Endoscopic Visualization of Anatomic Structures as a Support Tool in Oral Surgery and Implantology

Endoscopic visualization of the inferior alveolar nerve associated with somatosensory changes after impacted mandibular third molar extraction

The aim of this study is to assess the relationship between somatosensory functional changes and inferior alveolar nerve (IAN) exposure after impacted mandibular third molars (M3M) removal. We recruited 35 patients who underwent impacted M3M extraction near the IAN. The M3Ms were extracted by combined endoscopy, piezosurgery, and contra-angle high-speed turbine handpiece. All IAN canal perforations and exposed regions were recorded and measured by endoscopy after extraction and on cone-beam computed tomography (CBCT) images before extraction. The patients were followed up 1, 7, and 35 days after surgery. A standardized quantitative sensory testing (QST) battery was performed on the lower lip skin. All of 35 cases had exposed IAN on CBCT images, 5 of which had no exposed IAN under endoscopy. For the other 30 cases, the endoscopy-measured IAN length and width were shorter than the CBCT measurements (P < 0.001). The warm and mechanical detection thresholds (MDT) on the operation side were significantly higher than the contralateral side after surgery (P < 0.05). Thermal sensory limen, MDT, and cold pain threshold were strongly correlated with the exposed IAN length and MDT also with the exposed IAN width one day after surgery. In conclusion, it was found that not all exposed IAN in CBCT images were real exposure after surgery. The intraoperative exposed IAN endoscopic measurements were smaller than by CBCT and strongly correlated with some QST parameters.

Endoscopically Assisted Marginal Mandibulectomy Using an Intraoral Approach Alone for Squamous Cell Carcinoma of the Posterior Mandibular Gingiva: A Technical Note

Study Design

Technical note.

Objective

Marginal mandibulectomy is a surgical procedure for treatment of mandibular gingival tumors. The intraoral approach to the posterior region of the mandible for marginal mandibulectomy is difficult due to limited access and operating field visibility; the conventional surgical procedure may require some skin incisions. This report discusses the effectiveness of endoscopic assistance in marginal mandibulectomy.

Methods

This article describes endoscopically assisted marginal mandibulectomy using an intraoral approach alone for squamous cell carcinoma of the posterior mandibular gingiva.

Results

The advantages of this surgical method are twofold: (1) superior visibility to the lower edge of the mandible without any skin incision; and (2) safe surgical confirmation of important anatomy on the buccolingual side (e.g., mental foramen, lingual nerve, mandibular foramen, and neurovascular bundle). This minimally invasive approach without any skin incision, as well as the superior visibility of the operating field, are important advantages of endoscopically assisted marginal mandibulectomy that cannot be obtained by other surgical methods.

Conclusions

Endoscopically assisted marginal mandibulectomy using an intraoral approach alone may be useful because it avoids damage to facial skin and improves safety by employing an enlarged bright field.

The dual-port endoscope-assisted cyst enucleation on the maxillofacial region

BACKGROUND

Endoscope-assisted surgery is a surgical method that has been used in oral and maxillofacial surgical fields. It provides good illumination, clear, and magnified visualization of the operative field. The purpose of this article is to describe the early clinical experiences to conduct minimally invasive surgery with endoscope-assisted enucleation of cysts on the jaw. It appears that this approach may be a superior alternative to the conventional approach.

METHODS

In this study, 24 patients (9 females, 15 males, average age 41.5) underwent endoscope-assisted cyst enucleation under general anesthesia. All operations were done by one surgeon. The cases were classified depending on whether bone penetration occurred at the cyst site. The cystic lesions were enucleated using an endoscope with a 0°, 1.9 mm diameter, or a 30°, 2.7 mm diameter. Two bony windows were used for the insertion of a syringe for irrigation, curettes, suction tips, sinus blades, surgical drills, and an endoscope. An additional small channel was made for the insertion of endoscopic instruments.

