Association between malocclusion and posture

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Background

In recent years, many researchers have reported an association between malocclusion and musculoskeletal disorders [1, 2]. This relationship is influenced not only by mechanical factors but also by imbalances in the function of connective tissue structures. Currently, without analysis of the temporomandibular joint (TMJ) status and neuromuscular coordination, management of malocclusion and full-mouth rehabilitation may result in relapses and complications.

For harmony within the neuromuscular system, paired body parts should be symmetrically aligned relative to the horizontal plane and the vertical axis of gravitational force [2]. When the position of a particular body segment is altered, tension develops, and the neuromuscular system attempts to restore postural balance.

The concept of the reciprocal relationship between posture and occlusion was first introduced in the early 20th century by Pierre Robin (1902) [3]. Since then, accumulating evidence has confirmed the mutual association between dentofacial abnormalities and postural deviations. It has been proposed that occlusal disturbances can alter posture in the frontal and sagittal planes and ultimately affect body mass distribution. Postural curvature, in turn, leads to displacement of the condylar head of the TMJ, producing joint pain and dysfunction, which subsequently contribute to malocclusion [4].

According to numerous studies, general health is closely interrelated with the health of the stomatognathic system. Any postural deviation triggers compensatory changes throughout the body, including the maxillofacial region [5, 6].

Posture is defined as the interaction between muscular chains, fasciae, ligaments, and skeletal structures across all body segments in the upright position [7]. Under ideal conditions, these processes are perfectly balanced, with minimal energy expenditure and maximal efficiency [8, 9]. Several studies have investigated the potential association between posture and temporomandibular joint status [10–23]. However, many reports lack quantitative data and sufficient information regarding the clinical application of this relationship.

Aim

This study aimed to investigate the impact of malocclusion on body posture parameters.

Methods

A group of 10 participants aged 20 to 30 years was recruited. All subjects had no symptomatic temporomandibular joint (TMJ) disorders, tooth loss, or dentofacial abnormalities.

After obtaining informed consent, simulated pathological mandibular deviations were performed in participants while simultaneously assessing postural parameters. Variants of occlusal changes included:

• mandibular deviation to the left
• mandibular deviation to the right
• unilateral occlusal elevation on the left side
• unilateral occlusal elevation on the right side
• protrusive mandibular position (see Fig. 1).

 

Fig. 1. Simulation of occlusal alteration variants.

 

Occlusal changes were accompanied by rasterstereographic light-optical analysis of the spine and posture using the Diers Formetric 4D system (Diers International GmbH, Germany). The system consists of a light projector that projects a grid of lines onto the patient’s back and a scanner that records the image. The software analyzes line curvature and generates a three-dimensional surface model of the back using photogrammetry, followed by evaluation of spinal curvature in sagittal and frontal planes, vertebral rotation, and pelvic position. The following spinal parameters were measured during occlusal alterations:

• vertical deviation
• pelvic tilt
• pelvic torsion
• vertebral rotation
• lateral deviation
• thoracic kyphosis angle
• lumbar lordosis angle.

Measurements were performed after an adaptation period to the new mandibular position: 15–20 minutes in static mode and dynamic mode (walking at a comfortable speed of 3–5 km/h for 5–10 minutes). For each participant, occlusal alterations and rasterstereographic analysis were performed three times; measurement errors exceeding 2 mm between results were considered unacceptable.

Measurement results were compiled into tables for each participant, indicating clinical relevance: green zone corresponded to minimal changes (possible measurement error), yellow zone corresponded to minor changes beyond measurement error, red zone corresponded to clinically significant changes. The evaluation criteria were as follows: vertical deviation; pelvic tilt; pelvic torsion; lateral deviation (yellow zone: 2 mm, red zone: ≥ 3 mm); vertebral rotation (yellow zone: 2°, red zone: ≥ 3°); thoracic kyphosis angle (yellow zone: 3–5°, red zone: ≥ 6°); and lumbar lordosis angle (yellow zone: 2°, red zone: ≥ 6°) (see Figs. 2–5).

 

Fig. 2. Patient 1, height 186 cm, weight 76 kg. Sedentary lifestyle, no physical activity. Rasterstereographic analysis in relation to mandibular position changes.

 

Fig. 3. Patient 2, height 185 cm, weight 90 kg. Physical activity present (plays soccer). Rasterstereographic analysis in relation to mandibular position changes.

 

Fig. 4. Patient 3, height 172 cm, weight 60 kg. Sedentary lifestyle, no physical activity. Rasterstereographic analysis in relation to mandibular position changes.

 

Fig. 5. Patient 4, height 186 cm, weight 76 kg. Sedentary lifestyle, no physical activity. Rasterstereographic analysis in relation to mandibular position changes.

 

Results and discussion

In centric occlusion, deviations from median body planes varied as follows: vertical deviation 0–4 mm, pelvic tilt 1–4 mm, pelvic torsion 1–3 mm, vertebral rotation 1–4°, lateral deviation 2–6 mm, thoracic kyphosis angle 48–68°, lumbar lordosis angle 35–40°.

Diagnostic evaluation revealed consistent patterns—alterations in spinal alignment associated with changes in mandibular position (dental arch relationship) and TMJ structures (see Table 1).

