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| ORIGINAL ARTICLE |
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| Year : 2013 | Volume
: 3
| Issue : 2 | Page : 109-113 |
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Evaluation of pattern of occlusal contacts in lateral excursion using articulating paper and shim stock: An in vivo study
Arshiya Gupta1, Vidya Kamalaksh Shenoy2, Thilak B Shetty3, Shobha J Rodrigues3
1 Consultant Prosthodontist, New Delhi, India
2 AJ Institute of Dental Sciences, Mangalore, India
3 Manipal College of Dental Sciences, Mangalore, India
| Date of Web Publication | 11-Feb-2014 |
Correspondence Address:
Vidya Kamalaksh Shenoy
AJ Institute of Dental Sciences, Mangalore
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/2229-5194.126874
 Abstract | | |
Aim: This study was done to evaluate the pattern of occlusal contacts in lateral excursion and compared the relative accuracy of shim stock and articulating paper for determining occlusal contact patterns. Material and methods: The patterns of occlusal contacts of 70 young adults were examined in various lateral positions with shim stock and articulating paper in regulated lateral positions 0.5, 1, 2, and 3 mm from the maximum intercuspation. Results: Most contact patterns belonged to group function and a few to canine protection when only working side contacts were considered. When both working and nonworking side contacts were considered, nearly half the contact patterns were those other than canine protection and group function. Shim stock exhibited superior accuracy and reliability as compared to the articulating paper. Conclusion: In the lateral excursion other than canine protected and group function, there exists some other occlusal contact pattern. Shim stock exhibits superior accuracy and reliability as compared to the articulating paper.
Clinical Relevance to Interdisciplinary Dentistry
- It is important to understand how to evaluate the type of existing occlusion before any restorative procedure is undertaken
- It helps to arrive at the best scheme of occlusion for any restorative procedure
- It also provides a background on the various methods used to assess the occlusal contact in restorative dentistry.
Keywords: Articulating paper, occlusion, shim stock
How to cite this article:
Gupta A, Shenoy VK, Shetty TB, Rodrigues SJ. Evaluation of pattern of occlusal contacts in lateral excursion using articulating paper and shim stock: An in vivo study. J Interdiscip Dentistry 2013;3:109-13 |
How to cite this URL:
Gupta A, Shenoy VK, Shetty TB, Rodrigues SJ. Evaluation of pattern of occlusal contacts in lateral excursion using articulating paper and shim stock: An in vivo study. J Interdiscip Dentistry [serial online] 2013 [cited 2023 Mar 29];3:109-13. Available from: https://www.jidonline.com/text.asp?2013/3/2/109/126874 |
| Introduction | |  |
Anterior guidance is important to develop a harmonious functional occlusion in the stomatognathic system. Canine protection and group function have been widely used as the two basic categories of occlusal contact patterns during lateral excursion in the normal dentition. [1]
However, several studies have reported other patterns of occlusal contacts other than the canine protection and group function occlusion during lateral excursion in the natural dentition. [2],[3] In addition, sensitivity, reliability, and validity of various methods used to assess occlusal contacts is a serious concern as inconsistent examination method could cause conflicting role of occlusal contacts in temporomandibular disorders, bruxism, and periodontal disease. [4],[5],[6]
Therefore, the present study was done to evaluate the pattern of occlusal contact in various mandibular lateral positions and to compare the relative accuracy of shim stock and articulating paper for determining occlusal contact patterns.
| Materials and Methods | | |
Seventy apparently healthy subjects between the age group of 18 to 30 years were selected for the study after obtaining voluntary informed consent to participate in the study. The inclusion criteria for selection were as follows: Complete permanent dentition except for third molars, sound periodontium and teeth without restorations, normal overjet, overbite, and occlusal alignment with an Angle Class I occlusal relationship; no history of orthodontic therapy, tooth grinding, and temporomandibular disorders. The study was approved by the institutional ethics committee.
Methods for recording occlusal contacts
The subject was required to sit upright in a dental chair with the Frankfurt plane almost horizontal. The subject's head was not supported. The evaluation was done by the same examiner. To rule out diurnal variation error, all measurements were taken from 9 am to 11 am in the morning. The subjects were taught to practice the required lateral mandibular excursions without the help from the examiner, using a hand mirror for assistance. Marks were made on the maxillary central incisors with a marker pen (LuxorOHP marker pen, Luxor writing instruments Pvt Ltd, New Delhi, India) to the right of the mandibular midline at the required lateral position.
