scholarly journals Over-bite and Vertical Changes following First Premolar Extraction in High Angle Cases

2012 ◽  
Vol 13 (6) ◽  
pp. 812-818 ◽  
Author(s):  
KS Girish ◽  
GC Ramesh ◽  
MC Pradeep ◽  
G Arun Kumar ◽  
BS Suresh

ABSTRACT Aims and objectives Orthodontists generally agree that nonextraction treatment is associated with downward and backward rotation of the mandible and an increase in the lower anterior face height (LAFH). They also agree that extraction line of treatment is associated with upward and forward rotation of the mandible and decrease in the LAFH. The intent of this cephalometric investigation was to examine the wedge hypothesis, that the vertical dimension collapses after first bicuspid extraction. The present study was undertaken to evaluate the cephalometric overbite and vertical changes following first premolar extraction in high angle cases. Materials and methods Forty-five adult patients having high mandibular plane angle, i.e. Gogn – SN more than or equal to 32° having class I molar and canine relation were included. Preand post-treatment lateral cephalograms were measured and compared to analyze the cephalometric changes. Results There was no decrease in the overbite and vertical changes following first premolar extraction in high angle cases. Clinical significance The facial complex does increase in size with growth, but mandibular plane while moving inferiorly, remain essentially parallel to its pretreatment position due to residual growth and treatment mechanics. Conclusion The study concluded that, There was no decrease in the vertical facial dimension, overbite and mandibular plane angle. However, it should be interpreted with caution, given the small sample size. How to cite this article Ramesh GC, Pradeep MC, Kumar GA, Girish KS, Suresh BS. Over-bite and Vertical Changes following First Premolar Extraction in High Angle Cases. J Contemp Dent Pract 2012;13(6):812-818.

2018 ◽  
Vol 23 (6) ◽  
pp. 48-55 ◽  
Author(s):  
Waqar Jeelani ◽  
Mubassar Fida ◽  
Attiya Shaikh

ABSTRACT Introduction: Maxillary incisal display is one of the most important attributes of smile esthetics. Objective: The aim of this study was to determine the relationship between maxillary incisal display at rest (MIDR) and various soft tissue, hard tissue and dental components. Methods: A cross-sectional study was conducted on 150 subjects (75 males, 75 females) aged 18-30 years. The MIDR was recorded from the pretreatment orthodontic records. The following parameters were assessed on lateral cephalograms: ANB angle, mandibular plane angle, palatal plane angle, lower anterior and total anterior facial heights, upper incisor inclination, upper anterior dentoalveolar height, and upper lip length, thickness and protrusion. The relationship between MIDR and various skeletal, dental and soft tissue components was assessed using linear regression analyses. Results: The mean MIDR was significantly greater in females than males (p = 0.011). A significant positive correlation was found between MIDR and ANB angle, mandibular plane angle and lower anterior facial height. A significant negative correlation was found between MIDR and upper lip length and thickness. Linear regression analysis showed that upper lip length was the strongest predictor of MIDR, explaining 29.7% of variance in MIDR. A multiple linear regression model based on mandibular plane angle, lower anterior facial height, upper lip length and upper lip thickness explained about 63.4% of variance in MIDR. Conclusions: Incisal display at rest was generally greater in females than males. Multiple factors play a role in determining MIDR, nevertheless upper lip length was found to be the strongest predictor of variations in MIDR.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Woei Li Koay ◽  
Yanqi Yang ◽  
Christine Shuk Kwan Tse ◽  
Min Gu

Aims. To assess the effects of two-phase treatment with the Herbst and the preadjusted edgewise appliances on upper airway dimensions and to investigate the correlation between changes in the upper airway dimensions and skeletal morphologies.Methods. A total of 27 Chinese male adolescents aged12.8±1.3years were selected. Lateral cephalograms were collected to assess the skeletal morphology and upper airway dimensions.Results. Following Herbst appliance treatment, the upper airway space was significantly enlarged, with the retropalatal (U-MPW) increasing by1.1±1.6 mm (P<0.001), the retroglossal (PASmin) increasing by1.3±2.9 mm (P<0.05), and the hypopharynx (V-LPW) enlarging by1.6±3.0 mm (P<0.01). PASmin was found to show a negative correlation to the mandibular plane angle (MnPl-SN) byr=-0.413(P<0.05). There was no significant change (P>0.05) in upper airway dimensions during the second-phase treatment.Conclusions. Herbst appliance treatment increased the oropharyngeal and hypopharyngeal airway dimensions among adolescents with Class II malocclusion, and the effects were maintained throughout the second treatment phase with a preadjusted edgewise appliance. There was a negative correlation between the change in the depth of the retroglossal pharynx and the mandibular plane angle.


