Modified protrusive wax record in recording condylar path angle and ethnic variations
Background and Aim: The condylar path angle (CPA) is an important measurement that is used to program articulators used in dental treatment. The purposes of the current study were to (1) investigate the CPA in Malay subjects, (2) to compare the measurements with average values (25˚-35˚ Camper’s; based on studies in Caucasians), and (3) to compare the right and left CPAs.
Methods: Thirty subjects aged 21-23 years were recruited. A wash technique impression was made, casts were poured, and face-bow transfers were taken. The casts were mounted to their centric position on a semi-adjustable articulator. Protrusive guides were constructed to allow the mandible to be protruded for 5 mm, and then the angles were measured using the protrusive record method.
Results: The right CPA was within the normal range for 43% (13/30) of participants and out of the normal range for 57% (17/30). The left CPA was within the normal range for 33% (10/30) of participants and out of the normal range for 67% (19/30). There was no statistically significant difference between the left and right CPAs (p = 0.72), but there was a strong linear relationship between left and right CPAs (p = 0.001).
Conclusions: Results of the current study indicated Malay subjects had measurable variations in the CPA, indicating that this population has an ethnic variation in the CPA.
Relevance for patients: To improve the quality of patient care, the CPA should be considered when constructing fixed/removable prostheses that use semi-adjustable articulators. Clinicians should not rely on the set average values that are pre-set on articulators when dealing with patients of Malay descent.
[1] Posselt U, Skytting B. Registration of the condyle path inclination: variation using the Gysi technique. J Prosthet Dent. 1960; 10: 243-247.
[2] Jagger R, Klineberg I. Articulators, transfer records, and study casts. In: Klineberg I, Eckert SE, eds. Functional Occlusion in Restorative Dentistry and Prosthodontics. St. Louis, MO: Elsevier; 2016:119.
[3] Melkers MJ. Condylar angle programming: the “missing link” in diagnostic and restorative dentistry. J Cosmet Dent. 2005; 21: 92-98.
[4] Christensen C. The problem of the bite. Dent Cosmos. 1905; 47: 1184-1195.
[5] dos Santos J, Jr., Nelson S, Nowlin T. Comparison of condylar guidance setting obtained from a wax record versus an extraoral tracing: a pilot study. J Prosthet Dent. 2003; 89(1): 54-59.
[6] Mani G. Simplified system of recording the condyle path and immediate lateral movement [in French]. Schweiz Monatsschr Zahnmed (1984). 1984; 94(12): 1241-1248.
[7] Preti G, Scotti R, Bruscagin C, Carossa S. A clinical study of graphic registration of the condylar path inclination. J Prosthet Dent. 1982; 48(4): 461-466.
[8] Rudd KD, Morrow RM, Jendresen MC. Fluorescent photoanthropometry: a method for analyzing mandibular motion. J Prosthet Dent. 1969; 21(5): 495-505.
[9] Fletcher AM. Ethnic variations in sagittal condylar guidance angles. J Dent. 1985; 13(4): 304-310.
[10] Chow TW, Clark RK, Cooke MS. The orientation of the occlusal plane in Cantonese patients. J Dent. 1986; 14(6): 262-265.
[11] Kinuta S, Wakabayashi K, Sohmura T, et al. Simple system to record jaw movements by a home digital camcorder. Int J Prosthodont. 2003; 16(5): 563-568.
[12] Carlsson GE, Arstrand P. Registrering av kondylbanelutingen medelst intraorala vaxindex hos patienter med totala plattprotesser. Svensk Tandlakare Tidskrift. 1964; 56(1).
[13] 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(3): 404-406.
[14] Freilich MA, Altieri JV, Wahle JJ. Principles for selecting interocclusal records for articulation of dentate and partially dentate casts. J Prosthet Dent. 1992; 68(2): 361-367.
[15] Gross M, Nemcovsky C, Friedlander LD. Comparative study of condylar settings of three semiadjustable articulators. Int J Prosthodont. 1990; 3(2): 135-141.
[16] Gross M, Nemcovsky C, Tabibian Y, Gazit E. The effect of three different recording materials on the reproducibility of condylar guidance registrations in three semi-adjustable articulators. J Oral Rehabil. 1998; 25(3): 204-208