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Stomatologija 2020; 22 (4): 99-106 384 KB

Musculomandibular morphology in individuals with different vertical skeletal growth patterns: an MRI and cone beam computed tomography study

Katrina Gardovska¹, Ilga Urtane¹, Gaida Krumina²

Summary

Objective. The aim of this study was to analyse the volumetric and crossectional parameters of masseter and medial pterygoid muscles in the relation with mandibular skeletal morphology in individuals with different underlying growth patterns in the vertical dimension.

Material and methods. The study originally involved 76 individuals with definite clinical and radiological criteria: 31 skeletal Class III and 26 skeletal Class II patients before the orthognathic surgery and 20 skeletal class I (normal) individuals with complaints of wisdom teeth and associated medical problems. On the basis of cephalometric measurement of the mandibular plane and sella-nasion (MP-SN), the study sample was categorised according to the vertical facial dimension in 3 different growth pattern subgroups: 19 subjects with horizontal growth pattern, 25 subjects with vertical growth pattern and 33 subjects with neutral growth pattern. MRI was performed for the masseter and medial pterygoid muscles, and volume and cross-sectional area measurements were performed. Cone beam computed tomography (CBCT) investigation was performed for the assessment of craniofacial structures and the following measurements of the mandibular parameters were obtained: height of ramus, length of mandibular corpus, overall mandibular length, inter-angular width and intercondylar width.

Results. There were statistically significant differences among all study groups regarding masseter volume (p<0.006) and CSA (p<0.006), with the highest values in the horizontal growth pattern group and the lowest values in vertical growth pattern group. After Bonferroni correction, statistically significant difference (p<0.004 and p<0.008) was noted between the horizontal and vertical growth pattern groups, respectively. A similar tendency was observed for the medial pterygoid, but with no statistical significance. A statistically significant negative correlation was observed between MP-SN and the volume of masseter and medial pterygoid in the overall sample. Of the seven muscular and mandibular variables included in the regression analysis, the final model included only four variables that were significantly associated with MP-SN and explained 37% of its variance (masseter volume (p=0.017), mandibular overall length (p<0.001), height of mandibular ramus (p=0.003), and length of mandibular corpus (p<0.001)).

Conclusions. The masseter muscle seems to be more sensitive to the variation in mandibular morphology than the medial pterygoid muscle, and volume as the biomechanical characteristic seems to be a more significant parameter of the size of the interaction with vertical skeletal growth patterns.

Key words: masseter, medial pterygoid, MRI, CBCT.

Received: 13 08 2018

Accepted for publishing: 21 12 2020

¹Department of Orthodontics, Institute of Stomatology, Riga Stradins University, Riga, Latvia

²Institute of Radiology, Riga Stradins University, Riga, Latvia

Address correspondence to Katrina Gardovska, Department of Orthodontics, Institute of Stomatology, Riga Stradins University, 20 Dzirciema Street, Riga, LV 1007, Latvia.

E-mail address: katrinagardovska@inbox.lv



	Baltic Dental and Maxillofacial Journal

December, 2020, Vol. 22, No. 4 CONTENTS SCIENTIFIC ARTICLES Musculomandibular morphology in individuals with different vertical skeletal growth patterns: an MRI and cone beam computed tomography study Katrina Gardovska, Ilga Urtane, Gaida Krumina 99-106 REVIEWS Various wound closure ways after impacted lower wisdom teeth removal: A review Žygimantas Petronis, Jonas Zigmantavičius, Albinas Gervickas 107-115 SCIENTIFIC ARTICLES The relationship between congenital cleft lip and palate malformation, skeletal and dental occlusal anomalies, and the infl uence of its treatment on affected patients’ oral health-related quality of life (OHRQoL) Reda Vaiciunaite, Austeja Mitalauskiene, Arunas Vasiliauskas 116-119 Family nurses, oral hygiene, and educational implications: a cross-sectional study Pablo Varela-Centelles, Rosendo Bugarín-González, Andrés Blanco-Hortas, Ana Estany-Gestal, Almudena Varela-Centelles, Juan M. Seoane-Romero 120-124 Stress in the bone and prosthetic components due to "all-on-4" system with polyether-ether-ketone screwing prosthesis. Analysis using 3D fi nite element method Ignas Vaitiekūnas, Justina Klimenko, Eglė Ivanauskienė, Juozas Žilinskas 125-128 © 2021 Stomatologija		Stomatologija 2020; 22 (4): 99-106 384 KB Musculomandibular morphology in individuals with different vertical skeletal growth patterns: an MRI and cone beam computed tomography study Katrina Gardovska¹, Ilga Urtane¹, Gaida Krumina² Summary Objective. The aim of this study was to analyse the volumetric and crossectional parameters of masseter and medial pterygoid muscles in the relation with mandibular skeletal morphology in individuals with different underlying growth patterns in the vertical dimension. Material and methods. The study originally involved 76 individuals with definite clinical and radiological criteria: 31 skeletal Class III and 26 skeletal Class II patients before the orthognathic surgery and 20 skeletal class I (normal) individuals with complaints of wisdom teeth and associated medical problems. On the basis of cephalometric measurement of the mandibular plane and sella-nasion (MP-SN), the study sample was categorised according to the vertical facial dimension in 3 different growth pattern subgroups: 19 subjects with horizontal growth pattern, 25 subjects with vertical growth pattern and 33 subjects with neutral growth pattern. MRI was performed for the masseter and medial pterygoid muscles, and volume and cross-sectional area measurements were performed. Cone beam computed tomography (CBCT) investigation was performed for the assessment of craniofacial structures and the following measurements of the mandibular parameters were obtained: height of ramus, length of mandibular corpus, overall mandibular length, inter-angular width and intercondylar width. Results. There were statistically significant differences among all study groups regarding masseter volume (p<0.006) and CSA (p<0.006), with the highest values in the horizontal growth pattern group and the lowest values in vertical growth pattern group. After Bonferroni correction, statistically significant difference (p<0.004 and p<0.008) was noted between the horizontal and vertical growth pattern groups, respectively. A similar tendency was observed for the medial pterygoid, but with no statistical significance. A statistically significant negative correlation was observed between MP-SN and the volume of masseter and medial pterygoid in the overall sample. Of the seven muscular and mandibular variables included in the regression analysis, the final model included only four variables that were significantly associated with MP-SN and explained 37% of its variance (masseter volume (p=0.017), mandibular overall length (p<0.001), height of mandibular ramus (p=0.003), and length of mandibular corpus (p<0.001)). Conclusions. The masseter muscle seems to be more sensitive to the variation in mandibular morphology than the medial pterygoid muscle, and volume as the biomechanical characteristic seems to be a more significant parameter of the size of the interaction with vertical skeletal growth patterns. Key words: masseter, medial pterygoid, MRI, CBCT. Received: 13 08 2018 Accepted for publishing: 21 12 2020 ¹Department of Orthodontics, Institute of Stomatology, Riga Stradins University, Riga, Latvia ²Institute of Radiology, Riga Stradins University, Riga, Latvia Address correspondence to Katrina Gardovska, Department of Orthodontics, Institute of Stomatology, Riga Stradins University, 20 Dzirciema Street, Riga, LV 1007, Latvia. E-mail address: katrinagardovska@inbox.lv