RESULTS

The 24 patients who underwent cyst enucleation were regularly observed for 3 to 12 months to evaluate for complications. Although some patients experienced swelling and numbness, these symptoms did not persist, and the patients soon returned to normal and there was no sign of recurrence.

CONCLUSIONS

The results of this study have suggested the possibility of minimally invasive surgery with endoscopes when it comes to cyst removal in the oral and maxillofacial region. Nevertheless, this study has limitations designed as a preliminary report focusing on the feasibility of endoscope-assisted cyst enucleation in the oral and maxillofacial regions.

In Situ Endoscopic Analysis of Vascular Supply and Regenerated Alveolar Bone in β-TCP Grafted and Ungrafted Postextraction Sites before Implant Placement: A Prospective Case Control Study

Background

Endoscopy has seen a significant development over recent years in various medical fields with its application expanding from the support of minimal invasive surgery to in situ imaging. In this context, the application of endoscopic techniques to assess the quality of the regenerated bone in situ in the drill hole before implant placement is an appealing approach.

Aim

The aim of this study was to use short distance support immersion endoscopy (SD-SIE) to compare the quality of regenerated bone in healed postextraction sites, which are grafted with an in situ hardening β-TCP, against ungrafted sites, before implant placement. This assessment was based on microscopic bone analysis in combination with the blood vessel count.

Method

13 spontaneously healed and 13 grafted postextraction sites in 3 men and 6 women, aged 26–83 years, were evaluated using SD-SIE after 4–6 months. SD-SIE was applied in drill holes before implant placement, and videos were taken from representative central buccal areas. The video recordings were analyzed using Image J software for (1) number of blood vessels per area (NBV), (2) relative area of vessels (VA), (3) relative area of mineralized bone (MBA), (4) relative area of unmineralized bone (UMBA), and (5) relative area of bone substitute (BSA).

Results

The grafted sites showed more (1) NBV as well as (2) VA (8.6 ± 1.1; 2.03 ± 0.28%) than the ungrafted sites (2.5 ± 0.6; 1.18 ± 0.36%) (independent t-test; p < 0.05); (3) MBA and (4) UMBA were similar to those in the grafted sites (86.3 ± 2.2 %; 13.7 ± 2.2 %) and to the ungrafted sites (89.5 ± 3.7%; 10.5 ± 3.6%) (independent t-test; p > 0.05); and (5) BSA in the grafted sites was 18.2 ± 5.4%.

Conclusion

SD-SIE is an interesting new approach for in situ assessment of bone quality and blood supply before implant placement. The regenerated bone in β-TCP grafted extraction sockets showed an increased vascularization compared to ungrafted sites providing a vital support for subsequent implant placement.

Sinus Floor Augmentation by Intraoral Endoscopic Approach for Biomaterial Study in a Rabbit Model

AIM

To develop a new surgical model for sinus floor augmentation (SFA) in rabbit for experimental purposes.

MATERIALS AND METHODS

Eight adult rabbits were used, two for a surgical design using the anatomical dissection study, and the other six for an endoscopically assisted intraoral approach of SFA unilaterally, creating a subantral space where an allograft biomaterial was deposited. SFA was verified through cone-beam computerized tomography. Healing, weight, food, feces, and behavior were evaluated for 4 weeks post-operatively.

RESULTS

All animals survived. There was no bleeding or infection; inflammation was mild. No changes were observed in terms of feeding, weight, feces, or behavior. Tissue healing was normal.

CONCLUSION

This model is a refinement of the experimental technique and is a real option for SFA, without compromising animal morbidity because of its conservative design. The minimally invasive approach with endoscopic assistance reduces bias and improves surgical predictability.

Hard Tissue Preservation in Minimally Invasive Mandibular Third Molar Surgery Using In Situ Hardening TCP Bone Filler

Background

Maintenance of hard tissue in the case of impacted third molars (M3M) with close relationship to the mandibular canal is still a surgical challenge which may be overcome using the inward fragmentation technique.

