Prevention of dry socket: an overview

Efficacy of Tranexamic Acid in Preventing Alveolar Osteitis in Post-extraction Sockets of First Premolars

OBJECTIVES

The present study is a randomized trial for comparing the effectiveness of tranexamic acid as an antifibrinolytic agent in preventing alveolar osteitis in the post-extraction period in patients receiving orthodontic therapy that requires extraction.

METHODOLOGY

This research was carried out in the Department of Oral and Maxillofacial Surgery, Saveetha Dental College and Hospitals, Chennai, India. A total of 40 patients were considered subjects for the research. Patients undergoing orthodontic treatment referred to the Department of Oral and Maxillofacial Surgery for the therapeutic extractions of the first premolars were considered for this study. Randomization was done to split the population into study and control. After the atraumatic extraction of the first premolars under local anesthesia using 2% lignocaine with 1:80000 adrenaline, a tranexamic acid solution of 500 mg soaked gauze over the extraction sockets was used as the intervention in the study group, and plain gauze was used on the control group. Patients were asked to hold the gauze in place for one hour. Participants were reviewed after three days for the incidence of alveolar osteitis and pain severity and healing of the extraction sockets.  Results: The prevalence of Alveolitis sicca dolorosa was found to be 5% in the research group and 15% in the control group. Patients in the control group showed more pain than the patients in the research group. The period taken for healing ranged from 7 days to 10 days in the control group and 10 days to 12 days in the study group.  Conclusion: This study gives an edge that tranexamic acid can be used as a local hemostatic agent in preventing fibrinolysis of clots and preventing alveolar osteitis.

Alveolar Osteitis: A Review of Current Concepts

PURPOSE

The purpose of the present review was to explore the pathogenesis and etiology of alveolar osteitis (AO) to obtain a more intuitive understanding of the clinical prevention and management of the condition. The different treatment modalities were discussed through both the mechanistic understanding of AO and the evidence regarding the different modes of prevention and management.

MATERIALS AND METHODS

The Ovid Medline, PubMed, and Cochrane Central Register online databases were used to complete an advanced search using the MeSH term "dry socket," generating 756 results.

RESULTS

A total of 8 studies on the prevention of AO were included, with 66 studies included for review of the reported data overall. The information was categorized into incidence, etiology and pathogenesis, prevention, and management. The relevant background information and evidence for each category were summarized.

CONCLUSIONS

Understanding of the pathogenesis and etiology of AO has improved in recent years, which has been helpful for developing effective evidence-based treatment and prevention of the condition. Clinicians should be aware of the complexity and multifactorial nature of the etiology of AO and the current concepts regarding the prevention and treatment of AO.

Hyaluronic Acid-Based Medical Device for Treatment of Alveolar Osteitis-Clinical Study

Alveolar Osteitis (AO) is a complication following the extraction of a tooth. AO manifests through localized pain in, and around, the extraction site, where the post-operative blood clot has been disintegrated. The aim of this single cohort study was to evaluate the outcome of a treatment of AO, using a pharmacological device composed of hyaluronic acid and octenidine dihydrochloride. The tested device is a sponge-like material, composed solely of a fully dissoluble medicaments (hyaluronic acid, calcium chloride, and octenidine dihydrochloride). It was designed to serve as a non-toxic, slow-dissolving antiseptic, that adheres to mucosa and obturates the wound. This study includes 58 subjects who were diagnosed with AO. The tested device was administered once daily until local pain subsided to < 20 mm of the Visual Analog Scale (VAS). The treatment was considered effective when the pain subsided to < 20 mm VAS in < 8 days of treatment; as per comparative studies. Our findings provide a statistically significant success rate of 96.0% (95.0% confidence interval of 75.75% to 97.8%) after pharmacological device administrations. No adverse medical effects were detected. Acquired data confirmed that lyophilized hyaluronic acid, combined with octenidine, is effective for the treatment of AO. The results are clinically important as AO is a common complication after third molar extractions.

