Seventeen adolescent and adult subjects, 8 males and 9 females aged 12 to 76 years, who were patients of record at the University of Texas Health Science Center at Houston Dental Branch Orthodontic Clinic and required TAD placement bilaterally for space closure, space maintenance, or intrusion or extrusion of teeth were included in this double-blind, prospective study. Exclusion criteria included allergy or other contraindication to any study medication, inability to consent to participation in the study, use of analgesics prior to the procedure, history of cardiovascular disease, and any contraindication to the use of TADs. The University of Texas Health Science Center at Houston Human Subjects Committee approved this study as protocol HSC-DB-07-0006, and written informed consent was obtained from each subject and, if applicable, the subject's guardian.
A random number table was used to determine which topical anesthetic was to be used first on each subject for the open-label study. The second anchor was placed after a washout period of at least 5 days, and the comparator drug utilized at the second visit.
TADs used were the Quattro temporary anchorage devices from the Mondeal Orthodontic Anchorage System (GAC International Inc, Bohemia, NY). Quattro temporary anchorage devices are self-drilling, self-tapping, polished titanium screws with a tube and slot on the head, which allow for 3-dimensional edgewise control. The threaded portion of the TAD is 1.5 mm in diameter and 7 mm in length (). Placement of the anchor is initiated in the mucosa by simply inserting the TAD through the gingival or alveolar mucosa to the periosteum, using a manual driver. All TADs were placed by the same, blinded orthodontist.
Diagram of Quattro temporary intraosseous orthodontic anchorage device (GAC International Inc) (enlargement approximately 13×).
Prior to placement of the TADs, a preoperative pulse rate was determined with a pulse oximeter (Comfort Cuff 506N3, Criticare Systems Inc, Waukesha, Wis) after the subject was allowed to sit in the dental chair for 10 minutes. Subjects were familiarized with the use of a Heft-Parker visual analogue scale25
(VAS) pain assessment instrument at the placement appointment. A baseline VAS score was taken preoperatively to quantitatively ensure that subjects were not in pain prior to the procedure, and to obtain information on the comparability/consistency of pain evaluations across the 2 groups. Pulse rate was continuously monitored for 30 minutes, because discomfort-related tachycardia will likely occur very early upon or shortly after beginning the TAD placement procedure.
The TAD placement site was marked with an intraoral dye marker. One of the 2 study drugs—20% benzocaine gel (HurriCaine Topical Anesthetic GEL, Beutlich LP Pharmaceuticals, Waukegan, Ill) or a combination product containing lidocaine 20%, tetracaine 4%, and phenylephrine 2% (TAC 20% Alternate Topical Anesthetic Gel Thick, Professional Arts Pharmacy, Lafayette, La)—was applied on the attached gingiva or alveolar mucosa overlying the intended anchorage site using a cotton-tipped applicator and was allowed to remain in contact with the tissue for the amount of time prescribed by the manufacturer (1.0 and 2.5 minutes, respectively). To blind the subject, goggles were placed over the patient's eyes while the anesthetic was applied. Placement of the TAD was then accomplished by a different orthodontist, who did not know which topical anesthetic preparation was utilized. All TADs were placed by the same, blinded orthodontist. The maximum postoperative pulse rate in beats per minute (BPM) observed within 30 minutes was recorded to be used in the experimental comparison with preoperative values. Subjects rated the pain of TAD placement on the postoperative VAS immediately after each placement procedure was completed. VAS and pulse rate data were analyzed by a blinded, independent evaluator.
In the event the subject did not tolerate placement of the orthodontic temporary anchorage device because of pain greater than mild at any time, the procedure was interrupted, the subject completed the VAS form, and the study drug was rated as a failure. A standard amide local anesthetic (2% lidocaine with 1
100,000 epinephrine) was then injected by infiltration, and the TAD placed. Subjects were monitored in the postoperative period for 1 day for the occurrence of pain and/or other complications, and appropriate analgesics and/or other interventions were provided as necessary.
Age, gender, study drug, preoperative and postoperative VAS scores, preoperative pulse rate in BPM, and maximum postoperative pulse rate in BPM data were recorded, and descriptive statistics calculated for each variable. The difference between maximum postoperative and preoperative pulse rates was calculated, as was the difference divided by the preoperative pulse rate (percent pulse rate change). A paired t
test was utilized to compare the 2 study drugs from the subjects (n
17) in which 2 TADs were placed—1 with each study drug for both VAS and percent pulse rate change. A Pearson chi-square test was utilized to compare the success rates of the 2 study drugs. The statistical significance level was set at P