Assessment of the referral system for surgical removal of third molars at the Dental Faculty, King Saud University

Abstract

Introduction: There is compelling evidence that prophylactic extraction of third molars is a health problem that needs to be addressed. In particular, the vast amount of evidence demonstrating complications after removal of third molars, rather than supporting the necessity of removal or the negative effects of retention, raise this concern. Objective: The aim of this study was to investigate the referral system for third molar extraction at our institution by assessing patient opinions and the experience of the oral surgeons and the referring dentists. The main outcome measures of concern were the reasons for third molar extraction, patient awareness about the surgery and the comorbidities that may accompany the surgery. Methods: Pilot cross-sectional survey questionnaires were distributed at the Dental Faculty Clinic at King Saud University, from 15 March 2015 to 30 June 2016 by the staff in charge of the patient waiting area, oral surgery clinic, primary care clinic and specialist clinic. Results: Of 400 potential respondents, 226 completed the survey (response rate: 54%). Of these patients, 91% knew why they had been referred to the oral surgery department, but 73.5% did not understand the surgical extraction procedure or its complications. In total, 45.2% of the patients referred had no signs or symptoms, and 36% were referred for prophylactic reasons. In conclusion, our system needs reassessment. To combat the subjective health practice of routinely referring patients for prophylactic extraction, the role of primary care should be emphasised by implementing a system for regular patient check-ups, and public awareness should be increased.

Introduction

Wisdom teeth, or third molars, generally erupt in the mouth when individuals are between 17 and 24 years of age1., 2.. Compared with other teeth, wisdom teeth often fail to erupt or erupt only partially³. Impaction occurs when complete eruption into a normal functional position is prevented before root growth is fully established. This may be caused by lack of space in the mouth, obstruction by another tooth or development in an abnormal position⁴. A tooth that is fully impacted can be completely covered by soft tissue, partially covered by bone and soft tissue or completely covered by bone. In contrast, partial eruption occurs when the tooth is visible in the dental arch of the jaw but has not erupted into a normal functional position⁵. A vast number of cases of wisdom tooth removal for either symptomatic or asymptomatic reasons have been reported. In 1994–1995, there were approximately 36,000 inpatient surgeries and 60,000 same-day wisdom tooth surgeries in England. Later figures for Wales indicate that there were up to 3,000 procedures in 1998–1999. Similarly, 10 million third molars (wisdom teeth) are extracted from approximately 5 million people in the USA each year⁶. The rates of hospitalisation for third molar removal in Australia and France, where no specific guidelines exist for removal of such teeth, are nearly seven and five times higher, respectively, than the rate in England⁷.

An impacted wisdom tooth is asymptomatic if the patient does not experience associated signs or symptoms of pain or discomfort⁸. The literature also uses the term ‘disease-free’ for this condition⁷. Asymptomatic impacted teeth are sometimes extracted for prophylactic reasons in routine clinical practice, such as to prevent crowding of the front teeth (incisors) in the future⁹. Late incisor crowding following orthodontic treatment during adolescence may also be considered as a risk associated with leaving asymptomatic third molars in place¹⁰. However, this finding was contradicted by a randomised trial that was performed by Harradine et al.¹¹: the authors stated that ‘There is no evidence that extraction of asymptomatic third molars influences lower incisor crowding after a 5-year follow up period’. Nevertheless, the removal of wisdom teeth is still one of the most common procedures performed by oral surgeons worldwide¹².

As with any surgical procedure, extraction of impacted third molars is associated with a degree of risk of adverse events. Short-term adverse effects of third molar extraction surgery include temporary nerve damage and postoperative complications, such as alveolar osteitis (AO; dry socket), infection, secondary haemorrhage, pain, swelling and trismus. Long-term adverse effects of third molar surgery are uncommon but may include permanent nerve damage (up to 1% of patient), damage to adjacent teeth or, very rarely, mandibular fracture¹⁰. The risk of general anaesthesia should not be underestimated either, as it includes a low risk of unpredictable outcomes. There is consensus that the removal of wisdom teeth is appropriate if symptoms of pain or pathological conditions related to the wisdom teeth are present¹². However, the cited review found no evidence to support or refute routine prophylactic removal of asymptomatic impacted wisdom teeth in adults¹².