2017 ◽  
Vol 7 ◽  
pp. 130-134
Author(s):  
Hasan Md Rizvi ◽  
Md Zakir Hossain

Introduction Tweed’s diagnostic triangle is simple yet provides a definite guideline in treatment planning. The aim of the present study was to establish the Tweed’s norms for Bangladeshi people. Methods The study was conducted for 89 Bangladeshi young adults (45 males and 44 females), aged 19–27 years, having balanced and harmonious facial profiles. Lateral cephalograms taken of these subjects were used for a series of morphometric analyses. Results All three angular parameters Frankfort-mandibular plane angle (FMA), Frankfort-mandibular incisal angle (FMIA), incise mandibular plane angle (IMPA)were measured and found to be 24.52°, 54.60°, and 100.88°, respectively. The mean FMA has been found to be 24.52° (with a range of 14°–36°) which is quite close to Tweed’s norm and found to be statistically insignificant. However, IMPA and FMIA values of Bangladeshis found to be statistically significantly different from that of the Caucasians. The linear regression equation of IMPA on FMA was fitted, and the estimated value of IMPA was computed for a given FMA. Conclusion The results support the idea that treatment objectives of IMPA should be considered according to the facial pattern, i.e., FMA. Ethnic variations of norms cannot be overlooked while outlining goals and planning the treatment.


2016 ◽  
Vol 21 (4) ◽  
pp. 41-49 ◽  
Author(s):  
Maheen Ahmed ◽  
Attiya Shaikh ◽  
Mubassar Fida

ABSTRACT Introduction: Multiple cephalometric analyses are used to diagnose vertical skeletal facial discrepancy. A multitude of times, these parameters show conflicting results, and a specific diagnosis is hard to reach. Objective: Hence, this study aimed to identify the skeletal analysis that performs best for the identification of vertical skeletal pattern in borderline cases. Methods: The sample consisted of 161 subjects (71 males and 90 females; mean age = 23.6 ± 4.6 years). Y-axis, Sella-Nasion to mandibular plane angle (SN.MP), maxillary plane to mandibular plane angle (MMA), Sella-Nasion to Gonion-Gnathion angle (SN.GoGn), Frankfort to mandibular plane angle (FMA), R-angle and facial height ratio (LAFH.TAFH) were used to evaluate vertical growth pattern on lateral cephalograms. The subjects were divided into three groups (hypodivergent, normodivergent and hyperdivergent groups), as indicated by the diagnostic results of the majority of parameters. Kappa statistics was applied to compare the diagnostic accuracy of various analyses. To further validate the results, sensitivity and positive predictive values (PPV) for each parameter were also calculated. Results: SN.GoGn showed a substantial interclass agreement (k = 0.850). In the hypodivergent group, MMA showed the highest sensitivity (0.934), whereas FMA showed the highest PPV (0.964). In the normodivergent group, FMA showed the highest sensitivity (0.909) and SN.GoGn had the highest PPV (0.903). SN.GoGn showed the highest sensitivity (0.980) and PPV (0.87) in the hyperdivergent group. Conclusions: SN.GoGn and FMA were found to be the most reliable indicators, whereas LAFH.TAFH is the least reliable indicator in assessing facial vertical growth pattern. Hence, the cephalometric analyses may be limited to fewer analyses of higher diagnostic performance.


