Current status of the anterior middle superior alveolar anesthetic injection for periodontal procedures in the maxilla

Periodontal procedures require adequate anesthesia not only to ensure the patient's comfort but also to enhance the operator's performance and minimize chair time. In the maxilla, anesthesia is often achieved using highly traumatic nerve blocks, apart from multiple local infiltrations through the buccal vestibule. In recent years, anterior middle superior alveolar (AMSA) field block has been claimed to be a less traumatic alternative to several of these conventional injections, and it has many other advantages. This critical review of the existing literature aimed to discuss the rationale, mechanism, effectiveness, extent, and duration of AMSA injections for periodontal surgical and non-surgical procedures in the maxilla. It also focused on future prospects, particularly in relation to computer-controlled local anesthetic delivery systems, which aim to achieve the goal of pain-free anesthesia. A literature search of different databases was performed to retrieve relevant articles related to AMSA injections. After analyzing the existing data, it can be concluded that this anesthetic technique may be used as a predictable method of effective palatal anesthesia with adequate duration for different periodontal procedures. It has additional advantages of being less traumatic, requiring lesser amounts of local anesthetics and vasoconstrictors, as well as achieving good hemostasis. However, its effect on the buccal periodontium appears highly unpredictable.

Effectiveness of anterior middle superior alveolar injection using a computer-controlled local anesthetic delivery system for maxillary periodontal flap surgery

BACKGROUND: Profound anesthesia with adequate duration is required in periodontal flap surgery, which involves the manipulation of both hard and soft tissues. The anterior middle superior alveolar (AMSA) injection may be an alternative to multiple injections required for this purpose in the maxilla. The present study aimed to assess the effectiveness of AMSA injection using computer-controlled local anesthetic delivery (CCLAD) system to anesthetize buccal hard tissue (BHT), buccal soft tissue (BST), palatal hard tissue (PHT), and palatal soft tissue (PST) around the maxillary teeth. METHODS: Thirty-five patients who were indicated for open flap debridement in a whole maxillary quadrant were given AMSA injection using the CCLAD. The effectiveness of anesthesia was evaluated using subjective and objective parameters around each tooth. Supraperiosteal infiltrations were administered to complete the surgery wherever the AMSA injection was ineffective. RESULTS: The AMSA injection was more effective on the palatal tissues than on the buccal tissues, as 94.14% of PST and 87.89% of PHT sites were anesthetized compared to 49.22% and 43.75% of BHT and BST sites, respectively. There was no significant difference in the frequency of anesthesia around the anterior and posterior teeth. The PHT was significantly more anesthetized (P = 0.003) in males than in females. CONCLUSIONS: The AMSA injection using CCLAD is highly effective on palatal tissues and could be used as a first-line anesthesia for periodontal flap surgery. However, its effect on buccal tissues is less predictable, with supraperiosteal infiltration often required to supplement the AMSA injection.

Comparison of pain intensity of anterior middle superior alveolar injection with infiltration anesthetic technique in maxillary periodontal surgery

PURPOSE: The aim of the present clinical trial was to compare pain during injection of anterior middle superior alveolar (AMSA) technique with that of infiltration injection technique in the maxilla in periodontal flap surgeries of patients referring to the Department of Periodontics, Faculty of Dentistry, Tabriz University of Medical Sciences. METHODS: Twenty subjects with an age range of 20 to 40 years were selected for the present study. One side of the maxilla was randomly selected as the test side and the other as the control side using a flip of a coin. AMSA technique was used on the test side and infiltration technique was used on the control side for anesthesia. On both sides 2% lidocaine containing 1:80,000 epinephrine was used for anesthesia. The operator obtained the visual analogue scale for each patient immediately after the injection and immediately after surgery. Data was analyzed using descriptive statistical methods (frequency percentages, means and standard deviations) and Wilcoxon's test using SPSS ver. 13 (SPSS Inc.). Statistical significance was defined at P<0.05. RESULTS: There were no statistically significant differences in pain during injection between the two techniques (P=0.856). There were statistically significant differences in postoperative pain between the two injection techniques (P=0.024). CONCLUSIONS: Postoperative pain in AMSA injection technique was less than that in the infiltration technique. Therefore, the AMSA technique is preferable in the periodontal surgeries for the anesthesia of palatal tissues given the fact that it has other advantages, too.

Comparison of pain intensity of anterior middle superior alveolar injection with infiltration anesthetic technique in maxillary periodontal surgery

PURPOSE: The aim of the present clinical trial was to compare pain during injection of anterior middle superior alveolar (AMSA) technique with that of infiltration injection technique in the maxilla in periodontal flap surgeries of patients referring to the Department of Periodontics, Faculty of Dentistry, Tabriz University of Medical Sciences. METHODS: Twenty subjects with an age range of 20 to 40 years were selected for the present study. One side of the maxilla was randomly selected as the test side and the other as the control side using a flip of a coin. AMSA technique was used on the test side and infiltration technique was used on the control side for anesthesia. On both sides 2% lidocaine containing 1:80,000 epinephrine was used for anesthesia. The operator obtained the visual analogue scale for each patient immediately after the injection and immediately after surgery. Data was analyzed using descriptive statistical methods (frequency percentages, means and standard deviations) and Wilcoxon's test using SPSS ver. 13 (SPSS Inc.). Statistical significance was defined at P<0.05. RESULTS: There were no statistically significant differences in pain during injection between the two techniques (P=0.856). There were statistically significant differences in postoperative pain between the two injection techniques (P=0.024). CONCLUSIONS: Postoperative pain in AMSA injection technique was less than that in the infiltration technique. Therefore, the AMSA technique is preferable in the periodontal surgeries for the anesthesia of palatal tissues given the fact that it has other advantages, too.

