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HIV infection is a global pandemic that affects CD4 cells in the immune system and leads to lethal opportunistic infections. The advent of highly active antiretroviral therapy (HAART) has induced a marked reduction in the viral load and an increase in the CD4 cell count, thereby changing the course of the disease from an acute life-threatening condition to chronic disease. Accordingly, need and demand for oral rehabilitation in HIV positive population have increased in recent years. However, few drugs used in the HAART regimen have also known to be associated with osteopenia and osteoporosis. Although HAART reduces the morbidity in HIV patients, it remains unknown to what extent the therapy influences the implant healing. Few scientific literatures have identified osteoporosis and HIV infection as an unconducive milieu for dental implant placement and survival but demonstrated favorable outcomes in short-term assessments. The long-term impact of bone metabolic effects of HAART on implant success remains a conundrum.

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Osseointegrated craniofacial implants have improved retention and patients' perceptions of implant-retained nasal prostheses; however, the determination of the available bone sites for implant placement post-rhinectomy is difficult. This case report describes the use of cone beam computed tomography scanning and computer-assisted virtual planning in conjunction with digital photographs for rehabilitation of a facial defect with an implant-retained silicon nasal prosthesis. Two implants were planned in the anatomical area with adequate bone volume to achieve favorable cosmetic outcomes and accessibility for hygiene maintenance. The implant-retained nasal prosthesis resulted in a meaningful improvement in the esthetics without the need for plastic surgery. In such cases, the post-rhinectomy reconstruction surgery should be limited to preparation of the surgical defect area for an implant-retained prosthesis. Silicone prostheses are reliable alternatives to surgery and should be considered in selected cases.

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The knowledge of teeth positions on the maxillary arch is useful in the rehabilitation of the edentulous patient. A combination of angular (θ), and linear (l) variables representing position of four teeth were initially proposed as the shape descriptor of the maxillary dental arch. Three categories of shape were established, each having a multivariate normal distribution. It may be argued that 4 selected teeth on the standardized digital images of the dental casts could be considered as insufficient with respect to representing shape. However, increasing the number of points would create problems with dimensions and proof of existence of the multivariate normal distribution is extremely difficult. This study investigates the ability of Fourier descriptors (FD) using all maxillary teeth to find alternative shape models. Eight FD terms were sufficient to represent 21 points on the arch. Using these 8 FD terms as an alternative shape descriptor, three categories of shape were verified, each category having the complex normal distribution.

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PURPOSE: The level of the implant above the marginal bone and flap design have an effect on the bone resorption during the healing period. The aim of this study is to detect the relationship between the level of the implant at the implant placement and the bone level at the healing period in the mesial and distal side of implants placed with flapless (FL) and full-thickness flap (FT) methods. METHODS: Twenty-two nonsubmerged implants were placed with the FL and FT technique. Periapical radiographs were taken of the patient at implant placement, and at 6 and 12 weeks. By using computer software, bone level measurements were taken from the shoulder of the healing cap to the first bone implant contact in the mesial and distal side of the implant surface. RESULTS: At 6 weeks, the correlation between the crestal bone level at the implant placement and crestal bone level of the FT mesially was significant (Pearson correlation coefficient=0.675, P<0.023). At 12 weeks, in the FT mesially, the correlation was nonsignificant (Spearman correlation coefficient=0.297, P<0.346). At 6 weeks in the FT distally, the correlation was nonsignificant (Pearson correlation coefficient=0.512, P<0.107). At 12 weeks in the FT distally, the correlation was significant (Spearman correlation coefficient=0.730, P<0.011). At 6 weeks in the FL mesially, the correlation was nonsignificant (Spearman correlation coefficient=0.083, P<0.809). At 12 weeks in the FL mesially, the correlation was nonsignificant (Spearman correlation coefficient=0.062, P<0.856). At 6 weeks in the FL distally, the correlation was nonsignificant (Spearman correlation coefficient=0.197, P<0.562). At 12 weeks in the FL distally, the correlation was significant (Pearson correlation coefficient=0.692, P<0.018). CONCLUSIONS: A larger sample size is recommended to verify the conclusions in this preliminary study. The bone level during the healing period in the FT was more positively correlated with the implant level at implant placement than in the FL.

