|Year : 2018 | Volume
| Issue : 4 | Page : 84-89
Revising Average Condylar Inclinations Using Electronic Pantograph Assessment: A Cross-Sectional Study
Safoura Ghodsi, Sasan Rasaeipour
Department of Prosthodontics, Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
|Date of Web Publication||29-Jan-2019|
Department of Prosthodontics, Dental Research Center, Dentistry Research Institute, School
of Dentistry, Tehran University of Medical Sciences, North Kargar St, Tehran, 14399-55991
Source of Support: None, Conflict of Interest: None
Introduction: Condylar inclinations produce a frame for the occlusal morphology of dental restorations. Applying arbitrary average values for the articulator settings has brought about more practicality to the prosthesis fabrication procedures. The present study aimed at determining the average sagittal condylar inclination (SCI) and Bennett angle (BA) using electronic pantograph and comparing the inclination quantities obtained from different methods to proposed average measurements. Materials and Methods: Using Cadiax Compact II, condylar inclinations were recorded in 50 participants, generally healthy without any signs of joint problems. The recorded average values were compared with proposed mean values using one sample t-test. The level of significance was set at P < 0.05. The available articles were also searched using electronic databases. Results: A statistically significant difference was observed in the mean SCI (41.66°) and the proposed average value (33°) (P < 0.05). The difference between BA mean value (10.10) and arbitrary proposed value (15) was even more pronounced (P < 0.05). Pantographic records show different values compared to average propositions for condylar inclinations. Conclusion: Ongoing controversies concerning the average values for articulator settings proposed a revision in traditionally used arbitrary settings as well as Hanau formulation on the sagittal and lateral inclination interrelationships.
Keywords: Anatomy, jaw biomechanics, jaw relation record/methods, occlusion
|How to cite this article:|
Ghodsi S, Rasaeipour S. Revising Average Condylar Inclinations Using Electronic Pantograph Assessment: A Cross-Sectional Study. Dent Hypotheses 2018;9:84-9
| Introduction|| |
Mandibular movements are naturally dictated by the anatomic structure of the bony components in mandibular joints, the thickness and shape of the medial portion of the articular disc, the ligaments, and the masticatory muscles. Whatever introduced to the mouth (including dental prostheses) is required to coordinate with this predetermined system to prevent future complications. Condylar inclination is a critical determinant of mandibular movements that plays a pivotal role in fabrication of different types of prostheses.,
Although various procedures have been proposed to register condylar inclination, some authors suggest using average values for the majority of restorative procedures.,,,,, Average condylar inclinations have been suggested many years ago by measuring values resulted from intraoral records; their application was proposed to simplify the prostheses fabrication. According to sagittal condylar inclination (SCI), Hanau in 1930 introduced a formula for Bennett angle (BA) determination that became very popular afterwards. With regard to the formula, L = H/8 + 12, in which L is BA and H represents SCI. As the proposed average SCI was 33°, the resulted average BA was 15°. These mean values have been routinely used in prosthetic treatments for years.
Average settings are able to satisfy the demands of treatment and are reliably applicable in a variety of situations. Factors like gender, nationality, and even age are the roots of extensive controversies on the amounts of average values.,,,,, Different quantities have been reported as average SCIs using different methods.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Following the introduction of the new recording instruments, the condylar guidance adjustments were reevaluated.,,,,,, The mechanism of inclination registration is the main difference between traditional methods of condylar guidance recording (by interocclusal materials) and the pantographic method. Interocclusal materials record just two points of condylar path: the centric relation (CR) point and the last point of mandibular excursive movement. However, condyle does not move in a straight line. The double ogee curve of the glenoid fossa will cause the apparent path of the condyle to be different with varying values of mandibular protrusion. This rang the bell for a revision of what normally considered as the average arbitrary settings.