Angiogenesis and the prevention of alveolar osteitis: a review study

Angiogenesis is one of the essential processes that occur during wound healing. It is responsible for providing immunity as well as the regenerative cells, nutrition, and oxygen needed for the healing of the alveolar socket following tooth extraction. The inappropriate removal of formed blood clots causes the undesirable phenomenon of alveolar osteitis (AO) or dry socket. In this review, we aimed to investigate whether enhanced angiogenesis contributes to a more effective prevention of AO. The potential pro- or anti-angiogenic activity of different materials used for the treatment of AO were evaluated. An electronic search was performed in the PubMed, MEDLINE, and EMBASE databases via OVID from January 2000 to September 2016 using the keywords mentioned in the PubMed and MeSH (Medical Subject Headings) terms regarding the role of angiogenesis in the prevention of AO. Our initial search identified 408 articles using the keywords indicated above, with 38 of them meeting the inclusion criteria set for this review. Due to the undeniable role of angiogenesis in the socket healing process, it is beneficial if strategies for preventing AO are directed toward more proangiogenic materials and modalities.

The Efficacy of Tranexamic Acid in the Reduction of Incidence of Dry Socket: An Institutional Double Blind Study

BACKGROUND

Alveolar osteitis (AO) is an important postoperative problem with an incidence of 20% to 35% especially prevalent after the removal of mandibular molars. Fibrinolysis with subsequent loss of blood clotting is believed to be the general cause of AO.

OBJECTIVES

This study aims to evaluate the efficacy of tranexamic acid, an antifibrinolytic agent in comparison with a placebo with respect to the reduction of incidence of AO after the extraction of mandibular molars by using following parameters: Pain, disintegration of Clot, halitosis.

MATERIALS AND METHODS

A double blind study consisted of 60 patients, who underwent routine dental extractions of mandibular molar teeth. Group A (30 patients) requiring routine dental extractions of mandibular teeth was randomly selected and was administered a dose of tranexamic acid orally (Pause 500mg) one hour prior to extraction of teeth. Gel foam soaked in tranexamic acid (160mg) was placed into the extraction socket postoperatively. A figure of eight silk suture was placed over the socket to secure the gelfoam. Group B (30 patients); a placebo (crocin) was given orally one hour prior to the extraction and gel foam soaked in saline was placed into the extraction socket postoperatively. A figure of eight silk suture was placed over the socket. Pain was rated individually by each patient at 3(rd), 7(th), 14(th) day after extraction and the results was statistically analysed.

RESULTS

This study supports that the use of tranexamic acid both locally and systemically following the removal of the teeth reduces the incidence of AO associated with the extraction of mandibular molars.

CONCLUSION

Tranexamic acid has several advantages also when used for simple dental extractions, namely: low cost and ready availability and therefore we recommend this treatment modality.

Dry socket: incidence, clinical features, and predisposing factors

Background. Dry socket is a global phenomenon. The purpose of the study was to investigate the incidence of dry socket in recent times in a Nigerian Tertiary Hospital. Methods. Patients who were referred for dental extractions were included in the study. The case files of patients were obtained and information retrieved included biodata, indication for extraction, number and type of teeth extracted, oral hygiene status, compliance to oral hygiene instructions, and development of dry socket. Results. One thousand, one hundred and eighty two patients with total of 1362 teeth extracted during the 4-year period of the study were analyzed, out of which 1.4% teeth developed dry socket. The mean age (SD) was 35.2 (16.0) years. Most of the patients who presented with dry socket were in the fourth decade of life. Mandibular teeth were affected more than maxillary teeth. Molars were more affected. Retained roots and third molars were conspicuous in the cases with dry socket. Conclusion. The incidence of dry socket in our centre was lower than previous reports. Oral hygiene status, lower teeth, and female gender were significantly associated with development of dry socket. Treatment with normal saline irrigation and ZnO eugenol dressings allowed relief of the symptoms.

Initial study on facilitating wound healing after tooth extraction by using microbial fiber membrane-flagyl

PURPOSE

The aim of the present study was to investigate the efficacy of microbial fiber membrane-Flagyl (MF-FLA) on facilitating hemostasis and wound healing and its anti-inflammatory ability after tooth extraction.

MATERIALS AND METHODS

For the animal experiment, 60 healthy male rabbits were randomly divided into control and treatment groups. Each group included 5 subgroups corresponding to different experimental periods (1, 2, 4, 8, and 12 weeks) and each subgroup had 6 rabbits. After the different experimental periods, the rabbits were killed, and the mandible was removed for histologic examination and analysis. For the human trial, 80 patients (32 males and 48 females; age range, 13 to 32 years), who were undergoing orthodontic treatment and who had undergone bilateral extraction of teeth were included. For every patient, the left tooth socket was treated with biting gauze for 30 to 60 minutes as the control group. The right fossa was covered with MF-FLA as the treatment group. The wound was inspected visually, its depth was measured, and radiographs were taken at the different experimental periods (1, 2, 4, 8, and 12 weeks) to evaluate the wound healing effect.

