Molar incisor hypomineralization (MIH) is a developmental condition that affects the enamel of permanent molars and incisors in children and may cause tooth sensitivity, discomfort, and difficulties during dental treatment. These problems can increase dental anxiety and lead to physiological stress responses during dental visits.

The purpose of this observational study is to evaluate physiological stress responses in children with MIH by measuring salivary cortisol levels, heart rate, and oxygen saturation, and to compare these findings with those of children without MIH. A total of 90 children aged 8 to 12 years will participate in the study, including 45 children diagnosed with MIH and 45 healthy control participants.

Participation involves no treatment or intervention beyond a routine clinical dental examination. Heart rate and oxygen saturation will be measured during the dental visit, and saliva samples will be collected immediately after the examination using a non-invasive method to assess cortisol levels. The results of this study may contribute to a better understanding of stress responses in children with MIH and support the development of more individualized and anxiety-sensitive dental care approaches.

Molar incisor hypomineralization (MIH) is a developmental enamel defect that may lead to hypersensitivity, discomfort during dental procedures, and increased dental anxiety in affected children. While behavioral aspects of anxiety in children with MIH have been investigated, objective assessment of physiological stress responses in this population remains limited.

This prospective observational study is designed to evaluate physiological stress responses in children with MIH by assessing salivary cortisol levels in conjunction with non-invasive physiological parameters recorded during a routine dental examination. The study includes a comparative design involving children with an MIH diagnosis and healthy control participants.

All procedures are conducted under standardized clinical conditions to minimize external factors that may influence stress responses. Saliva samples are collected using a non-invasive absorption-based method immediately after the dental examination to assess cortisol levels. Physiological parameters are recorded at predefined time points during the dental visit to capture stress-related changes associated with the clinical environment.

The study aims to provide objective data on stress-related physiological responses in children with MIH, which may contribute to improved understanding of anxiety-related mechanisms and support the development of more individualized, child-centered dental care strategies.

Inclusion Criteria:

• Children aged between 8 and 12 years.
• Children diagnosed with molar incisor hypomineralization (MIH) according to the European Academy of Paediatric Dentistry (EAPD) criteria or healthy children without MIH.
• Ability to cooperate sufficiently to complete the clinical dental examination and study procedures.
• Written informed consent obtained from a parent or legal guardian.

Exclusion Criteria:

• Presence of systemic, hormonal, or metabolic diseases.
• Regular use of medications known to affect salivary cortisol levels or cardiovascular parameters (e.g., corticosteroids, beta-blockers).
• History of systemic conditions that may influence stress response.
• Refusal of participation by the child or parent/legal guardian.

The study population consists of children aged 8 to 12 years attending the Department of Pediatric Dentistry. Participants include children diagnosed with molar incisor hypomineralization and age-matched healthy control children without MIH.

Individual participant data will not be shared due to the pediatric nature of the study and ethical considerations regarding participant confidentiality.