Relying on an electronic pantograph (Cadiax Compact II, Whip Mix Corp, GAMMA Medizinisch-wissenschaftliche Fortbildungs-GmbH, Klosterneuburg, Austria), the present study aimed at determining the average SCI and BA among a group of participants. Furthermore, reviewing the available articles, the present study tried to evaluate the condylar inclination quantities resulted from different measuring procedures. The null hypothesis was that the average values for SCI and BA obtained from different measuring methods would have no significant difference compared to routinely accepted average quantities.
| Materials and Methods|| |
All procedures were in accordance with the ethical standards of the institutional research committee and the 1964 Helsinki declaration. All persons gave their informed consent prior to their inclusion in the study. The study was authorized to use human participants by the university human research ethics committee (ethical approval code: 139).
The inclusion criteria were as follows: The absence of any symptoms of temporomandibular joint diseases, myofascial pain, and intra/extracapsular disorders, normal or near normal overjet and overbite (2–4 mm), and the capability to move the mandibular jaw at least 6 mm in all excursive movements.
Based on the requirements of the study, the exclusion criteria consisted of these conditions: physical or psychological illnesses preventing the attachment of a facebow for registration purposes, the lack of capability to follow or carry out the attending dentist’s instructions correctly, and dental or periodontal diseases.
According to inclusion/exclusion criteria, 50 healthy cases were selected. The cases came in both genders (17 females and 33 males) with an average age of 26 years; the participants had all their teeth to support the clutch. They were selected from the under/postgraduate students of dentistry who were familiar with the requested jaw movements. This, indeed, minimized the errors resulted from movements’ inaccuracy. All the measurements were performed by the same operator (the first author).
Pantographic records were made using Cadiax Compact II. The patients were guided to centric position, and all movements (forward and lateral movements, and open/close) were recorded three times. Before each, the system was calibrated. Cadiax Compact recorded the average SCI and BA values. The results were compared with routinely used mean values (33° for SCI, and 15° for BA) using Epicalc 2000 software (Brixton Health, http://www.brixtonhealth.com/epicalc.html) by one sample t-test.
The search for available literature up to the year 2016 was performed through electronic databases (PubMed, Google Scholar, Medline, and Cochrane) applying each or combinations of following keywords: condylar inclinations, horizontal condylar angle, BA, average inclination, condylar guidance, interocclusal records, Pantographic records, radiographic evaluation, jaw relation records, and Hanau’s formula. After reviewing the abstracts of more than 230 articles, the most relevant literatures were selected, their full texts were obtained, and the results of condylar guidance recording were extracted. The predetermined inclusion
criteria were any English language article published in a peer-reviewed journal containing any of the search terms; the articles published between 1959 and 2016; and any article that evaluated and measured the condylar inclinations using any of the different methods. The articles that did not measure or report the posterior guidance angulations were excluded.
| Results|| |
Assessing the included participants, who were apparently healthy without any symptom of temporomandibular, occlusal, dental, and periodontal problems, the following results were obtained. The average values for SCI obtained by Cadiax Compact (41.66) were considerably higher than what proposed as the mean value (33°) (P < 0.05). The mean (standard deviation) SCI was 42.15 (5.35) for right the temporomandibular joints (TMJ), and 41.18 (5.74) for left side.
The average values for BA recorded by Cadiax (10.10) were much less than what is obtainable using Hanau formula (15°) (P < 0.05). The mean (standard deviation) BA quantity was 10.19 (3.49) for right side, and 10.02 (5.11) for left TMJ. All the differences between recorded values and routinely used average values were statistically significant (P < 0.05). [Table 1] shows the detailed results.
[Table 2] demonstrates the separated data extracted from articles reviewed. Pantograph recordings showed more SCI quantities compared to intraoral records, and mean BA recorded by pantograph was less than what proposed using intraoral records or Bennett formulation.
|Table 2: Different articles recorded dissimilar average condylar inclination values|
Click here to view
| Discussion|| |
For dental restorations to be durable and cause no long-term discomfort for the patients, harmony with individual jaw movements is crucial. Complicated dental reconstructions call for accurate condylar guidance recording. However, in routine prosthetic procedures, average value could simplify the process while fulfilling the treatment purposes.
