|Year : 2021 | Volume
| Issue : 1 | Page : 121-126
Reproducibility of sagittal condylar path inclination assessed by protrusive interocclusal record with two different techniques of facebow registration: A clinico-radiographic study
Ajay Jain1, Sridevi Ugrappa1, Ooi Jia Hui2, Ooi Wan Jun2, Pang Siao Ting2
1 Department of Oral Medicine and Radiology, Faculty of Dentistry, AIMST Dental Institute, AIMST University, Kedah, Malaysia
2 Department of Oral Medicine and Radiology, AIMST Dental Institute, AIMST University, Semeling, Kedah, Malaysia
|Date of Submission||21-Oct-2019|
|Date of Decision||20-Nov-2020|
|Date of Acceptance||21-Jan-2021|
|Date of Web Publication||29-Jul-2021|
Dr. Ajay Jain
Faculty of Dentistry, AIMST Dental Institute, AIMST University, Semeling 08100 Bedong, Kedah
Source of Support: None, Conflict of Interest: None
Purpose: The purpose is to validate whether the data obtained for sagittal condylar inclination are correctly reproduced on the semi-adjustable articulator using protrusive interocclusal records for conventional facebow registration method (orbitale (OR) as an anterior point of reference) and facebow registration using bubble leveler (BL) as an anterior point of reference and compared these values with the values obtained by lateral cephalogram (gold standard). Materials and Methods: In total, 30 individuals (20 males and 10 females) with proper teeth alignment, facebow registrations were recorded using OR as an anterior point of reference (Group A, conventional technique) and WBL as an anterior point of reference (Group B). The sagittal condylar path inclination was measured and compared using protrusive interocclusal records for both the groups. These values compared with the values for sagittal condylar path inclination obtained using lateral cephalogram (Group C) using one-way analysis of variance (P < 0.05). Results: There was no statistically significant differences observed in the values of sagittal condylar inclination for all three groups with P = 0.583. Conclusion: This study suggests that BL technique can be used for the orientation of maxillary cast on the semi-adjustable articulator as accurately as the conventional approach, for those practitioners who find difficulty in locating the OR for those patients with deformity in facial region. Lateral cephalogram provides almost the same measurements of sagittal condylar path inclination as obtained using protrusive interocclusal record on facebow registrations using OR and BL as an anterior point of references.
Keywords: Bubble leveler, facebow registration, protrusive interocclusal records, sagittal condylar path inclination, semi-adjustable articulators
|How to cite this article:|
Jain A, Ugrappa S, Hui OJ, Jun OW, Ting PS. Reproducibility of sagittal condylar path inclination assessed by protrusive interocclusal record with two different techniques of facebow registration: A clinico-radiographic study. J Datta Meghe Inst Med Sci Univ 2021;16:121-6
|How to cite this URL:|
Jain A, Ugrappa S, Hui OJ, Jun OW, Ting PS. Reproducibility of sagittal condylar path inclination assessed by protrusive interocclusal record with two different techniques of facebow registration: A clinico-radiographic study. J Datta Meghe Inst Med Sci Univ [serial online] 2021 [cited 2021 Sep 16];16:121-6. Available from: http://www.journaldmims.com/text.asp?2021/16/1/121/322603
| Introduction|| |
Semi-adjustable articulators play an important role in diagnosing the occlusion at protruded and lateral eccentric jaw positions as well as for formulating the appropriate treatment plan. The maxillary cast is mounted in a correct relationship to the condylar hinge axis using a facebow transfer. The main goal of any facebow registration is to locate the axis-orbital plane, which is the most horizontal plane, in which the restorations are fabricated to fulfill the esthetic and functional requirements.
The use of two posterior points and an anterior reference point for orienting a maxillary cast to an articulator has long been encouraged. The orientation of the casts in an articulator in a three-dimensional space entails the presence of an anterior point of reference. The recommended anterior reference point is Orbitale (Or) for mounting casts in a semi-adjustable articulator. OR is a notch present in the lower rim of the orbit in line with the pupil of the eye. Sometimes, it is difficult to locate the OR by the practitioners, may be because of its anatomical location, or the patients might be having some kind of facial deformity. Improper positioning of the casts in an articulator may result in an inadequate restoration with an undesirable appearance and cause damage to the supporting structures.
In many articulators, the Frankfort plane is more popularly being used as the plane of orientation for the facebow records and to mount the maxillary casts in the articulator. This is achieved using the infraorbital notch from the patient as the third point of reference, for which an alignment pointer was made. The record is then transferred to the articulator in the same relation by having the OR pointer coincide with OR indicator counterpart on the articulator. The use of OR as a third point of reference is said to orient the maxillary cast to the upper member of the articulator, as the maxilla is oriented to the Frankfort horizontal plane.