Methods

A consecutive case series of 12 patients required the extraction of 13 impacted M3M with a close relationship to the inferior alveolar nerve (IAN). Via occlusal miniflaps, M3M were exposed occlusal under endoscopic vision and removed by inward fragmentation. All patients received socket preservation with resorbable in situ hardening TCP particles to reduce the risk of pocket formation at the second molar.

Results

All 13 sites healed uneventfully. Bone height was assessed using CBCT cross-sectional reformats pre- and 3 months postoperatively. The bone height was reduced by 1.54 mm lingual (SD 0.88), 2.91 mm central (SD 0.93), and 2.08 mm buccal (SD 1.09). Differences were significant at a 0.05% level. No tissue invagination at the extraction sites was observed.

Conclusions

Major bone defects can be avoided safely using inward fragmentation surgery. The self-hardening bone filler appears to enhance the mineralization of the intrabony defect.

Endoscopically Assisted Intraoral Removal of an Ectopic Third Molar in the Mandibular Subcondylar Region

The ectopic placement of mandibular third molars in the subcondylar region is an uncommon phenomenon. Most patients are asymptomatic but can present with acute infection or associated pathology necessitating surgical intervention. Surgical approaches have been described utilizing both extraoral and intraoral approaches to the region.This paper presents a clinical report of a patient presenting with acute fascial space infection arising from an ectopic third molar in the mandibular subcondylar region, managed with surgical removal via an endoscopically assisted intraoral approach.

Support Immersion Endoscopy in Post-Extraction Alveolar Bone Chambers: A New Window for Microscopic Bone Imaging In Vivo

Using an endoscopic approach, small intraoral bone chambers, which are routinely obtained during tooth extraction and implantation, provide visual in vivo access to internal bone structures. The aim of the present paper is to present a new method to quantify bone microstructure and vascularisation in vivo. Ten extraction sockets and 6 implant sites in 14 patients (6 men / 8 women) were examined by support immersion endoscopy (SIE). After tooth extraction or implant site preparation, microscopic bone analysis (MBA) was performed using short distance SIE video sequences of representative bone areas for off-line analysis with ImageJ. Quantitative assessment of the microstructure and vascularisation of the bone in dental extraction and implant sites in vivo was performed using ImageJ. MBA revealed bone morphology details such as unmineralised and mineralised areas, vascular canals and the presence of bleeding through vascular canals. Morphometric examination revealed that there was more unmineralised bone and less vascular canal area in the implant sites than in the extraction sockets.

Visualization techniques of the inferior alveolar nerve (IAN): a narrative review

Purpose

The purpose of this study was to produce an overview of the present visualization techniques of the inferior alveolar nerve (IAN) in order to reduce the rates of nerve damage after third molar (M3) removal and bilateral sagittal split osteotomy (BSSO).

Methods

An electronic literature search was performed of the English-language scientific literature published prior to December 31, 2014 using the LIMO KU Leuven search platform. Information on the specifications of the different imaging techniques, their clinical application, advantages, disadvantages, and duration was extracted from 11 reports.

Results

Five methods for IAN visualization were obtained from the search results, which are cone-beam computed tomography (CBCT) and automatic extraction of the IAN canal using computed tomography (CT), magnetic resonance imaging (MRI), panoramic radiography, endoscopy, and ultrasonographic visualization.

Conclusion

The results of this study suggest that high-resolution MRI is the most commonly used method for direct visualization of the IAN. Six out of the eleven manuscripts use this technique. Recently, there have been some (experimental) modifications to the conventional MRI in the form of diffusion tensor tractography (DTT), phase-contrast magnetic resonance angiography (PC-MRA), and dental MRI. Future studies will focus on an intraoperative application of MRI to visualize the IAN during surgery.