Mutagenicity of some topoisomerase II-interactive agents

Among the anticancer drugs currently used in the treatment of human malignancies, as well as several new series of drugs under development, are targeted at topoisomerase II enzymes. Besides of inducing cell death due to both 'mitotic catastrophe' and the induction of apoptosis, topoisomerase-II-targeted drugs can increase the frequency of cells bearing mutations. These cells can develop resistance to the therapeutic agents or may lead to the development of secondary tumours and abnormal reproductive outcomes. This review focuses on the mutagenic properties of the topoisomerase II poisons etoposide, doxorubicin and amsacrine, which are front-line therapies for a variety of malignancies, and genistein, which is prominent in soybean foods and is believed to be a chemopreventative agent that contributes to the low incidence of specific cancers among Asian populations. In addition, the topoisomerase II catalytic inhibitor merbarone that is in clinical trials as an anticancer agent will be discussed. It clear from the present review that, the topoisomerase II-interactive anticancer agents appear to be mutagenic. Therefore, the clinical use of these mutagenic drugs must be weighed against the risks of secondary malignancies in cured patients and persistent genetic damage of their potential offspring

Interactions between antiplasmodial 3,6-diamino-1'-dimethyl-9-anilinoacridine and hematin and concanamycin A.

Antiplasmodial 9-anilinoacridine derivatives exert their effects either by inhibiting DNA topoisomerase (topo) II or by interfering with heme crystallization within the parasite acidic food vacuole. Previous studies have shown that analogs of 9-anilinoacridine containing 3,6-diamino substitutions (in the acridine ring) inhibit Plasmodium falciparum DNA topo II in situ, whereas those with a 3,6-diCl substitution act by inhibiting beta-hematin formation, a property also seen with 3,6-diamino-1'-dimethyl-9-anilinoacridine (DDAA). To understand this seemingly anomalous property of DDAA, studies of its interaction with hematin and localization within the parasite food vacuole were undertaken. A weak interaction with hematin was demonstrated spectroscopically. Antagonism of DDAA inhibition of Plasmodium falciparum growth in culture by concanamycin A, a macrolide antibiotic inhibitor of vacuolar H(+)-ATPase derived from Streptomyces sp, was equivocal.

In vitro sensitivity of Trichomonas vaginalis to DNA topoisomerase II inhibitors.

Vaginal trichomoniasis is a highly prevalent sexually transmitted disease caused by a microaerophilic protozoan Trichomonas vaginalis. The disease is one of the most common sexually transmitted disease and can augment the predisposition of individuals to human immunodeficiency virus (HIV) infection. Although the disease can be treated with metronidazole and related 5-nitroimidazole, cases of trichomonal vaginitis which are refractory to standard treatment seems to be increasing. Clearly, new antitrichomonad agents are needed and DNA topoisomerase II may acts as a new target for antitrichomonad agents. In this study, in vitro sensitivity of T. vaginalis to DNA topoisomerase II was investigated. Axenic culture of local strain of T. vaginalis was performed. Both eukaryotic and prokaryotic DNA topoisomerase II inhibitors such as ellipticine, amsacrine and fluoroquinolones were tested for effectiveness against T. vaginalis in vitro compared to metronidazole. T. vaginalis was sensitive to metronidazole under aerobic conditions. Minimal inhibitory concentrations (MICs) of eukaryotic DNA topoisomerase II inhibitors, ellipticine and amsacrine, were 6.4 mM and 64 mM, respectively. The MICs of prokaryotic DNA topoisomerase II or DNA gyrase inhibitors; ciprofloxacin, ofloxacin and norfloxacin were 64, 960 and 1,280 mM, respectively. Based on the results, among DNA topoisomerase II inhibitors ellipticine was the most effective drug against T. vaginalis in vitro whereas fluoroquinolones did not show high antitrichomonad activity.

Genotoxic effects of poly-D-lysine in m-AMSA (amsacrine) treated Chinese hamster ovary (CHO) cells.

Cultured Chinese hamster ovary (CHO) cells were pre-treated with m-AMSA (amsacrine) and post-treated with different doses of polycationic compound poly-D-lysine (PDL) during G2 period in order to test on the frequency of chromatid-type aberrations. The present results indicate that PDL enhances the genotoxic action of m-AMSA measured as induced chromatid aberrations.

Amsacrine binds in a cooperative manner to deoxyribonucleic acid.

The intercalative binding of the acridine antitumour drug 4'-(9-acridinylamino) methane-sulphonate-m-anisidine, a known inhibitor of nucleic acid synthesis, to native calf thymus DNA has been studied using optical titration method. Amsacrine (AMSA) exhibits positive cooperativity in their equilibrium binding to DNA as indicated by the positive slope in the initial region of the binding isotherms (Scatchard plots) under conditions simulating physiological ionic strengths. m-AMSA binds with a higher degree of cooperativity than o-AMSA. Although this correlates with the effectiveness of the drugs as antitumour agents, the exact relationship between the observation of cooperative binding and pharmacological activity is yet to be determined.