Endoscopic and ultrasonographic evaluation of the maxillary sinus after combined sinus floor augmentation and implant insertion

Overview of Ultrasound in Dentistry for Advancing Research Methodology and Patient Care Quality with Emphasis on Periodontal/Peri-implant Applications

BACKGROUND

Ultrasound is a non-invasive, cross-sectional imaging technique emerging in dentistry. It is an adjunct tool for diagnosing pathologies in the oral cavity that overcomes some limitations of current methodologies, including direct clinical examination, 2D radiographs, and cone beam computerized tomography. Increasing demand for soft tissue imaging has led to continuous improvements on transducer miniaturization and spatial resolution. The aims of this study are (1) to create a comprehensive overview of the current literature of ultrasonic imaging relating to dentistry, and (2) to provide a view onto investigations with immediate, intermediate, and long-term impact in periodontology and implantology.

METHODS

A rapid literature review was performed using two broad searches conducted in the PubMed database, yielding 576 and 757 citations, respectively. A rating was established within a citation software (EndNote) using a 5-star classification. The broad search with 757 citations allowed for high sensitivity whereas the subsequent rating added specificity.

RESULTS

A critical review of the clinical applications of ultrasound in dentistry was provided with a focus on applications in periodontology and implantology. The role of ultrasound as a developing dental diagnostic tool was reviewed. Specific uses such as soft and hard tissue imaging, longitudinal monitoring, as well as anatomic and physiological evaluation were discussed.

CONCLUSIONS

Future efforts should be directed towards the transition of ultrasonography from a research tool to a clinical tool. Moreover, a dedicated effort is needed to introduce ultrasonic imaging to dental education and the dental community to ultimately improve the quality of patient care.

A computational modeling method for root canal endoscopy using a specific CBCT filter: A new era in the metaverse of endodontics begins

A contemporary technological revolution has started a new era in the metaverse of Endodontics, a world of virtual operational possibilities that use an exact replica of the natural structures of the maxillofacial complex. This study describes a modeling method for root canal endoscopy using modern cone-beam CT (CBCT) software in a series of clinical cases. The method consists in acquiring thin CBCT slices (0.10mm) in the coronal, sagittal, and axial planes. A specific 3D volume filter, the pulp cavity filter of the e-Vol DX CBCT software, was used to navigate anatomical root canal microstructures, and to scan them using root canal endoscopy. The pulp cavity filter should be set to synchronize CBCT scans from 2D mode - multiplanar reformations (MPR) - to 3D mode - volumetric reconstruction. This filter, when adopting the option of volumetric reconstruction, the developed algorithm leaves the dentin density in transparent mode so that the pulp cavity may be visualized. The algorithm applied performs the suppression (visual) of areas with dentin density. This ensures 3D visualization of the slices and the microanatomy of the root canal, as well as a dynamic navigation throughout the pulp cavity. This computational modeling method adds new resources to Endodontics, which may impact the predictability of root canal treatments positively. The virtual visualization of the internal anatomy of an exact replica of the canal ensures better communications, reliability, and clinical operationalization. Root canal endoscopy using this novel CBCT filter may be used for clinical applications together with innovative digital and virtual-reality resources that will be naturally incorporated into the principles of Endodontics.

Double sleeve guided placement of quadruple zygomatic implants for rehabilitation of a patient with ectodermal dysplasia: A clinical report

The surgical and prosthodontic treatment for a 22-year-old man with ectodermal dysplasia is described and illustrated. He had never managed to wear complete dentures, and implant-retained or implant-supported prostheses were indicated. However, the placement of conventional maxillary endosseous implants was contraindicated. A novel surgical template with double sleeves was used to guide osteotomies for 4 zygomatic implants used with an unloaded, one-stage approach. After confirming osseointegration, prosthetic rehabilitation began with an interim implant-supported fixed prosthesis to evaluate esthetics, phonetics, and hygiene maintenance. Clinical challenges included lip biting and speech articulation.

Endoscope-controlled maxillary sinus floor elevation: a review of the literature

A systematic review of the literature was conducted to assess the safety and efficacy of endoscope-assisted maxillary sinus elevation. PubMed, Embase, Web of Science, and the Cochrane database were searched for articles in English. Published studies involving patients who had undergone endoscope-assisted maxillary sinus floor augmentation were selected. The validity of the included articles was evaluated. After going through full texts, a total of 12 studies met the eligibility criteria and were included. It was concluded that endoscope-controlled maxillary sinus floor elevation was a viable and beneficial method, providing direct visualisation of the integrity of the mucosa and placing of bone graft material. The endoscope could be inserted into the maxillary sinus lumen, subantral space below the Schneiderian membrane, or through the alveolar crest. With the endoscope, perforations can be detected and managed precisely. However, high-quality clinical trials are still needed to validate the predictability and advantages of this surgical procedure.

Endoscopically monitored maxillary sinus augmentation - The chairside approach (Rationale and protocol)

Sinus augmentation procedures have been reported since the time of Boyne, with variable techniques and outcomes. Sinus membrane perforations may or may not be detected at the intra-operative stage, thereby compromising the outcome. The aim of this study is to evaluate the usefulness and feasibility of an endoscope used intraorally during manipulation of the schnederian membrane. This would help confirm sinus health and integrity of the membrane during and after the augmentation.

Perforation of the Schneiderian membrane during sinus floor elevation: a risk factor for long-term success of dental implants?

PURPOSE

In cases of highly atrophic alveolar ridges, augmentation procedures became a frequent procedure to gain optimal conditions for dental implants. Especially in the maxilla sinus floor elevation procedures represent the gold standard pre-prosthetic and mainly successful procedure. The perforation of the Schneiderian is one of the most common complications. The aim of this study was to evaluate whether the intraoperative perforation of the Schneiderian membrane has an impact on long-term implant success.

METHODS

Thirty-four patients from a former study collective of the years 2005 and 2006 with a total of 41 perforations were invited for a follow-up examination to determine the long-term success rates after sinus floor elevation and subsequent implantation.

RESULTS

Twenty-one patients with 25 perforations were subsequently re-evaluated. One implant was lost due to a of periimplant infection after 232 days, resulting in an implant survival rate of 98% within a mean follow-up period of 8.9 years (± 1.5 years).

