Objective: To get the desired outcome and minimize the complications in rhinoplasty it is essential that the anatomy of the nose be precisely known and an appropriate surgical technique should be chosen for the existing problem in a given patient. Preoperative assessment in rhinoplasty is usually based on a physical examination and photographs of the patient. To date, there has been no objective diagnostic test for nose anomalies such as bulbous nasal tip.Methods: In this study we measured the interdomal distance and size of the interdomal fat pad using USG in a total of 40 rhinoplasty patients. Open rhinoplasty was performed in all patients. Also, interdomal fat pad was dissected and excised in all patients. The size of the specimens was determined and their histopathological diagnoses were made. All the cases were evaluated in the 6th month after the operations. Reviewing of the literature was performed.Results: Before the operation, six patients had been diagnosed as bulbous nasal tip clinically. In the patients with bulbous nose both interdomal distance and interdomal fat pad proportions were found to be larger than normal. In the cases in which tip refinement had been performed the interdomal distance was measured as zero.Conclusions: Joseph in 1931 used the "profilometer"; Webster et al. in 1977 used the projectometer in the evaluation of the nose. The evaluation of the anatomical structure of the nose has been the topic of many anthropometric studies and advanced and highly detailed studies with 3 dimensional facial plaster models; digitizer or laser surface scanners have appeared the literature. Tasman and Helbig used the ultrasonography in the evaluation of the nasal tip area. Evaluation of the interdomal space by using USG is quite simple, cheap and easily applicable. In addition, interdomal fat pad can be visualized and an objective criterion can be obtained for bulbous nose by measuring the interdomal distance on USG. Since the excision of interdomal fat pad could only be achieved by open rhinoplasty, and that tip refinement is required in order to correct the increased interdomal distance, pre-operative interdomal USG will guide the surgeon and provide objective criteria in determination of the operative technique in bulbous nose. This is the first study to show interdomal fat pad by a diagnostic test and it can be concluded that interdomal fat pad excision is necessary for the prevention of supratip.