Improvement of the Impacted Level of Lower Third Molars After Orthodontic Treatment.

OBJECTIVES: The early or delayed surgical removal of an asymptomatic lower third molar (M3) in orthodontic patients remains controversial. This study aimed to determine the changes in the impacted level of M3 such as angulation, vertical position, and eruption space, after orthodontic treatment in 3 groups, namely non-extraction (NE), first premolar (P1) extraction, and second premolar (P2) extraction. METHODS: Relevant angles and distances related to 334 M3s from 180 orthodontic patients were assessed pre- and posttreatment. Angle between lower second molar (M2) and M3 (M3-M2) was used for evaluating M3 angulation. For M3 vertical position, distances from occlusal plane to the highest cuspid (Cus-OP) and fissure (Fis-OP) of M3 were used. Distances from the distal surface of M2 to anterior border (J-DM2) and centre (Xi-DM2) of the ramus were used for assessing M3 eruption space. Pre- and posttreatment values of the angle and distance in each group were compared using a paired-sample t test. Measurements of the 3 groups were compared using analysis of variance. Hence, multiple linear regression (MLR) analysis was used to determine significant factors that impacted changes in M3s' related measurements. Independent factors used for MLR analysis included sex, treatment starting age, pretreatment respective angle/distance, and premolar extraction (NE/P1/P2). RESULTS: M3 angulation, vertical position, and eruption space at posttreatment were significantly different from those at pretreatment in all 3 groups. MLR analysis showed that P2 extraction significantly improved M3 vertical position (P < .05) and eruption space (P < .001). P1 extraction significantly decreased Cus-OP (P = .014) and eruption space (P < .001). Treatment starting age was significant factor that affected Cus-OP (P = .001) and M3 eruption space (P < .001). CONCLUSIONS: After orthodontic treatment, M3 angulation, vertical position, and eruption space changed in favour of the impacted level. These changes in the 3 groups were clearer in order: NE, P1, and P2, respectively.

Endoscopic-Assisted Intraoral Approach for Osteosynthesis of Mandibular Subcondylar Fractures.

INTRODUCTION: The aim of this study is to follow-up and evaluate the treatment result of mandibular subcondylar (MSC) fractures by osteosynthesis via endoscopy-assisted intraoral approach. MATERIALS AND METHODS: This is a prospective study, in which 47 patients with 51 sites of MSC fractures treated osteosynthesis via endoscopic-assisted intraoral approach at the Department of Maxillofacial Surgery, National Hospital of Odonto-Stomatology HoChiMinh City-Vietnam were followed-up and evaluated clinically and radiographically up to 6 months postoperative. RESULTS: Before surgery, all of the patients were malocclusion, 15% of patients were isolated MSC fractures, the rate of concomitant midface fractures were 30%, 92.2% of fracture sites with moderate displacement, 7.8% of fracture sites with severe displacement, 5.9% of fracture sites with dislocation. After surgery, all of the patients had preinjured centric occlusion; no patient had facial paralysis; 6% of patients had surgical site infection within 1 week; pain frequency were 56.9% at 1 month, 35.3% at 2 months, 7.8% at 3 months, and 2.0% at 6 months with Visual Analog Scale (VAS) means of pain were 1.74±1.85 at 1 month, 0.55±1.12 at 2 months, 0.08±0.27 at 3 months and 0.02±0.14 at 6 months; 90% of fracture sites had precise anatomy at 1 week and 96% at 6 months; 96% fracture sites had no displacement the of correlation between condyle and articular fossa at 1 week and 98% at 6 months; 1 fracture site had screw loosening at 2 months; 88% fracture sites had stage-4 radiographic bone healing at 6 months. CONCLUSION: Endoscopic-assisted intraoral approach for osteosynthesis of MSC fractures have provided the esthetic and functional success and good bone healing.