Evaluation of the utility of cephalometric parameters in constructing complete denture. Part I: placement of posterior teeth F. BASSI*, A. DEREGIBUS ² , V. PREVIGLIANO*, P. BRACCO ² & G. PRETI* *Department of Prosthodontics and ² Department of Orthodontics, Dental School, University of Turin, Corso Dogliotti 14, 10126 Turin, Italy SUMMARY SUMMARY Various types of parameters, including cephalometric ones, have been used in the construc- tion of complete denture. This study aimed to evaluate the utility of cephalometric parameters for this purpose. The position of the posterior teeth in a group of 42 edentulous patients, successfully rehabilitated with complete denture according to clinical parameters, was evaluated by cephalomet- rics. The following were determined: vertical dimen- sion of occlusion (VDO); orientation of the occlusal plane; and subdivision of the denture space. The cephalometric parameters do not correspond to the clinical positioning of the posterior teeth in success- ful rehabilitation with complete denture. Introduction Cephalometry has been widely used to study endentu- lous patients. Various types of parameters have been evaluated: position of the occlusal plane in relation to the commissure of the lips (Douglas & Maritano, 1965); reduction in the height of the face in long-term follow up (Tallgren, 1966) or within a year of rehabilitation (Hull & Junghans, 1968; Ismail et al., 1968) in totally or partially endentulous patients; changes in vertical dimension (Swerdlow, 1964) or in intermaxillary rela- tionship (Tallgren et al., 1980) immediately after pros- thetic rehabilitation. Cephalometry has also been used to evaluate changes in mandibular position following muscular relaxation achieved pharmacologically (Dikshit & Mirza, 1979); and to quantify the interoc- clusal rest space. In one speci®c case, Potgieter et al. (1983 2 ) found a net inverse correlation between the Gonian angle and the interocclusal rest space. Cephalometry has also been used to determine and/ or evaluate the position and inclination of the occlusal plane, with con¯icting results: L'Estrange and Vig (1975) found a correlation between the orientation of the occlusal and maxillary planes in two groups of subjects, one dentate (25±35 years) the other enden- tulous (36±78 years). Sloane and Cook (1953) found an inverse correlation between the length of the maxillary plane and the inclination of the occlusal plane. Monteith (1985a,b, 1986) postulated a relationship between the anterior Porion-Nasion-Anterior Nasal Spine (Po N Spna) and the angle between the Frankfort plane and the occlusal plane, and proposed a mathe- matical formula to calculate the inclination of the occlusal plane with respect to the Frankfort plane. He also devised an instrument to reproduce the inclination of the cephalometrically determined occlusal plane in the articulator. Karkazis and Polyzois (1991) applied Montheit's formula to two groups of subjects: a group of dentate subjects (10 men, 12 women) with good occlusodental morphology, and a group of edentulous subjects (22 men, 22 women) rehabilitated with complete denture. They failed to achieve the same results as Monteith. These researchers used two types of cephalometric measurements: either of the anthropometric type (measurements of cranial dimensions made on cranial radiographs) or of the purely cephalometric type (measurements of cranial dimensions made through coded and repeatable anatomical points). In some cases, methods proposed by cephalometrists over the years were followed, while in others the researchers them- selves proposed new methods. ã 2001 Blackwell Science Ltd 234 Journal of Oral Rehabilitation 2001 28; 234±238