RESULTS

In the animal experiment, the results of the histologic examination indicated MF-FLA could facilitate the growth of fibroblasts and osteoblasts and inhibit inflammatory cells. In the human trial, the clinical observation indicated that the MF-FLA treatment showed better hemostatic ability than the biting gauze. After 4 weeks, the wound depth of the control and treatment groups was 3.08 ± 0.05 mm and 1.26 ± 1.06 mm (P < .01), respectively. The radiographs showed that the treatment group was superior to control group in the degree and rate of wound healing.

CONCLUSION

The results of our study have shown that the MF-FLA can promote early wound healing and reduce the incidence of postextraction complications because of its biocompatibility, isolating and anti-inflammatory ability, and supporting the formation of blood clot in the tooth socket.

Alveolar osteitis: a comprehensive review of concepts and controversies

Alveolar osteitis, "dry socket", remains amongst the most commonly encountered complications following extraction of teeth by general dentists and specialists. A great body of literature is devoted to alveolar osteitis addressing the etiology and pathophysiology of this condition. In addition numerous studies are available discussing methods and techniques to prevent this condition. To this date though great controversy still exists regarding the appropriate terminology used for this condition as well as the actual etiology, pathophysiology, and best methods of prevention and treatment. This article is a comprehensive critical review of the available literature addressing the concepts and controversies surrounding alveolar osteitis. We aim to assist the dental health care professional with patient preparation and management of this commonly encountered postoperative condition should be encountered.

Effectiveness of chlorhexidine gel versus chlorhexidine rinse in reducing alveolar osteitis in mandibular third molar surgery

PURPOSE

Chlorhexidine is an antimicrobial agent used in the prevention of postextraction alveolar osteitis, tooth decay, and periodontal diseases. There are various forms of chlorhexidine application. The most extensively studied is one that uses the rinse as the form of application. Recently, a bioadhesive gel form has become available. Its main advantage is that it prolongs the bioavailability of chlorhexidine in the application area. The purpose of this study was to compare the effectiveness of chlorhexidine gel versus a chlorhexidine rinse in reducing postoperative alveolar osteitis after the extraction of mandibular third molars.

MATERIALS AND METHODS

The experimental or gel group (n = 41) applied the bioadhesive 0.2% chlorhexidine gel to the wound during the first postoperative week and a control or rinse group (n = 32) used a 0.12% chlorhexidine rinse during the first week postextraction.

RESULTS

We observed a 70% decrease in postoperative alveolar osteitis in the gel group (P = .040). The rinse group had 25% incidence postoperative alveolar osteitis, while the gel group had 7.5%.

CONCLUSIONS

It was concluded that the topical application of bioadhesive chlorhexidine gel to the surgical wound during the postoperative week may decrease the incidence of alveolar osteitis after extraction of the mandibular third molars.

Does prophylactic administration of systemic antibiotics prevent postoperative inflammatory complications after third molar surgery?

PURPOSE

To estimate and compare the frequencies of inflammatory complications after third molar (M3) surgery in subjects receiving intravenous prophylactic antibiotics or saline placebo.

MATERIALS AND METHODS

Using a placebo-controlled, double-blind, randomized clinical trial, the investigators enrolled a sample composed of subjects who required extraction of at least 1 impacted M3 and requested intravenous sedation or general anesthesia. The predictor variable was treatment group classified as active treatment (penicillin or clindamycin for penicillin-allergic subjects) or placebo (0.9% saline). Study medications were randomly assigned. Both surgeon and subject were blinded to treatment assignment. The medication was administered intravenously prior to any incision. The outcome variable was postoperative inflammatory complication classified as present or absent and included alveolar osteitis (AO) or surgical site infection (SSI). Other variables were demographic, anatomic, or operative. Descriptive and bivariate statistics were computed. Statistical significance was set at P < or = .05, single-tailed test of hypothesis.