CONCLUSION

Regarding the long-term success, there was no increased risk for implant failure or other persisting complications, e.g., sinusitis, after intraoperative perforation during sinus floor elevation in this study.

The endoscopically assisted transcrestal sinus floor elevation with platelet-rich fibrin at an immediate implantation of periapical lesion site: A case report

RATIONALE

The traditional maxillary sinus floor elevation has serious postoperative complications and long healing periods, for patients with insufficient residual bone height (RBH). The endoscopic technique improves the blind nature of the sinus floor elevation procedure. Platelet-rich fibrin (PRF) can promote tissue healing and prevent perforation.

PATIENT CONCERN

A 25-year-old female with residual roots in the maxillary right second molar visited our hospital for dental implants.

DIAGNOSE

CBCT results showed a low-density shadow at the root tip, and the height of the periapical distance from the maxillary sinus floor was less than 1 mm.

INTERVENTION

Patient was immediately subjected to implant after root extraction. Two-step sinus floor elevation was performed under endoscopy. A 12 mm-long implant was installed.

OUTCOMES

At 10 months after surgery, the hard and soft tissues were stable, and a full-ceramic crown was placed.

LESSONS

Immediate implant and endoscope-guided sinus floor elevation through a transcrestal approach by using PRF as the only grafting material is viable in periapical infected sites with a RBH of less than 1 mm.

Minimally invasive endoscopic maxillary sinus lifting and immediate implant placement: A case report

BACKGROUND

This case report discusses a modified approach for maxillary sinus augmentation, in which platelet-rich fibrin, endoscope, simultaneous implant placement, and sinus floor elevation (PESS) were applied for a maxillary sinus floor lift in a 40-year-old patient.

CASE SUMMARY

A 40-year-old woman suffered missing upper right first molar. Implant stability quotient and cone-beam computed tomography (CBCT) were used to evaluate the diagnosis. CBCT showed insufficient posterior maxillary bone with a mean residual alveolar bone height of only 3.5 mm. The patient underwent a minimally invasive sinus floor elevation endoscopically. The sinus membrane was elevated in two stages, and a 12-mm implant was placed immediately. At 3 mo postoperatively, the final impressions were accomplished, and a full-ceramic crown was fit-placed. A 6-mo follow-up demonstrated satisfactory aesthetic and functional results.

CONCLUSION

This is the first report to use an endoscope for maxillary sinus floor lifting in cases with severe and insufficient bone height. This case report demonstrates the advantages of the PESS technique, which include minimal invasiveness with high precision, being applicable in cases with a residual alveolar bone height < 4 mm with a promising result, and a shortened treatment period from 12 to 3 mo.

Histological and clinical outcomes of lateral sinus floor elevation with simultaneous removal of a maxillary sinus pseudocyst

BACKGROUND

Maxillary sinus pathologies are a potential risk for failure of implant and bone augmentation. Management of lateral sinus floor elevation in the presence of a pseudocyst remains controversial, and reports on histological outcomes of endo-sinus bone augmentation with maxillary cysts are scarce.

PURPOSE

To present a modified surgical technique for removal of maxillary pseudocyst with simultaneous sinus floor elevation, and to evaluate clinical and histological outcomes of the bone grafting.

MATERIALS AND METHODS

Patients with a radiographic dome-shaped opacity in the posterior maxillary sinus were included to receive lateral sinus floor elevation with simultaneous pseudocyst removal. Bone core specimens harvested from the lateral aspect of the augmentation sites were histomorphometrically analyzed. Data were recorded and evaluated in terms of survival rates and complications.

RESULTS

A total of 15 patients were included who underwent 17 maxillary sinus augmentation surgeries. Implant survival rate was 97.0%. Bone biopsy specimens were obtained at 6 months after surgery. Histomorphometric analysis revealed that mean percentages of mineralized bone, bone substitute, and nonmineralized tissue were 24.9% ± 18.1%, 14.4% ± 12.5%, and 60.1% ± 12.44%, respectively. No recurrence of the pseudocyst was detected on radiographic examination.

CONCLUSIONS

The described technique could be successfully applied in clinical practice to perform sinus augmentation in the presence of pseudocysts.

Endoscopically controlled flapless transcrestal sinus floor elevation with platelet-rich fibrin followed by simultaneous dental implant placement: A case report and literature review

RATIONALE

In this case study, a modified transcrestal approach was applied to the patient of extremely atrophic posterior maxilla. We analysis the Implant Stability Quotient values (ISQ) to monitor implant stability, and the cone-beam computer tomography (CBCT) to evaluate the bone regeneration.

PATIENT CONCERN

A 26-year-old female patient visited our hospital with no contraindications for dental implants and a loss of the maxillary right first molar.

DIAGNOSE

Examination by CBCT demonstrated the posterior maxilla was extremely atrophic, the residual bone height (RBH) of #16 was 3.5 mm.

INTERVENTION

Patient underwent a endoscopically controlled flapless sinus floor elevation. The maxillary sinus membrane was elevated by two-step, and an implant of 12 mm length was placed simultaneously.

OUTCOMES

Twelve weeks post-surgery, the implant-level impression was finished and a full-ceramic crown was placed thereafter.

LESSONS

The modified transcrestal approach can be applied to augment maxillary sinus with a residual bone height less than 4 mm.

Impact of surgical management in cases of intraoperative membrane perforation during a sinus lift procedure: a follow-up on bone graft stability and implant success

Background

Until now, sinus floor elevation represents the gold standard procedure in the atrophic maxilla in order to facilitate dental implant insertion. Although the procedure remains highly predictive, the perforation of the Schneiderian membrane might compromise the stability of the augmented bone and implant success due to chronic sinus infection. The aim of this retrospective cohort study was to show that a membrane tear, if detected and surgically properly addressed, has no influence on the survival of dental implants and bone resorption in the augmented area.

Methods

Thirty-one patients with 39 perforations could be included in this evaluation, and a control group of 32 patients with 40 sinus lift procedures without complications were compared regarding the radiographically determined development of bone level, peri-implant infection, and implant loss.

Results

Implant survival was 98.9% in the perforation group over an observation period of 2.7 (± 2.03) years compared to 100% in the control group after 1.8 (± 1.57) years. The residual bone level was significantly lower in the perforation group (p = 0.05) but showed no difference direct postoperatively (p = 0.7851) or in the follow-up assessment (p = 0.2338). Bone resorption remained not different between both groups (p = 0.945). A two-stage procedure was more frequent in the perforation group (p = 0.0003) as well as peri-implantitis (p = 0.0004).

