Localized alveolar osteitis: the role of suture technique following disimpaction of mandibular third molars in a Nigerian Teaching Hospital

Objective: The formation of localized alveolar osteitis following mandibular third molar disimpaction is a result of a complex interaction between systemic factors, local infection and surgical trauma. This study evaluates the relationship between wound closure techniques in the development of localized alveolar osteitis (Dry Socket) following disimpaction of mandibular third molar teeth in Aminu Kano Teaching


Introduction
Localized alveolar Osteitis (Dry Socket) is a recognized and a common complication following tooth extraction. 1-3 It develops as a result a breakdown of blood clot in the extraction socket. Clinically, it is characterized by severe pain around the extraction sites with associated exposed bony walls of the extraction socket, high sensitivity on gentle probing and a foul-smelling odor with occasional lodgment of food debris inside the extraction socket. 4, 5 These clinical symptoms usually begin from the fifth day post disimpaction. 6-8 The first description of localized alveolar osteitis as 'Dry Socket' was by Crawford 6 in 1896. Other terms presently used include postoperative alveolitis, septic socket, delayed extraction wound healing, fibrinolytic alveolitis, alveolar sicca dolorosa, necrotic socket and localized osteomyelitis.
The formation of localized alveolar osteitis following mandibular third molar disimpaction is a result of a complex interaction between systemic factors, local infection and surgical trauma. 8- 12 Notable among these factors are intraoperative complications such as alveolar bone fracture, root fracture, surgical difficulty, wound closure technique, 11, 12 and, in some few cases, patient's non-adherence to post-disimpaction instructions. Findings from literature have suggested an increase in the frequency of localized alveolar osteitis following tooth extraction in female. Studies have shown that patients who had mandibular third molar disimpacted as a result of caries, infection and cystic lesion are more likely to develop localized alveolar osteitis than patients who had their disimpaction for prophylactic reasons. 13-21 The risk of developing localized alveolar osteitis and other postoperative compilations have been noted to be higher in smokers and females who use oral contraceptive drugs, but not much has been recorded of the suture techniques following mandibular third molar dismpaction. However, the incidence of localized alveolar osteitis can be reduced to 2-8% by the application of mediations such as metronidazole, tetracycline, clindamycin, chlorhexidine mouth rinse and local antiseptic pack following mandibular third molar disimpaction. [22][23][24][25] The aim of this study was to evaluate the role of wound closure technique in the development of localized alveolar osteitis among patients who had 1 third molar disimpaction at Aminu Kano Teaching Hospital, Kano, Nigeria.

Material and Methods
This study was conducted amongst consenting patients between the ages of 18 and 45 years that presented in our oral surgery and dental retainership clinics for surgical extraction of their impacted mandibular third molars. Patients with bleeding disorder, facial cellulitis, breast feeding women and patients who were receiving treatment with analgesic, anti-inflammatory treatment (both steroidal and non-steroidal anti-inflammatory) were excluded from the study.
Ethical approval for the study was provided by Aminu Kano Teaching Hospital Ethical Review Committee. (AKTH/MAC/SUB/12A/P-3/VI/1443) The surgical extraction was carried out in the Oral and Maxillofacial Surgery Clinics of the Aminu Kano Teaching Hospital (AKTH), Kano. Patients who met the inclusion criteria were randomly allocated into two groups by simple balloting (random sampling). In group I (partial wound closure) the flap was repositioned and sutured with one or two stitches (silk 3-0) with the soft and hard tissues still maintaining their anatomical configuration. In group II (complete wound closure) the socket was hermetically closed by rotating the mesial mucoperiosteal flap and sutured over the socket to the mucoperiostium on the lingual side to cover the extraction socket. The mean duration of surgery from incision to completion of suturing was recorded in minutes.
All patients received postoperative instructions and were placed on amoxicillin, 500mg 8 hourly for 5 days, metronidazole 400mg 8 hourly for 5 days and diclofenac sodium 50mg 12 hourly for 3 days, to prevent possible wound infections and pain.
The patients were evaluated for signs and symptoms of dry socket 3rd, 7th and 10th postoperative days with the aid of a questionnaire. Information collected included patient's demographics, pattern of impaction, reasons for surgical extraction and presence or absent of postoperative symptoms of dry socket formation.
The data was analyzed using statistical package for social sciences (SPSS) version 20.0 (SPSS Inc, Chicago, IL). Absolute numbers and simple percentages were used to describe categorical variables. Quantitative variables were described using measures of central tendency (mean, median) and measures of dispersion (range, standard deviation) as appropriate. No tests of significance were done.

Results
A total of 120 research participants were recruited into the study. Mean age of the participants was 31.7±5.7. Most patients fell within the 26 to 35-year-old age groups. Table 1 the overall gender distribution was almost even; there were 51.7% (n=62) males and 48.3% (n=58) females. The subjects were made up of students 38.3% (n=46), civil servants 33.4% (n=40), housewives 15.0% (n=18) and business owners/ traders 13.3% (n=16). The Hausa and Fulani ethnic groups have almost equal number of representations in the study with 51(42.5%) and 48 (40.0%) respectively. The other ethnic groups, Ibo 10.0% (n=12), Yoruba 6.7% (n=8) and others 0.8% (n=1) represented a smaller percentage in the study population table 1.
A total number of 23 patients (7.2%) developed localized alveolar osteitis from both groups. In group I (suture-less/partial wound closure), 21 patients (91.3%) developed dry socket while 2 patients (8.7%) developed dry socket in group II (complete wound closure technique). Table 2 and  table 3.

