Sinus floor elevation or referral for further diagnosis and therapy: A comparison of maxillary sinus assessment by ENT specialists and dentists using cone beam computed tomography

Incidental findings in cone beam computed tomography (CBCT) scans for implant treatment planning: a retrospective study of 404 CBCT scans

OBJECTIVES

To investigate the prevalence of incidental findings and need for further dental treatment and analyse the influence of size of field-of-view (FOV) and age in cone beam computed tomography (CBCT) for pre-implant planning.

METHODS

404 CBCT scans were examined retrospectively for incidental findings and need for further dental treatment. Incidental finding-frequencies and need for further treatment were assessed for different age (< 40 years, 40-60 years, > 60 years) and FOV groups (small, medium, large). Intraexaminer and interexaminer agreements were evaluated.

RESULTS

In 82% of the scans at least one incidental finding was found, with a total of 766 overall. More incidental findings were found in scans with large FOV (98% vs. 72%, OR = 22.39 large vs. small FOV, p < 0.0001) and in scans of patients > 60 years (OR = 5.37 patient's age > 60 years vs. < 40 years, p = 0.0003). Further dental treatment due to incidental findings was needed in 31%. Scans with large FOV were more likely to entail further treatment (OR = 3.55 large vs. small FOV, p < 0.0001). Partial edentulism and large FOV were identified as risk factors for further treatment (p = 0.0003 and p < 0.0001). Further referral of the patient based on incidental findings was judged as indicated in 5%. Intra- and inter-examiner agreements were excellent (kappa = 0.944/0.805).

CONCLUSIONS

A considerable number of incidental findings with need for further dental treatment was found in partially edentulous patients and in patients > 60 years. In pre-implant planning of elderly patients, the selection of large FOV CBCT scans, including dentoalveolar regions not X-rayed recently, help to detect therapeutically relevant incidental findings.

Survival analysis of implants placed simultaneously with lateral sinus floor elevation in severely atrophic maxilla: A 3- to 12-year retrospective cohort study

OBJECTIVES

To retrospectively evaluate whether implants placed simultaneously with lateral sinus floor elevation (LSFE) in severely atrophic maxilla (residual bone height [RBH] ≤3 mm) could achieve long-term survival and comprehensively analyze the factors influencing their survival rates.

MATERIALS AND METHODS

A total of 123 patients receiving LSFE and simultaneous implant placement from 2010 to 2019 and their 123 implants in sites with RBH ≤3 mm were included in this study. Basic characteristics of patients and implants were collected from the medical record system and cone-beam computed tomography (CBCT) images. Kaplan-Meier survival curves were applied to estimate cumulative survival rates (CSRs) and Cox proportional hazards regression models were used to detect factors influencing implant survival.

RESULTS

The 6-year and 12-year CSR of implants placed in sites with RBH ≤3 mm were 95.7% (95% confidence interval [CI]: 92.1%-99.5%) and 76.6% (95% CI: 58.1%-100%), respectively. Eight patients presented late implant failure. Univariate and multivariate Cox regression analyses demonstrated that RBH ≤2 mm (hazard ratio [HR]: 20.63, p = 0.000) and smoking habit (HR: 6.055, p = 0.024) were significantly associated with long-term implant survival. Specifically, the 10-year CSR of implants in sites with RBH ≤2 mm (53.3%, 95% CI: 27.5%-100%) was dramatically lower than those in sites with RBH >2 mm (92.9%, 95% CI: 81.7%-100%, p = 0.000).

CONCLUSIONS

Implants placed simultaneously with LSFE in sites with RBH ≤3 mm can achieve long-term survival. However, caution is required especially for implantation in sites with RBH ≤2 mm. Besides, the smoking habit is also considered a risk factor jeopardizing long-term implant survival.

Clinical, radiographic, and histological/histomorphometric analysis of maxillary sinus grafting with deproteinized porcine or bovine bone mineral: A randomized clinical trial

OBJECTIVE

The present study aimed to compare histomorphometrically evaluated new bone formation, radiographically measured graft stability, and clinical implant outcome between maxillary sinus grafting with either deproteinized porcine bone mineral (DPBM) or deproteinized bovine bone mineral (DBBM).

MATERIALS AND METHODS

Thirty maxillary sinuses were initially included and randomly assigned to the test group (TG; DPBM, n = 15) or control group (CG; DBBM, n = 15). After a healing period (6 months), axially retrieved bone biopsies of the molar region were used for histological/histomorphometric analysis of new bone formations. Additionally, radiographically measured graft stability and clinical implant outcome were assessed.

