Tongue microbiota in relation to the breathing preference in children undergoing orthodontic treatment

Objectives Mouth breathing (MB) and craniofacial anomalies are interrelated and linked to pediatric obstructive sleep apnea. Both MB and orthodontic therapy can influence the oral microbiome. This study examines the relationship between tongue microbiota and breathing preference in children with orthodontic anomalies. Materials and Methods The study included 30 children, 15 with MB and 15 with nose breathing (NB), matched by age, sex, and BMI. They underwent clinical and orthodontic examinations, sleep apnea monitoring, and collection of tongue swabs before (M0) and six months into orthodontic therapy (M6). Oral candidas were analyzed using MALDI-TOF mass spectrometry, and bacteriome analysis was conducted using 16S rRNA sequencing. Results At M0, oral candidas were equally present in both groups. At M6, Candida sp. were found in six children with MB but in none with NB (p = 0.01). No significant differences in bacterial diversity were observed between groups. However, children with MB had higher relative abundance of Solobacterium than others (q = 0.01). Conclusions Oral candidas are more common during orthodontic therapy in children with MB. While the study didn't find broad impacts of MB on oral bacteriome composition, it identified a significant link between Solobacterium and MB, highlighting the importance of managing halitosis in these patients.