Introduction
Abstract: The masticatory system, encompassing teeth, occlusion, muscles, joints, and the central nervous system, is increasingly understood as a complex system rather than a simple biomechanical mechanism. This shift in perspective aligns with Thomas Kuhn's phases of paradigm shifts, where anomalies in traditional models trigger the search for new paradigms. In the context of Masticationpedia, a new interdisciplinary approach to diagnosing and treating malocclusion emerges, focusing on "Occlusal Dysmorphisms" rather than "malocclusion."
Recent advancements in electrophysiological testing, such as motor-evoked potentials and jaw reflexes, reveal functional symmetry in the masticatory system, even in patients with occlusal discrepancies. This finding challenges the traditional understanding of malocclusion, suggesting that neuromuscular dynamics play a crucial role in maintaining masticatory function. Consequently, interdisciplinary diagnostics that consider both occlusal and neuromuscular factors are necessary for accurate diagnosis and effective treatment.
This paradigm shift has implications for current rehabilitative therapies, including orthodontics and prosthetics, which have traditionally focused on achieving occlusal stability. However, considering the masticatory system as a complex system requires an integrative approach that incorporates both aesthetic and neurophysiological factors to prevent relapses and achieve long-term functional stability. The emerging field of OrthoNeuroGnathodontic treatments exemplifies this interdisciplinary approach, offering innovative strategies for addressing masticatory disorders.
By viewing the masticatory system through the lens of complexity science, the field of dentistry can expand its understanding of occlusal stability and dysfunction, ultimately leading to new treatment paradigms that enhance patient outcomes. This new model does not replace traditional treatments but seeks to enrich them with a broader interdisciplinary perspective, aligning with the evolving science of masticatory rehabilitation.
Ab ovo[1]
Before delving into the analysis of Masticationpedia, we must first introduce some preliminary considerations, particularly regarding two fundamental dimensions—social, scientific, and clinical—that characterize both the present era and the one immediately preceding it.
The phases of paradigm change according to Thomas Kuhn
Over the past century, technological and methodological innovations[2] have exponentially increased, especially in dentistry. These developments have significantly impacted decision-making, schools of thought, and fundamental principles, with the explicit goal of improving quality of life, as emphasized in the "Science of Exposure in the 21st Century".[3] However, this exponential growth hides conceptual ambiguities—or, practically speaking, "side effects"—that, though often underestimated, can challenge scientific certainties, making them more probabilistic.[4] These sensitive aspects of current social, scientific, and clinical reality, seemingly in conflict, will ultimately prove to be complementary by the end of this analysis. This evolution follows the concept of "Progress of Science," according to Kuhn’s interpretation of "Epistemology."
In his most famous work, Thomas Kuhn argues that science advances through distinct cycles reflecting its operational dynamics.[5][6] Kuhn posits that science is structured around paradigms and establishes a clear demarcation between science and pseudoscience based on the presence of a shared paradigm. The evolution of scientific progress is depicted as a continuous curve interrupted by discontinuities, represented by paradigm shifts.
In these periods of crisis, scientists act as problem solvers, seeking to resolve anomalies. These "scientific revolutions" occur when the existing paradigm can no longer interpret new anomalies, pushing the scientific community toward new paradigms that better align with observations.
Kuhn's phases in Dentistry
Thomas Kuhn identifies five distinct phases in the evolution of a scientific paradigm—a process crucial for Masticationpedia. However, to align with the project’s scope, we will focus on the three most significant phases, as indicated in the book’s index.
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Kuhn’s concept gives priority to discipline-specific expertise, yet this contradicts the interdisciplinary nature of modern science. A detailed analysis of this discrepancy is therefore appropriate.