Conclusions

Within the limits of our study, the perforation of the Schneiderian membrane did not have a negative impact on long-term graft stability or the overall implant survival.

A prospective controlled trial comparing xenograft/autogenous bone and collagen-stabilized xenograft for maxillary sinus augmentation-Complications, patient-reported outcomes and volumetric analysis

OBJECTIVE

Compare maxillary sinus augmentation (MSA) using two different materials-anorganic bovine bone mineral (ABBM) + autogenous bone (AB) (control group) vs. collagen-stabilized ABBM (test group) in terms of complications, patient-reported outcome measures (PROMs) and volumetric analysis.

MATERIALS AND METHODS

Sixty patients underwent sinus augmentation (30 control + 30 test group). Intra- and postoperative complications were recorded. PROMs measured the impact of grafting on daily activities, pain and morbidity. CT scans were used to measure graft volume, ridge height, material selection and degree of contact of graft-to-surrounding sinus walls. Dental implant placement parameters were also recorded.

RESULTS

All complications were minor and did not prevent completion of the augmentation or subsequent implant placement. Schneiderian membrane perforation was the most frequently encountered complication. Both treatment groups reported moderate limitation in the 1st 48 hr post-surgery but little or none by day 3 or 4. Jaw opening, chewing and bruising were significantly higher in the control group. The impact on work and social life was moderate initially but reduced to little or none by the 2nd day. Mild to moderate pain and interference to daily activities were reported for the first 3 days requiring the use of NSAIDs only. A mean graft volume of 1.46 cm³ (±0.77) was calculated in the control group and 1.27 cm³ (±0.65) in the test group. Extent of contact between graft and surrounding sinus walls had a significant impact on bone volume. Shorter (8 mm) implants were utilized more frequently in the test group, which was also more likely to require additional vertical augmentation, but this was not statistically significant.

CONCLUSION

MSA using a lateral wall approach is safe and associated with mild to moderate pain and restrictions to daily activities for 48-72 hr. Patients' reports of morbidity were greater with autogenous bone harvesting. Collagen-stabilized ABBM provides comparable bone volume to AB + ABBM that is sufficient for placement of implants of adequate size with no need for further vertical augmentation. Engaging the surrounding sinus walls had a significant positive impact on graft volume.

Autogenous bone grafts in oral implantology-is it still a "gold standard"? A consecutive review of 279 patients with 456 clinical procedures

Background

This study assessed the clinical outcomes of graft success rate and early implant survival rate after preprosthetic alveolar ridge reconstruction with autologous bone grafts.

Methods

A consecutive retrospective study was conducted on all patients who were treated at the military outpatient clinic of the Department of Oral and Plastic Maxillofacial Surgery at the military hospital in Ulm (Germany) in the years of 2009 until 2011 with autologous bone transplantation prior to secondary implant insertion. Intraoral donor sites (crista zygomatico-alveolaris, ramus mandible, symphysis mandible, and anterior sinus wall) and extraoral donor site (iliac crest) were used. A total of 279 patients underwent after a healing period of 3–5 months routinely computer tomography scans followed by virtual implant planning. The implants were inserted using guided oral implantation as described by Naziri et al. All records of all the consecutive patients were reviewed according to patient age, history of periodontitis, smoking status, jaw area and dental situation, augmentation method, intra- and postoperative surgical complications, and surgeon’s qualifications. Evaluated was the augmentation surgical outcome regarding bone graft loss and early implant loss postoperatively at the time of prosthodontic restauration as well a follow-up period of 2 years after loading.

Results

A total of 279 patients underwent 456 autologous augmentation procedures in 546 edentulous areas. One hundred thirteen crista zygomatico-alveolaris grafts, 104 ramus mandible grafts, 11 symphysis grafts, 116 grafts from the anterior superior iliac crest, and 112 sinus lift augmentations with bone scrapes from the anterior facial wall had been performed. There was no drop out or loss of follow-up of any case that had been treated in our clinical center in this 3-year period. Four hundred thirty-six (95.6%) of the bone grafts healed successfully, and 20 grafts (4.4%) in 20 patients had been lost. Fourteen out of 20 patients with total graft failure were secondarily re-augmented, and six patients wished no further harvesting procedure. In the six patients, a partial graft resorption was detected at the time of implantation and additional simultaneous augmentation during implant insertion was necessary. No long-term nerve injury occurred. Five hundred twenty-five out of 546 initially planned implants in 259 patients could be inserted into successfully augmented areas, whereas 21 implants in 20 patients due to graft loss could not be inserted. A final rehabilitation as preplanned with dental implants was possible in 273 of the 279 patients. The early implant failure rate was 0.38% concerning two out of the 525 inserted implants which had to be removed before the prosthodontic restoration. Two implants after iliac crest augmentation were lost within a period of 2 years after loading, concerning a total implant survival rate after 2 years of occlusal loading rate of 99.6% after autologous bone augmentation prior to implant insertion.

Conclusions

This review demonstrates the predictability of autologous bone material in alveolar ridge reconstructions prior to implant insertion, independent from donor and recipient site including even autologous bone chips for sinus elevation. Due to the low harvesting morbidity of autologous bone grafts, the clinical results of our study indicate that autologous bone grafts still remain the “gold standard” in alveolar ridge augmentation prior to oral implantation.

Effect of Schneiderian membrane perforation on sinus lift graft outcome using two different donor sites: a retrospective study of 105 maxillary sinus elevation procedures

Background: Sinuslift is meanwhile an established method of bone augmentation in the posterior maxilla. Aim of the study was to evaluate the significance of intraoperative Schneiderian membrane perforations during maxillary sinus floor elevation surgery using autogenous bone harvested from two different donor sites using a Safescraper device on the success rate, graft survival and implant integration.

Methods: The investigators conducted a retrospective cohort study at the Department of Oral and Maxillofacial Surgery of Military Hospital Ulm composed of patients with severe maxillary atrophy who underwent sinus augmentation from January 2011 until December 2011. Ninety-nine consecutive patients (89 men, 10 women) with a mean age of 43.1 years underwent sinus graft procedures in a 2-stage procedure using the lateral wall approach, as described by Tatum (1986). Data on patient age, smoking status, donor site and surgical complications were recorded and the relationship between Schneiderian membrane perforation and complication rate was evaluated. Dental implants were inserted 4 months after grafting.

