Long-term impact of molar-incisor hypomineralisation and its management on children and their families: an 8-year follow-up study with mixed methods analysis

Purpose To investigate long-term changes in oral health-related quality of life (OHRQoL) and dental fear/anxiety (DFA) following specialist management of molar-incisor hypomineralisation (MIH), assess family impact, and explore patient/parent experiences through qualitative analysis. Methods This prospective follow-up study re-recruited participants from a 2015–2017 baseline cohort of children with MIH referred to a UK specialist centre. Participants completed the same validated instruments used at baseline: Child Oral Health Impact Profile-Short Form 19 (COHIP-SF19) and Modified Child Dental Anxiety Scale-faces version (MCDASf). Additionally, parents completed the Family Impact Scale (FIS). Clinical records were reviewed retrospectively. Qualitative content analysis was performed on open-ended responses about treatment experiences. Changes were analysed using descriptive statistics and thematic analysis. Results Eighteen participants (22% re-recruitment rate; mean age 15.6 years; 13 males) were followed up 7–8 years post-baseline. At baseline, 11 had severe, 4 moderate, and 3 mild MIH. Treatment modalities included local anaesthesia (n = 9), general anaesthesia (n = 8), and inhalation sedation (n = 2). Mean COHIP-SF19 scores showed minimal overall change (baseline: 56.3, follow-up: 53.6), with functional well-being showing greatest improvement. MCDASf scores remained stable (baseline: 20.1, follow-up: 20.5). However, individual variation was substantial, with OHRQoL and DFA changes inversely correlated in 14/18 participants. Permanent molar extractions under local anaesthesia were associated with the largest DFA increases. Family impact was generally low (mean FIS: 6/56) but increased with journey time to the specialist centre (> 60 minutes). Qualitative analysis revealed two main themes: positive communication experiences and system challenges (waiting times, appointment availability). Conclusions This long-term follow-up study demonstrates heterogeneous outcomes following MIH management. While group means suggest stability, individual trajectories varied considerably. The inverse relationship between OHRQoL and DFA changes, the potential anxiety impact of extractions under local anaesthesia, and the burden of travel distance represent novel findings requiring further investigation. The mixed-methods approach provided valuable insights into patient/family experiences that quantitative measures alone would miss.