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Grafting of the alveolar ridge with autogenous bone is an integral stage of contemporary management of complete cleft lip and palate cases. Alveolar bone grafting restores continuity of the dental arch, closes oronasal fistulae, supports the alar base, and facilitates spontaneous eruption of permanent teeth adjacent to the cleft. However, timing of the graft and the selection of materials have been topics of much debate in the literature.

This article discusses an alternative donor site in cases where rehabilitation has passed the recommended time. Harvesting bone from the third molar regions allows not only the removal of impacted third molars during the same surgical procedure, but also eliminates the morbidity associated with additional surgical sites such as the ilium or mandibular symphysis. This report should not be interpreted as a recommendation for the use of this alternative site in cases where grafting is carried out within the optimal time period, which is usually in the mixed dentition stage. However, when grafting is necessary in young adults suffering from complete cleft lip and palate, the third molar region may provide another acceptable donor site.

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There is a paucity of information on the morphological assessment of the temporomandibular joint in relation to varying skeletal and dental relationships. The purpose of this study was to evaluate the morphologic relationship of the condyle and fossa in patients with different malocclusions and skeletal relationships. Pretreatment records of 232 orthodontic patients, 95 males and 137 females, of Caucasian descent and ranging in age from 9 years 4 months to 42 years 6 months, were examined. Records included dental casts, lateral cephalometric radiographs, hand-wrist radiographs, and corrected tomograms of right and left TM joints. Nonconcentricity and mild asymmetry of the condyle-fossa relationship were commonly observed. The left condyle was found to be more anteriorly positioned than the right, with the mean percentage of joint space being 6.93% on the left side and −1.24% on the right. Skeletal and dental Class III patients demonstrated significantly more anteriorly positioned condyles (P<0.05). There were no significant differences in condylar position between Class I and Class II groups based on ANB or Angle's classification. Further, no significant difference in condylar position was observed between groups based on overbite or crossbite.

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Digital imaging has several potential advantages over traditional cephalometry. These include storage, transmission, and enhancement of images, reduced exposure to radiation for patients, and the possibility of automated cephalometric analysis. This paper outlines some of these advantages, discusses the limitations of digital imaging and suggests possible future developments.

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The aim of this study was to compare the diagnostic quality of conventional cephalometric radiographs with that of digital image counterparts. The random error associated with angular and linear measurements recorded on the digital images was greater than on the conventional radiographs. In addition, there was a systematic error producing statistically significant differences in the majority of angular and linear measurements between the digital images and the conventional radiographs. The errors that occurred with some measurements were of sufficient magnitude to be of clinical significance, particularly in a cephalometric situation where a high degree of accuracy is required. It is therefore suggested that, for digital imaging of cephalometric radiographs, a pixel matrix larger than 512 × 512 with more than 64 gray levels is required to maintain the diagnostic quality of the original radiograph.

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This study examined the effect of head rotation about the vertical and transverse axes on posterior anterior cephalometric landmarks. Radiographs were taken on 25 skulls, first in a normal position, then in four positions each rotated 5° from normal. The identification errors of 52 bilateral and midline landmarks were determined in the horizontal and vertical dimensions. The landmark identification errors for each of the five orientations were compared and those landmarks affected by 5° rotation were identified. Landmarks with significantly larger identification error in a rotated position were: nasal cavity, mandible/occiput, foramen rotundum and orbitale. Best fit vertical and horizontal reference lines were determined, and the effect of head rotation on the choice of best fit reference lines was assessed. Rotation about the transverse axis did not affect the relationship of landmarks to the best vertical or horizontal lines. Rotation about the vertical axis did not affect the relationship of landmarks to the best horizontal line but did affect their relationship to the best vertical line.

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The purpose of this study was to determine the shear bond strength and debonding failure modes of orthodontic brackets bonded to teeth that have been treated with various fluoride concentrations. Thirty-six recently extracted human premolars were divided into three groups: prophylaxis with pumice only, prophylaxis using a 13,500 ppm fluoridated pumice, and prophylaxis with pumice followed by application of a 2500 ppm fluoridated paste. The teeth were etched with a 37% phosphoric acid gel, then bonded with a metal orthodontic bracket. The teeth were mounted in phenolic rings and stored in de-ionized water at 37°C for 72 hours. A Zwick Universal Testing Machine was used to determine shear bond strengths. The residual adhesive on the enamel surface was estimated using the Adhesive Remnant Index. Analysis of variance was used to compare the various groups, and significance was predetermined at p ≤ .05.

The results indicate that there were no significant differences in bond strengths between the treated and untreated teeth (p = .233). The Chi Square test evaluating the residual adhesive on the enamel surfaces also showed no significant differences (p = .456). In conclusion, the use of fluoridated prophylactic pastes with varying fluoride concentrations does not significantly affect shear bond strength or bond failure location.

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An in vitro investigation was carried out to compare CCD-based intraoral radiographic systems with E-speed film for the detection of proximal enamel defects beneath orthodontic bands, with and without added niobium filtration to attenuate the x-ray beam. Twenty caries-free extracted teeth were randomly divided into five groups. Fifteen of 30 contacting proximal surfaces remained lesion free; the other 15 received a small, medium, or large mechanically induced enamel defect. Images were made with and without the addition of 30µm niobium filtration, and with and without orthodontic bands. Six dentists were viewers. Receiver operating characteristic (ROC) curves were developed for each modality under each test situation. The area under the curve (A_Z) was used as an index of diagnostic accuracy, and the critical ratio was used for statistical comparisons. In the absence of orthodontic bands, the A_Z values for E-speed film and for nonenhanced RVGS were greater than for all other modalities tested, indicating that they have the greatest diagnostic accuracy. With orthodontic bands, the RVG-S with steep gradient enhancement (X-function) had a higher A_Z value than all other modalities. Addition of niobium had no significant effect on defect detection. CCD-based devices hold no diagnostic advantage over conventional film for detecting changes in the density of enamel not covered by orthodontic bands. Contrast enhancement of digital images (RVG-S X-function) holds promise for the detection of such changes beneath orthodontic bands.

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To determine whether the positions of the palatal rugae were affected by orthodontic therapy, pre- and posttreatment maxillary dental casts of 57 adult patients treated in the graduate orthodontic clinic at the University of North Carolina were evaluated. The orthodontic extraction group (n=27) was composed of patients whose treatment included the extraction of two maxillary premolars. The remaining patients (n=30) had been treated without extractions. Transverse changes observed over time were significantly different from zero only for the medial points of the first rugae in the nonextraction group and for the lateral points of the first rugae in the extraction group. None of the changes observed in the transverse measures were statistically different between the two groups. In the extraction group, there were significant anteroposterior changes in the right lateral points between the first and second rugae and between the second and third rugae, and in the right medial points between the second and third rugae. There were no statistically significant anteroposterior changes observed in the nonextraction group over time. When the two groups were compared, the average distance between the lateral first and second right rugae, and the average distance between the lateral second and third right rugae were significantly different. The medial and lateral points of the third rugae appear to be stable landmarks for the construction of anatomic reference points in longitudinal cast analysis.

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