Impact of Glass-Hybrid Restoration on Occlusal Force Distribution and Masticatory Muscle Activity in Children With Molar-Incisor Hypomineralization

Impact of Restorative Treatment on Occlusal Characteristics and Masseter Muscle Activity in Children With Molar-Incisor Hypomineralization: A T-Scan and sEMG Pilot Study

This prospective pilot study evaluates the effect of restoring symptomatic, carious molar-incisor hypomineralization (MIH)-affected permanent molars using a glass-hybrid restorative material on occlusal force distribution and masticatory muscle activity. Digital occlusal analysis using the T-Scan system and surface electromyography (sEMG) recordings of the masseter and anterior temporalis muscles are performed before treatment and three months after restoration. Hypersensitivity is assessed using the Schiff Cold Air Sensitivity Scale.

This single-arm prospective pilot study investigates whether restorative rehabilitation of MIH-affected permanent molars leads to functional improvements in occlusal balance and neuromuscular activity. Children aged 7-13 years with symptomatic MIH requiring restorative treatment undergo standardized glass-hybrid restorations. Functional occlusal analysis is conducted using the T-Scan Novus system to assess lateral occlusal force distribution, while bilateral surface electromyography (sEMG) evaluates masseter and temporalis muscle activity during maximum voluntary clenching. Dentin hypersensitivity is assessed using the Schiff Cold Air Sensitivity Scale. Pre- and post-treatment outcomes are compared to explore early functional adaptation following MIH rehabilitation.

Inclusion Criteria:

• Children aged 7 to 13 years
• Diagnosis of molar-incisor hypomineralization (MIH) according to the criteria of Ghanim et al.
• Presence of at least two MIH-affected first permanent molars with post-eruptive enamel breakdown requiring restorative treatment
• Presence of dentin hypersensitivity in the affected molars
• Ability to comply with T-Scan and surface electromyography (sEMG) recording procedures
• Written informed consent obtained from parents or legal guardians, and assent from the child
• Exclusion Criteria:
• Previous or ongoing orthodontic treatment
• Presence of craniofacial anomalies or syndromes
• Diagnosis of temporomandibular disorders
• Parafunctional habits (e.g., bruxism)
• Clinically evident facial asymmetry
• Malocclusions such as crossbite or open bite
• Systemic diseases or medications affecting neuromuscular function -Inability to cooperate with functional assessment procedures -