Intramasseteric versus pterygomandibular space dexamethasone injection for oedema and trismus after mandibular third...

This study compared intramasseteric versus pterygomandibular space dexamethasone injection for postoperative oedema and trismus after mandibular third molar surgery.

This prospective, randomised, participant- and outcome assessor-blinded, active-comparator split-mouth clinical trial with sequential interventions was conducted at Afyonkarahisar Health Sciences University between April 28, 2023 and April 27, 2024. Twenty adults aged 18-25 years, classified as American Society of Anesthesiologists Physical Status I and requiring bilateral surgical extraction of comparable mandibular third molars, were enrolled. The two interventions were performed in randomised order at a three-week interval.

All 20 participants completed both interventions. Operative time did not differ between injection sites (18.1 ± 2.8 vs. 18.1 ± 2.9 min; p = 1.000). Change in oedema was lower in the intramasseteric group on days 2 (4 [1-8] vs. 6 [4-12]; p < 0.001; difference between site-specific medians favouring intramasseteric injection, 2.0 mm) and 7 (0.5 [0-1] vs. 1 [0-3]; p = 0.006; difference between medians, 0.5 mm). Trismus was less severe on days 2 (10.4 ± 2.7 vs. 13.1 ± 3.2 mm; p = 0.006; mean difference, 2.7 mm; 95% CI, 0.9 to 4.5) and 7 (0.7 ± 0.8 vs. 1.2 ± 1.2 mm; p = 0.006; mean difference, 0.5 mm; 95% CI, 0.2 to 0.8). Between-group pain, salivary cortisol level, Oral Health Impact Profile-14 score, and analgesic consumption differences were nonsignificant.

Intramasseteric injection was associated with lower oedema and trismus severity. Patient-reported recovery outcomes did not differ significantly between the injection sites. The clinical relevance of these differences remains uncertain.

ClinicalTrials.gov NCT06604286; first submitted 17 September 2024 and first posted 19 September 2024 (retrospectively registered).