Evaluation of efficacy of twisted 120 degree plating system in mandibular angle fracture: an in-vitro and in-vivo study.

Screws near the fracture site experiences greatest load. Using more screws and increasing the length of the plates helped to distribute the stress throughout the plates and screws which prevents complications like:

1. splaying at the lower border

2. lack of stability  against rotational forces

3. dehiscence of overlaying mucosa and

4. hardware failure.

So, we designed a noble twisted 1200 plating system and study of which will play an important role in improving the design and producing successful materials for medical and clinical purpose.

Thirty patients who fulfill the inclusion criteria and sign the consent form will be included in the study.  A detailed Case history and necessary information will be recorded

Methodology:

Pre-op screening examination (1st visit)

Photographic records

Preoperative, intraoperative and postoperative photographs will be made.

Radiographic record

1. Preoperative panoramic view and mandibular occlusal view will be done to evaluate the site and type of fracture.

2. Immediate postoperative panoramic and occlusal view will be taken to evaluate the fracture reduction and placements of plates and lingual splay.

3. Follow up panoramic view and occlusal radiographs will be taken at 12th week of postoperative healing process.

Treatment

In all the patients Preoperative Erich’s arch bar will be placed. An intraoral mucosal incision will be made depending upon the anatomical location of fracture. Extraction of teeth in line of fracture, including impacted third molars, will be performed if indicated. The fracture fragments will be reduced in accurate anatomic pretraumatic occlusion state by open method and internal fixation will be done using 2.0mm twisted 120 degree stainless steel miniplate, and 2 mm × 8 mm screws. The intra oral incision sites will be closed with resorbable sutures.

All patients will be given intravenous antibiotics from the time of admission until discharge. On discharge, patients will be prescribed a 5, 7 day course of oral antibiotics All patients will be instructed to continue on soft diet for 4 weeks.

Patients will be observed for postoperative complication like Paresthesia, infection, masticatory difficulty, nonunion and malunion

Postoperative evaluation**:** Assessment of occlusal stability and lingual splaying

a)   The occlusion achieved after fixation of mandibular fracture will be recorded and evaluated for change and stability during the first, second, fourth and 12th weeks following surgery.

Occlusal score proforma is given to operative surgeon who gives score accordingly:

i.   1. Complete bilateral loss of occlusal contact of molars or cross bite or open bite: -1

ii.    2. Unilateral loss of molar relationship: 0.

iii.    3. No/minimal loss of molar relationship: +1.

Patient will be questioned about symptoms of possible complications and clinically evaluated postoperatively in the first, second, fourth and 12th weeks following surgery and details were recorded. The amount of mouth opening and patient’s ability to return to normal activities will be recorded.

The amount of reduction of lingual splay is evaluated by the operating surgeon using occlusal radiographs taken preoperatively and 3rd postoperative day.

The score for lingual splay evaluation is given as follows:

**1.**There is increase in lingual splay: -1.

2. Minimal/no change in lingual splay: 0.

3. Significant reduction in lingual splay: +1.

**c)**Infinite Element analysis to determine: CBCT reports will be collected and the document will be transferred to COMSOL MultiPhysics Software along with pull forces of Masseter, Temporalis and medial Pterygoid muscle to determine:

**1.**Stability of the plate.

2. Stress distribution along the plate and bone.

3. Ability to withstand the torsional and rotational forces