agar perawatan dapat berhasil. Periode percepatan pertumbuhan berkisar antara 10-12 tahun untuk perempuan dan 12-14 tahun untuk laki-laki. Aktivator dengan skrup ekspansi digunakan untuk menstimulasi pertumbuhan mandibula, untuk mendapatkan ruang dari ekspansi pada kedua lengkung rahang dan untuk menghentikan kebiasaan buruk. Tujuan dari studi kasus ini adalah untuk memaparkan tata laksana perawatan dengan aktivator pada masa percepatan pertumbuhan. Pasien seorang laki-laki berusia 12 tahun datang dengan keluhan utama gigi atas maju dan kurang menarik. Kebiasaan buruk pasien adalah bernafas melalui mulut. Pemeriksaan objektif menunjukkan hubungan klas I pada kedua sisi, pola skeletal klas II, jarak inter P1 atas 35,7 mm dan jarak inter P1 bawah 30,3 mm. Maloklusi Angle Klas I tipe dentoskeletal dengan tipe skeletal kelas II dan incisivus maksila protrusif, overjet: 9,5 mm, overbite: 6,2 mm, palatal bite, scissorbite, malposisi gigi individual, kebiasaan buruk bernafas melalui mulut dan pergeseran midline RA kekanan sebesar 1,6 mm. Setelah 4 bulan perawatan, kebiasaan buruk telah berhenti, overjet menjadi 5 mm, overbite menjadi 3,2 mm, jarak inter P1 atas 36,5 mm dan jarak inter P1 bawah 31,6 mm. Aktivator dengan skrup ekspansi efektif untuk mencegah terjadinya disharmoni rahang dengan modifikasi pertumbuhan dan perkembangan rahang serta untuk menghentikan kebiasaan buruk dalam waktu singkat. Beberapa hal tersebut dapat dicapai dengan ketepatan pemilihan waktu perawatan yaitu dalam periode percepatan pertumbuhan. ABSTRACT: Interceptive Orthodontic Treatment Using Activator in Growth Spurt Period. Interceptive orthodontic treatment is effective to reduce the severity of malocclusion with oral bad habits. Time treatment is an important thing to make the treatment become successful. Growth spurt period in range 10-12 years old for female and 12-14 years old for male. Activator with an expansion screw was used to stimulate the mandibula growth, to create space by expanding both arches and to stop the bad habit. A 12 years old male patient with a chief complaint of protruded maxillary teeth and unpleasant appearance. The oral bad habit of patient was mouth breathing. Objective examination showed class I molar relationship on both sides, skeletal class II pattern, inter upper premolars was 35,7 mm and inter lower premolars was 30,3 mm. Angle malocclusion class I with skeletal class II and protruded incisive maxilla, overjet 9,5 mm, overbite 6,2 mm, mouth breathing bad habit, upper midline shifting 1,6 mm to the right side. After 4 months of treatment the oral bad habit was stop, overjet 5 mm, overbite 3,2 mm, inter upper premolars 36,5 mm and inter lower premolars 31,6 mm. Activator with an expansion screw was effectively prevent the skeletal disharmony by modification of growth and development of jaw, and stop the oral bad habit in short period of time. Those can be achieved by the right time choosing in growth spurt period for the treatment.


2021 ◽  
Vol 10 (9) ◽  
pp. 562-566
Author(s):  
Monika M. Ahuja ◽  
Ranjit H. Kamble ◽  
Sunita Shrivastava ◽  
Navjeet S. Gurudatta ◽  
Pooja S. Bidwai ◽  
...  

BACKGROUND Palatine rugae are small transverse structures present in the anterior 2 / 3rd of the palate. These rugae are protected by various structures of the oral cavity. They are immovable structures but variations in the oral cavity may lead to alterations in these small structures. There have been many studies that have quoted changes in these rugae patterns with various tooth movements whereas various other studies demonstrate no significant changes. None of the studies in specific have mentioned about palatal rugae changes with myofunctional appliances. The objective of this research was to evaluate the palatal rugae morphology and its stability after myofunctional therapy, as expansion and movement of teeth might lead to changes in these rugae. METHODS A total of 90 maxillary casts, 30 of Class I, 30 of Class II pre-treatment and casts of same subjects after myofunctional therapy, patients age ranging between 10 and 13 years were selected for the study. Length, intermedial and interlateral distances, angle of divergence and position of rugae were studied based on Lysell Classification 1955 and Thomas and Kotze Classification 1983. RESULTS Secondary and fragmentary rugae were found to be statistically significant as they were increased in Class II samples compared to Class I. The rugae in Class II samples were found to be shorter and therefore significant results were seen. IM1, IM2, IM4, IM5 and IM6 were found to be statistically significant respectively. Similarly, IL2, IL4, IL5 and IL6 were appreciable. IM1 was found to be appreciable. IL1, IL2, IL3 and IL4 were statistically significant. Significant difference was found in mean rugae value among Class I and Class II pre-treatment groups. Statistically significant difference was found in mean rugae value among Class I and Class II pre-treatment group. Incisive papilla to posterior border of last rugae (IP-PBA) was found to be statistically significant. CONCLUSIONS Myofunctional therapy did have an effect on the rugae pattern. But the age group of 10 – 13 years consisted of growing individuals. Therefore, it could not be concluded as to whether the changes were because of growth taking place or because of myofunctional therapy. KEY WORDS Palatine Rugae, Myofunctional Appliances, Class II Malocclusion


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