The authors hypothesized that, as an alternate to the OR (as anterior point of reference), a bubble leveler can be used to orient the maxillary cast to the upper member of the articulator, as the maxilla is oriented to the Frankfort horizontal plane as accurately as oriented using OR. A spirit level or bubble level is an instrument [Figure 1] designed to indicate whether a surface is horizontal (level) or vertical (plumb). Different types of spirit levels may be used by carpenters, stonemasons, bricklayers, other building trade workers, surveyors, millwrights, and other metalworkers, and in some photographic or videographic work.
The orbit produced by the centers of the right and left condyles during protrusive movement is referred to as the protrusive condylar path. The angle formed by the protrusive condylar path and the horizontal reference plane is called the sagittal inclination of the protrusive condylar path or protrusive condylar guidance angle.
When determining the sagittal condylar path inclinations for clinical procedures, the protrusive interocclusal record method is preferred as the usual method for reproducing them in a semi-adjustable articulator. However, it has often been suggested that the sagittal condylar path inclinations obtained by this method are unstable.
Gross et al. studied the horizontal reference plane by lateral cephalogram and adjusted the sagittal condylar inclination of three types of semi-adjustable articulators using protrusive interocclusal records. Santos and Ash measured the mandibular movement using Cyberhoby computer pantographs of three subjects and the movements of six types of articulators. There is a plethora of studies that compare various anatomic reference points with sagittal condylar path inclination.,,,
However, no studies exist that compare the various types of face bow registrations on semi-adjustable articulators to achieve sagittal condylar inclination by utilizing protrusive interocclusal records and then compare these values with the lateral cephalogram (gold standard).
The aim of the present study is to evaluate the change in sagittal condylar inclination when recorded by bubble level water level indicator on Hanau wide veu semi-adjustable articulator. The objectives of the study are as follows:
- To evaluate and compare the sagittal condylar inclination when facebow record is done using OR as an anterior reference point and using digital lateral cephalogram
- To evaluate and compare sagittal condylar inclination when facebow record is done using bubble leveler (BL) as anterior point of reference and by using digital lateral cephalogram
- To evaluate and compare the sagittal condylar inclination when facebow record is done using OR and water bubble as an anterior reference point.
| Materials and Methods|| |
The study was conducted in the patient visited AIMST Dental Centre, AIMST University, after taking the consent from the patient. Thirty individuals were used in this study. Three techniques are used and divided into groups:
- Group A: Sagittal condylar path inclination obtained using protrusive interocclusal record by face-bow registration using OR as anterior reference point (Technique 1)
- Group B: Sagittal condylar path inclination obtained using protrusive interocclusal record by face-bow registration using BL as anterior reference point (Technique 2)
- Group C (control): Sagittal condylar path inclination obtained after tracing the lateral cephalogram (Technique 3).
Materials used [Figure 2],[Figure 3],[Figure 4]
|Figure 2: Maxillary and mandibular casts, protrusive interocclusal record and bite fork|
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- Hanau Wide Vue articulator (Whip Mix Corporation, Louisville, KY, USA)
- Maxillary and mandibular casts
- Digital lateral cephalogram
- Protrusive records obtained from the subjects.
- Complete set of teeth
- No history of extraction and orthodontic treatment
- The presence of Angle's class I malocclusion
- The absence of any temporomandibular joint dysfunction and occlusal disharmony.
The impression of both of the arches was obtained, and the cast was poured in type 3 dental stone (Kalabhai Karson Pvt. Ltd., Mumbai, India). Two facebow registrations (Hanau spring face bow, US) were performed, first using OR as anterior point of reference [Figure 5] and second using bubble leveler (Dura International Sdn Bhd, Kuala Lumpur, Malaysia) [Figure 6]. To perform this procedure, the individuals are made sit on a stool four feet away from the face mirror, which is attached to the wall, and asked to sit upright and in most horizontal position, so that bubble in the BL is in the center and most horizontal. At this point, the final thumb screw of the face bow is tightened and then transferred to the Hanau Wide Vue arcon articulator (Whip Mix Corporation, Louisville, KY, USA).