Endoscopic-assisted infraorbital nerve release

Endoscopic-assisted techniques in plastic and craniofacial surgeries are limited. We present a patient with infraorbital nerve entrapment following traumatic facial injury that failed conservative management. Compression of the nerve was treated with an endoscopic-assisted nerve release of the surrounding soft tissue with a circumferential foraminal osteotomy.

Endoscopic Removal of a Supernumerary Premolar in the Mandible during a Dental Implant Placement

The surgical removal of supernumerary teeth is necessary in some cases, especially before the commencement of any orthodontic or implant treatment procedure. In the mandibular supernumerary premolar, a more conservative approach is required because of the presence of complications associated with conventional surgery due to the close proximity of the said premolar to the alveolar inferior and mental nerves, and the need for bone conservation for implant placement. The endoscopic surgical approach has been used for the removal of the maxillary supernumerary tooth, impacted third molar, and implants. In this case report, we present an endoscopically assisted surgical technique for the removal of an unerupted supernumerary premolar in the mandible associated with a dental implant placement procedure.

Endoscopically assisted removal of a lingually displaced third molar adjacent to the inferior alveolar nerve

BACKGROUND

Osteotomy of impacted lower third molars still represents a major trauma because of periosteal flap preparation and buccal bone loss. We present a new occlusal flapless approach for the removal of lingually impacted lower third molars adjacent to the inferior alveolar nerve without lateral or lingual osteotomy.

METHOD

After occlusal exposure under local anesthesia, visualization of the third molar region is obtained from a posterior perspective using support endoscopy. Under magnifying endoscopic visualization, the crown is removed using an inward fragmentation technique. After exposure of the furcation area, the roots are separated and removed via the occlusal cavity.

CONCLUSIONS

Endoscopically assisted removal of mandibular third molars allows the maintenance of the adjacent bone structures and the integrity of the mandibular canal. It is valuable in complex anatomic sites in particular.

Removal of impacted mandibular third molars using an inward fragmentation technique (IFT) - Method and first results

PURPOSE

Conventional surgical extraction of impacted mandibular third molars (M3M) requires a lateral flap reflection in conjunction with lateral bone removal for outward mobilization of the tooth. The aim of this report is to outline a novel inward fragmentation technique (IFT) in conjunction with an occlusal miniflap approach to reduce the amount of bone removal to a minimum.

PATIENTS AND METHODS

Seventeen consecutive patients (7 men and 10 women; mean age 24.4 years, range 18-36 years) required the extraction of 21-impacted M3M with a close relationship to the inferior alveolar nerve (IAN). Occlusal miniflaps were used and only occlusal bone removal was performed to expose the M3M under endoscopic vision. A central space-making cavity was created followed by inward fragmentation and mobilization of the crown and subsequent root removal through the space created.

RESULTS

20 of 21 sites healed uneventfully, one late infection was observed, no permanent neurosensory lesion occurred. The mean preoperative buccal bone height was 15.5 (11-18) mm and the postoperative buccal bone height 14.7 (11-17) mm. On the 2nd day, the mean swelling level was 1.38 (0-2) on a 4 point scale, the pain level was 2.30 (0-5) on a 10 cm VAS, mean pain duration was 2.04 days.

CONCLUSION

An inward fragmentation technique allows preservation of >90% of the buccal bone height adjacent to mandibular third molars and may reduce postoperative morbidity without raising the risk of IAN lesions.

Endoscopic removal of a maxillary third molar displaced into the maxillary sinus via the socket

Removal of a maxillary third molar is a common dental procedure, and oral surgeons rarely experience accidental displacement of a maxillary impacted third molar into the maxillary sinus as a complication of this procedure. In the case in which such displacement occurs, the molar is removed via a transantral (Caldwell-Luc) approach through bone removal or window osteotomy of the anterior wall of the maxillary sinus. However, this approach is highly invasive because 2 surgical fields are required at the socket and the anterior wall of the maxillary sinus. Here, we report as a minimally invasive approach endoscopic removal of a maxillary third molar displaced into the maxillary sinus via the socket.