RESULTS

Twenty-three sinus sites with 10 sinuses of the TG and 13 of the CG were ultimately available for data and statistical analysis. In the TG, a slightly, but yet significantly (p = .040) higher proportion of new bone formation (TG: 27.7 ± 5.6% vs. CG: 22.9 ± 5.1%) and a lesser (p = .019) amount of connective (non-mineralized) tissue (TG: 47.5 ± 9.5% vs. CG: 56.1 ± 9.5%) was found than in the CG. However, both xenografts showed comparable (n.s.) residual bone graft (TG: 23.7 ± 7.2% vs. CG: 21.1 ± 9.85.6%), bone-to-graft contacts (TG: 26.2 ± 9.8% vs. CG: 30.8 ± 13.8%), similar graft height reduction over time (TG: 12.9 ± 6.7% CG: 12.4 ± 5.8%) and implant survival/success rate (100%). At the 3-year post-loading evaluation, the peri-implant marginal bone loss (TG: 0.52 ± 0.19 mm; CG: 0.48 ± 0.15 mm) and the peri-implant health conditions (TG: 87.5%/CG: 81.2%) did not differ between implants inserted in both xenografts used.

CONCLUSIONS

The use of DPBM or DBBM for maxillary sinus augmentation is associated with comparable bone formation providing stable graft dimension combined with healthy peri-implant conditions.

Change in Maxillary Sinus Mucosal Thickness in Patients with Preoperative Maxillary Sinus Mucosal Thickening as Assessed by Otolaryngologists: A Retrospective Study

Background and Objectives: Maxillary sinus pathologic conditions may increase the risk of complications during posterior maxillary sinus augmentation surgery. The purpose of this study was to evaluate the changes in participants with preoperative maxillary sinus mucosal thickening and to assess this factor as a preoperative risk indicator for sinusitis after maxillary dental implantation. Materials and Methods: We compared the preoperative and postoperative maxillary sinus mucosal thickness (MSMT), the distance between the maxillary sinus ostium and sinus floor (MOD), and the MSMT/MOD ratio. The participants were divided into three groups (sinus augmentation, bone grafting, and no grafting). Results: The mean preoperative MSMT was 4.3 ± 2.0 mm, and the mean MSMT/MOD ratio was 0.13 ± 0.05. No postoperative sinusitis was observed in these patients, including cases caused by anatomical variations. The mean postoperative MSMT was 4.5 ± 2.3 mm, and the mean postoperative MSMT/MOD ratio was 0.15 ± 0.06. There was no statistically significant difference between the groups at each time point (p > 0.05). Conclusions: The study found no significant change in MSMT at post-treatment evaluation, even when considering different subgroups. It underscores the importance of preoperative maxillary sinus radiographic assessments and collaboration between dentists and otolaryngologists for better outcomes in patients with preoperative maxillary sinus mucosal thickening.

SinusC-Net for automatic classification of surgical plans for maxillary sinus augmentation using a 3D distance-guided network

The objective of this study was to automatically classify surgical plans for maxillary sinus floor augmentation in implant placement at the maxillary posterior edentulous region using a 3D distance-guided network on CBCT images. We applied a modified ABC classification method consisting of five surgical approaches for the deep learning model. The proposed deep learning model (SinusC-Net) consisted of two stages of detection and classification according to the modified classification method. In detection, five landmarks on CBCT images were automatically detected using a volumetric regression network; in classification, the CBCT images were automatically classified as to the five surgical approaches using a 3D distance-guided network. The mean MRE for landmark detection was 0.87 mm, and SDR for 2 mm or lower, 95.47%. The mean accuracy, sensitivity, specificity, and AUC for classification by the SinusC-Net were 0.97, 0.92, 0.98, and 0.95, respectively. The deep learning model using 3D distance-guidance demonstrated accurate detection of 3D anatomical landmarks, and automatic and accurate classification of surgical approaches for sinus floor augmentation in implant placement at the maxillary posterior edentulous region.

The referral pattern and treatment modality for peri-implant disease between periodontists and non-periodontist dentists

OBJECTIVES

This study is to investigate the referral pattern and treatment modality of dentists in the management of peri-implant diseases between periodontists and non-periodontist dentists (NPDs).

MATERIALS AND METHODS

A total of 167 validated questionnaires were obtained from periodontists and NPDs, who had experience of placing implants for at least one year. Question I to IV asked how the dentist would respond if a patient came for treatment of their peri-implant diseases with four different scenarios according to resource of patient and disease severity. For each Scenario, dentists also replied which treatment procedures they would use if they decide to treat the patient.