Results: A total of 105 sinus lift procedures were performed in 99 patients. Sixty-one patients (61.6%) underwent sinus elevation with autogenous bone from the buccal sinus wall, while 38 patients (38.4%) bone harvesting from the iliac crest. Intraoperative perforation of the Schneiderian membrane was observed in 11 of the 105 sinuses (10.4%). These perforations resulted in 4 (36.3%) of the cases in major postoperative complications accompanied by swelling and wound infection. Membrane perforations were slightly associated with the appearance of postoperative complications (p=0.0762). In 2.4% of all cases, regarding 2 patients the final rehabilitation with dental implants was not possible because of extensive bone resorption.

Conclusion: Intraoperative complications performing sinus augmentation may lead to postoperative complications. With careful clinical and radiographic evaluation and appropriate treatment, the complications and risk for graft material displacement and implant loss can be eliminated.

A histomorphometric assessment of collagen-stabilized anorganic bovine bone mineral in maxillary sinus augmentation - a prospective clinical trial

OBJECTIVE

To histomorphometrically compare the use of collagen-stabilized anorganic bovine bone (ABBM-C) (test) to anorganic bovine bone + autogenous bone (ABBM + AB) (control) in maxillary sinus augmentation.

MATERIALS AND METHODS

Forty (n = 40 sinuses) patients underwent sinus augmentation and received either control (20 sinuses) or test bone graft (20 sinuses). Bone samples were harvested from the augmented sinuses 5 months postgrafting. The samples were processed for histomorphometry, which assessed within the primary region of interest (ROI-1), the area fraction of new bone (%NB), graft particle osseointegration (% OI), residual graft (%RG), and soft tissue components (% STM). The same analysis was also carried out in a second region of interest (ROI-2) located in a zone 1 mm proximal to the previous maxillary sinus floor.

RESULTS

In both ROI-1 and ROI-2, the mean % NB, %RG, and %STM in the control group were similar to mean values in the test group. The % OI was significantly greater in the control group (42.0 +/- 26.8) when compared to the test group (19.6 +/- 27.3) in ROI-2 (P < 0.05). No statistically significant differences were seen when ROI-1 and ROI-2 were compared except for improved %OI in ROI-2 in the control group. The mean proportion of lamellar bone to woven bone in the control group (1.22 ± 1.48) was significantly greater than the test group (0.38 ± 0.29) (P < 0.05).

CONCLUSION

ABBM-C exhibited very similar histomorphometric parameters to the composite graft of ABBM + AB. The ABBM + AB group was more mature as indicated by the significantly greater proportion of lamellar bone when compared to the ABBM-C. Improved % OI was seen in the zone proximal to the resident bony floor in the ABBM + AB group. Based on histological assessment, ABBM-C is a suitable bone substitute for the purposes of maxillary sinus augmentation. Its clinical utility may be indicated in cases of sinus membrane perforation and insufficient autogenous bone in the local area.

Endoscopic lift of the maxillary sinus floor in Beagles

The aim of this study was to introduce a modified endoscopic lift of the floor of the maxillary sinus in Beagles. Twelve operations (bilateral and randomly chosen) were done in 6 Beagles each in the test group (modified endoscopic operation), and the control group, in which the operation was done with an osteotome. All operations were evaluated by two indices of safety (perforation of the sinus membrane and nasal bleeding) and 3 effective indices (the intraoperative height after lifting, volume of bone grafts, and dislocation of the sinus grafts). The sinus membrane was not perforated and there were no nasal bleeds in either group. The intraoperative height after lifting was 13.7 (0.8) mm in the test group and 9.1 (0.5) mm in the control group, so it was significantly higher in the test group than the control group (p=0.0001). Similarly, the volume of bone graft was 0.9 (0.04) ml in the test group and 0.5 (0.02) ml in the control group (p=0.0001). The volume of the anterior and posterior bone grafts in the implant cavity in the test group did not differ significantly (p=0.102), while there were significant differences in the control group (p=0.002). Endoscopic lifting of the floor of the maxillary sinus is a safe and effective approach based on direct observation in Beagles.

Direct vs. indirect sinus lift procedure: A comparison

BACKGROUND

There are different techniques for the sinus augmentation; the factors that contribute to the survival rate of sinus augmentation and dental implant placement are still the subject of discussion. So we compare the two different ways of sinus floor elevation: a) Lateral antrostomy as a one or two step procedure as direct method. b) Osteotome technique with a crestal approach as indirect method.

MATERIALS AND METHODS

A total of twenty partially edentulous patients in maxillary posterior region who opted for implant retained prosthesis but had a low sinus and deficient alveolar ridge within the age group of 20-55 years were taken up, 25 implants were placed in combination with bone grafting material for sinus augmentation. The final bone height was measured from Orthopantomogram. Post-operative Clinical Evaluation was based on pain, gingival inflammation status, stability, swelling and bone height. Statistical analysis was done by using Statistical Package for Social Sciences (version 15.0) (SPSS Inc., Chicago, IL, USA).

RESULTS

The gain in bone height was significantly greater in direct procedure through lateral antrostomy (mean 8.5 mm) than in indirect method through crestal approach by osteotome technique (mean 4.4 mm).

CONCLUSIONS

Osteotome technique can be recommended when more than 6 mm of residual bone height is present and an increase of 3-4 mm is expected. In case of more advanced resorption direct method through lateral antrostomy has to be performed. Both sinus elevation techniques did not seem to affect the implant success rate.

The Incidence of Maxillary Sinus Membrane Perforation During Endoscopically Assessed Crestal Sinus Floor Elevation: A Pilot Study

Transcrestal sinus membrane elevation is a surgical procedure performed to increase the bone volume in the maxillary sinus cavity. Because of visual limitations, the potential for maxillary sinus membrane perforations may be greater than with the lateral approach technique. The aim of this study was to macroscopically investigate ex vivo the occurrence of sinus membrane perforation during surgery using 3 transcrestal sinus floor elevation methods. Twenty fresh human cadaver heads, with 40 intact sinuses, were used for simultaneous sinus membrane elevation, placement of graft material, and dental implants. Real-time sinus endoscopy, periapical digital radiographs, and cone-beam computerized tomography (CBCT) images were subsequently used to evaluate the outcome of each surgical procedure. Perforation rates for each of the 3 techniques were then compared using a significance level of P &lt; .05. No statistically significant differences in the perforation rate (P = .79) were found among the 3 surgical techniques. Although the sinus endoscope noted a higher frequency of perforations at the time of implant placement as compared with instrumentation or graft insertion, the difference was not statistically significant (P = .04). The CBCT readings were judged to be more accurate for identifying evidence of sinus perforations than the periapical radiographs when compared with the direct visualization with the endoscope. This pilot study demonstrated that a sinus membrane perforation can occur at any time during the sinus lift procedure, independent of the surgical method used.

