scholarly journals Lower incisor dentoalveolar compensation and symphysis dimensions among Class I and III malocclusion patients with different facial vertical skeletal patterns

2013 ◽  
Vol 83 (6) ◽  
pp. 948-955 ◽  
Author(s):  
Núria Molina-Berlanga ◽  
Jaume Llopis-Perez ◽  
Carlos Flores-Mir ◽  
Andreu Puigdollers

ABSTRACT Objective: To compare lower incisor dentoalveolar compensation and mandible symphysis morphology among Class I and Class III malocclusion patients with different facial vertical skeletal patterns. Materials and Methods: Lower incisor extrusion and inclination, as well as buccal (LA) and lingual (LP) cortex depth, and mandibular symphysis height (LH) were measured in 107 lateral cephalometric x-rays of adult patients without prior orthodontic treatment. In addition, malocclusion type (Class I or III) and facial vertical skeletal pattern were considered. Through a principal component analysis (PCA) related variables were reduced. Simple regression equation and multivariate analyses of variance were also used. Results: Incisor mandibular plane angle (P < .001) and extrusion (P  =  .03) values showed significant differences between the sagittal malocclusion groups. Variations in the mandibular plane have a negative correlation with LA (Class I P  =  .03 and Class III P  =  .01) and a positive correlation with LH (Class I P  =  .01 and Class III P  =  .02) in both groups. Within the Class III group, there was a negative correlation between the mandibular plane and LP (P  =  .02). PCA showed that the tendency toward a long face causes the symphysis to elongate and narrow. In Class III, alveolar narrowing is also found in normal faces. Conclusions: Vertical facial pattern is a significant factor in mandibular symphysis alveolar morphology and lower incisor positioning, both for Class I and Class III patients. Short-faced Class III patients have a widened alveolar bone. However, for long-faced and normal-faced Class III, natural compensation elongates the symphysis and influences lower incisor position.

2013 ◽  
Vol 84 (2) ◽  
pp. 304-309 ◽  
Author(s):  
Susan N. Al-Khateeb ◽  
Emad F. Al Maaitah ◽  
Elham S. Abu Alhaija ◽  
Serene A. Badran

ABSTRACT Objective: To assess the morphology and dimensions of mandibular symphysis (MS) in different anteroposterior jaw relationships and to investigate whether craniofacial parameters have any correlation with its shape and/or dimensions. Materials and Methods: Lateral cephalograms of subjects with Class I, Class II, and Class III skeletal relationships were traced. Several craniofacial and MS parameters were measured. MS parameters were compared between the three groups using analysis of variance and were correlated with the craniofacial parameters using the Pearson correlation coefficient. Results: Larger angle of concavity of the chin, more inclination of the alveolar bone toward the mandibular plane, and larger MS dimensions and area (P < .001) were found with a Class III skeletal relationship compared to Class I and Class II relationships. The Pearson correlation coefficient between Id-Me and AFH was r  =  0.83 and between Id-Me and LAFH it was r  =  0.81. Conclusions: The dimensions and configuration of MS in the Class III relationship were different than those in Class I and Class II relationships; the alveolar part of MS compensated for the skeletal relationship in the Class III pattern. MS dimensions were strongly correlated to anterior facial dimensions.


2020 ◽  
Vol 93 (1) ◽  
pp. 97-104
Author(s):  
Sandhya Jain ◽  
Prateek Puniyani ◽  
Arwa Saifee

Objective. The purpose of the present study was to assess the symphyseal morphology and lower incisor angulation in different anteroposterior relationship and in different growth patterns and to investigate whether the symphyseal morphology had any correlation with dentofacial parameters. Method. Random Sampling method and lateral cephalograms of 90 subjects, age group 16-30 years, were divided into 30 in each group, i.e. Class I, Class II & Class III after calculating the following parameters (ANB angle, wits appraisal). After that, groups were again divided into 10 in each subgroup i.e. Average, Horizontal and Vertical growers. Results. Results showed the increase in actual symphysis width, inclination of the alveolar part, total height of symphysis and reduction in overall width along with retroclination of lower incisors in class III subjects as compared to class I and class II. Similarly actual and overall width of the symphysis were decreased and inclination of the alveolar part, symphyseal height and symphyseal ratio were increased in vertical growers. Conclusion. The dimensions and configuration of Mandibular Symphysis in class III was found to be different than those in Class I and Class II relationships; the alveolar part of Mandibular Symphyseal compensated for the skeletal relationship in the Class III pattern. Mandibualr Symphysis dimensions were strongly correlated to anterior facial dimensions. Similarly the dimensions and configuration of Mandibular Symphysis was also different in vertical growers as compared to horizontal and average growers, moreover symphyseal morphology and lower incisor angulation had a correlation with dentofacial parameters.


