MINIMALLY INVASIVE TECHNIQUES FOR REGENERATIVE THERAPY.

Dr. Kanchan Jadhav, Dr. Asha Prabhu, Dr. Susannah Thomas, Dr. Purvi Sampat, Dr. Sweety Agarwal. 802Harigovinddham, plot no 17, sector 15 Ghansoli, Navi Mumbai400701. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

Periodontal regeneration remains the corner stone of periodontal therapy. Newer techniques have emerged to overcome the pitfalls in conventional surgical techniques. Minimally invasive surgery (MIS) is a method of surgical access that minimizes flap reflection and tissue trauma, resulting in maintenance of critical blood supply, stability of the blood clot within the wound site, and better esthetic outcome. These techniques have evolved from magnification devices to advanced surgical instruments and modified procedures This review summarizes the rationale, indications, contraindications, technique and future prospects of minimal invasive periodontal surgery .

Introduction:-
For the past 150 years, mortality & morbidity for all surgical procedures have been accepted as unavoidable parts of the therapeutic process, However since the early 1980s, it has become evident that less invasive methods of interventional treatment in some areas have produced far fewer complications with a reduced risk of cell death and morbidity. This rationalised the need for minimally invasive treatment with its general aim to minimize the trauma of any interventional process & still achieve satisfactory therapeutic result.
In the last decade, some clinical investigators have focused their interest on the development of minimally invasive surgical approaches in periodontal surgery. Harrel & Rees (1995)  Microsurgery has become an indispensible asset in medicine in the recent years and the application of its principle to periodontal surgery has been extremely valuable. Periodontal microsurgery is a natural transition and extension of surgical principles and techniques by which exceedingly accurate and precise preparation, atraumatic handling of soft and hard tissue enhances primary wound closure through optical magnification.Improvements in flap designs & soft tissue manipulation are considered key elements in improving the outcomes of regenerative periodontal surgery..
The purpose of periodontal surgery is to reconstruct the attachment apparatus with retention or enhancement of the pre-surgical soft tissue contour and height. However, the results generated by traditional surgeries seemed unsatisfactory due to limited regenerated periodontal tissue. It appears that functional periodontal tissue regeneration remains a challenge. This led the way towards a technique called as minimally invasive periodontal surgery.
Minimally Invasive Periodontal Therapy:-Minimally invasive periodontal surgery (MIS) for periodontal regeneration is based on the concept of using 1. very small split thickness incisions 2. loupes for better access 3. sharp dissection of the tissue overlying the area of bone loss 4. preservation of the periosteum to the greatest extent possible in order to preserve blood supply to periodontal tissue, 5. replacement of the soft tissue flap at or coronal to the pre-surgical height, 6. the closure of the flap using minimal suturing.
A prospective study of MIS using an enamel matrix derivative (EMD) was performed in two centres with results reported from 160 surgical sites. Results were reported at 1 and 6 years post-operative (Harrel et al. 2005, 2010). At 1 year post-operative, there was a statistically significant mean improvement in all clinical measures with a mean pocket probing depth of 3.09 mm and a mean improvement in CAL of 3.33 mm. This improvement was maintained at the 6-year post-surgical evaluation. Great clinical significance can be attributed to the fact that all postsurgical pocket probing depths were less than 4 mm and these were maintained at 6 years with no sign of periodontal breakdown or indication of a return of deeper pocket probing depths. Also of clinical significance was that a clinically undetectable mean recession of 0.01 mm was noted at 1 year and 0.08 mm at 6 years.
In 2007, a similar minimally invasive surgical approach based on the concepts of MIS and incorporating elements of the papilla preservation technique was introduced. This technique was described as the Minimally Invasive Surgical Technique (MIST) and a later modification was termed the Modified Minimally Invasive Surgical Technique (MMIST) (Cortellini & Tonetti 2007, 2011). The initial MIST approach used somewhat larger incisions and flaps than the later M-MIST approach. A major factor in both MIST and M-MIST was the moderately complex suturing technique originally developed for the papilla preservation technique. This complex suturing technique is markedly different from that used with MIS which consists of a single suture at the base of the papilla. One year data for the MIST approach reported statistically significant improvements of all clinical measures with mean pocket probing depths of 3 mm, mean improvement in CAL of 4.9 mm, and mean recession of 0.4 mm. The clinical improvements were also significant with all pockets at 1 year being less than 4 mm. The improvement in pocket probing depth and CAL reported for both MIS and MIST appear equal to or greater than most past results reported for other types of regenerative periodontal surgery. Also, both minimally invasive approaches have resulted in less post-surgical recession than reported with other regenerative periodontal surgical modalities. The report of a mean recession following MIS of 0.01 mm appears to be less than the recession reported following any other periodontal regenerative surgery. In addition to these improvements in clinical measures, patients reported minimal post-surgical pain or morbidity following both MISs and MIST (Harrel 2005, Cortellini & Tonetti 2007).

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Future Trends:-Robotic microsurgery:-Shrinking robots and growing processors are taking minimally invasive techniques where they have never gone before. The delicate steps of operation are performed with the system that controls instruments inserted through small incisions, or "ports". The movements of the tools are least 20 feet away. The surgeon manipulates the telerobo, watches the operation through a three dimensional video, through a port in the skin and is able to complete each step of the complex operation which was previously considered impossible.
Videoscope assisted minimally invasive periodontal surgery (V-MIS):-In the study conducted by Harrel S K et al (2014); a 6 month re-evaluation post-surgery, showed a statistically significant improvement (p < .001) in mean Probing Pocket Depth ( PPD) & mean Clinical Attachment Level (CAL) [PPD 3.88 ± 1.02 mm, CAL 4.04±1.38 mm] in 1, 2, and 3 walled defects. All PPD at re-evaluation were 3 mm or less. There was a mean post-surgical increase in soft tissue height (0.13 ± 0.61 mm, p = 0.168) with a decrease in recession. The improvement in PPD and CAL from V-MIS, in the authors' opinion, appears to be favourable when compared to previously reported results of periodontal regenerative surgery. The lack of postsurgical recession following V-MIS has not been reported with traditional regenerative surgery.

Conclusion:-
Minimally invasive periodontal therapy allows a higher quality of work to be undertaken and has opened a new avenue for periodontal regeneration. The cardinal essentials of access & visibility, gentle tissue handling, accurate approximation, meticulous hemostasis, and minimal tissue destruction are the hallmarks of this approach. They play a vital role in attaining the elusive goal of periodontal regeneration .Presently with the wide array of equipments & surgical techniques present today a better attempt can be made to achieve periodontal regeneration.