Sinus augmentation surgery after endoscopic sinus surgery for the treatment of chronic maxillary sinusitis: a case report

Chronic sinusitis develops when the ostiomeatal complex becomes stenosed by the swelling of the sinus mucosa. Previously, the Caldwell-Luc method was performed for the treatment of chronic sinusitis. But postoperative complications, such as discomfort of the buccal skin and recurrence of sinusitis, frequently occurred after the operation. Today, endoscopic sinus surgery (ESS) has become widely used for the treatment of chronic sinusitis. The features of ESS allow for the restoration of the physical function of the sinus membrane and preservation of the physiological environment of the sinus. Therefore, sinus augmentation surgery can be safely performed at an insufficient alveolar bone height below the maxillary sinus when sinusitis is eliminated by the ESS. This article documents a patient history involving chronic sinusitis that was treated by the ESS therapy before sinus augmentation surgery as a pretreatment for insertion of dental implants.

Effect of maxillary sinus floor augmentation on sinus membrane thickness in computed tomography

BACKGROUND

Little is known about maxillary sinus compliance, i.e., the intrinsic potential of the sinus membrane to resume its homeostatic status after the surgical trauma caused by sinus floor elevation. The aim of the present study is to investigate the effect of maxillary sinus floor augmentation on sinus membrane thickness.

METHODS

Within-patient comparison of computed tomographic scans before bone grafting versus 4 to 6 months after bone grafting was performed. Changes in membrane thickness were evaluated in 65 maxillary sinus floor augmentation procedures via a lateral approach in 35 patients without clinical signs of sinus pathology at any time.

RESULTS

Sinus membrane thickness differed significantly before (0.8 ± 1.2 mm) versus after (1.5 ± 1.3 mm) augmentation surgery (P <0.001), with a mean increase of 0.8 ± 1.6 mm (maximum: 4.4 mm). Only 28% of augmented sinuses did not show membrane thickening. In non-augmented control sinuses, there was no evidence of membrane thickness increase.

CONCLUSIONS

The results indicate that the maxillary sinus membrane, even in healthy clinical conditions, undergoes morphologic modifications after sinus floor elevation, yet membrane reactions demonstrate significant variability. Future research on the effect of augmentation surgery on maxillary sinus physiology is recommended.

Endoscopic approach to dental implantology

OBJECTIVE

To describe an innovative miniature visualization surgical endoscope and endoscopic techniques applicable to dental implant procedures.

MATERIALS AND METHODS

A newly developed modular dental implant endoscope is introduced, and the first impressions from its use in different implant procedures are reported.

RESULTS

Details of the device that combines an endoscope, irrigation cannulas, and a surgical microinstrument channel are presented. The advantages of using it in dental implant procedures are described, and examples of how miniature visualization and surgical endoscopic techniques can be applied to increase the success of implantation are outlined. The new modular implant endoscope accurately identified all microanatomical and pathological structures, and simplified dental implant procedures.

CONCLUSION

Endoscopy should be considered not only for intraoperative observation and assessment of implant sites, but also should be applied for active assistance during implant placement procedures.

Indirect sinus floor elevation for osseointegrated prostheses. A 10-year prospective study

The aim of this study was to evaluate the indirect/closed maxillary floor elevation technique for the insertion of osseointegrated implants to support fixed prostheses clinically. Thirty-one patients (19 female, 12 male) with a mean age of 62 +/- 9 years were selected for this study. All patients needed implants in the posterior maxillary region to support osseointegrated prosthesis. Forty-seven implants were inserted using the indirect/closed sinus floor elevation method, and another 31 implants were placed in the same individuals as intra-individual control. No augmentation material was used along with implantation. The mean bone height before sinus lift was 9.78 +/- 1.68 mm (minimum 5.6 mm), and for controls it was 15.62 +/- 3.44 mm. The average length of the implants used was 12.00 +/- 1.70 mm, whereas for controls it was 13.39 +/- 1.60 mm. The patients were recalled for periodic checkups every 6 months, and the radiographic controls were made every 12 months. One control fixture failed after uncovering; 77 implants were loaded, and 5 of them failed (2 controls and 3 of the sinus lift group) between 3 and 59 months following loading. One hundred nineteen months after surgery (112 months following loading), the censored survival rate (Kaplan-Meier) was 93.6% for sinus lift implants and 90.3% for controls. The crestal bone level changes were not significant either before loading or after loading for both sinus lift and control implants. None of the remaining implants showed any signs of mobility or peri-implant disease, and none of the patients exhibited sinus problems during the entire observation period.

Sinus floor elevation from a maxillary molar tooth extraction socket in a patient with chronic inflammation

BACKGROUND

The compromised nature of the residual interradicular bone after extraction of periodontally hopeless maxillary molars often requires a sinus elevation procedure to ideally place the implants to accept future prosthesis. Maxillary sinus elevation surgery is a procedure used to increase the volume of bone mass so that dental implants can be placed. This article documents a sinus floor elevation technique through an extraction socket in a 65-year-old white male with chronic inflammation to increase the bone mass after the extraction of a periodontally involved maxillary molar tooth.

METHODS

Computerized tomography revealed an increased thickness of the sinus membrane, which was attributed to possible chronic sinus inflammation and periodontal inflammation. After consultation with the Department of Otolaryngology, it was diagnosed as chronic inflammation without any contraindication for sinus elevation surgery or implant placement. One month after the extraction, the sinus floor elevation surgery was performed through the extraction socket, and implants were placed 4 months later.

RESULTS

An uneventful healing was noted after 6 months of osseointegration; two porcelain-fused-to-metal crowns were fabricated. Clinical follow-up took place every 3 months for 3 years, and successful healing was achieved. The patient was satisfied with the esthetic and functional results of the oral rehabilitation.