Mercier and Precious carried out a critical review of the literature on third molar removal in 1992¹³. They found that there were no absolute indications or contraindications for removal of asymptomatic third molars and argued that the surgeon must weigh the facts and put the interests of the patient above all else. In light of this paper, in 1999, the South African Society of Maxillo-Facial and Oral Surgeons recommended that each case be assessed based on its own merits. The decision of whether to remove the third molars should specifically be based on the overall benefit to the patient's oral status and general health. However, the benefits of practicing preventative medicine and dentistry are also endorsed¹⁴. In 1998, Kostopoulou et al. conducted a study that tested the intra-observer reliability of the removal of asymptomatic third molars. This study involved 10 oral surgeons and 10 general dentists with up to 28 years of experience and concluded that there was no rational basis for treatment. Therefore, the decision to remove third molars prophylactically cannot be made reliably¹⁵. Similarly, in Finland, a study was conducted to evaluate the need for third molar removal in university students, 20–32 years of age. The author of that study concluded that the routine prophylactic extraction of asymptomatic third molars in young adults was not recommended. Well-defined indications for prophylactic removal of third molar teeth are therefore needed¹⁶. The literature reports that changes in the practice of removal of wisdom teeth in Europe may have occurred in response to the 2000 National Institute for Health and Care Excellence (NICE) guidelines of the Royal College of Surgeons, which recommended that third molar removals should be restricted to symptomatic cases⁵.

However, many dentists and patients share the belief that prophylactic removal of asymptomatic wisdom teeth is justified to avoid future problems and complications associated with these teeth, which may be both more difficult and more costly to treat in older patients¹⁰. This belief is supported in the following statement by the American Association of Oral and Maxillofacial Surgeons (AAOMS): ‘if there is insufficient anatomical space to accommodate normal eruption… removal of such teeth at an early age is a valid and scientifically sound treatment rationale based on medical necessity’¹⁷.

A study by Renton et al.¹⁸ was conducted in 2012 to assess the effectiveness of the NICE guidelines in changing the frequency of third molar surgery in the UK. The study specifically found that the frequency of impacted third molar surgeries decreased from 80% to 50% of patients admitted to hospital and that the mean age of the patients who presented for surgery increased. In contrast, there were increases in ‘caries’ and ‘pericoronitis’ as aetiologic factors for removal, in accordance with the NICE guidelines¹⁸.

Recently, in response to these data, a Cochrane review was carried out to compare surgical removal and retention of asymptomatic impacted wisdom teeth to determine whether there is evidence to support this practice¹². The review showed that there was no evidence from randomised controlled trials that prophylactic removal of wisdom teeth prevents pain or infection that may arise from the retention of these teeth. There is thus no evidence of a difference between removal or retention of third molars. Accordingly, oral surgeons can rely on clinical experience and patient preferences to make decisions concerning treatment¹².

In Saudi Arabia, to date, there are no national statistical data, covering the entire country, on this topic. However, various retrospective cross-sectional studies have reported the frequency of this procedure in different regions of Saudi Arabia. The estimated frequency of the procedure in the western region was 40.5%, which is higher than the frequency estimated in the central region, of 32.3%¹⁹. Another study reported that the prevalence and pattern of impacted third molars among Saudi subjects are similar to those in other populations, with a prevalence of 72.3% for mandibular third molars and a prevalence of 13.4% for maxillary third molars. A lower prevalence was reported in the city of Jeddah, Saudi Arabia, in 2014. A prevalence of impacted third molars of 19.2% was specifically reported, based on the finding that in the time period spanning 2011 to 2013, 768 patients in a total sample size of 4,000 exhibited at least one impacted third molar²⁰.