RESULTS

The sample was composed of 118 subjects (n = 59 per study group). In the active treatment group, there were no postoperative inflammatory complications. In the placebo group, 5 subjects (8.5%) were diagnosed with SSI, (P = .03). No subject met the case definition for AO. All SSIs were associated with the removal of partial bony or full bony impacted mandibular M3s.

CONCLUSION

In the setting of third molar removal, these results suggest that the use of intravenous antibiotics administered prophylactically decrease the frequency of SSIs. The authors cannot comment on the efficacy of intravenous antibiotics in comparison to other antibacterial treatment regimens, eg chlorhexidine mouthrinse or intrasocket antibiotics.

In vitro comparison of chlorhexidine and povidone-iodine on the long-term proliferation and functional activity of human alveolar bone cells

This work reports the behaviour of osteoblastic human alveolar bone cells (first subculture) in the presence of chlorhexidine (CHX) and povidone-iodine (PI). Short contact (2 min) of 24-h cultures with CHX, at 0.12 and 0.2%, and PI, at 5 and 10%, caused cell death within minutes; contact with 1% PI resulted in loss of the elongated characteristic cell shape. Cell adhesion was adversely affected at concentrations higher than 5 x 10(-5)% CHX or 0.05% PI. Long-term exposure to CHX at 10(-5) and 10(-4)% or PI at 10(-4)% had little effect on cell growth and caused an induction in the synthesis of alkaline phosphatase (ALP). Concentrations of CHX and PI similar and higher than, respectively, 5 x 10(-4)% or 0.05% caused dose-dependent deleterious effects. CHX affected mainly the cell growth, whereas the effects of PI were observed mostly in ALP production and matrix mineralization. Considering the levels of CHX and PI used routinely in the oral cavity, results suggest that CHX has a higher cytotoxicity profile than PI. This observation might have some clinical relevance regarding the potential utility of PI in the prevention of alveolar osteitis.

The time to onset and overall analgesic efficacy of rofecoxib 50 mg: a meta-analysis of 13 randomized clinical trials

OBJECTIVE

To determine the time to onset of analgesia of rofecoxib based on a patient-level meta-analysis of randomized, placebo-controlled, postoperative oral surgery pain studies.

METHODS

A search on MEDLINE and of Merck data on file was conducted to identify studies that met the inclusion criteria. Meta-analysis inclusion criteria required that patients were treated with a single oral dose of rofecoxib 50 mg when they experienced moderate or severe pain after surgical extraction of > or = 2 third molars; study design involved patient randomization, double-blinding, and matching placebo, and onset data from individual patients were available. The meta-analysis of time to onset also required that studies used the two-stopwatch method. Eleven studies fulfilled the onset criteria and included patients who received a single dose of rofecoxib 50 mg (N = 1220) or placebo (N = 483). These studies were analyzed to determine time to onset of analgesia, time to perceptible pain relief, percentage of patients achieving onset of analgesia, and duration of analgesia. Six of the 11 studies included a nonselective nonsteroidal anti-inflammatory drug (N = 303) and were included in the onset meta-analysis for comparison. The meta-analysis of overall efficacy also required that data on total pain relief scores over 8 hours were available. Over-all effectiveness of analgesia was based on analysis of 13 studies involving 1330 rofecoxib patients and 570 placebo patients on the endpoints of total pain relief scores over 8 hours and patient global assessment of response to therapy at 24 hours. Eight of the 13 studies with a nonselective nonsteroidal anti-inflammatory drug comparator (N = 391) were included for the efficacy meta-analysis.

RESULTS

Patient demographics and baseline characteristics were similar across treatment groups in each study. Median time to onset of analgesia for rofecoxib was 34 minutes (95% CI, 31-38 minutes), significantly faster than placebo, which did not achieve onset within the 4 hours the assessment was conducted (P < 0.001). Duration of analgesia for rofecoxib 50 mg was > 24 hours. Rofecoxib achieved a greater mean total pain relief score over 8 hours than placebo (17.4 versus 4.4; P < 0.001) and a greater patient response rate on patient global assessment of response to therapy at 24 hours than placebo (73% versus 16%; P < 0.001). Outcomes were similar between the rofecoxib group and the nonselective nonsteroidal anti-inflammatory drug group.

CONCLUSION

In this meta-analysis of over 1200 rofecoxib-treated patients, a single dose of rofecoxib 50 mg demonstrated a rapid onset of analgesia in approximately half an hour combined with sustained effectiveness, supporting its use as a treatment of acute pain.

