Efficacy of cooled saline irrigation vs. pre-operative intravenous Dexamethasone in reducing post-operative swelling, pain and trismus after surgical removal of lower impacted third molar: A single center split mouth prospective clinical trial.

This is a single-center split-mouth clinical trial. Patients reporting to Department of Oral and Maxillofacial Surgery, MCODS, Manipal with bilateral mandibular mesioangular or horizontal third molar teeth and satisfying all other inclusion criteria will be included in the study. Radiographic evaluation (orthopantomogram) will be done to classify the impaction and those with Class I or II, level A or B impaction will be considered.

 For the control group (n=32), IV Dexamethasone will be administered 1 hour before the procedure in the cubital fossa. For the test group (n=32), saline bottles will be refrigerated in the department to attain a temperature of 4°C (to be confirmed with non-contact thermometer). A gap of 21 days will be ensured between procedures on either side. The operator and patient will not be blinded. However, the outcome assessor, who will be another surgeon in the department, will be blinded to the procedure. Blinding will be achieved by ensuring that the surgeon is not present in the operatory during the procedure.

 All procedures will be carried out by the same maxillofacial surgeon in the department. The routine steps for lower third molar removal will be followed:

• Local anaesthesia with inferior alveolar, lingual and long buccal nerve blocks (lignocaine with adrenaline 1:2,00,000).
• Modified Ward’s incision and raising a full thickness mucoperiosteal flap.
• Osteotomy or drilling of bone around the tooth and sectioning of tooth (702 straight carbide bur attached to a micromotor handpiece will be used). For the test side, irrigation will be carried out with cold saline at 4°C. For the control side, irrigation will be carried out with saline at room temperature.
• After tooth removal, irrigation and curettage of the socket, Gelfoam placement and closure with simple interrupted 3-0 silk sutures will be done.
• Placement of gauze pack at the local site for 1 hour will be advised to all patients.
• All post-extraction instructions will be given to the patient in written format.
• Suture removal to be done on 7th post-operative day.

 Medications prescribed to both groups will be the same: Antibiotic (Amoxicillin 500mg + Clavulanic acid 125mg 2 times/day for 5 days), analgesic (Paracetamol 650mg 3 times/day for the first 3 days, and then SOS), and chlorhexidine mouthwash (3 times/day) after the first 24 hours.

 The parameters that will be measured are:

1. Facial measurement: This parameter will help us determine facial swelling. It will be measured with the help of 4 reference points on the face and a flexible scale (cm):

• Lateral canthus of eye to gonium on the same side
• Tragus to corner of mouth on the same side

2. Pain: Visual analogue scale (1-100) will be used to document the level of pain the patient is feeling (1 being the least pain and 100 being the most pain)
3. Mouth opening: The distance between the upper right and lower right central incisors will be measured with a scale (cm).

 These parameters will be measured and documented across 4 time points:

1. Pre-operative (POD 0)
2. First post-operative day (POD 1)
3. Third post-operative day (POD 3)
4. Seventh post-operative day (POD 7)

 Additionally, patients will be asked to record the number of additional analgesics they are taking. We will also assess and compare any inferior alveolar and/or lingual nerve injury (hypoesthesia/ paresthesia/ anaesthesia) that may have occurred on either side. This assessment will be done with the help of fine touch and two-point discrimination tests. On the 7th post-operative day, soft tissue healing will be evaluated for both the groups in terms of persistent signs of inflammation, wound dehiscence, and dry socket.