Oral Flap Outline and Local Blood Supply After Surgical Removal of Lower Third Molar Teeth

Overview

Wisdom teeth in the lower jaw are frequently buried in bone and must be taken out surgically. To reach the tooth, the surgeon lifts the gum away from the bone as a flap, and the shape of that flap is left to the surgeon's judgement. Two outlines are in everyday use. The first runs only along the necks of the teeth, so the gum is lifted without any additional cut. The second adds a short downward cut in front, which opens the field more widely but also divides some of the small vessels that run within the gum. Because the tissues around a wound rely on a rich network of tiny vessels while they repair themselves, it is worth knowing whether these two outlines leave the local circulation in a different state. This project measured that circulation directly. A laser probe was placed against the tooth in front of the extraction site and against three points on the cheek-side gum, and the amount of moving blood beneath the probe was recorded. To make sure the probe returned to exactly the same spots at every visit, a thin clear plastic guide with prepared openings was made for each participant from a plaster model of the mouth. Measurements were taken before the operation and again on the third and the seventh day afterwards. Facial swelling and how widely the mouth could be opened were recorded on the same occasions. Participants were assigned to one of the two flap outlines in turn, and every operation was carried out by the same surgeon so that the comparison depended on the flap outline alone.

Fifty-six systemically healthy adults presenting for surgical removal of a single fully bone-impacted mandibular wisdom tooth were assigned to one of two mucoperiosteal flap outlines by an alternating (non-random) sequence, giving twenty-eight participants per arm. Assignment was stratified by angulation according to Winter's scheme, so that each of the four angulation categories contributed seven cases to each arm. Microvascular perfusion was quantified in perfusion units using a laser Doppler flowmeter (Perimed, Järfälla, Sweden). One recording site lay on the mid-buccal aspect of the tooth immediately anterior to the extraction site, at the crossing of its mesiodistal and occlusocervical axes, and served as an index of pulp circulation; three further sites were distributed over the adjacent buccal mucosa. Probe position was reproduced across visits by a 2 mm transparent acrylic stent carrying prepared probe housings, constructed individually on a stone model. Each site was sampled for 30 seconds. Swelling was derived from three facial reference distances (gonion to labial commissure, tragus to labial commissure, and gonion to lateral canthus), averaged to a single value. Mouth opening was taken as the greatest interincisal distance. Every assessment was carried out immediately before surgery and repeated on the third and seventh postoperative days, sutures being removed at the final visit. All operations were performed by one operator with a standard armamentarium under inferior alveolar, lingual and buccal block anaesthesia, using no more than two cartridges of articaine 40 mg/mL with epinephrine 1:100,000. Bone was removed and the tooth divided with a physiodispenser and steel burs under saline cooling, and the socket was closed with 3/0 silk. All participants received amoxicillin-clavulanate, paracetamol and a benzydamine-chlorhexidine mouthrinse after the procedure. Group means were compared by repeated-measures analysis of variance with Tukey HSD pairwise testing.