Epistemology
| The black swan symbolizes one of the historical problems of epistemology: if all the swans we have seen so far are white, can we decide that all swans are white? | _RWD.jpg) |
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Kuhn used optical illusion to demonstrate how a paradigm shift can cause a person to see the same information in a completely different way. |
Epistemology (from Greek ἐπιστήμη, epistēmē, meaning "certain knowledge" or "science", and λόγος, logos, "discourse") is the branch of philosophy that studies the necessary conditions for acquiring scientific knowledge and the methods through which it is achieved.[7] Specifically, it refers to the investigation of the foundations, validity, and limits of scientific knowledge. In English-speaking countries, the term "epistemology" is often synonymous with the theory of knowledge or gnoseology, which examines the study of knowledge in general.
The central problem of epistemology, today as in the times of Hume,[8][9] is the issue of verifiability. According to Hempel’s paradox, every example that does not contradict a theory confirms it, which is described as:
No theory can be definitively true; while there are finite experiments to confirm it, an infinite number could refute it.[10]
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But it’s not all so obvious... |
...because epistemology evolves continually, even in medicine:
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Interdisciplinarity
A superficial view might suggest a conflict between the disciplinarity of the "Physics Paradigm of Science" (which highlights anomalies) and the interdisciplinarity of the "Engineering Paradigm of Science" (focused on metacognitive scaffolds). However, these perspectives are not in conflict; they are complementary and drive "Paradigmatic Innovation" in science.
It could be said that "Innovations" represent "Progresses of Science," as illustrated in the article "Scientific Bases of Dentistry" by Yegane Guven, which explores the impact of biological and digital revolutions on dentistry.[19] True scientific progress is not solely achieved through "Incremental Innovations" or "Radical Innovations" but through "Paradigmatic Innovations."
"Paradigmatic Innovations" represent a change in thinking that spreads through humanity, affecting society on many levels, from the Copernican revolution to the stochastic methods applied to biological phenomena.[20]
This epistemological context, which includes initiatives like the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and Evidence-Based Medicine, aligns with Masticationpedia’s aim to highlight anomalies that stimulate changes in scientific thought, ultimately leading to "Paradigmatic Innovation."
Dental Malocclusion
"Malocclusion" derives from the Latin "malum," meaning "bad" or "wrong," and refers to improper closure of the teeth.[21] The notion of "closure" may seem intuitive, but "bad" requires careful consideration in a medical context.
A search for "Malocclusion" on PubMed yielded 33,309 articles,[22] reflecting a lack of consensus on the term. Smaglyuk and colleagues’ study underscores the importance of an interdisciplinary approach to diagnosing malocclusions.[23]
Another notable observation from PubMed queries on interdisciplinary malocclusion diagnostics is the drastic drop to only four articles.[24]
These findings suggest the emergence of phase 4 in Kuhn’s model, indicating a potential paradigmatic shift. Some prefer incremental innovations, while others favor a new path of "Paradigmatic Innovation."
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What does "Malocclusion" mean? |
In this clinical case of malocclusion, characterized by a unilateral posterior crossbite and anterior open bite, orthodontic appliances and possibly orthognathic surgery are recommended.[25] The crossbite requires concurrent treatment due to its functional relationship with the open bite.[26]
In this case, the patient refused treatment, insisting that their chewing function was fine. The dentist responded by explaining the long-term risks of leaving the malocclusion untreated, but respected the patient's decision to decline treatment.
The case illustrates the complexity of diagnosing malocclusion, which involves more than occlusal discrepancies. Specific electrophysiological tests, such as the motor-evoked potential and jaw reflex tests, can reveal functional symmetry in the masticatory system despite occlusal issues.
Figure 1a: Patient with malocclusion, open bite, and right posterior crossbite who should be treated with orthodontic therapy and/or orthognathic surgery.
Figure 1b: Motor-evoked potential test showing symmetry in the right and left masseter muscles.
Figura 1c: Jaw reflex test revealing functional symmetry in the masticatory system.
Figura 1d: Evoked mechanical silent period showing balanced neuromuscular dynamics despite malocclusion.
