The aims of the study were to determine the periodontal status of the teeth in contact with removable partial dentures (RPDs) and to compare them with other teeth in the opposing arch not related to any prosthesis. The periodontal status was also assessed in relation to the age of the dentures. Four hundred and twenty-seven patients treated with RPDs from 1981 to 1986 were recalled for examination. Prior to prosthetic treatment they were given periodontal treatment and fillings when required. Initially all were given oral hygiene instructions and motivation. They were reviewed regularly only on a short-term basis. Eighteen patients were suitable for the present study comprising of eight males and 10 females whose mean age was 41 years. The RPDs were in use from 1.5 to 8 years (mean 4.6 years). The following parameters were assessed: Plaque index (P1I), Gingival index (GI), loss of attachment (LA) and tooth mobility. The wearing of RPDs resulted in higher P1I, GI and LA compared to the controls and these differences were statistically significant. There was an increased frequency of higher P1I, GI and LA with the increase in denture age. Minor changes in tooth mobility were observed. It was concluded that the wearing of RPDs was detrimental to periodontal health in patients whose oral hygiene was less than adequate.

Using regression methods, the widths of the anterior teeth within the population tested may be predicted by a combination of the facial dimensions studied.

No abstract

We investigated the relationship of the maxillary central incisors to the incisive papilla in wearers of complete dentures. First, image analyzer software was used to examine the relationship of the midpoint of the incisive papilla to the labial surface of the maxillary central incisors on occlusal photographs of 120 maxillary casts from dentate Malaysian adults. Then, an Alma denture gauge was used to identify the position of the labial surface of the maxillary central incisors in relation to the midpoint of the incisive papilla in complete dentures from 51 patients who requested replacement dentures at the Faculty of Dentistry, University of Malaya. The mean incisor distance to the incisive papilla in dentate adults was 9.59 ± 1.00 mm, while the mean incisor distance to the incisive papilla in complete dentures was 6.34 ± 1.87 mm. Thus, in our sample of edentulous patients, the anterior teeth in complete dentures were positioned approximately 3 mm closer to the incisive papilla, as compared with the position of the central incisors in natural dentition, and did not duplicate the position of the natural anterior teeth. (J Oral Sci 54, 159-163, 2012)

Selected landmarks from each of 47 maxillary dental casts were used to define a Cartesian-coordinate system from which the positions of selected teeth were determined on standardized digital images. The position of the i-th tooth was defined by a line of length (l(i)) joining the tooth to the origin, and the angle (θ(i)) of this line to the horizontal Cartesian axis. Four teeth, the central incisor, lateral incisor, canine and first molar were selected and their position were collectively used to represent the shape of the dental arch. A pilot study using clustering and principal component analysis strongly suggest the existence of 3 groups of arch shape. In this study, the homogeneity of the 3 groups was further investigated and confirmed by the Dunn and Davies-Bouldein validity indices. This is followed by an investigation of the probability distribution of these 3 groups. The main result of this study suggests 3 groups of multivariate (MV) normal distribution. The MV normal probability distribution of these groups may be used in further studies to investigate the issues of variation of arch shape, which is fundamental to the practice of prosthodontics and orthodontics.