Assessment of Positional Variation of Maxillary Permanent First Molar with respect to the Infrazygomatic Crest (Key Ridge) in Skeletal Class I, II and III Cases

Kamble, Ranjit; Hazarey, Ananya; Hazarey, Pushpa V; Singh, Jeet

doi:10.5005/jp-journals-10015-1237

Cited by 4 publications

(7 citation statements)

References 7 publications

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“…for positional variation of permanent maxillary first molar with infrazygomatic crest in skeletal Class I, II, and III cases. [2] Mesiodistal root angulation alterations of the maxillary and mandibular incisors may significantly change the molar relationship. [3] In Angle's Class I molar relation, mesiobuccal cusp of upper first permanent molar lies in the buccal groove of lower first permanent molar.…”

Section: Kamble Et Al Assessed 103 Lateral Cephalogramsmentioning

confidence: 99%

“…It helps in diagnosis and treatment planning of malocclusion and to determine the magnitude of the problem. [2] Second, classification facilitates communication between specialists.…”

Section: Introductionmentioning

confidence: 99%

“…[8] However, the most universally accepted classification system still in use today is EH angles method which was developed in 1889 and was based on the position of maxillary permanent first molar in the craniofacial anatomy. [2,9] All teeth are essential, yet in function and influence: Some are of greater importance than others, the most important of all being maxillary first molar which is often called as: "Key to occlusion." [2] Angle in 1906 published his article where he proposed the virtues of this tooth.…”

Section: Introductionmentioning

confidence: 99%

“…[2,9] All teeth are essential, yet in function and influence: Some are of greater importance than others, the most important of all being maxillary first molar which is often called as: "Key to occlusion." [2] Angle in 1906 published his article where he proposed the virtues of this tooth. [9] George Risse suggested that maxillary first molar was the key to occlusion because of the following virtues: [2] 1.…”

Section: Introductionmentioning

confidence: 99%

“…[2] Angle in 1906 published his article where he proposed the virtues of this tooth. [9] George Risse suggested that maxillary first molar was the key to occlusion because of the following virtues: [2] 1. Largest teeth.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of Mesiodistal Inclination of Permanent Maxillary and Mandibular First Molar in Different Angle’s Molar Relation - A Cephalometric Study

2018

IJDA

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Context: Angle's molar relationship is the most widely used classification in spite of introduction of various other classifications. At the end of the treatment, the molars are finished in a Class I, II, or III molar relation. Achieving a proper cusp to fossa relation is necessary for attaining a balanced occlusion. Thus, it is important to know the ideal inclinations of the upper and lower first molars, thereby assisting in achieving stable relationship. Aims and Objectives: This study aims to evaluate mesiodistal inclination of permanent maxillary and mandibular first molars in Angle's Class I, II, and III molar relationships in relation to the occlusal plane. Materials and Methods: Lateral cephalograms of 16-30 years old individuals with Class I, II, and III molar relations were selected from the archives of the department of orthodontics. They were traced in Dolphin Imaging software, and the angle between the first molar and occlusal plane was calculated. Results: There was a statistically significant difference in the inclination of maxillary first molar in between Class I and Class III. No significant difference was noted in the inclination of maxillary first molar in case of Class I and Class II. In case of mandibular molars, there was statistically significant difference in case of Class I and Class II and between Class I and Class III. Conclusion: When the end molar relationship of a case is planned to be Class I, the upper molar should be at an angle of 84.12° to the occlusal plane. When the end molar relationship of a case is planned to be Class II, the upper molar should be 84.15° to the occlusal plane. When the end molar relationship of a case is planned to be Class III, the upper molar should be inclined at an angle of 87.07° to the occlusal plane. This helps in achieving an ideal cusp to fossa relationship, thereby stabilizing the occlusion.

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Section: Kamble Et Al Assessed 103 Lateral Cephalogramsmentioning

confidence: 99%

“…It helps in diagnosis and treatment planning of malocclusion and to determine the magnitude of the problem. [2] Second, classification facilitates communication between specialists.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Evaluation of Mesiodistal Inclination of Permanent Maxillary and Mandibular First Molar in Different Angle’s Molar Relation - A Cephalometric Study

2018

IJDA

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Natural reference structures for three-dimensional maxillary regional superimposition in growing patients