1979 ◽  
Vol 6 (4) ◽  
pp. 187-193 ◽  
Author(s):  
S. N. Bhatia ◽  
T. A. Akpabio

A study was carried out to compare the two current methods, Downs' method and the conversion (Ballard's) method, of assessing skeletal pattern. Correlations were moderate to high for the Class I and Class III groups (+0·6 and +0·76 respectively), but low for the Class II group(+0·35). The latter correlation, however, improved to +0·54 when the angle ANB was corrected for the value of the angle SNA. The point of rotation of the incisors, whether at the apex or apical third of the root, and the adjustment in the lower incisor angulation for the maxillary-mandibular plane angle value did not make any appreciable difference to the correlations obtained. The correlation for the total sample was about +0·7. When the cases were classified into the three skeletal categories the correspondence between the two methods was about 69 per cent. It is concluded that there are insufficient grounds for the recent criticism of the conversion method.


2014 ◽  
Vol 40 (6) ◽  
pp. 661-669 ◽  
Author(s):  
Marwa Madi ◽  
Osama Zakaria ◽  
Shohei Kasugai

In this study, hydroxyapatite coated vs uncoated implants were used to evaluate the type and dimensions of bone defects after progressive peri-implantitis in dogs. Thirty-two dental implants with 4 different surfaces—machined (M), sandblasted acid-etched (SA), 1-μm thin sputter hydroxyapatite (HA)-coated (S), and plasma-sprayed HA-coated (P)—were inserted into the mandibles of 4 beagle dogs after extracting all mandibular premolars. Experimental peri-implantitis was induced after 3 months using ligature to allow for plaque accumulation. After 4 months, ligatures were removed and plaque accumulation continued for 5 months (progression period). The open flap surgery demonstrated 3 patterns of peri-implantitis bone defect: (1) Class I defect: represented as circumferential intra-alveolar bone loss; (2) Class II defect: circumferential intra-alveolar defect with supra-alveolar bone loss exposing the implant surface; and (3) Class III defect: represented as circumferential intra-alveolar defect with supra-alveolar bone loss and buccal dehiscence. Class I was the most frequent (62.5%) defect pattern around implant types M, SA, and S; while implant type-P showed a recurring majority of Class II (62.5%). Comparison among the 4 implant groups revealed a significant defect width (DW) in implant type-P relative to other types (P < 0.01). However, no statistically significant differences were noted for defect depth (DD) (P > 0.05). We concluded that the shape and size of peri-implantitis bone defects were influenced by the type and thickness of the HA coat together with the quantity of the available peri-implant bone. Plasma-sprayed HA-coated implants showed larger peri-implant defects than did thin sputter HA-coated implants.


2021 ◽  
Vol 5 (1) ◽  
pp. 30-36
Author(s):  
Theresia Tarigan ◽  
Ismet Danial Nasution

The alveolar ridge consists of denture bearing mucosa, sub-mucosa and periosteum, and residual alveolar bone. After tooth extraction, the remaining alveolar bone undergoes a remodeling process that leads to morphological reduction and alteration, which results in the change in alveolar ridge forms. However, it does not change alveolar arch shapes. This literature review aimed to analyze the relationship of alveolar arch shapes with complete denture retention. According to House (1958), alveolar arch shapes classified into three classes: Class I-square, Class II-tapering, Class III-ovoid. Those three alveolar arch shapes have a difference in the denture bearing area, with the largest denture bearing site on Class I-Square alveolar arch shape. Some factors that influence complete denture retention are adhesion, cohesion, interfacial force, oral and facial musculature, atmospheric pressure, undercut, rotational insertion path, parallel walls, and gravity. The alveolar arch shapes can affect retention regarding the size of the denture bearing area.The alveolar arch forms with a wider denture bearing area provide more considerable surface contact between the denture and mucous membranes. The forces resulting from those factors of retention might produce more excellent complete denture retention. The square arch shape is the alveolar arch shape with the largest denture bearing area. Hence, the square arch shape is believed to have the best complete denture retention.KEYWORDS: arch shape; retention; complete denture; denture bearing area 