RESULTS

Periodontal training, resource of patient, and disease severity were shown to significantly influence the referral pattern and treatment modality in the management of peri-implant disease (p < 0.05). Periodontists were more likely to use variable treatment procedures, including occlusal adjustment (OR = 2.283, p < 0.01), oral hygiene instruction (OR = 3.751, p < 0.001), topical antiseptic agent (OR = 2.491, p < 0.005), non-surgical mechanical therapy (OR = 2.689, p < 0.001), surgical therapy (OR = 2.009, p < 0.01), and remove implant (OR = 3.486, p < 0.001) to treat peri-implant diseases, compared to NPDs.

CONCLUSION

The periodontal specialty training, resource of patient, and disease severity significantly influenced the referral pattern and treatment modality of dentist treating an implant diagnosed with peri-implant disease. This study also highlighted the importance of educating basic periodontal and peri-implant disease-related knowledge to all dentists regularly performing dental implant treatments.

CLINICAL RELEVANCE

Peri-implant diseases are highly prevalent among patients with dental implants. Periodontal specialty training could enhance using variable treatment procedures to treat peri-implant diseases for dentists.

CBCT for Diagnostics, Treatment Planning and Monitoring of Sinus Floor Elevation Procedures

Sinus floor elevation (SFE) is a standard surgical technique used to compensate for alveolar bone resorption in the posterior maxilla. Such a surgical procedure requires radiographic imaging pre- and postoperatively for diagnosis, treatment planning, and outcome assessment. Cone beam computed tomography (CBCT) has become a well-established imaging modality in the dentomaxillofacial region. The following narrative review is aimed to provide clinicians with an overview of the role of three-dimensional (3D) CBCT imaging for diagnostics, treatment planning, and postoperative monitoring of SFE procedures. CBCT imaging prior to SFE provides surgeons with a more detailed view of the surgical site, allows for the detection of potential pathologies three-dimensionally, and helps to virtually plan the procedure more precisely while reducing patient morbidity. In addition, it serves as a useful follow-up tool for assessing sinus and bone graft changes. Meanwhile, using CBCT imaging has to be standardized and justified based on the recognized diagnostic imaging guidelines, taking into account both the technical and clinical considerations. Future studies are recommended to incorporate artificial intelligence-based solutions for automating and standardizing the diagnostic and decision-making process in the context of SFE procedures to further improve the standards of patient care.

Changes in sinus mucosal thickening in the course of tooth extraction and lateral sinus augmentation with surgical drainage: A cone-beam computed tomographic study

OBJECTIVES

The objective of the study was to evaluate the radiographic changes in sinus mucosal thickness (SMT) in patients with mucosal thickening of odontogenic origin after maxillary molar extraction and lateral sinus augmentation with simultaneous surgical drainage and implant placement.

MATERIALS AND METHODS

Forty-six patients were included in this study. The changes in SMT were evaluated using cone-beam computed tomography images produced at four time points: before extraction (T0), before surgery (T1), immediately after surgery (T2), and after prosthesis delivery (T3), and statistical differences between time points were analyzed. The changes in SMT and augmented bone height (ABH) regarding the reason of extraction, smoking, ostial patency, and the presence of postoperative sinusitis were also evaluated.

RESULTS

Over time points, SMT gradually decreased (T0: 19.44 ± 9.22 mm, T1: 15.10 ± 8.89 mm, T2: 8.42 ± 6.01 mm, and T3: 4.16 ± 4.91 mm) (p < .05). Five out of 6 patients with ostial obstruction at T1 presented ostial patency at T3. Two patients developed postoperative sinusitis but recovered with medication. Ostial patency at T1, SMT at T1, and reason of extraction did not statistically significantly influence SMT at T3. SMT at T1 had no statistically significant impact on ABH change between T2 and T3.

CONCLUSION

Sinus mucosal thickness was gradually reduced by extraction of compromised teeth and drainage during lateral sinus augmentation. The drainage contributed more to the reduction in SMT.

Implant failure and associated risk factors of transcrestal sinus floor elevation: A retrospective study

OBJECTIVES

This retrospective study aimed to evaluate early and late implant loss rates after transcrestal sinus floor elevation (TSFE) and to identify the risk factors related to these failures.

MATERIAL AND METHODS

All patients treated with TSFE and simultaneous implant placement during October 2015 to March 2019 were evaluated for inclusion. A total of 802 patients with 976 implants met the inclusion criteria. Clinical and radiographic information was collected from medical records and image software. Univariate and multivariate Cox proportional hazards frailty regression models were performed to identify potential risk factors associated with early and late implant loss after TSFE.