Tetracycline compound placement to prevent dry socket: a postoperative study of 200 impacted mandibular third molars

PURPOSE

Our objective was to study whether the placement of intra-alveolar tetracycline prevents dry sockets or improves the postoperative period.

PATIENTS AND METHODS

A comparative clinical study of the surgical removal of 200 impacted mandibular third molars is made, with particular reference to postextraction pain, inflammation, trismus, and the incidence of dry socket. In 50% of these cases, a pharmacologic preparation that includes tetracycline was placed in the socket after removal of the impacted molar.

RESULTS

Dry socket was diagnosed in 4 cases (2%), with no relation to intra-alveolar tetracycline placement being observed. The patients who were administered intra-alveolar tetracycline had less pain and trismus and consumed fewer analgesics than the patients who received no such treatment, although statistical significance was not reached.

CONCLUSIONS

The intra-alveolar placement of tetracycline compound after the surgical removal of impacted mandibular third molars did not affect the incidence of dry socket.

Alveolar osteitis prevention by immediate placement of medicated packing

OBJECTIVE

The purpose of this study was to evaluate whether immediate placement of medicated dry socket packing would decrease the incidence of alveolar osteitis (dry socket) with lower third molar extractions.

STUDY DESIGN

In 100 patients, 200 lower third molars were extracted. One half of the sockets were packed to the crest of the alveolar ridge with a one-quarter-inch radiograph-detectable filament gauze that contained 9% eugenol, 36% balsam of Peru, and 55% petroleum jelly. The medicated packing was removed 1 week after surgery. None of the patients were taking antibiotics. Patients were instructed to increase their oral hygiene before and after surgery and were to use 0.12% chlorhexidine gluconate 2 days before and 3 days after surgery. RESULTS; Two hundred bilateral lower third molars of varying difficulty were extracted. The overall alveolar osteitis rate was 34 (17%). The immediately packed lower third molar sites had an alveolar osteitis rate of 8 (8%). The sockets that were not packed with medicated packing the day of surgery had an alveolar osteitis rate of 26 (26%). The difference was statistically significant (P =.001).

CONCLUSION

The results of this study suggest that placement of medicated dry socket packing immediately after lower third molar extraction decreases the alveolar osteitis rate.

Eleven myths of dentoalveolar surgery

Through the years, dentists who perform dentoalveolar surgery have perpetuated many myths and other unproven beliefs from one generation to another. Sometimes, these beliefs originated in older textbooks, while others were given birth by mentors sharing anecdotal experiences with their students. Even today, many of these scientifically unsupported statements are perpetuated in surgical textbooks and in continuing education forums and are passed on to students in dental schools. In today's evolving environment of evidence-based medicine and dentistry, these anecdotal observations do not withstand scrutiny. The purpose of this article is to review the more common surgical myths and to test their validity against scientific evidence.

Alveolar osteitis (dry socket) in a dog: a case report

Following extraction of a maxillary left first molar tooth in an eight year-old retriever, the dog re-presented five days later because of oral pain, which did not respond to analgesic therapy. The extraction site contained a foul-smelling fluid, but did not contain a clot or granulation tissue. Alveolar osteitis (dry socket) was diagnosed. The alveolus was curetted and flushed, and the dog was given cefalexine and prednisolone. The alveolus was filling with healthy granulation tissue one week later and the dog was no longer in pain.

Evaluation of topical viscous 2% lidocaine jelly as an adjunct during the management of alveolar osteitis

PURPOSE

This study evaluated the efficacy of topical viscous 2% lidocaine jelly for the alleviation of pain experienced during the instrumentation of mandibular third molar extraction sites diagnosed with alveolar osteitis and for pain relief during the postinstrumentation period.

PATIENTS AND METHODS

Thirty adult patients with a diagnosis of alveolar osteitis in a mandibular third molar extraction site were included in this prospective, double-blind study. Each patient had their sutures removed, the socket irrigated, and 2% lidocaine jelly placed on the tip and side of the tongue to blind the patient against the test substances. The subjects were then randomly distributed into two groups. Group 1 had a nonactive jelly base placed into the socket 2 minutes prior to the placement of a standard obtundant dressing. Group 2 had viscous 2% lidocaine jelly placed into the socket in the same manner. Patients subjectively quantified their pain intensity pretreatment, during instrumentation, immediately postmanipulation, at 5-minute intervals to 30 minutes, and at 45 and 60 minutes. They also subjectively quantified their pain relief at each of the time intervals following instrumentation.