Fan,

Han,

Zhang

et al. 2023

BMC Oral Health

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Background Assessment of growth-related or treatment-related changes in the maxilla requires a reliable method of superimposition. Such methods are well established for two-dimensional (2D) cephalometric images but not yet for three-dimensions (3D). The aims of this study were to identify natural reference structures (NRS) for the maxilla in growing patients in 3D, opportunistically using orthodontic mini-screws as reference; and to test the applicability of the proposed NRS for maxillary superimposition by assessing the concordance of this approach with Björk’s ‘stable reference structures’ in lateral projection. Methods The stability of the mini-screws was tested on longitudinal pairs of pre- and post-orthodontic cone-beam computed tomography (CBCT) images by measuring the distance changes between screws. After verifying the stability of the mini-screws, rigid registration was performed for aligning the stable mini-screws. Then, non-rigid registration was used to establish the dense voxel-correspondence among CBCT images and calculate the displacement of each voxel belonging to the maxilla relative to the mini-screws. The displacement vectors were transformed to a standardized maxillary template to categorize the stability of the internal structures statistically. Those voxels that displaced less relative to the mini-screws were considered as the natural reference structures (NRS) for the maxilla. Test samples included another dataset of longitudinal CBCT scans. They were used to evaluate the applicability of the proposed NRS for maxillary superimposition. We assessed whether aligning the maxilla with proposed NRS is in concordance with the maxillary internal reference structures superimposition in the traditional 2D lateral view as suggested by Björk. This was quantitively assessed by comparing the mean sagittal and vertical tooth movements for both superimposition methods. Results The stability of the mini-screws was tested on 10 pairs of pre- and post-orthodontic cone-beam computed tomography (CBCT) images (T1: 12.9 ± 0.8 yrs, T2: 14.8 ± 0.7 yrs). Both the loaded and the unloaded mini-screws were shown to be stable during orthodontic treatment, which indicates that they can be used as reference points. By analyzing the deformation map of the maxilla, we confirmed that the infraorbital rims, maxilla around the piriform foramen, the infrazygomatic crest and the hard palate (palatal vault more than 1 cm distal to incisor foramen except the palatal suture) were stable during growth. Another dataset of longitudinal CBCT scans (T1: 12.2 ± 0.63 yrs, T2: 15.2 ± 0.96 yrs) was used to assess the concordance of this approach with Björk’s ‘stable reference structures’. The movement of the maxillary first molar and central incisor showed no statistically significant difference when superimposing the test images with the proposed NRS or with the classic Björk maxillary superimposition in the lateral view. Conclusions The infraorbital rims, maxilla around the piriform foramen, the infrazygomatic crest and the hard palate (palatal vault more than 1 cm posterior to incisal foramen except the palatal suture) were identified as stable regions in the maxilla. These stable structures can be used for maxillary superimposition in 3D and generate comparable results to Björk superimposition in the lateral view.

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Cephalometric analysis of upper lip thickness as a critical aid in formulating a treatment plan in skeletal Class I malocclusion in adults

Khan

Joneja²,

Choudhary³

2022

JCO

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It is very crucial to understand that both soft tissue drape and the underlying skeletal malocclusion, are sometimes overlooked and this could be misleading for diagnosis and treatment planning .Therefore a sound knowledge of underlying malocclusion and CTP (cephalometric treatment planning) along with accurate clinical examination can aid in better diagnosis and treatment planning. The objective of this study is to understand that soft tissue drape and underlying skeletal malocclusion in Angle’s class I malocclusion could be misleading in treatment planning and therefore to perform necessary cephalometric hard and soft tissue analysis. Lateral cephalograms were obtained in NHP (Natural head position) position of size (20×25cm) FUJIFILM and lateral cephalograms were obtained on radiographic films. Evaluation of lateral cephalograms and the above mentioned parameters were traced and assessed by manual tracing of 150 lateral cephalogram was done using tracing papers with the help of tracing backlight box .Tracing was done with lead pencil point (0.3 mm HB). 150 patient of central Indian population with Angle’s class I malocclusion full permanent dentition between ages 18-45 years were included. Out of these 150 patients 75 males and 75 females patients are included in the study. Upper lip anterior and lip angle shows moderate positive correlation with W angle. The key ridge shows a strong positive correlation with W angle. The upper lip thickness can be used as a treatment plan predictor in Angle’s class I malocclusion as it is strong correlated with W angle. Soft tissue drape especially the upper lip thickness is an essential parameter along with identification of underlying skeletal malocclusion with cephalometric treatment planning measurement like W angle, for treatment planning of even a simple Angle’s class I malocclusion case.

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Assessment of Positional Variation of Maxillary Permanent First Molar with respect to the Infrazygomatic Crest (Key Ridge) in Skeletal Class I, II and III Cases

Abstract: Introduction:To assess the positional variations of maxillary horizontal and vertical plane with respect to infrazygomatic crest (key ridge) in skeletal class I, II and III cases.

Cited by 4 publications

References 7 publications

Evaluation of Mesiodistal Inclination of Permanent Maxillary and Mandibular First Molar in Different Angle’s Molar Relation - A Cephalometric Study

Evaluation of Mesiodistal Inclination of Permanent Maxillary and Mandibular First Molar in Different Angle’s Molar Relation - A Cephalometric Study

Natural reference structures for three-dimensional maxillary regional superimposition in growing patients

Cephalometric analysis of upper lip thickness as a critical aid in formulating a treatment plan in skeletal Class I malocclusion in adults

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