SCI, by definition, is the angle of condylar guidance inclination to Frankfort horizontal plane. Condyle moves through a rather steeper incline in the first 3 mm., Two points recording will not register this steeper part [Figure 1], whereas pantographs record the whole condylar pathway, and show the mean measurement according to the amount of condylar Travers. Therefore, it will be apparent that SCI recorded by intraoral bite registration materials would be less than pantographic average. This is in agreement to several studies.,,,,,,,,,,,,,
|Figure 1: Condylar guidance anatomy and different inclinations recorded using different methods (a: the angle recorded by pantograph, b: the angle recorded by intraoral record, AO: the pathway depicting first few millimeters of condylar movement with steeper incline, BO: the pathway recorded using intraoral records that misses the most important part of the incline)|
Click here to view
BA is the angle formed by the sagittal plane and the path of the advancing condyle during lateral mandibular movement as viewed in the horizontal plane. According to Boulos et al., intraoral records do not depict the immediate mandibular lateral translation that is expressed in a 10th of a millimeter. Therefore, the recorded BA using conventional two points registration method, or Hanau formula (which was introduced using conventional method) will always be higher than what is recorded by pantographic device (which shows the mean quantity of whole condylar lateral pathway) [Figure 2]. This result is in agreement to Hernandez et al., Torabi et al., and several other studies.,,,,,
|Figure 2: Diagram shows the nonworking condyle pathway during excursive movements (a: the Bennett angle recorded by two-points intraoral record, b: the angle recorded including immediate lateral side shift, OA: immediate lateral side shift, OB: nonworking condylar pathway in mediotrusion)|
Click here to view
A review on available literature from 1959 up to now, showed that what had been proposed as average condylar settings (and were widely accepted and applied for years), are not supported by the application of new equipment. Although there are differences in average values according to age, sex, and nationality, generally, average SCI reported by pantographs and different types of pantronics is more than what could be obtained using intraoral records, and mean BA recorded by new devices is far less than what proposed using intraoral records and Bennett formulation [see [Table 2].,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, New apparatus helped us to improve our scientific visions in many aspects; it seems now is the time to revise our assumption regarding condylar adjustment.
In the present article, mean SCI was 41.66, with scanty difference between right (42.15) and left (41.18) sides. The average BA was 10.10 (10.19 on right, and 10.02 on left). The results rejected the null hypothesis. It seems Hanau formula for BA is not applicable for relating these values, and BA could be related to SCI by a revised formulation: BA = horizontal condylar inclination (HCI)/8 + 5.
| Conclusion|| |
SCI measurement using electronic pantograph (Cadiax Compact II) showed significantly higher values in comparison to routinely used average quantities (33°) (P < 0.05).
Electronic pantograph records significantly lower values for BA compared to what has been proposed for arbitrary articulator adjustment (15°) (P < 0.05).
The relationship between SCI and BA, obtained through the application of pantographs and new recording devices, does not follow Hanau formula for BA.
All the authors substantially contributed in
- Concept and design of study or acquisition of data or analysis and interpretation of data;
- Drafting the article or revising it critically for important intellectual content; and
- Final approval of the version to be published.
Manuscript has been read and approved by all the authors.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Dawson P. The determinants of occlusion. In: Dawson P, editor. Functional occlusion from TMJ to smile design. Mosby: Elsevier; 2007. pp 27-33.
Price RB, Kolling JN, Clayton JA. Effects of changes in articulator settings on generated occlusal tracing. Part I: Condylar inclination and progressive side shift settings. J Prosthet Dent 1991;65:237-43.
Cimić S, Simunković SK, Badel T, Dulcić N, Alajbeg I, Catić A. Measurements of the sagittal condylar inclination: intraindividual variations. Cranio 2014;32:104-9.