The shim stock (12 μm thick; Arti-Fol metallic articulating film Dr. Jean Bausch KG, 50769 Köln, Germany) was placed on the occlusal surface of the right side and the subject was requested to close the mandible to the maximum intercuspation. The subject was requested to perform a habitual gliding movement to the right with the teeth in light contact at 0.5, 1.0, 2.0, and 3.0 mm positions, while a constant pulling force was maintained on the shim stock. The similar act was repeated once again after the articulating paper strip (200 μm thick; Articulating Paper, Jaypee General Agencies, Calicut, Kerala, India) was placed on the occlusal surface of the right side in the same respective positions. The occlusal contact patterns were then evaluated intraorally.
The nonworking side contacts were examined when the shim stock and articulating paper were placed one by one on the occlusal surfaces of mandibular posterior teeth on left side and the subject was asked to move the mandible toward the right side at 0.5 mm, 1 mm, 2 mm, and 3 mm positions. After the movement, the occlusal contact patterns were examined.
The same procedure was repeated by taking the left side as the working side and the right side as the nonworking side.
The following classification system was used to determine the occlusal contact pattern based on the previous study [2] on validity of canine protection and group function in classifying guidance patterns.
Classification system 1: Based on contact pattern on working side only
Group 1: (Canine protected occlusion)
Canine protection was defined as the contact of only working side maxillary and mandibular canines in the total range of lateral positions from 0.5 to 3.0 mm.
Group 2: (Group function occlusion)
Group function was defined as the contacts of two or more working side teeth in at least one lateral position.
Group 3: (Unclassifiable occlusal pattern)
Unclassifiable pattern was identified when a contact pattern other than those previously described was observed.
Classification system 2: Contact pattern on working and nonworking sides
Group 1: (Canine protected occlusion)
Canine protection was defined as the contact of only working side maxillary and mandibular canines in the total range of lateral positions from 0.5 to 3.0 mm. No nonworking side contacts were observed.
Group 2: (Group function occlusion)
Group function was defined as the contacts of two or more working side teeth in at least one lateral position. No nonworking side contacts were observed.
Group 3: (Balanced occlusion)
Balanced occlusion was defined as the contacts of both working and nonworking side teeth in at least one lateral position.
Group 4: (Unclassifiable occlusal pattern)
Unclassifiable pattern was identified when a contact pattern other than those previously described was observed, namely, contact of only working side first premolars throughout the lateral positions or contacts of only nonworking side teeth throughout the lateral positions.
The data were analyzed using the statistical software SPSS (Statistical Package for Social Sciences) version 11.5.
| Results | | |
[Table 1] shows the result for classification system-1 using shim stock where majority (81%) of the contact patterns were group function, 13% were canine protected occlusal patterns, and the rest 6% were unclassifiable pattern.
[Table 2] shows the result for classification system-2 using shim stock where 11% occlusal patterns were the canine protected, whereas the group function, balanced occlusal pattern, and unclassifiable occlusal contact patterns were found to be 47%, 34%, and 8%, respectively.
[Table 3] shows the result for classification system-1 using articulating paper where 93% of the contact patterns were the group function type, the canine protected occlusal patterns were as less as 3%, and the unclassifiable pattern were 4%. | Table 3: Result of classification system 1, using articulating paper (N=70)
Click here to view |
[Table 4] shows the result for classification system-2 using articulating paper where the canine protected, the group function, balanced occlusal pattern, and unclassifiable occlusal contact patterns were found to be 1.4%, 30%, 60%, and 8.6%, respectively. | Table 4: Result of classification system 2, using articulating paper (N=70)
Click here to view |
Graph 1 [Additional file 1] shows the intergroup comparison of occlusal contact pattern using shim stock and articulating paper for classification system 1. This revealed that the canine protection pattern decreased from 13% (using shim stock) to 3% (using articulating paper) with Chi-square value of 4.3 giving probability level value (P value) 0.04 that was statistically significant; whereas, the group function occlusal pattern increased from 81% (using shim stock) to 93% (using articulating paper) with Chi-square value of 8.6, giving probability value (P value) 0.03, that was again statistically significant too. However, the unclassified occlusal pattern decreased from 6% (using shim stock) to 4% (using articulating paper) with Chi-square value of 0.08, giving probability level value (P value) 0.05, which was statistically nonsignificant.