An earlier study at King Abdul-Aziz University reported that 642 third molars were removed between 1987 and 1990 from patients in the western province and that 182 (28%) of the impacted teeth were removed for prophylactic reasons²¹. Patients are therefore being unnecessarily exposed to the risk of a surgical procedure, given that there is insufficient evidence to support or refute the routine prophylactic removal of asymptomatic impacted wisdom teeth in adults.

Therefore, the current study was conducted to evaluate our institution's referral system governing the removal of impacted third molars, either because of symptoms or for prophylaxis, in light of the available scientific evidence.

Materials and methods

All patients who were referred to the Oral and Maxillofacial Clinic of the Dental Faculty at King Saud University, from 15 March 2015 to 30 June 2016, for the removal of impacted third molars were considered for inclusion in the study. Surgical removal of the impacted third molar was performed under local anaesthesia in a dental chair. A cross-sectional survey was performed across different departments, primary case units and student courses. The study was independently reviewed and approved by the Dental Faculty Ethical Review Board (DERB) at King Saud University, and it complied with the rules related to the ‘Research Ethics on Living Organisms’ issued by Royal Decree no. M/29 and with the World Medical Association's Declaration of Helsinki. Patients, or their formal guardians in cases involving young adults (under 17 years of age), provided verbal consent; this protocol was advised and approved by the DERB. The consent form was prepared in accordance with the Research Ethics Review Committee of the World Health Organization. Subsequently, each patient was asked to complete the survey while waiting in the patient waiting area. A second survey was designed for the referring dentists, who were mostly from primary care units, student courses and specialty clinics. A third survey was directed at the surgeons with different levels of experience: consultants, specialists and residents – who performed the surgery in the oral and maxillofacial units.

The design of our survey instruments was informed by previously published surveys [the Canadian Medical Association (CMA) Referral Survey²², the College of Family Physicians of Canada (CFPC) survey²³ and the Royal Colleges survey²⁴]. The instruments were pretested by five clinical investigators unaffiliated with the research team and were modified iteratively to improve clarity, face validity and content validity. The content validity was improved by adding the referring dentist to the survey; these referrals were received from student courses that were always supervised by faculty teaching staff. The face validity was adjusted by modifying certain questions on both the patient and the oral surgeon survey forms.

Short descriptive questions were used to decrease patient and surgeon effort. For the patient questionnaire, yes/no questions were used to assess the level of awareness about the reason for the referral. We used multiple-choice questions to ascertain the main reason for prophylactic or symptomatic referral, and Likert-type questions were used to assess the difficulty of the surgery. Furthermore, multiresponse questions and open-ended questions were used. For the questions related to concerns about, and reasons for, the referral, the respondents were first asked to select any or all the overarching categories (therapeutic or prophylactic) of concern, and reasons were provided as multiple-choice responses; when the respondents selected a category, more detailed concerns and reasons were provided as non-exclusive multiple-choice responses.

Similarly, in the referring dentist questionnaire, multiresponse questions and open-ended questions were used (Tables 1 and 2).

Table 1.

Summary of the patient responses and the corresponding percentages

Patient's questions	Options	Response [% (n)]
Specify the reason for presenting for surgery today	Extraction	49.5 (58)
	Consultation	4.2 (2)
	Other (jaw pain, treatment of wisdom tooth/teeth, discomfort)	13.6 (16)
	No answer	35.8 (42)
Did you ask your dentist for a referral to the oral surgery clinic?	Yes	43.5 (41)
	No (were advised by their dentist to visit the oral surgery clinic)	56.4 (76)
Did the dentist explain the surgical extraction procedure?	Yes	73.5 (82)
	No	26.4 (35)
Did you experience or have you been informed of the presence any of the following symptoms or signs in relation to your wisdom tooth or teeth?	Single episode of pain	17.9 (12)
	Chronic (recurrent) pain	31.3 (21)
	Inflammation of the gum around the tooth	25.3 (17)
	Swelling and limitation of mouth opening	10.4 (7)
	Tumours or sac containing fluid around the tooth	5.9 (4)
	Other (malposed tooth/teeth)	4 (3)
What is the reason for your wisdom tooth removal?	Orthodontic reason	11 (13)
	To prevent caries of an adjacent tooth	19 (22)
	To prevent root resorption of an adjacent tooth	3 (4)
	I do not know	10 (11)

Table 2.