2009 ◽  
Vol 79 (6) ◽  
pp. 1063-1069 ◽  
Author(s):  
Aya Kurusu ◽  
Mariko Horiuchi ◽  
Kunimichi Soma

Abstract Objective: To clarify the relationship between occlusal force and mandibular condyle morphology using clinical data. Materials and Methods: The subjects were 40 female patients with malocclusion. The mandibular condyle morphology was assessed by using limited cone-beam CT imaging. The maximum occlusal force was calculated by using pressure-sensitive films. Maxillofacial morphologies were analyzed by using data from lateral cephalograms. Results: Correlation analysis showed that the occlusal force was correlated with the lateral and posterior radii of the condyles, and with the mandibular plane angle to the Frankfort horizontal plane (FH). Moreover, condylar length was significantly correlated with the occlusal plane angle to the FH, the mandibular plane angle to the FH, the ramus inclination, and the posterior facial height (S-Go). Low-occlusal-force patients tended to have smaller mandibular condyles. This size-related difference was more remarkable on the lateral and posterior side. Conclusions: Occlusal force influences not only maxillofacial morphology but also mandibular condyle morphology.


2020 ◽  
Author(s):  
Chang Yoon Jung ◽  
Jae Hyun Park ◽  
Ja Hyeong Ku ◽  
Nam-Ki Lee ◽  
Yoonji Kim ◽  
...  

ABSTRACT Objectives To compare the dental and skeletal treatment effects after total arch distalization using modified C-palatal plates (MCPPs) on adolescent patients with hypo- and hyperdivergent Class II malocclusion. Materials and Methods The study group included 40 patients with Class II malocclusion (18 boys and 22 girls, mean age = 12.2 ± 1.4 years) treated with MCPPs. Fixed orthodontic treatment started with the distalizing process in both groups. Participants were divided into hypo- or hyperdivergent groups based on their pretreatment Frankfort mandibular plane angle (FMA) ≤22° or ≥28°, respectively. Pre- and posttreatment lateral cephalograms were digitized, and 23 variables were measured and compared for both groups using paired and independent t-tests. Results The hyper- and hypodivergent groups showed 2.7 mm and 4.3 mm of first molar crown distalizing movement, respectively (P &lt; .001). The hypodivergent group had a slight 2.2° crown distal tipping of first molars compared with 0.3° in the hyperdivergent group. After distalization, the FMA increased 3.1° and 0.3°, in the hypodivergent and hyperdivergent groups, respectively (P &lt; .001). SNA decreased in the hypodivergent group, while other skeletal variables presented no statistically significant differences in the changes between the groups. Conclusions The hypodivergent group showed more distal and tipping movement of the maxillary first molar and increased FMA than the hyperdivergent group. Therefore, clinicians must consider vertical facial types when distalizing molars using MCPPs in Class II nonextraction treatment.


2020 ◽  
Vol 44 (4) ◽  
pp. 274-282
Author(s):  
Jong-Moon Chae ◽  
Jae Hyun Park ◽  
Seon-Hye Kim ◽  
Utkarsh Mangal ◽  
Hye Young Seo

Objective: To investigate the cephalometric changes following anterior repositioning of the mandible for predicting the treatment effects in Class II adolescent patients. Study Design: Lateral cephalograms of 28 patients (ANB &gt; 4°) were taken in centric occlusion (CO) and edge-to-edge bite (EtoE) before orthodontic treatment. The patients were classified into two groups according to their mandibular plane angle [MPA; low MPA (LMPA) ≤ 28° and high MPA (HMPA) &gt; 28°]. Cephalometric changes of hard and soft tissues were measured and analyzed with an x-y cranial base coordinate system. Results: For CO to EtoE, there were no significant cephalometric changes between HMPA and LMPA, but the horizontal ratio of soft to hard tissue pogonion (H-Pog′/H-Pog) change was significantly greater with LMPA than with HMPA while the vertical ratio (V-Pog′/V-Pog) showed vice versa. For CO to EtoE, MPA showed significant correlations with H-Pog′/H-Pog and V-Pog′/V-Pog. Y-axis angle, V-Pog′/V-Pog and H-Pog′/H-Pog can be used as good tools to discriminate between HMPA and LMPA. Conclusion: Cephalometric findings for CO to EtoE may be useful in predicting the vertical and horizontal changes of hard and soft tissues with the treatment of growing adolescents having various vertical skeletal patterns of Class II malocclusion.


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