Mantout B, Giraudeau A, Perez C, Ré JP, Orthlieb JD. Technical validation of a computerized condylographic system. Int J Stomat Occ Med 2008;1:45-50.
Shillingburg HT, Hobo S, Whitsett LD, Jacobi R, Brackett SE. Fundamentals of fixed prosthodontics. 3rd ed. Chicago: Quintessence; 1997. pp 12-34.
Caro AG, Peraire M, Martinez-Gomis J, Anglada JM, Samso J. Reproducibility of lateral excursive tooth contact in a semi-adjustable articulator depending on the type of lateral guidance. J Oral Rehabil 2005;32:174-9.
Lundeen HC, Wirth CG. Condylar movement patterns engraved in plastic blocks. J Prosthet Dent 1973;30:866-75.
Dawson P. Evaluation, diagnosis, and treatment of occlusal problems. 2nd ed. St. Louis: Mosby 1989. pp 227-8.
Anderson J. Biological and clinical considerations making jaw relation records and transferring records from the patient to the articulator. In: Zarb G, editor. Prosthodontic treatment for edentulous patients: Complete dentures and implant-supported prostheses. 12th ed. St. Louis: Mosby 2003. pp 296-7.
Javid NS, Porter MR. The importance of the Hanau formula in construction of complete dentures. J Prosthet Dent 1975;34:397-404.
Payne JA. Condylar determinants in a patient population: Electronic pantograph assessment. J Oral Rehabil 1997;24:157-63.
Jasinevicius TR, Pyle MA, Lalumandier JA, Nelson MS, Kohrs KJ, Turp JC et al.
The angle of the articular eminence in modern dentate African-Americans and European-Americans. J Craniomandib Pract 2005;24:249-56.
Hernandez AI, Jasinevicius TR, Kaleinikova Z, Sadan A. Symmetry of horizontal and sagittal condylar path angles: An in vivo study. Cranio 2010;28:60-6.
Sreelal T, Janardanan K, Nair AS, Nair AS. Age changes in horizontal condylar angle: A clinical and cephalometric study. J Indian Prosthodont Soc 2013;13:108-12.
Alshali RZ, Yar R, Barclay C, Satterthwaite JD. Sagittal condylar angle and gender differences. J Prosthodont 2013;22:561-5.
Boulos PJ, Adib SM, Naltchayan LJ. The horizontal condylar inclination: Clinical comparison of different recording methods. Gen Dent 2007;55:112-6.
Isaacson D. A clinical study of the condyle path. J Prosthet Dent 1959;9:927-35.
Ecker GA, Goodacre CJ, Dykema RW. A comparison of condylar control settings obtained from wax interocclusal records and simplified mandibular motion analyzers. J Prosthet Dent 1984;51:404-6.
Torabi K, Pour SR, Ahangari AH, Ghodsi S. A clinical comparative study of Cadiax Compact II and intraoral records using wax and addition silicone. Int J Prosthodont 2014;27:541-3.
Prasad KD, Shah N, Hegde C. A clinic-radiographic analysis of sagittal condylar guidance determined by protrusive interocclusal registration and panoramic radiographic images in humans. Contemp Clin Dent 2012;3:383-7.
] [Full text]
Shahidi S, Adibi S, Vojdani M, Khaledi A. Comparison of condylar inclination attained by interocclusal records and radiographic tracing. J Isfahan Dent Sch 2012;8:117-25.
Goyal MK, Goyal S. A comparative study to evaluate the discrepancy in condylar guidance values between two commercially available arcon and non-arcon articulators: A clinical study. Indian J Dent Res 2011;22:880. [Full text]
Vankateshwaran R, Karthigeyan S, Manoharan PS, Konchada J, Ramaswamy M, Bhuminathan XX. A newer technique to program a semi adjustable articulator. J Pharm Bioall Sci 2014;6:135-9.