 

Table 1. Prevalence and degree of postural changes in relation to mandibular deviation, %

Mandibular position Spinal parameter	Deviation to the left			Deviation to the right			Occlusal elevation on the left			Occlusal elevation on the right			Mandibular protrusion			Total
Vertical deviation	20	40	40	20	20	60	40	20	40	20	–	80	40	–	60	28	16	56
Pelvic tilt	60	20	20	80	–	20	60	20	20	80	20	-	60	20	20	68	16	16
Pelvic torsion	60	20	20	40	40	20	100	–	–	60	–	40	80	–	20	68	12	20
Vertebral rotation	100	–	–	100	–	–	100	–	–	100	–	-	100	–	-	100	–	–
Lateral deviation	60	20	20	40	20	40	60	20	20	60	20	20	60	–	40	56	16	28
Thoracic kyphosis angle	60	20	20	20	60	20	40	20	40	40	–	60	20	–	80	36	20	44
Lumbar lordosis angle	60	20	20	60	40		20	60	20	40	40	20	60	20	20	48	36	16
Total	60	20	20	51.5	25.7	22.8–	60	20	20	57.1	11.4	31.5	60	5.7	34.3	57.7	16.6	25.7

Note: Green zone indicates minimal changes (possible measurement error); yellow zone indicates minor changes beyond measurement error; red zone indicates marked changes.

 

Deviations in parameters after mandibular postural shifts, compared with centric occlusion, reached up to 10 mm and 13°.

Particularly notable were changes in vertical deviation, thoracic kyphosis angle, and lateral deviation: 56.0%, 44.0%, and 28.0% of changes, respectively, were within the red zone, indicating clinical significance. Parameters of “vertical deviation” and “thoracic kyphosis angle” changed significantly, which was expected, as they are directly influenced by mandibular position.

Vertebral rotation remained practically unchanged (100% of changes within the green zone); changes in lumbar lordosis angle, pelvic tilt, and pelvic torsion were also minimal: 48.0%, 68.0%, and 68.0% of changes, respectively, fell within the green zone. Pelvic tilt and vertebral rotation are not primary zones of influence for mandibular position and TMJ alignment.

The most pronounced effects on postural parameters were produced by mandibular protrusion and occlusal elevation on the right side, accounting for 34.3% and 31.5% of all spinal alignment changes classified as clinically significant (red zone). The most affected parameters were the thoracic kyphosis angle and vertical spinal deviation.

Lateral mandibular deviation influenced posture primarily in terms of vertical and lateral spinal deviation, i.e., body balance in space.

Thus, the study clearly demonstrated an association between stomatognathic structures and axial skeletal structures. Alterations in mandibular position influenced rasterstereographic parameters to varying degrees, including vertical and lateral spinal deviation, pelvic tilt and torsion, vertebral rotation, and spinal curvature angles (kyphosis and lordosis). The most significant changes were observed in vertical spinal deviation and thoracic kyphosis angle; mandibular protrusion and occlusal elevation produced the greatest postural alterations.

Conclusion

Rasterstereographic parameters were defined in individuals with intact dentition in centric occlusion. Postural parameters were found to change with alterations in mandibular position and, consequently, temporomandibular joint structures. The most statistically significant changes involved vertical spinal deviation and lateral spinal deviation (56.0% and 28.0% of changes in the red zone), and thoracic kyphosis angle (44.0%). The greatest influence on postural changes was exerted by mandibular protrusion (34.3% of red-zone changes) and occlusal elevation (31.5%).

These findings are important for interdisciplinary management of malocclusion and, conversely, in addressing postural disturbances.

Additional information

Author contributions: S.I. Malanyin: investigation, methodology, writing—original draft; A.Yu. Seleznev: investigation, data curation; V.N. Olesova: formal analysis, writing—review & editing; A.L. Peterikov: data curation. All the authors approved the version of the manuscript to be published and agreed to be accountable for all aspects of the work, ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Ethics approval: The clinical study was approved by the local Ethics Committee of the Innovation Center of the Russian Dental Association, Krasnodar (extract from Minutes No. 1/2, dated October 20, 2024).

Consent for publication: Written informed consent was obtained from all patients for the publication of personal data, including photographs (with faces obscured), in a scientific journal and its online version (signed on April 17, 2024; April 3, 2024; May 27, 2024; March 27, 2024; and April 9, 2024).

Disclosure of interests: The authors have no relationships, activities, or interests for the last three years related to for-profit or not-for-profit third parties whose interests may be affected by the content of the article.

Statement of originality: No previously published material (text, images, or data) was used in this work.

Data availability statement: The editorial policy regarding data sharing does not apply to this work, as no new data was collected or created.

Generative AI: No generative artificial intelligence technologies were used to prepare this article.

Provenance and peer-review: This paper was submitted unsolicited and reviewed following the standard procedure. The peer review process involved two external reviewers, a member of the Editorial Board, and the in-house scientific editor.

About the authors

Sergei I. Malanyin

ABC Clinic

Author for correspondence.
Email: abc@s-malanin.ru
ORCID iD: 0009-0001-9168-4756
Russian Federation, Moscow

Aleksandr Yu. Seleznev

ABC Clinic

Email: aleks.seleznev777@gmail.com
ORCID iD: 0009-0000-2268-3437
Russian Federation, Krasnodar

Valentina N. Olesova

State Research Center — Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency

Email: olesova@implantat.ru
ORCID iD: 0000-0002-3461-9317
SPIN-code: 6851-5618

MD, Dr. Sci. (Medcine), Professor

Russian Federation, Moscow

Anton Leonidovich Peterikov

State Research Center — Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency

Email: tony_riko@mail.ru
ORCID iD: 0009-0003-4305-7162
SPIN-code: 7420-7896

аспирант кафедры стоматологии

Russian Federation, Moscow

References

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