Oral Surgery

25. Multi-disciplinary extraction

Extraction of mandibular third molars (M3s) in close proximity to the mandibular canal has some inherent risks to adjacent structures, such as neurologic damage to teeth, bone defects distal to the mandibular second molar (M2), or pathologic fractures in association with enlarged dentigerous cysts. The procedure for extrusion and subsequent extraction of high-risk M3s is called orthodontic extraction and this is a systematic review of the approaches and their outcomes. Thirteen articles met the inclusion criteria. A total of 123 impacted teeth were extracted by orthodontic extraction. Three biomechanical approaches were used: using the posterior maxillary region as the anchor for orthodontic extrusion of lower M3s; simple cantilever springs attached to an M3 buttonhole, and cantilever springs tied to a bonded orthodontic bracket on the M3 plus multiple-loop spring wire for distal movement of the M3. Osteo-periodontal status of M2s also improved uneventfully. Despite the drawbacks of orthodontic extraction, removal of deeply impacted M3s using the described techniques is safe with regard to mandibular nerve injury and neurologic damage.

Kalantar Motamedi MR et al. Orthodontic extraction of high-risk impacted mandibular third molars in close proximity to the mandibular canal: a systematic review. J Oral Maxillofacial Surg 2015 73: 1672-1685.

Q Orthodontic extraction:

A Usually means exodontia of all four first premolars

B Increases the risk of nerve damage

C Jeopardises the periodontal health of second mandibular molars

D Involves biomechanical approaches to the safe removal of mandibular third molars

26. Uplifts

The purpose of this study was to determine the effect of orthognathic surgery on psychological status. The subjects were 119 patients who underwent orthognathic surgery. They were divided into class III (84 patients), class II (20 patients), and class I (15 patients) groups according to the anteroposterior skeletal pattern, and they were also divided into an asymmetry group (51 patients) and a symmetry group (68 patients). Psychological status was assessed before surgery and at more than 6 months later. Scores for depression, hysteria and social introversion were significantly higher than standard values before surgery, and the hypomania scale significantly lower. The depression and hysteria scales decreased significantly after surgery. A comparison of scores among the groups showed the depression scale in the class III group to be higher than those in the class I and II groups; there was no significant difference between the asymmetry and symmetry groups. Orthognathic surgery has a positive influence on the psychological status of patients with jaw deformities, especially patients with skeletal class III malocclusion.

Takatsuji H et al. Effects of orthognathic surgery on psychological status of patients with jaw deformities. Int J Oral Maxillofacial Surg 2015 44: 1125-1130.

Q Orthognathic surgery:

A Has a positive influence on the psychological status of patients with jaw deformities

B Tends to have a lesser effect on patients with class II skeletal pattern

C Severely raises depression and hysteria scales

D Has a greater beneficial outcome for patients with asymmetry

27. A tale of two agents The objective of this study was to assess the efficacy of propofol and midazolam as an intravenous sedative agent in minor oral surgical procedures. The double blind randomised study had one group of 20 patients who received propofol with the induction dose of 0.5 mg/kg and 50 mug/kg/min which was administered by syringe infusion pump as a maintenance dose and the other group who received midazolam in a single dose of 75 mug/kg. There were no significant differences in either patient demographics or surgical characteristics between the two groups. The propofol group was less co-operative than the midazolam group. Pain during the injection of sedative was a significant adverse effect in the propofol group. Cardiovascular parameters remained stable throughout the procedure in both study groups and no intervention was required. The onset of action in the propofol group was significantly faster. The maximum increase in heart rate in the propofol group was at 10 min intraoperatively and that in the midazolam group was at 15 min. However, recovery and onset of action was faster in the propofol group as compared with the midazolam group.

Hari Keerthy P et al. Comparitive evaluation of propofol and midazolam as conscious sedatives in minor oral surgery. J Maxillofacial Oral Surg 2015 14: 773-783.

Q Pick the characteristic of the propofol group which was distinct from the midazolam group:

A Slower onset of action

B More cooperative patients

C Maximum heart rate at 10 mins intraoperatively

D Slower recovery

28. What’s the bleeding difference? The authors assessed the incidence of postoperative bleeding in highly anticoagulated patients who underwent extensive oral surgical procedures while continuing therapy. Patients receiving anticoagulant therapy (n=125) were divided into three groups. Group A (n=54) who were highly anticoagulated (INR > 3.5) in whom up to 3 teeth were extracted. Group B (n=60) with INR 2.0-less than 3.5 in whom higher-risk dentoalveolar surgery (extraction of more than 3 teeth or other procedure: raising a mucoperiosteal flap, osteotomy, or biopsy) was performed. Group C (n=11) with INR values of 3.5+ and who required higher-risk dentoalveolar surgery. Eighty-five healthy participants who underwent procedures similar to Groups A and B were the control group. Two patients in group A (3.7%), 3 in group B (5.0%), and 2 in group C (18.2%) experienced postoperative bleeding. In the control group, a single bleeding event (1.2%) occurred. Tooth extractions and even more extensive surgical procedures can be performed safely in patients who continue using anticoagulant therapy if proper local haemostatic measures are used and if no other coagulopathies are present.

Bajkin BV et al. Risk factors for bleeding after oral surgery in patients who continued using oral anticoagulant therapy. JADA 2015 146: 375-381.

Q Patients using anticoagulant therapy:

A And who have an INR > 3.5 should not undergo oral surgery under any circumstances

B Cannot be relied upon to have bleeding controlled by local haemostatic measures

C Must cease their anticoagulant therapy for two weeks before oral surgery

D Can have tooth extractions and even more extensive surgical procedures performed safely