Patients referring for orthodontic consultation at the Unit of Orthodontics and Pediatric Dentistry, Section of Dentistry, Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy, will be enrolled for the study according to the inclusion criteria. For each patient, lateral cephalometric radiograph and panoramic radiograph will be performed. For each lateral cephalometric radiograph, a cephalometric tracing will be performed with DeltaDent software (version 2.5.12, Outside Format, Pandino, Italy). Riedel's ANB angle [Riedel 1952] has been chosen to determine patients' skeletal class. Steiner's SN^GoGn angle [Steiner 1953] has been chosen to evaluate skeletal divergence. Facial axis (BaNa^CCGn), Lower Facial Height (LFH) and mandibular plan angle (FH^GoMe) from Rickett's analysis [Rickett's 1961] have been adopted to determine facial growth. According to Jaraback's cephalometric analysis [Jaraback 1985], saddle angle, articular angle, upper gonial angle, lower gonial angle will be measured to assess the growth pattern. Linear measurements of sella depth, sella diameter and interclinoid distance [Silverman 1957; Kisling 1966] will be calculated. Linear regressions between craniofacial patterns, sella turcica bridging and third molar agenesis will be calculated.
The aim of this retrospective study is to analyze the third molar agenesis with respect to sella turcica bridging and other craniofacial patterns in patients asking for orthodontic consultation. The main question[s] it aims to answer are:~is there a relationship between third molar agenesis and sella turchina bridging?~is there a relationship between third molar agenesis and craniofacial patterns?