CONCLUSION

Sinus floor elevation through an extraction socket without any residual bone, followed by dental implant placement, provided successful functional results and acceptable stability.

A combination of three minimally invasive surgical procedures for implant placement in the posterior maxilla with insufficient bone quantity

We describe a combination of 3 surgical procedures for implant placement in the posterior maxilla with insufficient bone quantity and quality. In these situations, we have performed 3 minimally invasive, safe, and reliable surgical procedures: buccal bone graft with bone harvested from the mandibular molar region, submucous vestibuloplasty using artificial dermis, and bone-added osteotome sinus floor elevation under endoscopic control. These modified procedures can be performed in the office setting under outpatient local anesthesia and may minimize patient discomfort and reduce postoperative complications.

The Effectiveness of Subgingival Scaling and Root Planing: An Evaluation of Therapy With and Without the Use of the Periodontal Endoscope

BACKGROUND

A fiber-optic periodontal endoscope was developed to aid in the visualization of subgingival structures and to improve the diagnosis and management of periodontal diseases. The purpose of this study was to determine whether use of the periodontal endoscope with scaling and root planing (SRP) resulted in a decrease in residual calculus compared to SRP alone.

METHODS

Fifteen subjects with 50 tooth pairs participated in this study. Each tooth per pair was randomized to receive SRP with or without the endoscope. Teeth were extracted, and a stereomicroscope and digital image analysis was used to determine percent residual calculus present in a masked fashion.

RESULTS

There was 2.14% (P < 0.001) more residual calculus at control versus test sites. At buccal/lingual and interproximal surfaces, mean differences in residual calculus were 1.30% (P <0.015) and 2.93% (P < 0.001), respectively. Test treatment time decreased significantly as operator experience increased. There were no statistically significant differences between residual calculus for test and control teeth at shallower probing depths; however, at deeper probing depths, the use of the endoscope resulted in significantly less residual calculus.

CONCLUSIONS

The use of the periodontal endoscope resulted in a statistically significant overall improvement in calculus removal during SRP, which was most evident in deeper probing depths. The clinical significance of this level of improvement is unknown.

Maxillary sinus augmentation in the presence of antral pseudocyst: a clinical approach

OBJECTIVE

The objective of this study is to present patients with sinus augmentation in the presence of an antral pseudocyst and the surgical procedure, complications, and outcome.

STUDY DESIGN

From 2002 to 2005, 109 patients were scheduled for 1- or 2-stage maxillary sinus floor augmentation (n = 129) because of inadequate alveolar bone height for implant placement. Radiographically, a significant antral pseudocyst was shown.

RESULTS

In 8 (7.3%) patients, an antral pseudocyst was diagnosed, and in 2 a history of inactive sinusitis was found preoperatively. A faint dome-shaped radiopacity was found at the lower border of the maxillary sinus. Average lesion size was 5.09 cm2. All implants functioned well at follow-up (mean 20 months).

CONCLUSION

A pseudocyst of the maxillary sinus is not a contraindication for sinus augmentation. The low frequency of sinus membrane perforation and postsurgery sinusitis make the operation safe. In large lesions and in cases with an unclear diagnosis, further evaluation is needed before sinus augmentation.

Onlay augmentation versus sinuslift procedure in the treatment of the severely resorbed maxilla: a 5-year comparative longitudinal study

Augmentation procedures in the severely resorbed maxilla are standard techniques in preprosthetic surgery. Aim of the present study was to compare onlay bone grafting and sinus floor elevation with autogenous bone grafts in edentulous patients in terms of bone resorption of the posterior alveolar crest and implant survival in a 5-year longitudinal study. A total of 100 patients (53 female and 47 male patients) requiring augmentation using autogenous bone due to a severely resorbed maxillae were evaluated. The degree of resorption and bone quality were preoperatively estimated in panoramic radiographs according to Lekholm and Zarb. The overall 5-year success rate of implants placed after augmentation procedures in the posterior maxilla was 93.1%. Following onlay augmentations 215 out of 235 implant insertions were successful, i.e. a success rate of 91.5% was achieved. In the sinuslift group, 330 out 349 implants remained successful, i.e. a success rate of 94.6% was found. The difference between both groups was statistically significant at the end of the evaluation period. Bone resorption, measured as loss of total bone height in panoramic radiographs, was initially more pronounced following onlay augmentations (>20% after 12 months of observation). The degree of resorption decreased in the further course of the study. Lower resorption rates and a higher overall success rate were demonstrated for the sinus lift group.

Prevalence of maxillary sinus disease and abnormalities in patients scheduled for sinus lift procedures

BACKGROUND

The purpose of the present study was to determine the prevalence of sinus disease and abnormalities among patients scheduled to undergo direct sinus augmentation.

METHODS

Forty-five patients attending a private periodontal practice and consecutively treatment planned for sinus augmentation were referred for otorhinolaryngologic evaluation, which included a medical history and radiographic (computed tomography), clinical, and endoscopic examinations. Pathological findings were recorded and otorhinolaryngologic treatment was provided. Six months later the sinus augmentation procedure was performed and followed by postoperative evaluations for 4 to 6 months.

RESULTS

Of the 45 subjects, 98% (44) were diagnosed with chronic periodontitis, 51% were smokers, and 27% reported a history of symptoms indicative of sinus disease. Eighteen subjects were diagnosed with sinus disease and/or abnormalities. The diagnosed conditions included chronic sinusitis, sinus cysts, nasal septum deviation, and ostium stenosis. No significant differences in age, gender, or smoking status between patients with and without sinus conditions were found (P >0.05). There was a significant association between history of symptoms and diagnosis of sinus conditions (P <0.0001). Three subjects (one treated for preoperative sinus conditions) experienced notable intra- or postoperative complications related to the sinus augmentation procedure.

CONCLUSIONS

The results indicate that, in a population of patients with chronic periodontitis, presence of sinus conditions is strongly associated with a history of indicative symptoms and is independent of age, gender, and smoking status. The results reinforce the importance of careful detailed history taking and thorough clinical and radiographic evaluation prior to performing sinus augmentation.

