Evaluation of maxillary arch dimensions and palatal morphology in mouth-breathing children by using digital dental casts

Objective: The aim of the present study was to analyze the variations of maxillary arch size and of palatalmorphology in subjects with prolonged mouth-breathing due to allergic rhinitis when compared with acontrol group with normal breathing pattern by using a three-dimensional analysis on digital casts.Methods: 26 Caucasian children (19 females and 7 males) with a mean age of 8.5 years (SD 1.6 years)were selected according to the following criteria: mouth-breathing pattern due to allergic rhinitis, earlymixed dentition, skeletal Class I relationship and prepubertal stage of cervical vertebral maturation. Thestudy group was compared with a control group of 17 nasal breathing subjects (9 females; 8 males, meanage 8.5 years SD 1.7 years). For each subject an initial dental cast was taken and the upper arch wasscanned by using a tridimensional scanner. On each digital model linear measurements were performedto analyze maxillary arch dimensions and palatal morphology. Significant between-group differenceswere tested with the Student t-test (p < 0.05).Results: the transverse dimension of the upper arch was significantly smaller in subjects of the studygroup thus confirming the influence of oral breathing on skeletal development with a significantconstriction of the whole palate. The study group showed a higher and sharper palatal vault at the levelof second deciduous molars and of first permanent molars.Conclusions: Children with mouth-breathing pattern showed a significant constriction of the maxillaryarch and an increased palatal height when compared with subjects with normal breathing pattern.