Discussion
The development of localized alveolar osteitis (dry socket) following mandibular third molar disimpaction has been a source of pain and discomfort, which has negative impact and adversely affects patient's quality of life (QoL). It is a serious challenge and of great concern to the dental surgeons. [26][27][28] Because of this and other long-term morbidity following mandibular third molar disimpaction, some countries had to develop management protocol for mandibular third molars. 29 Surgeons must weigh the benefit as well as explain in details the possible complications to patients before the procedure. 30 Disimpaction of impacted mandibular third molar is one of the most frequently performed procedures in oral surgery clinic. 30-31 This surgical intervention involves traumatic injury to adjacent soft and bony tissues with resultant postoperative complications; such as pain, swelling, limitation of mouth opening and local alveolitis. 30 Studies have shown that the severity of the postoperative complications varies and they can significantly influence patient's quality of life for days. 31 This immediate postoperative complication is as a result of inflammatory response secondary to trauma. 30 The intensity of this trauma-induced inflammatory response and the resultant post-operative complication has been attributed to various factors; such as age and gender of the patient, the degree of impaction, surgical method, soft tissue handling as well as wound closure techniques. [31][32][33][34][35] Literature review on the morbidity following surgical removal of mandibular third molar indicates that factors that increase the risk of operative difficulty of the impacted tooth significantly will also increase postoperative inflammatory pain and swelling as well as local alveolitis. It means an older female patient, above 30 years, with a horizontally impacted tooth may have increased duration of surgery and a more severe postoperative complication as a consequence. 34, 36 In a standard setting, the commonest method for the removal of mandibular third molars consist of flap development (buccal extension flap, envelope flap or triangular flap), bone removal, luxation and tooth removal. Once an appropriate flap is reflected, the next logical progression is the removal of bone around the tooth, which is carried out by use of a mallet and chisel or Guttering Teachnique. 37 Depending on the level of the third molar impaction, bone is removed from the occlusal, buccal and distal positions as required. In some cases with distoangular impactions, bone may need to be removed from the mesial aspect. The use of lingual bone split technique has also been advocated, but this method is not routinely used as it is often associated with more postoperative complications with a higher incidence of lingual nerve injury. [37][38][39] Surgical removal of mandibular third molar like any other surgical procedures may result in iatrogenic trauma to soft and hard tissues with moderate to severe inflammatory response. This position is corroborated by data obtained from previous studies which show that the incidence of postoperative complication is related to the degree of surgical trauma as well as the size of mucoperiosteal flap raised during the procedure. 34 for example, most patients report lesser incidences of postoperative local alveolitis when a small incision is made during flap development, with minimal reflection of the mucoperiosteum.  After a third molar surgery, the wound can either be left alone (suture-less), 36 closed partially or closed completely as the case may require. Though some authors advocated a suture-less technique, 40-41 This is not a common practice in our clinics as no surgeon feels comfortable leaving extraction socket of surgically extracted mandibular third molar open without a single suture. In the complete wound closure technique, the socket is hermetically closed by rotating the mesial mucoperiosteal flap and sutured over the socket to the mucoperiostium on the lingual side to cover the extraction socket. It has been said that, the completely closed socket does not allow free drainage of this inflammatory exudate, which may lead to significant swelling and pain postoperatively. 41 However, comparative studies on the effect of wound closure techniques on complications after impacted mandibular third molar surgery show minimal variation on the severity of postoperative pain and swelling using different  The formation of localized alveolar osteitis following mandibular third molar disimpaction is as a result of a complex interaction between systemic, local infection and surgical trauma. Other factors that could influence the formation of localized alveolar osteitis are the intraoperative complications such as alveolar bone fracture, root fracture, surgical difficulty and, in some few cases, patients' non-adherent to post-disimpaction instructions. The increase of fibrinolytic activity within the socket and interaction of many other factors have been reported. Though the exact pathophysiology and etiology of localized alveolar osteitis is not yet understood, studies have identified other risk factors which can contribute to its occurrence in most patients. 19, 20 The risk factor include patients with poor oral hygiene practice, surgical difficulty, surgeons' experience, use of oral contraceptive, tobacco smoking, female gender and flap design. However, the exact mechanism by which most of these risk factors influence the development of dry socket in most patients is still not understood. Findings from the present study show that wound closure technique, irrespective of other variables, was a major determinant in the development dry socket amongst the patients that underwent disimpaction of mandibular third molar teeth in our study. 42 An example was a case of a 39-year-old man who presented with bilateral mesioangular impacted mandibular molars. There was no caries on either tooth. Patient was not a known smoker nor had any systemic diseases. One side was surgically extracted with the socket completely closed and three months later the other side was also surgically removed with the socket partially closed. The patient developed dry socket on the partial closed extraction socket.
This study however, does not in any way invalidate findings from different literature from various authors the role of gender, surgeon's experience, tobacco smoking, use of oral contraceptive and all other factors that have so far be implicated in the development localized alveolar osteitis. 22 However, identification of predisposing factors and application of preventing measure is a key to the overall success in the management of dry socket. 43

Conclusion
This study showed that wound closure technique following disimpaction of mandibular third molar teeth play a major role in the development of localized alveolar osteitis. Though much work still needs to be done in this area, it is the authors' belief that the relationship between wound closure technique and dry socket formation deserve further investigation.