Unilateral posterior crossbite in adolescents: surface electromyographic evaluation

Area of Science:

• Orthodontics
• Biomedical Engineering
• Craniofacial Biology

Background:

• Unilateral posterior crossbite (UPCB) is a malocclusion defined by reversed buccal cusp relationships.
• UPCB can affect dental and skeletal development, potentially influencing masticatory muscle function.
• Electromyography (EMG) is a valuable tool for assessing muscle activity patterns.

Purpose of the Study:

• To compare the electromyographic (EMG) activity of masticatory muscles in adolescents with UPCB versus healthy controls.
• To investigate potential differences in muscle activation symmetry between the two groups.

Main Methods:

• Surface electromyography (sEMG) was used to record muscle activity.
• Fifteen adolescents diagnosed with UPCB and fifteen age-matched healthy controls participated.
• EMG data was analyzed for muscle activation levels and symmetry in temporal and masseter muscles.

Main Results:

• Patients with UPCB demonstrated significantly lower muscle activation compared to healthy controls (p<0.0001).
• Asymmetric muscle activation was observed in the UPCB group: 89.23% balancing for temporals and 83.21% for masseters.
• Healthy controls exhibited higher muscle balancing: 99.32% for temporals and 97.77% for masseters.

Conclusions:

• Adolescents with UPCB exhibit reduced and asymmetric masticatory muscle activation.
• These findings suggest that altered muscle function may play a role in the craniofacial development of individuals with UPCB.
• Further research is warranted to explore the long-term effects of asymmetric muscle activation on maxillary and mandibular growth.