Higher caries experience in individuals with neurofibromatosis 1: a matched case-control study

This study evaluated dental caries experience in individuals with neurofibromatosis type 1 (NF1) compared with matched controls and investigated its associations with salivary parameters, behavioral factors, and socioeconomic characteristics.

In this case-control study, 42 individuals with NF1 and 42 controls matched for age and sex were included. Caries were diagnosed according to World Health Organization criteria, and the decayed, missing, and filled teeth (DMFT) index was used to assess caries experience. Oral hygiene was evaluated through the Simplified Oral Hygiene Index (OHI-S), tongue coating was quantified from standardized photographs, and questionnaires were used to assess cariogenic diet frequency and socioeconomic variables (educational level, housing status, and family income). Salivary assessments included unstimulated whole saliva flow rate (UWSFR), chewing-stimulated whole saliva flow rate (CSWSFR), pH, buffering capacity, viscosity, and levels of calcium, phosphorus, potassium, magnesium, amylase, and lipase.

Participants with NF1 showed higher caries experience than matched controls (DMFT index: 18.5 ± 8.6 vs. 12.6 ± 7.4; p = 0.001). Hyposalivation (UWSFR: 57.1% vs. 2.4%; CSWSFR: 40.5% vs. 0%) and high salivary viscosity (71.4% vs. 11.9%) were significantly more frequent in NF1 (all p < 0.001). While bivariate analysis within the NF1 group showed no direct association between DMFT and salivary flow, post hoc power analysis indicated limited statistical power (20.4%) for this comparison. A significant positive correlation was found between DMFT and tongue coating index (ρ = 0.312; p = 0.044). In multivariable regression, NF1 was independently associated with higher DMFT compared to matched controls (p < 0.001). Additionally, lower family income (p < 0.001) and poorer oral hygiene (p = 0.016) were significantly associated with higher DMFT. A significant interaction between group and cariogenic diet (p < 0.001) was also observed, indicating that the association between dietary habits and DMFT differed between groups.

Individuals with NF1 present significantly higher DMFT compared to matched controls. Our findings suggest that this is a multifactorial process, characterized by an independent association between NF1 status and DMFT, even after adjusting for salivary flow, oral hygiene, socioeconomic status, and dietary habits. Notably, the high prevalence of hyposalivation and altered salivary viscosity-combined with the significant positive correlation between tongue coating and DMFT-highlight a complex and compromised oral environment in NF1.

These findings support that individuals with NF1 represent a high-risk group for dental caries and significant salivary impairment. This dual vulnerability necessitates specialized preventive protocols, including intensive biofilm control and regular dental monitoring, to reduce the high cumulative caries experience and its impact on oral health in this population.