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UNLABELLED: Flapless implant placement requires punch removal of the gingiva without flap reflection, suggesting this technique will be less invasive, and with less tissue destruction, than comparable alternative techniques. METHODS: Eleven implants were placed with flapless (FL) technique and 11 implants were placed with full-thickness flap (FT) technique in split mouth technique. FL technique was done with dermal tissue puncture, while FT was performed with crestal incision, including the papillae. Patients were followed-up postoperatively for clinical and morbidity evaluation in both groups. RESULTS: There was no pain, and there were only mild signs of inflammation, at the sites of flapless implant placement in the 11 patients studied. In contrast, there were complaints of mild to moderate pain and signs of inflammation at the site of full-thickness flap implant placement in the 11 patients studied. In addition, there was gingival overgrowth over the healing cap noted in this group. CONCLUSIONS: FL technique may be recommended for the apprehensive or hyperalgesic patient because of the absence of pain it conveys, as well as the decreased postoperative swelling. Periosteal disruption is responsible for the patient's morbidity postoperatively.

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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.

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Standardized digital images of maxillary dental casts of 47 subjects were analyzed using MATLAB software whereby the two hamular notches and the incisive papilla defines the Cartesian vertical and horizontal axes, as well as the origin. The angle and length of the midpoints of the anterior teeth, mesiobuccal and distobuccal cusp of the posterior teeth were measured from the origin and denoted as θ(1), …, θ(18) and l(1), …, l(18) respectively. These values were collectively used to represent the shape of each dental cast. Clustering and principal component analyses were employed to find possible groups of dental arches using the above measure of shape. The main result of this study is that the 3 groups of dental arch shape may be represented by the novel feature vector v(k) = (θ(k)(1), l(k)(1), θ(k)(3), l(k)(3), θ(k)(5), l(k)(5), θ(k)(13), l(k)(13)), k = 1, 2, 3. Knowledge of v(k) implies three impression trays should be sufficient in a particular prosthetic dentistry application for Malaysian patients. Further, given that v(k) are accurately measured they may be potential candidates as evidence in specific application of forensic dentistry.

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STATEMENT OF PROBLEM: In rehabilitating edentulous patients, selecting appropriately sized teeth in the absence of preextraction records is problematic. PURPOSE: The purpose of this study was to investigate the relationships between some facial dimensions and widths of the maxillary anterior teeth to potentially provide a guide for tooth selection. MATERIAL AND METHODS: Sixty full dentate Malaysian adults (18-36 years) representing 2 ethnic groups (Malay and Chinese), with well aligned maxillary anterior teeth and minimal attrition, participated in this study. Standardized digital images of the face, viewed frontally, were recorded. Using image analyzing software, the images were used to determine the interpupillary distance (IPD), inner canthal distance (ICD), and interalar width (IA). Widths of the 6 maxillary anterior teeth were measured directly from casts of the subjects using digital calipers. Regression analyses were conducted to measure the strength of the associations between the variables (alpha=.10). RESULTS: The means (standard deviations) of IPD, IA, and ICD of the subjects were 62.28 (2.47), 39.36 (3.12), and 34.36 (2.15) mm, respectively. The mesiodistal diameters of the maxillary central incisors, lateral incisors, and canines were 8.54 (0.50), 7.09 (0.48), and 7.94 (0.40) mm, respectively. The width of the central incisors was highly correlated to the IPD (r=0.99), while the widths of the lateral incisors and canines were highly correlated to a combination of IPD and IA (r=0.99 and 0.94, respectively). CONCLUSIONS: Using regression methods, the widths of the anterior teeth within the population tested may be predicted by a combination of the facial dimensions studied.

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