Summary of the referring dentist questionnaire results

Questions for the referring dentist	Option	Response [% (n)]
What was the reason for the referral?	Patient complaint	60 (34)
	An accidental finding during routine examination (i.e. asymptomatic tooth/teeth)	32.7 (20)
	Other	7.2 (2)
Did you order OPG for your patient before referral (if no OPG performed yet)?	Yes	81.8 (45)
	No	18.1 (9)
Is your patient aware of the possible surgical complications?	Yes	40 (21)
	No	18 (10)
	I do not know	41.8 (23)
Did you explain the procedure and its possible complications?	Yes	84.2 (36)
	No	15.7 (18)

OPG, orthopantomography.

A five-level Likert scale was used in the oral surgeon questionnaire to rate the difficulty of the surgery. The respondents were offered multiple-choice questions as well as yes/no questions.

We also collected the respondents (patients) sociodemographic characteristics, including age and gender. For the referring dentists, professional characteristics were obtained, including academic rank and the location of clinical training, as well as the source of the referral; certain referrals were from primary care units that were mostly covered by intern dentists who were supervised by general dentists, and other referrals were from specialist clinics that were mostly covered by lecturers (specialists) or assistant professors. Additionally, several referrals were from student courses in which care was usually administered under faculty supervision. To minimise bias, the questionnaires were only distributed to oral surgeons and residents who were blinded to the study objectives.

A descriptive analysis was conducted to calculate the proportion of respondents who were referred for symptomatic reasons compared with asymptomatic reasons and to identify the most common reasons in each category. For the Likert-scale responses, we collapsed ‘strongly difficult’ and ‘somewhat difficult’ into one category (‘difficult’), and we collapsed ‘strongly agree’ and ‘somewhat agree’ into one category (‘agree’) with regard to the difficulty of extraction. No variables were missing >1% of responses.

Results

A total of 400 questionnaires were distributed, of which 226 were completed.

Patient forms

Data collected from 117 questionnaires revealed that approximately one-third of the referred patients, presented to the clinic for both consultation and possible management, whereas two third were presented for definitive surgical removal (Table 1). Moreover, 76 (56.4%) of the respondents were advised by their dentist to visit the oral surgeon, implying that the patients were asymptomatic. However, only 41 (43.5%) respondents expected to undergo surgical extraction (symptomatic). The data regarding the indication for surgery showed that 67 (57.3%) and 50 (42.75%) respondents were referred for surgical removal of their wisdom teeth for therapeutic or prophylactic reasons, respectively. Regarding the therapeutic indications, 21 (31.3%), 17 (25.3%), 12 (17.9%), seven (10.4%) and four (5.9%) patients were experiencing or had experienced recurrent chronic pain, pericoronitis, one episode of acute pain, swelling and/or trismus and cystic changes or periapical pathosis, respectively. In contrast, 42.75% of the respondents thought that they had been referred for prophylactic removal of their wisdom teeth. The data showed that from the patients’ perspective, the three most common reasons for prophylactic removal were to prevent caries of the adjacent tooth, to prevent crowding of the lower anterior teeth, or as a procedure before orthodontic treatment and to prevent root resorption, as reported by 22 (19%), 13 (11%) and four (3%) patients, respectively. The remainder of the respondents, or 11 (10%) patients, indicated that they did not know the reason for the prophylactic removal of their wisdom teeth (Figure 1).

Figure 1.

Graph summarising the percentage of patients with symptomatic or asymptomatic wisdom teeth.

