Likelihood of needing facial bone augmentation in the anterior maxilla of Chinese Asians: A cone beam computed tomography virtual implant study

Relevant factors of posterior mandible lingual plate perforation during immediate implant placement: a virtual implant placement study using CBCT

BACKGROUND

To explore the influence of cross-sectional type and morphological parameters at the mandibular molar sites on lingual plate perforation (LPP) during the immediate implant placement (IIP).

METHODS

181 implants were virtually placed in the mandibular molar sites on the cone beam computed tomography (CBCT). Each cross-section of the implantation site was divided into the Undercut (U)/Parallel (P)/Convex (C) types. Morphologically relevant parameters were measured on the cross-sections, including width of the upper end (Wb), width of the lower end (Wc), vertical height (V), angle between the natural crown axis and the alveolar bone axis (∠β), LC depth (LCD), LC height, and angle between the horizontal line and the line connecting the most prominent point and the most concave point of lingual plate (∠α). Besides, the distance from the end of the virtual implant and the lingual bone plate of the cross-section (D_IL) was calculated. Relationships between all the morphologically relevant parameters and the D_IL were further analyzed.

RESULTS

A total of 77 (42.5%) cross-sections were classified as U-type, which was the most common one, accounting for 63% of the second molar regions. All LPP cases and most of the nearly LPP (87.9%) cases occurred at the U-type cross-sections, and the relationship between the D_IL and the morphological parameters can be expressed by a multivariate linear equation.

CONCLUSIONS

The occurrence rate of U-type cross-sections in the second molar region was very high, and the risk of LPP should be considered during IIP. Except for the U-type, significant large LCD, small Wc, and large ∠β were the important relevant factors. CBCT and multivariate linear equations could help to assess the LPP risk and provide a reference for implant placement design pre-surgery.

Measuring the Facial Plate of Bone in the Upper Anterior Teeth Utilizing Cone Beam Computed Tomography at King Abdulaziz University, Jeddah, Saudi Arabia

Background and aim

Radiographic assessment is an important diagnostic tool in dental practice.Cone beam computed tomography (CBCT) is among the most important imaging examinations. By providing multiplanar visualization of the maxillofacial region, CBCT enables practitioners to assess various conditions three-dimensionally. CBCT is utilized in different fields within dentistry, including oral and maxillofacial surgery, endodontics, orthodontics, periodontics, implant dentistry, and others. Having access to accurate 3D images is crucial in implant dentistry. This study aimed to measure the crestal bone height loss and facial alveolar bone thickness in the maxillary anterior teeth using CBCT to investigate its effect on surgical planning for dental implant placement in adult patients.

Material and methods

CBCT scans (N = 119) of adults, aged 18-65 years, with bilateral permanent maxillary anterior teeth present were included in this retrospective study. The mean alveolar bone plate thickness and crest bone height loss adjacent to the maxillary anterior teeth were measured and differences were examined.

Results

The results suggest that additional care and assessment of dental implant placement should be considered when replacing the permanent lateral incisors and canines. The frequency of fenestrations and dehiscence is higher in older adults. Possible management includes guided bone regeneration or “pink restorative solutions.”

Conclusion

CBCT analysis to assess the bone morphology surrounding “hopeless” maxillary anterior teeth is important to ensure proper diagnosis and management, including the use of dental implants.

Accuracy evaluation of cone beam computed tomography applied to measure peri-implant bone thickness in living patients: an ex vivo and in vivo experiment

OBJECTIVES

This study aims to study the accuracy of cone beam computed tomography (CBCT) for measuring peri-implant bone thickness in living patients via a novel visualization method (NVM).

MATERIAL AND METHODS

The validity of the NVM was verified ex vivo by measuring the same peri-implant bone thicknesses in bovine ribs by using raw postoperative CBCT (clinical measurement, CM), the visualized fused images obtained using the NVM (visualized fused measurement, VF), and hard tissue sections (gold standard measurement, GS). The NVM was applied by deconstructing the postoperative CBCT model into the Model_post-bone and Model_implant and replacing it with bone from preoperative CBCT and standard implant models, respectively. In vivo, 52 implants were included, and the VF of each implant was obtained using data processing methods similar to those used ex vivo. Then, we compared the results of CM and VF.

RESULTS

Ex vivo, the VF was similar to GS, while CM usually underestimated the peri-implant bone thickness, especially at the implant shoulder (P < 0.01). In vivo, on CBCT, areas with a peri-implant bone thickness of 0-0.50 mm were not visible, while those with a thickness of 0.50-1.00 mm were occasionally visible. There was less underestimation of bone along the implant long axis.

CONCLUSIONS

Thin peri-implant bones could be completely underestimated on CBCT. CBCT scans alone are insufficient to warrant surgical intervention. Our NVM facilitates the accurate visual assessment of implant dimensions.

CLINICAL RELEVANCE

The thickness of peri-implant bone could be completely underestimated when thinner than 1.0 mm in living patients. Familiarity with these confusing CBCT results may help clinicians and patients avoid further unnecessary evaluation, misdiagnosis, and invasive treatment.