RESULTS

The 3-year cumulative implant survival rate was 96.9% (95% CI 95.8%-98.0%). Twelve implants in 12 patients were lost before or at the abutment connection, while 24 implants in 24 patients were lost after functional loading. The Cox frailty regression analyses indicated that two factors were correlated with early implant loss: TSFE with grafting materials, and operators with less clinical experience. As for late implant loss, RBH ≤6 mm, male sex, and certain implant brands were associated with a significantly increased failure rate.

CONCLUSIONS

Transcrestal sinus floor elevation with simultaneous implant placement is a predictable treatment option in the atrophic maxilla. The presence of grafting materials and the lack of clinical experience of the surgeon were possibly associated with early implant loss, while low RBH, male sex, and certain implant brands tended to increase late implant loss.

Deep learning-based fully automatic segmentation of the maxillary sinus on cone-beam computed tomographic images

The detection of maxillary sinus wall is important in dental fields such as implant surgery, tooth extraction, and odontogenic disease diagnosis. The accurate segmentation of the maxillary sinus is required as a cornerstone for diagnosis and treatment planning. This study proposes a deep learning-based method for fully automatic segmentation of the maxillary sinus, including clear or hazy states, on cone-beam computed tomographic (CBCT) images. A model for segmentation of the maxillary sinuses was developed using U-Net, a convolutional neural network, and a total of 19,350 CBCT images were used from 90 maxillary sinuses (34 clear sinuses, 56 hazy sinuses). Post-processing to eliminate prediction errors of the U-Net segmentation results increased the accuracy. The average prediction results of U-Net were a dice similarity coefficient (DSC) of 0.9090 ± 0.1921 and a Hausdorff distance (HD) of 2.7013 ± 4.6154. After post-processing, the average results improved to a DSC of 0.9099 ± 0.1914 and an HD of 2.1470 ± 2.2790. The proposed deep learning model with post-processing showed good performance for clear and hazy maxillary sinus segmentation. This model has the potential to help dental clinicians with maxillary sinus segmentation, yielding equivalent accuracy in a variety of cases.

Modified Osteotome Sinus Floor Elevation Technique for Multiple Edentulous Spaces: A Non-Randomized Controlled Trial

Objectives: We aimed to demonstrate our modified osteotome sinus floor elevation (OSFE) technique for placing two implants in multiple maxillary posterior edentulous spaces with residual bone height (RBH) < 5 mm, to evaluate the clinical effect and explore the prognosis. Methods: We identified 18 appropriate patients with RBH < 5 mm and 12 patients with RBH ≥ 5 mm. After drill preparation, variously shaped curettes were applied to adequately release the tension of the membrane around the cavity and between two implants by blunt dissection. Then, an osteotome was used to elevate the membrane to the desired height. After filling bone graft into the elevated space, dental implants were inserted. Cone-Beam Computed Tomography (CBCT) was performed after surgery and 6 months later. Results: The implant survival rate was 100%, and after the 6-month resorption, the height of the graft apically between the two implants gradually stabilized at 8.92 mm. Compared with 12 patients with RBH ≥ 5 mm, their graft bone resorption demonstrated no significant difference. Conclusions: It can be suggested that the modified OSFE technique could yield predictable clinical results for placing adjacent implants in patients with RBH less than 5 mm after six months of follow-up. Clinical Significance: Our modified OSFE technique could be applied to place adjacent implants in patients with RBH less than 5 mm, especially for elderly patients or patients with bone crests and vessels on the lateral wall, owing to its advantages including less trauma and fewer complications, minimizing the risk of membrane perforation, shortening the treatment period, avoiding another surgery area or second-stage surgery, improving not only the bone around the implant apex but also between implants, etc.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.

Complication and Salvage of Sinus Floor Elevation in the Maxillary Sinus With Asymptomatic and Noncalcified Fungus Colonization: A Case Report

The present study aimed to report (1) the sequela of sinus floor elevation (SFE) in the posterior maxilla with severe sinus membrane thickening and an undiagnosed fungal colonization but a patent ostium and (2) a treatment course without implant removal. A 73-year-old woman underwent dental implant placement in the left posterior maxillary area. Although the patient was asymptomatic, severe sinus membrane thickening with Haller cells was observed on a radiographic examination, but the ostium was patent. After SFE and simultaneous implant placement, the patient developed acute sinusitis and was referred to an otolaryngologist. Functional endoscopic sinus surgery (FESS) was performed, resulting in resolution of the infection and salvage of the augmentation and the implant. The histopathologic examination revealed the fungal ball that could not be diagnosed on preoperative dental radiography. During the 2 years after the delivery of the final prosthesis, a significant reduction in membrane thickness was observed. The implants were functioning well. Clinicians should recognize fungal colonization as an etiology of sinus membrane thickening and provide proper pre- and postoperative management, including FESS.