Graph 2 [Additional file 2] shows the intergroup comparison of occlusal contact pattern using shim stock and articulating paper for classification system 2. This revealed that the Canine protection pattern was decreased from 11% (using shim stock) to 1.4% (using articulating paper) with Chi-square value of 14.5, giving probability level value (P value) 0.02 that was statistically significant; whereas, the group function occlusal pattern decreased from 47% (using shim stock) to 30% (using articulating paper) with Chi-square value of 11.2, giving probability value (P value) 0.04, which was again statistically significant. The balanced occlusal contact pattern increased from 34% (using shim stock) to 60% (using articulating paper) with Chi-square value of 16.3, giving probability level value (P value) 0.01 that was statistically significant. However, the unclassified occlusal pattern increased from 8% (using shim stock) to 8.6% (using articulating paper) with Chi-square value of 0.03, giving probability level value (P value) 1.02, which was statistically nonsignificant.
| Discussion | | |
A young adult population sample with intact natural dentition, normal occlusion, head posture, training to ensure independent performance of the lateral mandibular movements, a single operator, and a fixed time for the recording of the occlusal contacts were used to minimize the experimental variables. Despite this, a repeated recording of the occlusal contact pattern was required in 8% of the cases to verify the contact pattern. This suggests that rather than a single recording, repeated recording should be made to confirm their clinical reproducibility.
The occlusal contact pattern varies according to the mandibular position examined and no specified position to examine occlusal contact has been described. Ogawa et al. [7] in their kinematical analysis suggested that the occlusal contact pattern in 0.5mm position must be evaluated when studying the role of occlusal contact on masticatory function as occlusal gliding contact during mastication would occur in the 0.5mm position. Pattern of occlusal contacts in regulated positions in the range of 1 to 3 mm from the maximum intercuspation have been investigated in the previous studies. [8],[9] Also, the range of the functional lateral movements used in the normal mastication has been measured at approximately 1 to 6 mm, with an average of 4 mm. [10] Therefore, in this study, occlusal contacts were examined in lateral positions from 0.5 to 3 mm.
Shim stock occlusal registration strips as well as articulating paper was evaluated for relative reliability in recording occlusal contacts. Thickness, strength, and the plastic deformation of occlusal registration strips have been identified as the most important requirements to identify the occlusal contacts. [11] A comparative study has shown that shim stock provides acceptable reliability in the clinical measurement of occlusal contacts. [12]
The definitions for canine protection and group function in the glossary of prosthodontics terms do not specify the type of occlusal contact on the nonworking side. Categorization of only the working side contacts revealed that most contact patterns were group function followed by canine guided and a few were unclassifiable patterns. Categorization of the tooth contacts in both working and nonworking sides during various lateral excursion confirmed that apart from canine protection and group function, there were several other contact patterns present in natural dentition. The contacts present in nonworking side are considered as balancing interferences. The lack of clinically relevant, descriptive classification of occlusal patterns continues the confusion among the clinicians.
In this study, with shim stock (12 μm thick), the majority of the contact patterns were group function (81%), whereas with the articulating paper (200 μm) it was 93%. The thickness of the articulating paper that exceeds the maximum recommended thickness of occlusal recording strips markedly must have given much more false contacts when the gap between opposing teeth was less than the thickness of paper itself. Similarly, the brittle nature of articulating paper without any plastic deformation and moisture sensitivity in the oral environment could have resulted in smeared and smudged markings. Flexibility and movement of the strip also could result in smudging, tearing, and distorting of the impressed marks. [12]
Occlusal guidance is an acquired relationship between form, function, and tooth wear. The occluding form of a restoration should be in harmony with the occlusal guidance so as not to disturb the masticatory system. Therefore, an understanding of type of occlusal contact including the examining methods is required.
The limitations of the study can be attributed to the difference in bite force of the subjects, effect of saliva, and repetition of the contact recordings in several positions also would have fatigued the patient.
| Conclusion | | |
Within the limitations of the study, following conclusions were drawn:
- Categorization of the tooth contacts in lateral excursion confirmed that apart from canine protection and group function, there exist some other patterns of occlusal contacts
- Shim stock exhibits superior accuracy and reliability as compared to the articulating paper recording the occlusal contacts suggesting the importance of recording material.
| References | | |
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[Table 1], [Table 2], [Table 3], [Table 4]
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