Endoscopic Perspective in Oral and Maxillofacial Surgery

Introduction

Oral and maxillofacial surgeries are quite difficult due to the complex anatomy and presence of numerous blood vessels. It requires skill and appropriate technology to restore the normal form and function of the orofacial region. Also, its association with underlying and adjacent vital structures such as brain, orbit, eyes, indicate a need for minimal invasive procedures to avoid damage to these structures.¹

Oral and maxillofacial surgeries have undergone potential advancements in terms of treatment modalities from conventional open surgeries to minimal invasive procedures and the search continues. Similarly, diagnostic procedures have also witnessed tremendous innovations to provide accurate and precise details. From conventional orthopantomography to digital radiography and now the endoscopy technique, all have facilitated the diagnosis and treatment planning in oral and maxillofacial surgeries. These innovations have proven to be more accurate, reliable and far more capable in diagnosis.^2,3 Endoscopy technique in oral surgeries is a promising method to achieve minimal invasiveness and preservation of vital structures and it has been widely accepted in many treatment protocols. Endoscopic oral surgery can now be considered as a standard surgical method.⁴

First endoscope was developed in 1843 by Desoman. Later in 1982, the digital video camera was introduced.⁵ Endoscope is used to appreciate and visualize the cavity which does not have an external opening. In oral surgery, endoscope has been used in implantology, maxillofacial trauma, arthroscopy of TMJ, functional endoscopic surgery of sinus.

This article aimed to overview the boons and applications of endoscopic procedures in oral and maxillofacial region.

Endoscopy in implantology With the advancement in implant techniques, microendoscopy has been introduced. Conventionally, blind drilling the bone and insertion of implant is done but with the recent advancements, implant placement can be accomplished by endoscopic viewing and computer guided surgery.^6,7

Endoscopes for dental implant placement has an optical system with a resolution of ten thousand pixels and wide lens field of about one twenty degrees. Implant endoscope has a monitor, a camera and uses xenon light source. Aim of using endoscope in dental implant placement is to prolong the durability of implant by attaching the implant and placing it accurately in bone with adequate density. Advantage of using endoscopy assisted surgery is safeguarding the maxillary sinus, inferior alveolar nerve, mandibular canal and other vital structures. At present, a few cases have reported the use of endoscopy in implant placement demonstrating that the use of endoscopy has led to decreased intraoperative trauma, decreased intra operative bleeding. It is a minimal invasive process, gives good stability for implant postoperatively, results in less postoperative complications and high success rates. The only disadvantage at present seems to be the need for intensive training to learn the process and techinique.^8,9

Endoscopy in maxillofacial trauma

In the traditional methods of treatment of mid face trauma, despite the careful and proper application, the selected incision leaves permanent surgical mark in pre-auricular, coronal, lower eyelid or buccal sulcus region. Other complications of conventional methods include prominent scarring, facial nerve palsy etc. In 1995, Kobayashi et al. reported the use of endoscope in management of midface fractures. Since then, use of endoscopy assisted surgeries for maxillofacial fractures became popular.^10,11

Scope of endoscopy in the management of maxillofacial fractures include condylar and sub condylar fracture management, fractures involving frontal sinus, fracture of zygomatic complex, orbital wall defects.¹²

For fractures involving condyle, the most widely accepted method is closed reduction. The post-operative function of TMJ and its restoration to normal form and function mainly depends on functional adaptation of the morphology of altered condyle. This appropriate functional adaptation and anatomic reduction cannot be obtained by conventional closed reduction procedure. There are chances of damage to facial nerve, increased post-operative complications and scars via open approach. All of the above-mentioned problems can be overcome with the use of endoscopic assisted minimally invasive surgical procedures.¹³

The endoscopic technique in the management of sub condylar fractures can be obtained via transoral approach and submandibular approach. In the beginning, a template of endoscopic plate application device was used through external approach. It had a diameter of four millimeters and an angle of three hundred degree. The endoscopic monitor and all the other equipment should be placed facing the operator in the operating room. In transoral or submandibular approach, the endoscope is inserted subperiosteally on the ascending mandibular ramus and advanced until the fracture gap is clearly seen on the monitor of endoscope.

In the treatment of fractures of orbit and zygomatic complex with endoscopy, minimal incisions with no extraoral incisions are required and the zygomatic bone position can be evaluated intra-operatively via endoscopy prior to osteosynthesis. Also, it specifies the accuracy of reduction of lateral wall of orbit. Osteosynthesis at the infraorbital rim can be done endoscopically by transoral approach. The dislocated orbital floor can be repositioned endoscopically.¹³

Endoscopy (Arthroscopy) of Temporomandibular joint (TMJ)

Arthroscopy is a diagnostic and therapeutic method. Temporomandibular joint arthroscopy was first reported in 1975 by Professor M. Ohnishi. Later in 1981, 1982 and in 1985, Dr. Ken Ichiro Murakami published reports on TMJ arthroscopy after which it gained popularity. Arthroscopy requires cannulas with diameter of about 1.9-2.7 mm, trocars, irrigation system, arthroscope and normal saline.^14-16

The cannulas are introduced in the upper joint cavity of TMJ through trocar. The arthroscope consists of lens at an angle of zero to thirty degrees for adequate visualization. Irrigation system consists of one inlet and one outlet for lavage of the joint cavity. Complete operative procedure can be performed under visualization with the help of endoscopy.^17,18

Endoscopy in sinus surgery

Blockage or inflammation in paranasal sinus may cause infection. Since last two decades, functional endoscopic sinus surgery has been widely accepted and has overruled the conventional sinus surgical procedures.¹⁹

Functional endoscopic sinus surgery can be done in cases of acute sinusitis, sinus mucoceles, fungal infections in sinus, nasal polyps etc. After achieving local anesthesia in the lateral wall of nose, the endoscopic surgery is started and the bone of maxillary sinus is visualized. The procedure is continued and the enlargement of the bone can be considered in anterior-inferior direction. The maxillary sinus can be examined thoroughly for any pathology via telescope. Functional endoscopic sinus surgery has proved to be very effective and safe procedure.^20-22

Challenges of using endoscopy assisted surgery

Benefits of endoscopy assisted minimally invasive surgeries outweigh the challenges the maxillofacial surgeon faces while using it. The major and the only challenge seems to be the need for intensive training as it is a very technique sensitive procedure and requires a lot of skill to operate via endoscopy. Also, the cost vs benefit ratio is under evaluation as it is still not a popular method of operative procedure.

Conclusion

Endoscopic assisted surgery is a minimally invasive procedure and can be applied in various surgical procedures in maxillofacial region. It is advantageous over the conventional method of surgeries in many ways. Decreased post-operative complications, increased operative efficiency, accuracy, precision, are all the benefits of using endoscopic surgical technique. It has made surgeries easier, more reliable and less invasive. However, further studies and research are required in this regard to make it simpler and more acceptable.

Source(s) of support:

Nil

Conflicting Interest

None