Functional Significance of the Curve of Spee: Electro-myographic Analysis of Young Adults—A Preliminary Study
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Keywords
Curve of spee, Electromyographic analysis, Young adults
Abstract
Background: The curve of Spee is a fundamental anatomic feature of dental occlusion that influences mandibular movement, muscle coordination, and masticatory efficiency. In contemporary orthodontics, standardized leveling and flattening of this curve are frequently adopted, as originally proposed by Andrews. However, in prosthetic and restorative dentistry, the management of the curve of Spee often requires a more individualized approach. Given the high prevalence of fixed orthodontic treatment, understanding the functional consequences of altering this occlusal curvature is clinically relevant. Objective: This pilot study aimed to investigate the effects of leveling the antero-posterior occlusal curve on muscular activity and functional harmony of the stomatognathic system in young adults previously treated with fixed orthodontic appliances. Materials and Methods: Sixteen young adult subjects with a history of fixed orthodontic treatment were enrolled. Muscular activity was assessed by surface electromyography using a four-channel Kinelock electromyographic device wirelessly connected to a dedicated personal computer. Electromyographic recordings were used to evaluate masticatory muscle function in relation to the occlusal configuration and the characteristics of the curve of Spee. Results: Electromyographic analysis revealed variations in muscular activity associated with modifications of the curve of Spee. The findings suggest that standardized flattening of the occlusal curve may influence neuromuscular balance and masticatory function, highlighting interindividual differences in functional adaptation. Conclusion: Within the limitations of this pilot study, the curve of Spee appears to be a parameter requiring individualized consideration to optimize functional harmony of the stomatognathic apparatus. Standardized leveling procedures may have unavoidable functional consequences, supporting the need for personalized occlusal management in orthodontic, prosthetic, and restorative treatments.
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References
2.Osborn, J.W. Orientation of the masseter muscle and the curve of Spee in relation to crushing forces on the molar teeth of primates. Am J Phys Anthropol. 1993;92(1):99–106. https://doi.org/10.1002/ajpa.1330920108.
3.Sambataro, S., Cervino, G., Fiorillo, L., et al. Upper first premolar positioning evaluation for the stability of the dental occlusion: anatomical considerations. J Craniofac Surg. 2016;29(5):1366–1369. https://doi.org/10.1097/SCS.0000000000004459.
4.Andrews, L.F. The six keys to normal occlusion. Am J Orthod. 1972;62:296–309. https://doi.org/10.1016/S0002-9416(72)90268-0.
5.De Praeter, J., Dermaut, L., Martens, G., et al. Long-term stability of the leveling of the curve of Spee. Am J Orthod Dentofac Orthop. 2002;121(3):266–272. https://doi.org/10.1067/mod.2002.121009.
6.Tamizharasi, S., Senthil Kumar, K. Significance of curve of Spee: an orthodontic review. J Pharm Bioallied Sci. 2012;4(Suppl 2):S323–S328. https://doi.org/10.4103/0975-7406.100287.
7.Baldridge, D.W. Leveling the curve of Spee: its effect on mandibular arch length. JPO J Pract Orthod. 1969;3:26–41. https://pubmed.ncbi.nlm.nih.gov/5250875/.
8.Shannon, K.R., Nanda, R.S. Changes in the curve of Spee with treatment and at 2 years post-treatment. Am J Orthod Dentofac Orthop. 2004;125(5):589–596. https://doi.org/10.1016/j.ajodo.2003.09.027.
9.Rozzi, M., Mucedero, M., Pezzuto, C., et al. Leveling the curve of Spee with continuous archwire appliances in different vertical skeletal patterns: a retrospective study. Am J Orthod Dentofac Orthop. 2017;151(4):758–766. https://doi.org/10.1016/j.ajodo.2016.09.023.
10.Krishnamurthy, S., Hallikerimath, R.B., Mandroli, P.S. An assessment of curve of Spee in healthy human permanent dentitions: a cross sectional analytical study in a group of young Indian population. J Clin Diagn Res. 2017;11(1):ZC53–ZC57. https://doi.org/10.7860/JCDR/2017/22839.9184.
11.Ogawa, T., Koyano, K., Suetsugu, T. The relationship between inclination of the occlusal plane and jaw closing path. J Prosthet Dent. 1996;76(6):576–580. https://doi.org/10.1016/S0022-3913(96)90432-1.
12.Casazza, E., Orthlieb, J.D., Giraudeau, A., et al. Balkwill’s angle, occlusal plane, mandibular shape, and curve of Spee. Cranio. 2024;42(5):583–591. https://doi.org/10.1080/08869634.2021.2024992.
13.Laird, M.F., Holton, N.E., Scott, J.E., et al. Spatial determinants of the mandibular curve of Spee in modern and archaic Homo. Am J Phys Anthropol. 2016;161(2):226–236. https://doi.org/10.1002/ajpa.23020.
14.Marshall, S.D., Caspersen, M., Hardinger, R.R., et al. Development of the curve of Spee. Am J Orthod Dentofacial Orthop. 2008;134(3):344–352. https://doi.org/10.1016/j.ajodo.2006.10.037.
15.Ash, M. Wheeler’s Dental Anatomy, Physiology and Occlusion, 7th ed. W.B. Saunders: Philadelphia, USA; 1993; pp. 76–98. https://books-library.website/files/download-pdf-ebooks.org-1518031365Wz3N5.pdf.
16.Okeson, J.P. Management of Temporomandibular Disorders and Occlusion, 5th ed. Mosby: USA; 2003; pp. 127–146. http://www.neoncursos.com.br/wp-content/uploads/2019/08/Management_of_Temporomandibular_Disorders-and-Occlusion-Okeson-2020.pdf.
17.Shillingburg, H.T., Hobo, S., Whitsett, L.D., et al. Fundamentals of Fixed Prosthodontics, 3rd ed. Quintessence Publishing: Chicago; 1997; pp. 85–103. https://www.scribd.com/doc/238913733/Fundamentals-of-Fixed-Prosthodontics-P-4355700.
18.Williamson, E.H., and Lundquit, D.O. Anterior guidance: its effect on electromyographic activity of the temporal and masseter muscle. J Prosthet Dent . 1983;49(6):816–823. https://doi.org/10.1016/0022-3913(83)90356-6.
19.Kanavakis, G., and Mehta, N. The role of occlusal curvatures and maxillary arch dimensions in patients with signs and symptoms of temporomandibular disorders. Angle Orthod. 2014;84(1):96–101. https://doi.org/10.2319/111312-870.1.
20.Pompa, G., DiCarlo, S., Mencio, F., et al. Determination of vertical dimension in implant prostheses with surface electromyography. J Stomat Occ Med. 2012;5:83–87. https://doi.org/10.1007/s12548-012-0043-x.
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