RESULTS

There was no statistical difference between the pretreatment pain experienced by both groups. The use of 2% lidocaine jelly had a measurable (P = .056), but not statistically significant, effect on pain due to instrumentation. At every time interval thereafter, the use of 2% lidocaine jelly elicited a statistically significant (P < .05) decrease in pain perception, and a statistically significant increase in pain relief when compared with the inactive jelly.

CONCLUSION

Topical viscous 2% lidocaine jelly is a useful adjunct during the treatment of alveolar osteitis, especially in the early (< or = 60 minutes) postinstrumentation period.

Prophylactic application of an intra-alveolar socket medicament to reduce postextraction complications in HIV-seropositive patients

A prospective, controlled trial was performed to investigate the effect of a prophylactic socket medicament containing chlortetracycline, aspirin, and local anesthetics, in reducing the incidence of postextraction pain and infection in patients who are HIV-seropositive. Fifty patients were in the study; 25 received the experimental dressing and 25 had no dressing. Patients were asked to complete a questionnaire rating the pain at 24 hours and 48 hours after surgery. Seven days after extraction, socket healing was scored, and sockets with delayed healing sampled for culture. Four of 25 (16%) patients who received the experimental dressing and 8 of 25 (32%) controls experienced pain during the 48 hours after extraction (p = not significant). None of the group who received the experimental dressing and 7 of 25 (28%) in the control group had delayed healing, of these 4 had alveolar osteitis and three had infected sockets (p = 0.0096). We conclude that the experimental agent is useful as a prophylactic agent to reduce delayed healing in HIV-positive patients who undergo exodontia.

Gingivitis/stomatitis in cats

Any alteration in the balance of bacterial challenge versus the host's ability to resist and repair will result in oral lesions that are similar in appearance. The bacterial cause of gingivitis and periodontitis in humans and in all other animals in which it has been studied is firmly established, and specific species of predominantly gram-negative anaerobes have been implicated. Naturally occurring or acquired immunopathologies are likely to result in premature dental disease. When oral disease is associated with the accumulation of plaque, a positive response can be achieved by reducing the bacterial challenge to the host through the maintenance of oral hygiene by timely professional dental prophylaxis and home care. Disease that is the result of atypical immune responses, however, can be much more difficult to manage. Such oral disease can occur with either immune deficiencies or exaggerated immune responses, and it is likely that multiple mechanisms are active concurrently. In any case, gram-negative anaerobes present in plaque are likely to be a major contributing factor. Therefore patients with chronic refractory gingivitis-stomatitis must be considered to be plaque intolerant. Only with a frequent regimen of aggressive and thorough professional dental treatment plus meticulous oral home care on a daily basis can one expect to keep these cases in remission. Because this is often unrealistic, the only other way to keep these patients free of disease is by total dental extraction. The tissues that are colonized by the causative organisms must be eliminated. All root tips and bony sequestra must be removed and healing with intact epithelium accomplished before these cases will go into remission. Edentulous feline patients that continue to have signs of gingivostomatitis have been found to have an area of nonhealed bony sequestrum and chronic osteomyelitis. Once effective debridement has been accomplished and epithelial healing completed, nonresponsive cases can be expected to go into remission (Color Plate 2, Figure 7). It is hoped that as more is learned about this frustrating problem, the many factors influencing feline oral disease will be scientifically documented. In the future, actual diagnoses can be systematically made early on in disease, and treatment will be more than just symptomatic.

Evaluation of 0.12% chlorhexidine rinse on the prevention of alveolar osteitis

A double-blind study evaluated the ability of 0.12% chlorhexidine rinse to decrease the incidence of localized alveolar osteitis after the removal of mandibular third molar teeth. One hundred sixty extraction sites in 80 patients were evaluated. A statistically significant decrease in the incidence of dry socket was seen in patients using the chlorhexidine rinse with no significant adverse reactions. Thus a 0.12% chlorhexidine rinse is shown to be an effective means of decreasing alveolar osteitis that may follow removal of third molar teeth.