Referring dentist survey

At the beginning of the research, we noticed that the dentists who referred patients for wisdom tooth/teeth removal completed the forms based on their general knowledge and not on their specific experience with the patients who were undergoing surgical removal. This discrepancy caused these dentists to choose more than one answer to the questions. As a result, their questionnaires were removed from the study, and the instructions were re-emphasised to the chief nurse at each target unit (Table 2). Subsequently, the data collected from 54 questionnaires revealed that the reason for referral for surgical removal of impacted wisdom teeth was either the patients’ chief complaint, which was reported in 34 (60%) of the referral cases, or findings noticed on routine examination (asymptomatic tooth), which was reported in 20 (32.7%) of the cases. Two (3%) of the referring dentists were confused and did not answer the question. A total of 36 (69%) referring doctors explained the surgical extraction procedure and its possible complications to their patients, and 45 (81%) requested orthopantomography (OPT) before referral to the oral surgery clinic. In contrast, 23 (41%) stated that they were not sure if their patients knew what was involved in the surgical extraction procedure or the possible complications; they believed that the oral surgeon should discuss these topics with the patients.

Treating surgeon survey

The demographic data collected from 55 questionnaires are summarised in Table 3. The medians and ranges of the age groups were 17 (14–20) years, 25 (20–30) years and 45 (40–50) years, and the numbers of patients in these age groups were four (8.2%), 32 (65.3%) and 13 (26.5%), respectively. A total of 37 (67%) patients were female and the rest were male. Most of the surgeons agreed that the referral form was informative and complete; however, 21 (39%) stated that the referral form was not complete (Figure 2). Additionally, 35 (63%) surgeons had patients who expected to undergo surgery and ate their breakfast in preparation for surgery (Table 3). Regarding the time taken to explain the surgery and the possible complications, 32 (58%), 18 (33%) and five (9%) of the surgeons stated that they allotted 1–3 minutes, 5–10 minutes or more than 10 minutes, respectively, for this purpose. Additionally, they reported that 44 (80%) of the patients were referred for therapeutic extraction and 11 (20%) were referred for prophylactic removal. The reasons were mainly to prevent caries of an adjacent tooth and for orthodontic treatment, reported in five (45%) and three (27%) patients, respectively (Figure 3). Moreover, there were one (2%), 16 (31%), 30 (54.5%), five (9%) and two (3%) responses regarding the difficulty of the surgery, corresponding to extremely simple, simple, moderate, difficult and complicated, respectively. Difficulty was assessed based on clinical and radiographic examinations. Difficult and complicated cases contribute to intraoperative and immediate postoperative complications and to the time taken to complete the surgery. Therefore, the surgeons were asked to report any intraoperative or immediate complications associated with the surgeries: 50 (91%) reported no complications, whereas 9% reported complications and, of those, two (3.6%) reported a vasovagal attack (VVA) (syncope) and three (5.4%) did not specify the type of complication. Finally, the average time required for the entire surgery, including the taking of a history, was 15, 30, 45 and 60 minutes for six (11%), 25 (45%), 15 (27%) and four (7%) patients, respectively.

Table 3.

Summary of the results of the questionnaire for the treating oral surgeons, which was completed after the surgery