Endoscopic removal of an implant from the maxillary sinus: a case report

Slippage of an implant into the maxillary sinus is an exceptional complication that may occur during immediate implant placement. In this study, removal of a displaced implant into the maxillary sinus with the aid of endoscopy via buccal window approach is reported. Management of such a rare complication is also addressed.

Growth and proliferation of human osteoblasts on different bone graft substitutes: an in vitro study

The purpose of this study was to investigate the effect of different bone graft substitutes onto the growth and proliferation pattern of bone cells derived from human iliac cancellous bone. Five different bone graft materials were used to investigate the effect on the proliferation of osteoblasts in vitro: phytogene hydroxyapatite (Algipore), alpha-Tricalcium phosphate (Bio-Base), bovine hydroxyapatite (low temperature) (Bio-Oss), bovine hydroxyapatite (high temperature) (Osteograf), and bovine hydroxyapatite (high temperature) enhanced with p-15, synthetic peptide (PepGen p-15). The osteoblasts were derived from human iliac cancellous bone and seeded with the different bone substitutes. The cell proliferation and viability (WST-1), alkaline phosphatase as an early marker of osteoblast proliferation, was evaluated after 6 and 9 days. The cultures were examined for cell growth pattern and morphology by normal light and scanning electron microscopy. The human osteoblasts showed a different proliferation pattern according to the type of applied bone graft substitute. PepGen P-15 showed the highest proliferation and differentiation rate followed by Osteograf, Algipore, and Bio-base. Bio-Oss showed the lowest. These results were confirmed by electron microscopy and light microscopy evaluation in which similar growth pattern were observed. Distinct bone graft materials have different impact onto the proliferation pattern of human osteoblasts in vitro.

A clinical long-term radiographic evaluation of graft height changes after maxillary sinus floor augmentation with a 2 : 1 autogenous bone/xenograft mixture and simultaneous placement of dental implants

The aim of the present study was to assess long-term changes in sinus-graft height after maxillary sinus floor augmentation and simultaneous placement of implants. A total of 191 patients who underwent maxillary sinus floor augmentation were radiographically followed for up to about 10 years. A 2 : 1 mixture of autogenous bone and bovine xenograft (Bio-Oss) was used as the graft material. Sinus-graft height was measured using 294 panoramic images immediately after augmentation and up to 108 months subsequently. Changes in sinus-graft height were calculated with respect to implant length and original sinus height. Patients were divided into three groups based on the height of the grafted sinus floor relative to the implant apex: Group I, in which the grafted sinus floor was above the implant apex; Group II, in which the implant apex was level with the grafted sinus floor; and Group III, in which the grafted sinus floor was below the implant apex. After augmentation, the grafted sinus floor was consistently located above the implant apex. After 2-3 years, the grafted sinus floor was level with or slightly below the implant apex. This relationship was maintained over the long term. Sinus-graft height decreased significantly and approached original sinus height. The proportion of patients classified as belonging to Group III reached a maximum from year 3 onwards. The clinical survival rate of implants was 94.2%. All implant losses occurred within 3 years after augmentation. We conclude that progressive sinus pneumatization occurs after augmentation with a 2 : 1 autogenous bone/xenograft mixture, and long-term stability of sinus-graft height represents an important factor for implant success.

Effects of platelet-rich plasma on bone healing in combination with autogenous bone and bone substitutes in critical-size defects

OBJECTIVES

An animal study was carried out to investigate the influence of platelet-rich plasma (PRP) on the regeneration of bony defects.

MATERIAL AND METHODS

Critical-size defects in the forehead region of a mini-pig were filled with randomly distributed combinations of autogenous bone, tricalcium-phosphate granules (CeraSorb), bovine spongious blocks (BioOss) and a bovine bone inducing collagenous sponge (Colloss) with and without PRP in two preparations (Cusasan, 3i). The animals were killed after 2, 4 and 12 weeks. The specimens were evaluated microradiographically and immunohistologically.

RESULTS

Autologous bone (38 +/- 9.9%) and Colloss (52.6 +/- 4.0%) showed the highest remineralization rates at 2 weeks. The initial high expression of BMP-2 in the Colloss-group gives evidence of an early initiation of bony regeneration. At 2 weeks PRP ad modum 3i was able to enhance bone healing significantly (P=0.028) only when applied in combination with autogenous bone (62.8 +/- 1.6%). Four weeks after surgery, both PRP preparations did no longer increase bony regeneration in the autogenous groups. The osteoconductive effect of Bio-Oss (38.7 +/- 5.5%) and CeraSorb (41+/-4.9%) was remarkable as well 4 weeks after surgery. Nevertheless, the addition of PRP hardly influenced bony regeneration, ceramic degradation or cytokine expression when bone substitutes were applied. At 12 weeks, the level of reossification had adjusted similarly in all groups.

CONCLUSION

PRP did not add additional benefit when xenogenic bone substitutes were used. However, a significant effect on bone regeneration was found in the autogenous group initially when PRP is added.

Endoscopic evaluation of the bone-added osteotome sinus floor elevation procedure

Sinus floor augmentation using the bone-added osteotome technique (BAOSFE) has been advocated as a predictable procedure when initial residual bone height is 4-6mm. In this report, 16 Osseotite implants were placed using the BAOSFE procedure in eight patients under endoscopic control. Intraoperative graft positioning, potential displacement of the graft material, Schneiderian membrane integrity and distension pattern were evaluated. A small-sized perforation of the sinus membrane was visualized during sinuscopic monitoring in two implant sites without significant loss of graft material confinement. Membrane vertical distension was restricted to the area surrounding the implant apices in four implant sites while a larger detachment of the membrane enfolding the implant tips, the in-between and circumferantial areas was observed in the remaining 12 sites. The two perforated sites demonstrated a localized vertical pattern of membrane distension limited to implant apices. None of the cases complicated by perforation showed clinical signs of ongoing sinus pathology throughout the follow-up period. This limited report suggests that: (1) the BAOSFE procedure in combination with implant placement yields various patterns of sinus membrane elevation; (2) potential membrane perforation may be expected when distension follows a localized vertical augmentation pattern; and (3) small membrane perforations during the BAOSFE procedure are compatible with clinically healthy postoperative sinus conditions.

