Letter to the editor regarding “The inconclusiveness of research on functional pathologies of the temporomandibular system and body posture: Paths followed, paths ahead: A critical review,” published online April 29, 2019*

After reading the article, “The inconclusiveness of research on functional pathologies of the temporomandibular system and body posture: Paths followed, paths ahead: A critical review,” published online in CRANIO: The Journal of Craniomandibular & Sleep Practice on April 29, 2019, I would like to clear out some concepts. Body posture is the “position or physical attitude of the body,” as described in the Medical Subject Headings (MeSH) terms in PubMed resources. There is a wide range of articles studying the human position standards, through more or less complex photographic analyses, X-ray measurements, or other devices. As the authors describe, literature concerning this issue is not new, as many articles can be read relating posture and the stomatognathic system. More than 4,300 articles can be found in a simple last-10-years search using the terms “temporomandibular joint disorders and posture” in three databases (PubMed, Web of Science, CINAHL). Regarding this definition, the authors review the steps taken in the study of functional pathologies of the temporomandibular system related to posture mentioning “static posture” and “dynamic posture” in the “Body posture standards within the sample” subheading, without explaining the difference among concepts. The problem lies in the many aspects that can be addressed in “posture”: a positional, static aspect or a dynamic feature in postural control. The former indicates the 3D situation in space in respect to coordinates, the relationship between body segments or body attitude. The latter explores the natural oscillation of the upright human body that relies on the central nervous system, mainly thanks to vestibular, visual, and proprioceptive afferents [1]. Normally, it is studied by posturographic devices or force platforms, which can offer a multitude of parameters as a function of time or space [2]. Returning to MeSH terms, we should use “postural balance” to refer to the second concept. However, studies on the stomatognathic system have been done mixing these two aspects with the label of “posture” or “body posture.” Thus, we find studies regarding body segment position [3–5], variables derived from the center of pressure excursions [6] or even both [7,8]. In order to clarify the subject of study, we should take the effort to correctly use the terms or clearly specify what are we talking about, “posture” in a sense of position or “posture” as the dynamic variable in sensorimotor control, since they are different aspects of the same concept [9,10]. The understanding of our readers and the clinician’s communication will be increased.