Masseter Muscle Thickness and Craniofacial Skeletal Patterns

The Relationship Between Masseter Muscle Thickness and Different Craniofacial Skeletal Patterns

Facial morphology is influenced by hard and soft tissues, including bone and muscle. While numerous factors can lead to changes in bone tissue, soft tissues such as muscle also have an important influence. It is widely acknowledged that the function, shape and thickness of masticatory muscles have substantial effects on facial morphology and skeletal development, and are correlate with other anthropometric variables. Furthermore, a correlation has been observed between masseter muscle thickness and various characteristics of the dental arches, such as alveolar process thickness and intermaxillary width.

The evaluation of soft tissue in the region of the face is a more challenging process in comparison to that of hard tissue.The recent development of cone beam computed tomography has improved the analysis of three-dimensional skeletal morphology and jaw. However, the radiographic assessment of soft tissue remains more difficult.The thickness of masticatory muscles can be measured using computerised tomography; however, this has the disadvantage of exposing the patient to radiation. Magnetic resonance imaging (MRI) is an imaging technique that can be used to assess soft tissues. However, this technique is expensive and time-consuming. Furthermore, MRI is a static rather than a dynamic imaging technique, which makes it difficult to analyse during muscle contraction and relaxation. Ultrasound is a technique that provides dynamic imaging that can assess the masticatory muscles without the use of ionising radiation.

There are many publications in the literature that indicate that malocclusions in the vertical and sagittal dimensions can be assessed with measurements from lateral cephalometric radiographs.

Study Overview

• Status: Completed
• Conditions: Ultrasonography; Masseter; Cephalometry; Malocclusions
• Intervention / Treatment: Other: Lateral cephalometric radiography; Other: Facial photograph; Other: Electronic caliper; Other: Weigth and Heigth; Other: Ultrasonography

• Study Type: Observational
• Enrollment (Actual): 101

Contacts and Locations

Study Locations

• Turkey
  • Kutahya, Turkey, 43100
    • Kutahya Health Science University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Healthy patients with orthodontic malocclusion were included in the study.

Description

Inclusion Criteria: Patients who

• Patients who were 18 years of age or older,
• had skeletal malocclusion,
• were systemically healthy,
• were not taking any medication,
• had no missing teeth except for the third molars,
• had no history of congenital and/or acquired anomalies in the lips, mouth and facial regions,
• had not received orthodontic treatment before

Exclusion Criteria: Patients who

• were younger than 18 years of age
• were with systemic disease,
• used antidepressant drugs before,
• has bruxism habit,
• had orthodontic treatment or has active orthodontic treatment,
• had history of trauma and surgery in the maxillofacial region

Study Plan

How is the study designed?

Number of groups / cohorts

12

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Class I; Patients with ANB angle between 0-4 degrees were classified as class I.	Other: Lateral cephalometric radiography; Standard lateral cephalometric radiographs were obtained from the patients.
Class II; Patients with ANB angle greater than 4 degrees were classified as class II.	Other: Lateral cephalometric radiography; Standard lateral cephalometric radiographs were obtained from the patients.
Class III; Patients with ANB angle less than 0 degrees were classified as class III.	Other: Lateral cephalometric radiography; Standard lateral cephalometric radiographs were obtained from the patients.
Normodivergent; Patients with SN/GoGn angle between 28 and 36 were classified as normodivergent.	Other: Lateral cephalometric radiography; Standard lateral cephalometric radiographs were obtained from the patients.
Hyperdivergent; Patients with SN/GoGn angle greater than 36 degrees were classified as hyperdivergent.	Other: Lateral cephalometric radiography; Standard lateral cephalometric radiographs were obtained from the patients.
Hypodivergent; Patients with SN/GoGn angle less than 28 degrees were classified as hypodivergent.	Other: Lateral cephalometric radiography; Standard lateral cephalometric radiographs were obtained from the patients.
Brachyfacial; If the facial index value was less than 84%, it was classified as brachyfacial.	Other: Facial photograph; Standard facial photographs were taken from a distance of 1.5 metres.
Mesofacial; A facial index value between 84% and 88% was classified as mesofacial.	Other: Facial photograph; Standard facial photographs were taken from a distance of 1.5 metres.
Dolichofacial; If the facial index value was greater than 88%, it was classified as dolichofacial.	Other: Facial photograph; Standard facial photographs were taken from a distance of 1.5 metres.
Body Mass Index; The Body Mass Index is calculated by measuring with a standardised scale and height chart.	Other: Weigth and Heigth; The Body Mass Index is calculated by measuring with a standardised scale and height chart.
Masseter muscle thickness	Other: Ultrasonography; The masseter muscle thickness measurements were performed in B mode of ultrasound, midline between the zygomatic arch and mandibular plane, parallel to the mandibular plane and perpendicular to the mandibular ramus. Prior to the examination being performed in the resting position, the patient was instructed to make minimal contact between the lips without the teeth touching each other.The first USG image was recorded in this position. The patient was then requested to clench their teeth as firmly as possible, after which a second USG image was recorded from the same area. The thickness of the muscles was measured again on second recorded images. To ensure the reliability of the measurements, these procedures were repeated by the same researcher after the patients rested for five minutes.
Intermolar width; The intertermolar distance was measured in millimetres. This measurement was taken from the mesiopalatinal surfaces of two maxillary first permanent molars at the level of the cervical. The measurement was taken using an electronic caliper.	Other: Electronic caliper; The intermaxillary distance is measured from the cervical level of the palatal surfaces of the first permanent molars to their mesial corners using an electronic caliper.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The correlation between masseter muscle thickness and sagittal skeletal malocclusions	The masseter muscle was measured in millimetres using ultrasound, while different skeletal malocclusions were classified using the angles between anatomical landmarks on lateral cephalometric radiographs. Intertermolar distance was measured in millimetres using an electronic caliper intraorally in the clinic. Facial index was calculated and classified using standard facial photographs, with millimetre measurements obtained using ImageJ software. The patients' height and weight were measured in centimetres and kilograms, respectively, and their body mass index was calculated.	Just at the enrollment of the patients

Collaborators and Investigators

• Sponsor: Kutahya Health Sciences University

Publications and helpful links

General Publications

• Togninalli D, Antonarakis GS, Papadopoulou AK. Relationship between craniofacial skeletal patterns and anatomic characteristics of masticatory muscles: a systematic review and meta-analysis. Prog Orthod. 2024 Sep 9;25(1):36. doi: 10.1186/s40510-024-00534-2.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2024
• Primary Completion (Actual): December 10, 2024
• Study Completion (Actual): February 24, 2025

Study Registration Dates

• First Submitted: March 5, 2025
• First Submitted That Met QC Criteria: March 5, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 11, 2025
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Keywords: malocclusion; ultrasonography; masseter muscle; cephalometry; maxillofacial development
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Malocclusion
• Other Study ID Numbers: 2023/14-28

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No