Author(s):  
INES DALLEL ◽  
SANA KANOUN ◽  
MARIEM NAHDI ◽  
MONCEF OMMEZINE ◽  
SAMIR TOBJI ◽  
...  

Objective: The aim of this study was to evaluate the association of the skeletal pattern and angle class with the occlusal plane (OP). This study also examined the effect of orthodontic treatment on this plane. Methods: Lateral cephalometric radiographs of a sample of 135 patients were collected. The angles between the Frankfort horizontal, palatal plane (PP), mandibular plane (MP), and the OP were analyzed and compared between several groups and subsequently before and after treatment. Results: The statistical comparison between 3 skeletal frame groups demonstrates that the cant of the OP showed a major difference. This difference was greater in class III subjects. Examination revealed that the OP was not meaningfully affected within the Angle classification. Statistically, a significant correlation was found between OP steepness and the vertical skeletal pattern. A significant rise of OP/sella-nasion (SN) for class I (p=0.019) and II (p=0.015) after orthodontic treatment. In addition, patients treated with elastics showed a significant decrease of OP/MP (mandibular plane) in Angle class III and considerable increase of OP/SN and OP/PP in Angle class II. Observations of the group treated with bimaxillary extractions showed that OP/SN (sella nasion line) and OP/PP differ in a meaningful way. Conclusion: This study confirms the association between the skeletal pattern and the OP inclination in adults. Concerning the Angle classification, there was no significant difference between the groups. Orthodontic therapy had an influence on the inclination of this plane for the different malocclusions. Premolars extraction in class I cases significantly modified the OP. For class II and III malocclusions, the OP inclination was mainly altered by the use of intermaxillary traction elastics.


Author(s):  
Maryam Maniyar ◽  
Ajit Kalia ◽  
Ashwith Hegde ◽  
Raja Ganesh Gautam ◽  
Nasim Mirdehghan

2017 ◽  
Vol 43 (3) ◽  
pp. 211-217 ◽  
Author(s):  
Humberto Velásquez ◽  
Sergio Olate ◽  
César Díaz ◽  
Pablo Navarro ◽  
Eduardo Borie ◽  
...  

The aim of this study was to quantify the cortical and cancellous bone in the mandibular symphysis and relate it to the teeth and to the skeletal class. A descriptive study was conducted using cone beam computerized tomography (CBCT). Class I and class III subjects were included, defined according to dental occlusion and cephalogram results. Linear measurements were taken on the CBCT of the mandibular canines, lateral incisors, and central incisors, where the analysis was related to the axial and apical axes considering the bone in relation to the dental area. With previous definitions, an observer took 2 measurements of the height of the mandibular symphysis, cortical bone of the buccal and lower region, and thickness of cancellous bone at different levels; the correlation coefficient between the first and second measurement was 0.99 and presented P = .001. The results were analyzed with analysis of variance and Tukey's honest significant difference test, with P < .05 being statistically significant. The symphysis height was significantly greater in class III subjects. The cortical bone was an average 1.67 ± 0.44 mm in vertical distance in the skeletal class I group and 1.74 ± 0.47 mm in the class III group. The cancellous bone had an average width of 5.03 ± 1.94 mm in the skeletal class I group and 4.74 ± 2.05 mm in the class III group. It was observed that cancellous bone was significantly thicker at the incisor level than at the canine level. There were anatomical differences between skeletal class I and class III subjects, although the clinical significance may be questionable. With the values from these analyses, it may be concluded that there are no significant differences in quantitation of the cortical and cancellous bone in the anterior mandibular symphysis.


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