Ridge Mapping Research Articles

Simple Diagnostic Method to Assess the Available Bone for Immediate Implant Placement in an Extracted Socket

The success rate of immediate tooth replacement has been well documented in the literature. To achieve long-term success of dental implants, evaluation of the dimensions of the resorbing alveolar process must be accurate because an implant should be surrounded by at least 1 mm of bone. To minimize facial gingival recession, an intact labial bony plate along with an osseous-gingival relationship of 3 mm on the facial aspect of the failing tooth has been suggested. This article mentions a technique wherein the amount of available labial and palatal bone of an extracted socket can be assessed by using the extracted tooth that is to be replaced with an endosseous implant and a ridge mapping procedure without reflecting the flap.

Comparison of Different Methods of Assessing Alveolar Ridge Dimensions Prior to Dental Implant Placement

The aim of this study was to compare ridge-mapping measurement before surgical flap reflection and measurement using images from cone beam computerized tomography (CBCT) to direct caliper measurement following surgical exposure of the bone. Sixteen subjects with 25 sites for planned implant placement or ridge augmentation were recruited. An acrylic stent was fabricated for each subject. The stent provided three buccal/lingual pairs of consistent measurement points for each implant site located 4, 7, and 10 mm from the summit of the alveolar soft tissue. Two independent examiners participated. Comparisons of bucco-lingual ridge width using ridge-mapping versus direct caliper measurements showed that 94% and 89% of the pairs of measurement deviations were within +/- 1 mm for examiners 1 and 2, respectively. The corresponding comparison of CBCT images versus direct caliper measurements showed 70% and 55% agreement for examiners 1 and 2, respectively. CBCT image measurements provided lower levels of agreement than ridge-mapping measurements because of the more frequent and larger magnitudes of deviations compared to direct caliper measurements. Most often, ridge mapping provides measurements of the bucco-lingual ridge width consistent with those obtained by direct caliper measurement following surgical exposure of the bone. As applied in this study, CBCT was less consistent compared to direct caliper measurements and did not provide any additional, significant diagnostic information.

Using the Support Immersion Endoscope for Socket Assessment

The purpose of this study was to determine the indications, efficacy, and advantages of the support immersion endoscope (SIE) method for extraction socket assessment. Twelve patients (four women and eight men; mean age: 28 years) in need of extraction with implant placement participated in the study. The teeth extracted included eight upper central incisors and six upper lateral incisors. Extraction sockets were evaluated with a conventional extraction site evaluation (CESE) method alone or with CESE + SIE. CESE includes: visual evaluation; periodontal probing; ridge mapping with calipers, dental mirror, and orthopantomogram; and diagnostic wax-up. CESE + SIE had significantly better accuracy in examining extraction socket labial plate vertical position, labial plate thickness, and bone quality compared to CESE alone. The results obtained from CESE assessment were inconsistent because of poor visualization. The SIE can be used as an adjunct tool in assessing extraction socket morphology and bone conditions without flap elevation.

Fingerprint Image Mosaicking by Recursive Ridge Mapping

To obtain a large fingerprint image from several small partial images, mosaicking of fingerprint images has been recently researched. However, existing approaches cannot provide accurate transformations for mosaics when it comes to aligning images because of the plastic distortion that may occur due to the nonuniform contact between a finger and a sensor or the deficiency of the correspondences in the images. In this paper, we propose a new scheme for mosaicking fingerprint images, which iteratively matches ridges to overcome the deficiency of the correspondences and compensates for the amount of plastic distortion between two partial images by using a thin-plate spline model. The proposed method also effectively eliminates erroneous correspondences and decides how well the transformation is estimated by calculating the registration error with a normalized distance map. The proposed method consists of three phases: feature extraction, transform estimation, and mosaicking. Transform is initially estimated with matched minutia and the ridges attached to them. Unpaired ridges in the overlapping area between two images are iteratively matched by minimizing the registration error, which consists of the ridge matching error and the inverse consistency error. During the estimation, erroneous correspondences are eliminated by considering the geometric relationship between the correspondences and checking if the registration error is minimized or not. In our experiments, the proposed method was compared with three existing methods in terms of registration accuracy, image quality, minutia extraction rate, processing time, reject to fuse rate, and verification performance. The average registration error of the proposed method was less than three pixels, and the maximum error was not more than seven pixels. In a verification test, the equal error rate was reduced from 10% to 2.7% when five images were combined by our proposed method. The proposed method was superior to other compared methods in terms of registration accuracy, image quality, minutia extraction rate, and verification.

Comparison of linear tomography and direct ridge mapping for the determination of edentulous ridge dimensions in human cadavers

The purpose of this study was to compare the accuracy of linear tomography (LT) and direct ridge mapping (RM) for determining alveolar ridge dimensions. One site in the posterior mandible was selected for evaluation in each of 5 cadaver heads. Vacuum-formed stents made from models of the cadaver ridges were used to identify 3 sets of measurement points for each specimen: coronal (intersection of coronal and middle third of ridge), middle (intersection of middle and apical third), and apical (base of vestibule). The imaging stent contained 2-mm metal balls at each point, while the RM stent had holes drilled at corresponding locations. Linear tomograms and periapical radiographs (PA) were taken of the selected sites. RM measurements were made with calipers. Five blinded examiners measured ridge width at the designated measurement points with both LT and RM as well as distance from the ridge crest to mandibular canal (using PAs for RM group). Mandibles were then sectioned and an independent examiner made direct measurements (DM). MANOVA was used to determine whether LT and RM differed significantly from DM. There were no significant differences between LT and RM for ridge width measurements. However, both techniques underestimated ridge dimensions compared to DM ( P < .05). Measurement of mandibular canal height was accurate when determined by periapical radiographs but not by LT. Neither LT nor RM proved to be completely accurate in determining ridge width in the posterior mandible.

Ridge mapping.

An important aspect of surgical diagnosis before implant placement is measurement of the width of the alveolar ridge. Besides the use of radiographic methods, alveolar crest width can be measured by ridge mapping. A ridge mapping technique using a specially designed caliper (Ultimapper) is presented. Results of a research investigation are presented, which suggest that the technique is reliable and easily performed.

Sonographic measurement versus mapping for determination of residual ridge width

To achieve long-term success of dental implants, evaluation of the dimensions of the resorbing alveolar process must be accurate because an implant should be surrounded by at least 1 mm of bone. Estimating the thickness of bone is more difficult because the mucosal contour can mask the actual dimension of the residual ridge. With ultrasound, it is possible to analyze and visualize the diameter of maxillary or mandibular residual ridges. Data obtained from ultrasound measurement of residual ridges were compared with the data from ridge mapping with the Wilson bone caliper and the Spoerlein caliper. The ultrasound measurement produced nearly the same data at all measurement points as ridge mapping. Ultrasound also provides exact information about the location of the mental foramen and the maxillary sinus. By using all three methods the initial stage of implant treatment can be planned.