These electrophysiological results challenge conventional interpretations of malocclusion, highlighting the importance of interdisciplinary diagnostics that consider neuromuscular function as well as occlusal discrepancies.
Occlusal Dismorphisms and Not Malocclusion ......which, as we will see shortly, is an entirely different matter.
Conclusion
Before concluding, we must clarify that the masticatory system is a "Complex System"[27], not a simple biomechanical mechanism focused solely on dental occlusion. Occlusion is just one subset within a broader context that includes periodontal receptors, neuromuscular spindles, motor units, the central nervous system, and the temporomandibular joint. This interaction creates "Emergent Behavior," or masticatory behavior.
Emergent behavior cannot be fully explained by analyzing a single subset; instead, the integrity of the entire system must be assessed. A notable intellectual movement addressing this challenge is Kazem Sadegh-Zadeh’s work, "Handbook of Analytic Philosophy of Medicine."[28]
The masticatory system's various subsets, such as teeth, occlusion, joints, and muscles, exhibit "Coherence" with the Central Trigeminal Nervous System, as shown in the electrophysiological tests. Therefore, "malocclusion" may not be the appropriate term; "Occlusal Dysmorphisms" would be more accurate.
This approach, exemplified in OrthoNeuroGnathodontic treatments, integrates aesthetic and neurophysiological aspects to achieve "Occlusal Stability" and prevent "Relapses."[29][30] While not replacing traditional treatments, this model seeks to expand medical knowledge and interdisciplinary practices in dentistry.
In the meantime, let us pause with a question from Linus Sapiens, our curious yellow figure on the left. He reminds us of the importance of remaining open to new perspectives in masticatory science.
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What do we mean by “Complex Systems” when we are talking about masticatory functions? |
- ↑ Latin for 'since the very beginning'
- ↑ Heft MW, Fox CH, Duncan RP, «Assessing the Translation of Research and Innovation into Dental Practice», in JDR Clin Trans Res, 2019».
DOI:10.1177/2380084419879391 Oct 7:2380084419879391 - ↑ «Exposure Science in the 21st Century. A Vision and a Strategy», Committee on Human and Environmental Exposure Science in the 21st Century; Board on Environmental Studies and Toxicology; Division on Earth and Life Studies; National Research Council.».
ISBN: 0-309-26468-5 - ↑ Liu L, Li Y, «The unexpected side effects and safety of therapeutic monoclonal antibodies», in Drugs Today, 2014, Barcellona».
DOI:10.1358/dot.2014.50.1.2076506 Jan;50(1):33-50 - ↑ Thomas Samuel Kuhn (Cincinnati, 18 luglio 1922 – Cambridge, 17 giugno 1996) was an American philosopher of science.
- ↑ Kuhn Thomas S, «The Structure of Scientific Revolutions», Univ. of Chicago Press, 2012, Chicago».
ISBN: 9780226458113 - ↑ The term was coined by Scottish philosopher James Frederick Ferrier, in his Institutes of Metaphysic (1854); see Internet Encyclopedia of Philosophy, James Frederick Ferrier (1808—1864).
- ↑ David Hume (1711–1776) was a Scottish philosopher.
- ↑ Srivastava S, «Verifiability is a core principle of science», in Behav Brain Sci, Cambridge University Press, 2018, Cambridge».
DOI:10.1017/S0140525X18000869 Jan;41:e150. - ↑ Evans M, «Measuring statistical evidence using relative belief», in Comput Struct Biotechnol J, 2016».
DOI:10.1016/j.csbj.2015.12.001 Jan 7;14:91-6. - ↑ Amrhein V, Greenland S, McShane B, «Scientists rise up against statistical significance», in Nature, 2019».
DOI:10.1038/d41586-019-00857-9 Mar;567(7748):305-307. - ↑ Rodgers JL, «The epistemology of mathematical and statistical modeling: a quiet methodological revolution», in Am Psychol, 2010».