Questions for the treating surgeon	Options	Response [% (n)]
Patient age	14–20 years	8.2 (4)
	20–30 years	65 (32)
	30–40 years	0 (0)
	40–50 years	26 (13)
	Greater than 50 years	0 (0)
Patient gender	Female	67 (37)
	Male	33 (18)
Do you think the referral form is informative and complete?	Yes	62 (34)
	No	38 (21)
What was the stated reason for the referral?	Consultation	2 (1)
	Surgical removal	91 (50)
	Both	7 (4)
Do you believe that your patient knows the reason for the oral surgery appointment?	Yes	96 (52)
	No	4 (3)
Do you believe that your patient is psychologically prepared for surgery (e.g. ate breakfast)?	Yes	63 (35)
	No	37 (20)
Do you think that the wisdom tooth/teeth extraction was indicated?	Yes	80 (44)
	No	20 (11)
If the extraction was performed for therapeutic reasons, what was the indication?	One episode of pericoronitis	7 (3)
	Chronic pericoronitis	38 (16)
	Trismus and cellulitis	2 (1)
	Caries of an adjacent tooth	25.4 (11)
	Periodontal reasons	3.6 (2)
	Pathology	13 (6)
	Other (cheek biting)	11 (5)
If the extraction was performed for prophylactic reasons, what was the indication?	Orthodontic reason	27 (3)
	Prevention of caries of adjacent tooth/teeth	45 (5)
	Prevention of resorption of adjacent roots	9 (1)
	Other (malalignment)	18 (2)
How much time was taken to explain the surgery and answer the patient's questions?	1–3 minutes	58 (32)
	5–10 minutes	33 (18)
	More than 10 minutes	9 (5)
	Less than 1 minute	3.6
How do you rate the difficulty of the extraction?	Extremely simple	2 (1)
	Simple	31 (16)
	Somewhat difficult	54.5 (30)
	Difficult	9 (5)
	No answer	3 (2)
Did the patient develop any complications?	Yes	3.6 (2)
	No	91 (50)
	No answer	5.4 (2)
How much time was taken for the entire surgery?	15 minutes	11 (6)
	30 minutes	45 (25)
	45 minutes	27 (15)
	60 minutes	7 (4)
	No answer	9 (5)

Figure 2.

Graph showing consistency between the information in the referral forms (informative and complete) and the patients’ preparation for surgery in terms of their knowledge about the surgery. There was a high correlation between the level of patient awareness and the completeness of the referral forms.

Figure 3.

Graph showing the percentages of patients who presented to the oral surgery clinic for therapeutic or prophylactic reasons from the oral surgeons’ perspective. The data show that the most common therapeutic and prophylactic reasons were chronic pain and the prevention of root resorption of the adjacent tooth, respectively.

Discussion

To practice evidence-based medicine, clinicians need to apply the findings of scientific research to the circumstances of individual patients as part of the clinical decision-making process. Based on this view, we conducted the primary survey, described here, to evaluate our referral system governing the surgical removal of impacted wisdom teeth at both the male and the female campuses of the Dental Faculty clinic at the College of Dentistry, King Saud University, from March 2015 to June 2016.

The data showed that female patients were predominant among those referred, accounting for 67% of the cases. This finding is not consistent with reports involving the Saudi population, including reports by Haider and Shalhoub and Bokhari et al.25., 26.. The difference may be a result of the participation of more respondents from the female campus in the present study. Meanwhile, a high impaction rate was reported among patients in the 20–30 years age group, which was consistent with data from the literature26., 27., 28..

In general, the data from the patient questionnaire showed that 57.2% and 42.7% of patients were referred for therapeutic (symptomatic) or prophylactic (asymptomatic) reasons, respectively. The data also showed that the percentage of patients who expected to undergo surgical extraction (patient questionnaire) was consistent with the percentage of patients who underwent surgery for therapeutic indications (surgeon questionnaire), which was found to be 57%. This result implies that a symptomatic reason is often the primary motive for a patient who chooses to undergo wisdom tooth/teeth extraction. The common symptoms reported by the patients in the current study included recurrent pain and pericoronitis, which were reported by 31.3% and 25.3% of patients, respectively. Based on evidence in the literature, these are considered as the appropriate indications for surgery; however, a single episode of pericoronitis, unless particularly severe, should not be considered as an appropriate indication for surgery, whereas a second or subsequent pericoronitis episode should be considered as an appropriate indication for surgery⁵. Irrigation of the pocket with saline and chlorhexidine, or even with an antibiotic solution in the case of an abscess, is the recommended first-line treatment²⁹. A single episode of pericoronitis was reported as the reason for extraction by 17.9% of the patients in the present study; in contrast, the oral surgeons reported that 7% of their patients required surgical removal because of a single episode of acute pain.

