Table 2. Cephalometric analysis of patients with snoring in four age groups as compared to the age-matched normative values obtained from the normal samples.

Data are reported as mean ± standard deviation.

Saddle A, Angle formed between the lines Sella-Nasion and Sella-Articular; SNA, anteroposterior position of the maxilla in relation to the anterior cranial base (angle formed between the lines Sella-Nasion and Nasion-A point); Nper-A, distance between the A point and a line perpendicular to the Frankfort plane from the Nasion; SNB, anteroposterior position of the mandible in relation to the anterior cranial base (angle formed between the lines Sella-Nasion and Nasion-B point); Nper-B, distance between the B point and a line perpendicular to the Frankfort plane from the Nasion; Nper-Pog, distance between the Pogonion and a line perpendicular to the Frankfort plane from the Nasion; ANB, mathematical difference between the SNA and SNB; SUM, sum of the angles Saddle-Articular-Gonial; Articular A, angle formed between the lines Sella-Articular and Articular-Gonion; FMA, angle between the Frankfort plane and mandibular plane; PFH/AFH, ratio of posterior facial height relative to anterior facial height (S-Go/N-Me); Gonial A, angle formed between the lines Articular-Gonion and mandibular plane; MP-H, perpendicular distance of the hyoid point from the mandibular plane; H-PTV, distance of the hyoid point to the vertical pterygoid; H-C3Me, perpendicular distance of the hyoid point from the C3-Menton line; ad1, distance from the PNS to the nearest adenoid tissue measured along the line PNS-Ba; ad2, distance from the PNS to the nearest adenoid tissue measured along the line through the PNS perpendicular to the Sella-Basion; SPAS, superior posterior airway space (anteroposterior width of the pharynx measured between the posterior pharyngeal wall and the dorsum of the soft palate); MAS, middle airway space (anteroposterior width of the pharynx measured between the posterior pharyngeal wall and the palate tip); IAS, inferior airway space (anteroposterior width of the airway space along the Gonion-B point line).

Independent t-test was preliminarily performed to determine significantly different cephalometric parameters between the patients with snoring and the normal samples, for further principal component analysis; ^*p < 0.05, ^†p < 0.01, ^‡p < 0.001.