Overall, individuals with UCLP and BCLP showed an increase in the upper airway after orthognathic surgery and this might explain the breathing and sleep improvements reported by the patients after the surgery.

The main purpose was to assess and compare nasal cavity (NC) volumes among adults with unilateral (UCLP) and bilateral cleft lip and palate (BCLP) and in noncleft controls (CON), by means of cone-beam computed tomography (CBCT) three-dimensional reconstructions. Forty-five scans of individuals with class III skeletal pattern, matched by age, were gathered in 3 groups: UCLP (n = 15), BCLP (n = 15) and (CON) (n = 15). The NC volume was assessed three-dimensionally, using Dolphin 11.8 software. Descriptive normally distributed data was presented as mean (±SD). Comparisons of NC volume among groups was performed using ANOVA test (P ≤ 0.05). The NC mean volumes corresponded to 14.7(±2.2) cm3 (UCLP), 17.1(±2.2) cm3 (BCLP) and 18.1(±3.8) cm3 (CON), respectively. UCLP individuals presented a significantly reduced NC volume when compared to controls (P = 0.006). No differences were observed between UCLP versus BCLP or BCLP versus CON. The intraclass correlation coefficient suggested a high intra- and inter-examiners agreement (>.075). Individuals with unilateral cleft lip and palate presented reduced NC when compared to individuals without cleft lip and palate. CBCT scans can be considered a highly accurate tool for morphometric assessments of craniofacial structures.