Shreshta P, Jain V, Bhalla A, Pruthi G. A comparative study to measure the condylar guidance by the radiographic and clinical methods. J Adv Prosthodont 2012;4:153-7.
Preti G, Scotti RS, Bruscagin C. A clinical study of graphic registration of the condylar path inclination. J Prosthet Dent 1982;48:461-6.
Zamacona JM, Otaduy E, Aranda E. Study of the sagittal condylar path in edentulous patients. J Prosthet Dent 1992;68:314-7.
El-Gheriani AS, Winstanley RB. Graphic tracings of condylar paths and measurements of condylar angles. J Prosthet Dent 1989;61:77-87.
Curtis DA. A comparison of protrusive interocclusal records to pantographic tracings. J Prosthet Dent 1989;62:154-6.
Theusner J, Plash O, Curtis DA, Hutton JE. Axiographic tracings of temporomandibular joint movements. J Prosthet Dent 1993;69:109-15.
Beard CC, Donaldson K, Clayton JA. Comparison of an electronic and a mechanical pantograph. Part I: Consistency of an electronic computerized pantograph to record articulator settings. J Prosthet Dent 1986;55:570-4.
Boulos PJ, Adib SM, Naltchayan LJ. The Bennett angle. Clinical comparison of different recording methods. N Y State Dent J 2008;74:34-8.
Aull AE. Condylar determinants of occlusal patterns. J Prosthet Dent 1965;15:826.
Ahangari AH, Torabi K, Pour SR, Ghodsi S. Evaluation of the Cadiax Compact II accuracy in recording preadjusted condylar inclinations on fully adjustable articulator. J Contemp Dent Pract 2012;13:504-8.
Clayton JA, Beard CC, Myers GE. Electronic computerized pantographic recording of a PRI TM dysfunction. J Dent Res 1984;63:208.
Anderson GC, Schulte JK, Arnold TG. An in vitro study of an electronic pantograph. J Prosthet Dent 1987;57:577-80.
Clayton JA, Beard CC, Donaldson K, Myers GE. Clinical evaluation of electronic pantograph with mechanical pantograph. J Dent Res 1983;62:200.
Price RB, Bannerman RA. A comparison of articulator settings obtained by using an electronic pantograph and lateral interocclusal recordings. J Prosthet Dent 1988;60:159-64.
Solberg WK, Clark GT. Reproducibility of molded condylar controls with an intraoral registration method. Part I. Simulated movement. J Prosthet Dent 1974;32:520-8.
Tamaki K. A study on objective assessment of pathway in areas of intercuspal position during chewing movements. An evaluation from movement-path angles by grinding patterns intercuspal position during chewing movements. J Jpn Prosthodont Soc 1992;36:367-80.
Ratzmann A, Mundt T, Schwahn C, Langforth G, Hutzen D, Gedrange T et al.
Comparative clinical investigation of horizontal condylar inclination using the JMA electronic recording system and a protrusive wax record for setting articulators. Int J Comput Dent 2007;10:265-84.
Prasad KD, Shetty M, Chandy BK. Evaluation of condylar inclination of dentulous subjects determined by axiograph and to compare with manual programming of articulators using protrusive interocclusal record. Contemp Clin Dent 2015;6:371-4.
] [Full text]
Galagali G, Kalekhan SM, Nidawani P, Naik J, Behersa S. Comparative analysis of sagittal condylar guidance by protrusive interocclusal records with panoramic and lateral cephalogram radiographs in dentulous population: A clinic-radiographic study. J Indian Prosthodont Soc 2016;16:148-53.
] [Full text]
Bhawsar SV, Marathe AS, Ansari SA. Evaluation of Hanau’s formula in determination of lateral condylar guidance: A clinical research study. J Indian Prosthodont Soc 2015;15:326-30.
] [Full text]
[Figure 1], [Figure 2]
[Table 1], [Table 2]