[Pilot study of laser-doppler flowmetry measurement of oral mucosa blood flow]

To explore and compare the perfusion pattern of oral mucosa on Han Chinese and Caucasian by laser-doppler flowmetry.

A cross-sectional study was carried out, in 20 healthy Han Chinese adult subjects (average age: 28.4 years) and 20 healthy Caucasian (average age: 25.3 years) adult subjects, either gender with 10 subjects. Gingival perfusion was evaluated at 8 points (including upper incisor labial gingival, lower incisor labial gingival, palatal mucosa, cheek mucosa) using a laser-doppler flowmetry(O2C, Medizintechnik GmbH, Germany). Each measurement was carried out 25 seconds consisting 5 seconds of fore period and 20 seconds of work period, without pressure. The measurements were taken by two well- trained doctors, each measurement was exammed 3 times by an examiner, and the average value was recorded as final data. Each measurement has 4 parame ters: SpO₂(oxygen saturation), rHB (relative amount of hemoglobin), flow (the blood flow of unit interval), and velocity (blood flow velocity). We compared the data by different sites, different genders, and different races.

For palatal gingival, the average SpO₂ was 77.1%±10.9%, the average rHB 67.8±11.1, and the average flow 194.1±63.7, which presented significant lower values than other oral mucosa. There was no significant difference among other sites. There was some significant difference between the Caucasian and the Han Chinese: the maxillary central incisor oxygen saturation (SpO₂) which were averages of 75.6%±8.2% and 70.4%±7.6%; buccal mucosa hemoglobin (rHB) averages of 79.9±5.8 and 83.5±6.6, which had statistical differences. For most measurement points, the oxygen saturation on men was lower than that on women, which had significant difference.

To investigate microcirculation pattern, oral mucosa can be the good observation site. Laser-doppler flowmetry is a well-documented instrument to survey on microcirculation.There may be differences between the genders in hemoglobin oxygen-binding capacity, which may have some impact on the ability of soft tissue healing. Oral mucosa display more blood perfusion than attached gingival. As the recipient site of gingival graft, maxilla and mandible have slight difference in blood supply.