DOI:10.1037/a0018326 Jan;65(1):1-12. - ↑ Meehl P, «The problem is epistemology, not statistics: replace significance tests by confidence intervals and quantify accuracy of risky numerical predictions», 1997».
- ↑ Sprenger J, Hartmann S, «Bayesian Philosophy of Science. Variations on a Theme by the Reverend Thomas Bayes», Oxford University Press, 2019, Oxford».
- ↑ Wasserstein RL, Schirm AL, Lazar NA, «Moving to a World Beyond p < 0.05», in Am Stat, 2019».
DOI:10.1080/00031305.2019.1583913 73, 1–19. - ↑ European Union, Horizon 2020
- ↑ Boon M, Van Baalen S, «Epistemology for interdisciplinary research - shifting philosophical paradigms of science», in Eur J Philos Sci, 2019».
DOI:10.1007/s13194-018-0242-4 9(1):16. - ↑ Boon M, «An engineering paradigm in the biomedical sciences: Knowledge as epistemic tool», in Prog Biophys Mol Biol, 2017».
DOI:10.1016/j.pbiomolbio.2017.04.001 Oct;129:25-39. - ↑ Guven Y, «Scientific basis of dentistry», in J Istanb Univ Fac Den, 2017».
DOI:10.17096/jiufd.04646 51(3): 64–71. Published online 2017 Oct 2. PMCID: PMC5624148 - PMID: 29114433 - ↑ Zhao XF, Gojo I, York T, Ning Y, Baer MR, «Diagnosis of biphenotypic acute leukemia: a paradigmatic approach», in Int J Clin Exp Pathol, 2010». Prepublished online 2009 Oct 10. PMCID: PMC2776262 - PMID: 19918331. 3(1): 75–86.
- ↑ Attributed to Edward Angle, the father of modern orthodontics, who coined it as a specification of occlusion.
- ↑ Pubmed, Malocclusion
- ↑ Smaglyuk LV, Voronkova HV, Karasiunok AY, Liakhovska AV, Solovei KO, «Interdisciplinary approach to diagnostics of malocclusions (review)», in Wiad Lek, 2019». 72(5 cz 1):918-922.
- ↑ Pubmed, interdisciplinary diagnostics of malocclusions
- ↑ Reichert I, Figel P, Winchester L, «Orthodontic treatment of anterior open bite: a review article--is surgery always necessary?», in Oral Maxillofac Surg, 2014».
DOI:10.1007/s10006-013-0430-5 Sep;18(3):271-7. - ↑ Miamoto CB, Silva Marques L, Abreu LG, Paiva SM, «Impact of two early treatment protocols for anterior dental crossbite on children’s quality of life», in Dental Press J Orthod, 2018». Jan-Feb; 23(1) 71–78.
- ↑ https://en.wikipedia.org/wiki/Complex_system
- ↑ Sadegh-Zadeh Kazem, «Handbook of Analytic Philosophy of Medicine», Springer, 2012, Dordrecht».
ISBN: 978-94-007-2259-0
DOI:10.1007/978-94-007-2260-6 . - ↑ Essam Ahmed Al-Moraissi, Larry M Wolford. Is Counterclockwise Rotation of the Maxillomandibular Complex Stable Compared With Clockwise Rotation in the Correction of Dentofacial Deformities? A Systematic Review and Meta-Analysis. J Oral Maxillofac Surg.. 2016 Oct;74(10):2066.e1-2066.e12.doi: 10.1016/j.joms.2016.06.001. Epub 2016 Jun 11.
- ↑ J Hoffmannová, R Foltán, M Vlk, K Klíma, G Pavlíková, O Bulik. Factors affecting the stability of bilateral sagittal split osteotomy of a mandible.Prague Med Rep. 2008;109(4):286-97.
particularly focusing on the field of the neurophysiology of the masticatory system