THE THICKNESS OF MASTICATORY MUCOSA IN THE HUMAN HARD PALATE AND TUBEROSITY AS POTENTIAL DONOR SITES FOR RIDGE AUGMENTATION PROCEDURES

THE AIM OF THE PRESENT INVESTIGATION was to clinically determine the t hickness of masticatory mucosa in the hard palate and tuberosity as po tential donor sites for ridge augmentation procedures. In 31 periodont ally healthy, fully dentate subjects the masticatory mucosa thickness was assessed by bone sounding with a periodontal probe. Eighteen stand ard measurement points were defined in the hard palate, located on 3 l ines which ran at different distances parallel to the gingival margin. Six positions were designated on each of these 3 Lines between the le vel of the canine and the second molar. In the tuberosity, 6 standard measurement points were defined, located on 2 lines running parallel t o the gingival margin at 2 different distances from the distal aspect of the second molar. Three positions were designated on each line. The hard palate and tuberosity were anesthetized by a spray followed by c articain injection with an epinephrine vasoconstrictor of 1:100,000. D ata were analyzed to determine differences in gender, between differen t positions, and between lines, using an analysis of variance and Wilc oxon test. The mucosa of the tuberosity was significantly thicker than in the hard palate region. Gender did not influence the thickness of masticatory mucosa, either in the hard palate or the tuberosity with t he exception of the most distant line in the palate. The mucosa was th ickest at the mid-distal position of the tuberosity. In the hard palat e, mucosa thickness increased with greater distances from the marginal gingiva. The mucosa over the palatal root of the maxillary first mola r was significantly thinner than at all other positions in the hard pa late. This represents an anatomical barrier in graft harvesting. It wa s concluded that two different regions may be defined for soft tissue graft harvesting from an anatomic point of view: 1) In the canine-prem olar region rather wide and shallow grafts may be harvested. This regi on extends distally to the first palatal molar root with a significant ly thinner mucosa. 2) The tuberosity revealed a significantly more sof t tissue thickness in comparison to the hard palate. This region allow s the harvesting of deeper grafts, but graft size is limited by the wi dth of keratinized tissue.