Maxillary sinus floor elevation surgery. A clinical, radiographic and endoscopic evaluation

Although augmentation of the maxillary sinus floor with autogenous bone grafts has become a well established preimplantology procedure, its effect on the function of the maxillary sinus has not been the subject of prospective human studies. In this prospective study the effects of sinus floor augmentation on maxillary sinus performance were evaluated. Seventeen consecutive patients who were to undergo augmentation of the maxillary sinus floor with an iliac crest autogenous bone graft agreed to participate in this study. All patients were subject to (i) extensive anamnestic and clinical investigation on sinusitis, (ii) conventional radiography (Waters' projection) and (iii) unilateral endoscopic inspection of the maxillary sinus. This triad of evaluations was performed preoperatively, immediately preceding the augmentation procedure (the maxillary sinus to be inspected endoscopically was randomly selected), and at 3 (at insertion of the implants) and 9 months (at uncovering of implants) postaugmentation. None of the 17 patients showed clinical or radiological signs of actual sinus pathology preoperatively, though 5 patients had a history of an impeded sinus clearance. By contrast, unilateral endoscopic evaluation revealed pre-existing subclinical mucosal pathology in two out of five patients with a history of sinus clearance impairment and in one out of the other 12 patients. At 3 months' postaugmentation, clinical and radiographical examination showed chronic maxillary sinusitis in one non-compromised patient. Moreover, serial unilateral endoscopic evaluation revealed subclinical maxillary mucosal pathology in four other patients (two of whom had a history of an impeded sinus clearance), confirmed by Waters' projection in three of these four patients. At 9 months' postaugmentation, only subclinical maxillary mucosal pathology was detected endoscopically in two patients (one compromised, one non-compromised patient), confirmed by Waters' projection in this last patient. Five implants were lost during the 9-month observation period. As is obvious from this prospective evaluation, the effects of the augmentation procedure on maxillary sinus performance in patients without signs of maxillary sinusitis are of no clinical significance.

Sinus floor augmentation with beta-tricalciumphosphate (beta-TCP): does platelet-rich plasma promote its osseous integration and degradation?

When dental implants are to be inserted, sinus floor augmentation is an effective treatment procedure to improve bone height in the posterior maxilla. In addition to autogenous bone material, allogenic materials, e.g. beta-tricalciumphosphate (beta-TCP), have been used successfully. The purpose of this study was to investigate whether the combination of beta-TCP with platelet-rich plasma (PRP) enhances bony regeneration and resorption of the tricalciumphosphate material. In a randomized prospective trial, 45 sinus floor elevations were performed in 39 patients. In 22 sites, PRP was added to the beta-TCP granules, while in 23 sites beta-TCP without PRP was used. Six months later, bone specimens were harvested from the augmented region during the implant insertion procedure. The formation of new bone was about 8-10% higher when PRP was applied. A faster degradation of the ceramic bone substitute was not observed. In conclusion, when PRP was added to beta-TCP, bone regeneration was supported to a small extent. However, the resorption of beta-TCP was not accelerated and foreign-body giant cells and soft tissue surrounding the beta-TCP granules were present.

Endoscopically assisted Le Fort I osteotomy to correct transverse and sagittal discrepancies of the maxilla

PURPOSE

The purpose of this report was to show the feasibility of the combination of a minimally invasive endoscopic approach to the maxilla with transverse and sagittal distraction procedures.

MATERIALS AND METHODS

Four human cadavers were used for training of a minimally invasive access to the maxilla to perform a endoscopically assisted Le Fort I osteotomy, before this technique was applied in 3 patients with transverse and sagittal growth deficits of the maxilla. Access to the maxilla was gained through a small mucosa incision in the vestibule to create a visualization port to the maxillary sinus through a bur hole. Landmarks were identified through the endoscope before a Le Fort I osteotomy was performed using chisels of different shapes and angulations. In 2 patients the maxilla was split sagittally to perform a transverse maxillary expansion; in 1 patient, a buried distractor was applied close to the piriform aperture to correct a sagittal growth deficit in a hypoplastic maxilla.

RESULTS

Endoscopic exposure of the maxillary sinus walls from within the sinus, the accurate identification of landmarks, and the creation of a Le Fort I osteotomy were achieved in all cases. Distractor application close to the piriform aperture rendered good stability.

CONCLUSION

The results of these cases indicate that the endoscopic approach to the maxillary sinus allows excellent exposure of the sinus walls to perform a endscopically assisted Le Fort I osteotomy. The combination of endoscopy and osteodistraction processes supports the tendency to perform minimally invasive, less-traumatizing surgical procedures, especially in individuals who are still growing.

The value of Waters' projection for assessing maxillary sinus inflammatory disease

OBJECTIVE

The significance of the Waters' projection for judging maxillary mucosal disease is, at the least, questionable. The aim of this study was to evaluate the diagnostic use of Waters' projection of the maxillary sinus with particular regard to sinus mucosal swelling as a consistent sign of maxillary sinusitis.

STUDY DESIGN

Forty consecutive adult patients were referred to an ear, nose, and throat surgeon for pain in the region of the paranasal sinus, recurrent mucopurulent rhinorrhea, and nasal congestion or obstruction for at least 3 months without any response to conservative treatment. Both conventional radiographs (Waters' projection) and coronal and axial computed tomography (CT) scanning of the maxillary sinuses were recorded. The conventional radiographs and CT scans, all made within an hour, were blinded and assessed in random order by 2 independent well-trained observers with standard radiodiagnostic criteria for sinus mucosal swelling. Intraobserver and interobserver agreements were quantified by calculating Cohen's kappa. The diagnostic significance of the Waters' projection was assessed with the CT scan images as criterion standard by calculating sensitivity and specificity, positive predictive value, likelihood ratio, and diagnostic odds ratio.

RESULTS

Cohen's kappa for the intraobserver agreement of Waters' examination was 0.96, and the intraobserver agreement for CT scanning was 0.92. The interobserver agreement for Waters' projection and CT scanning was 0.76 and 0.92, respectively. With CT scanning as criterion standard, the sensitivity and specificity of Waters' projections to detect maxillary sinus mucosal swelling were 83.3% and 69.2%, respectively. The positive predictive (diagnostic) value of Waters' projections was 83.3%, the positive likelihood ratio 2.7, and the diagnostic odds ratio 11.25.

CONCLUSIONS

From this study it can be concluded that Waters' projections do not necessarily rule out the presence of maxillary sinus mucosal swelling. Additional examinations may be indicated, especially in patients with compromised sinus clearance.