Immediate Implant Placement in the Maxillary Aesthetic Zone: A Cone Beam Computed Tomography Study

This study aimed to investigate the factors that could be associated with the risk of labial cortical bone wall perforation with immediate implant placement (IIP) in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 126 qualified subjects (756 teeth) were included. Implants were virtually positioned in two different positions: in the long axis of the tooth (prosthetically-driven position) and in an ideal position in relation to adjacent anatomical structures (bone-driven position). Two different implant diameters were planned for each tooth position, namely, 3.75 and 4.3 mm for central incisors and canines, and 3.0 and 3.3 mm for lateral incisors. The incidence of perforation was nearly 80% and 5% for prosthetically- and bone-driven position, respectively. Factors associated with a higher risk of cortical bone wall perforation (bone-driven position), according to logistic regression analysis, were women, wider implants, Sagittal Root Position class IV, and decrease of the labial concavity angle. Perforation of the labial cortical bone wall can be greatly minimized when the implant is placed in a bone-driven position compared to a prosthetically-driven position. It is important to preoperatively evaluate the morphological features of the implant site for risk assessment and to individualize the treatment plan.

Buccal Bone Thickness in Anterior and Posterior Teeth-A Systematic Review

(1) Background: Immediate dental implant placement has been a subject of great interest over the last decade. Here, information regarding the anatomy and bone thickness of the jaw prior to dental implant placement is crucial to increase the surgery's success and the patient's safety. The clinical premises for this approach have been controversially discussed. One of those heavily discussed premises is a buccal bone thickness of at least 1 mm thickness. This meta-analysis aims to systematically review buccal bone thickness (BBT) in healthy patients. Thus, the feasibility of immediate dental implant placement in daily practice can be assessed. (2) Methods: A search in the electronic databases was performed to identify articles reporting on BBT that was measured by computed tomography in adults. (3) Results: We were able to find 45 studies, including 4324 patients with 25,452 analyzed teeth. The analysis showed a BBT at the alveolar crest of 0.76 ± 0.49 mm in the maxillary frontal and of 1.42 ± 0.74 mm in the maxillary posterior region. In the mandible, the average measured values were similar to those in the maxilla (front: 0.95 ± 0.58 mm; posterior: 1.20 ± 0.96 mm). In the maxillary frontal region 74.4% and in the mandibular frontal region 61.2% of the crestal buccal bones showed widths <1 mm. (4) Conclusions: In more than 60% of the cases, the BBT at the alveolar crest is <1 mm in maxillary and mandibular frontal regions. This anatomic data supports careful pre-surgical assessment, planning of a buccal graft, and critical selection of indication for immediate implant placement, especially in the maxillary and mandibular frontal and premolar region.

Comparison of regular- and slope-configured dental implants placed in the edentulous ridge with height discrepancy: A pilot randomized controlled trial

BACKGROUND/PURPOSE

Edentulous ridges with height discrepancies (RHDs) could jeopardize the outcome of implant placement. This study aimed at evaluating the outcomes of placing regular- and slope-configured implants in RHDs.

METHODS

Patients with >1 mm RHDs requesting implant rehabilitation were recruited and randomly assigned to regular- (control) or slope-configured (test) implant treatment using a submerged installation protocol. Thread exposure (TE) and implant stability quotient (ISQ) were evaluated during implant installation (S1) and uncovered surgery (S2), and marginal bone level (MBL) was evaluated after implant installation (T1) and uncovery (T3), and one year after implant placement (T4). Periodontal status and gingival crevicular fluid (GCF) biomarkers of adjacent teeth were evaluated before implant installation (T0), before uncovery (T2), and at T4. Peri-implant clinical status and peri-implant crevicular fluid (PICF) biomarkers of examined implants were evaluated at T4.

RESULTS

Nineteen patients with 17 control and 13 test implants were included. All of the implants survived with acceptable peri-implant health, and PICF biomarkers were at equivalent levels as GCF biomarkers of the adjacent teeth at T4. Compared with the control group, the test group showed reduced TE and equivalent ISQ at S1 and S2, and the loss of MBL was reduced at T4. Regarding the adjacent teeth, all periodontal parameters and GCF biomarkers were slightly decreased from T0 to T2, and the reductions in probing pocket depth and clinical attachment level were slightly greater at T4.

CONCLUSION

Slope-configured implants maintained the implant-supporting structures and minimally altered periodontal status of the adjacent teeth in RHDs.

Evaluation of factors affecting alveolar ridge height and facial bone thickness in Chinese maxillary central incisors by cone beam CT

Background/purpose

In the immediate implantation of maxillary central incisors, the height of the alveolar bone is lost, and there is often a risk of bone fracture due to the thin buccal bone wall (BBW). The purpose of this study was to assess the effects of smoking, age, and root position in the alveolar bone on the BBW and the distance between the cemento-enamel junction (CEJ) and the facial bone crest (FBC) of Chinese maxillary central incisors.

Materials and methods

The patients were divided by smoking, gender, age, and root sagittal position in the alveolar bone. BBW thickness was measured at the following sites: the 4 mm apical to the CEJ, the middle of the root, and the apex. The distance from the CEJ to the FBC was also evaluated.

Results

Cone beam CT (CBCT) data for the maxillary central incisors of 645 patients (323 males and 322 females) were selected and analyzed. The CEJ-FBC distance in patients who smoked (2.79 ± 0.78 mm) was significantly greater than that of non-smokers (2.54 ± 0.69 mm). The BBW in subtype III (0.74 ± 0.43 mm, 0.81 ± 0.36 mm) was thinner than that in subtypes I and II at 4 mm apical to the CEJ and in the middle of the root, with a statistically significant difference (p < 0.05).

Conclusion

In most Chinese people, smoking, gender, age, and the position of the root in alveolar bone are all important factors that must be considered before immediate implantation is undertaken.