A prospective study of lip adaptation during six months of simulated mandibular dental arch expansion

The stability of dental arch expansion with conventional orthodontic treatments is disappointing. An increase in labial soft tissue pressure resulting from the expansion may contribute to this instability. An 8-month study of lip pressure changes resulting from lip bumper wear has been conducted, but no long-term studies have been conducted on pressure changes resulting from conventional expansion using fixed appliances. The purpose of the current study was to investigate changes in labial soft tissue pressures when conventional expansion was simulated. Twenty-two subjects wore a stent simulating mandibular dental arch expansion. They were instructed to wear the stent full-time. Lip pressure was recorded initially at 1 week, and monthly for 6 months. A repeated measures ANOVA was used for statistical analysis. A statistically significant (P < or = 0.05) increase in pressure was documented after initial insertion of the expansion-simulating stent. The increase was not maintained, suggesting an adaptation of the labial soft tissues.

The feasibility and reliability of using a home screening test to detect gingival inflammation

The purpose of this study was to evaluate the feasibility and reliability of using a home screening occult blood test to detect the presence of gingival inflammation. Fifty (50) healthy male and female subjects participated in this study. Pre- and post-stimulation saliva samples were obtained and tested for occult blood. Subjects brushed for one minute to stimulate gingival bleeding associated with inflammation. Saliva samples were obtained and tested for occult blood using a commercial screening kit. Following the screening test, a bleeding index (BOP) was determined and used as an indicator of gingival inflammation. Those with a BOP > 50% were assigned to the high group. Those with a BOP of 31 to 50% were assigned to the middle group, and those with a BOP of < or = 30% were assigned to the low group. Twelve subjects in the high group, 10 subjects in the mid group, and 2 subjects in the low group tested positive for occult blood following stimulation. A chi-square analysis showed an association between the screening test for occult blood and the groups (P = 0.0001). The test sensitivity was 75.9% and the specificity was 90.5%.

A comparison of postoperative pain experience following periodontal surgery using two local anesthetic agents

This controlled, double-blind, split-mouth study was designed to evaluate postoperative pain experience following periodontal surgery on 20 patients. Two commercially available local anesthetic agents, bupivacaine HCl and lidocaine HCl, were used. Periodontal surgeries were standardized to minimize differences in difficulty, extent and time. A patient questionnaire was used to collect data for the 24-hour observation period following periodontal surgery. During this period, pain perception was assessed by visual analogue scales. The results indicated that when bupivacaine was used, there was less postoperative pain, fewer postoperative analgesics taken and a longer period of "numbness" (anesthesia) as compared to lidocaine. The patients expressed a strong preference for bupivacaine over lidocaine.

Lip adaptation to simulated dental arch expansion. Part 2: One week of simulated expansion

An increase in resting lip pressure and the resulting disruption of the intraoral pressure equilibrium may be responsible for the poor stability found with orthodontically expanded dentitions. Passive expansion strategies seek improved stability by altering lip pressure, thus creating a new equilibrium. One of these strategies has been shown to alter pressure favorably. However, pressure changes associated with conventional expansion need to be studied before conclusions regarding the superiority of passive expansion can be drawn. The purpose of this study was to examine lip pressure changes after 1 week of simulated conventional expansion. Twenty-two subjects agreed to wear a mandibular expansion-simulating stent full-time for 1 week. Resting pressure was measured in the midline and right canine areas. Midline lip pressure decreased significantly after 1 week. Resting pressure was measured in the midline and right canine areas. Midline lip pressure decreased significantly after 1 week while pressure in the canine area did not change significantly. This finding suggests an adaptive response that varies according to anatomic location.