After mounting the maxillary cast using the facebow registrations [Figure 7] and [Figure 8], the mandibular cast is articulated and mounted in maximum intercuspal position. Later, the articulator was programmed using protrusive interocclusal record [Figure 9] for both the facebow registrations and sagittal condylar path inclinations values were recorded. Digital lateral cephalogram was obtained for all the subjects, and tracing was done on the radiograph to evaluate the sagittal condylar path inclination [Figure 10]. The results obtained for the sagittal condylar path inclination for all three groups were tabulated and analyzed [Table 1] and [Table 2] using analysis of variance (ANOVA) test with a significant level set at P < 0.05 [Table 3]. For the statistical analysis, a statistical software program (IBM, Armonk, New York, USA ).
|Figure 7: Facebow transfer on the articulator using conventional approach|
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|Figure 8: Facebow transfer on the articulator using bubble level technique|
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|Figure 10: Tracing on digital lateral cephalogram to obtain sagittal condylar path inclination|
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|Table 2: Comparison of the mean values obtained for three Groups A, B, C|
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The Institutional Ethics Committee of AIMST UNIVERSITY, approved the study with ref no AUHEC/FOD/2018/16 on 15th August 2018.
| Results|| |
The mean for Group A, B, and C is 28.00, 28.83, and 28.37, respectively, and standard deviation is 3.37, 3.13, and 2.78, respectively [Table 2] and [Graph 1], [Graph 2], [Graph 3], [Graph 4]. No significant difference was observed in the measurement of sagittal condylar path inclination in all the three groups as a result of ANOVA with P value obtained is 0.583, which is >0.05 [Table 3].
| Discussion|| |
Accurate positioning of the maxilla relative to the skull is essential for reliable treatment planning. The position of the occlusal plane in the patient and the articulator should be analogous, and it is an essential link for attaining the functional and esthetic goals of treatment. The substantial error in the occlusion of the final prosthesis is anticipated if anteroposterior relationship of maxillary occlusal cant to the articulator is not transferred accurately. Failure to transfer the anterior reference point can result in an unnatural axial inclination of the maxillary anterior teeth. Hence, it is authoritative to have a face-bow registration.
Frankfurt horizontal plane is considered to be the most horizontal plane, and mounting the maxillary cast relative to this plane will accomplish the objective to have a natural appearance in the form and position of anterior teeth. It is universally accepted that upper arm of the articulator represents Frankfort horizontal plane. Gonzalez and Kingery found that the relationships of the planes of reference are not maintained during the transfer from the patient to the articulator and suggested using an anterior point of reference 7 mm below the OR. However, the 7-mm difference between the orbital plane and the condylar plane is being compensated in the Hanau Arcon H2 and Hanau Wide Vue articulators.
The authors of the present study propose that the casts should be mounted using the relation between the horizontal plane and the resting head position to define the position of the skull. Walker et al. conducted a photographic study of 10 individuals confirmed the reproducibility of the head position and its relation to the horizontal plane. A facebow incorporating a circular spirit level was used to transfer the relation between the horizontal and the maxillary dentition to a semi-adjustable articulator. The angle between the horizontal and maxillary occlusal planes was measured from six lateral cephalograms and compared with those of casts mounted on a semi-adjustable articulator using a face bow with either an orbital pointer or a spirit level. The face bow with a spirit level produced considerably more accurate results.
The present study showed that there was not a significant difference in the three techniques used. Chitre conducted a study and showed that there is no evidence from controlled trials of any benefit from locating an anatomically related anterior reference point during face-bow transfer. This research supports the result of our study, as there is nonsignificant effect of changing the anterior point of reference sagittal condylar inclination. According to Prajapati et al. and Nooji and Sajjan, a change in anterior reference point in a face bow transfer caused a change in the orientation of the occlusal plane and resulted in different protrusive condylar guidance values.
Thus, after discussing the result of the study and within the research limitations, we can conclude that BL technique can be used for the orientation of maxillary cast on the semi-adjustable articulator as accurately as the conventional approach, for those practitioners who find difficulty in locating the OR or for those patients with deformity in facial region. Lateral cephalogram provides almost the same measurements of sagittal condylar path inclination as obtained using protrusive interocclusal record on facebow registrations using OR and BL as an anterior point of references.
| Conclusion|| |
The use of the bubble leveler facebow registration on articulator made it possible to mount the dental casts of patients having difficulty locating the OR to reproduce their clinical appearance. The values obtained were evaluated by comparing the measurements of anatomical variables obtained from cephalometric radiographs with equivalent values obtained from the articulator and casts mounted on the articulator using conventional approach. The measurements showed that there is no significant difference among all the techniques utilized. Since there is no difference in all the three techniques, any technique can be used in normal patients with symmetrical appearance, but bubble level can be used more effectively in patients with asymmetrical appearance.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published, and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10]
[Table 1], [Table 2], [Table 3]