Based on evidence in the literature, the surgical removal of impacted third molars should be limited to patients with evidence of pathology⁵. Such pathology includes the following: unrestorable caries; non-treatable pulpal and/or periapical pathology; cellulitis; abscess and osteomyelitis; internal/external resorption of the tooth or adjacent teeth; tooth fracture; follicle disease, including cysts and tumours; tooth/teeth impeding surgery or reconstructive jaw surgery; and tooth involvement within the field of a tumour resection⁵.

In the present study, based on the patient survey, the data also showed that 42.7% of patients were symptom free. However, the patients’ main concerns were: (i) the prevention of caries of adjacent teeth or the prevention of crowding of anterior teeth; and (ii) orthodontic issues, which were reported by 44% and 26% of the respondents, respectively. Similarly, the data from the oral surgeon survey revealed that 20% of patients were referred for prophylactic reasons, either for an extraction to prevent caries of adjacent teeth (63.6% of patients) or for orthodontic treatment (36.4% of patients). The difference in percentages occurred because the number of patients referred was larger than the number of referrals seen by the surgeons because certain patients either failed to present to the surgery clinic or changed their minds about surgery. The finding that one-third of the patients were referred for prophylactic reasons (i.e. an asymptomatic tooth/teeth) is significant. The estimated proportion of such patients at our centre is consistent with the results of a study that was performed in the western province of Saudi Arabia 25 years ago, in which the authors stated that 28% of impacted teeth were removed prophylactically²¹. In the literature, the incidence rate of distal caries related to an impacted third molar varies. In 2012, Sheikeh et al.³⁰ reported that 42.5% of such cases showed caries on the distal aspect of mandibular second molars in a retrospective study of 200 impacted third molars. However, in 2015, Silva et al.³¹ reported that the incidence of distal caries of the second molar was 25.5%; the authors stressed that factors such as oral hygiene and the caries index should be considered before deciding to remove third molars prophylactically. In contrast, in 2002, Bataineh et al.³² reported that an orthodontic indication (0.3%) and caries of the second molar (0.5%) were rare indications for prophylactic removal of a third molar in a retrospective study. Finally, in 2008, Torres et al.³³ found that orthodontic reasons were the second principal indication for third molar extraction, accounting for 19.4% of extractions, as reported by oral surgeons, and for 34.8% of extractions according to general dentists.

Little evidence regarding the comorbidities of retaining third molars can be found in the literature. Recently, a prospective study (funded by the AAOMS) that included 6 years of periodontal follow-up for asymptomatic third molars, was published³⁴. The study concluded that good oral health practices could effectively maintain a healthy third molar periodontal status. Moreover, in 2015, Bouloux et al.³⁵ performed a systematic review regarding the risk of future extraction of asymptomatic third molars. The study showed that 3% of previously asymptomatic third molars were removed every year, with more wisdom teeth being removed as the patient age increased. In contrast, there was a significant, inverse association between the development of symptoms and age³⁶; thus, older patients were less likely to develop signs/symptoms that warranted removal. A reviewer for this study highlighted the role of practitioners in discussing the risks and benefits of both retention and removal of asymptomatic lower wisdom teeth with even a slight risk of future loss³⁷. Furthermore, the role of informed consent in each case that involved removal for prophylactic reasons was emphasised³⁷. Regarding the orthodontic indication for the extraction of a third molar, our survey showed that 26–36% of patients had orthodontic reasons for extraction. The orthodontist has a role in the decision-making process, and the risks and benefits should be discussed with patients before referral. Based on evidence in the literature, the orthodontic indication for wisdom tooth removal is limited to preparation for future orthognathic surgery or, in the case of molar distalisation, is required to correct Class II or Class III malocclusion if indicated³⁸. Nevertheless, premolar extraction may be the treatment of choice when more than 3 mm of molar distalisation is necessary³⁸. In contrast, the presence of a third molar has little influence on late mandibular incisor crowding, although it influences the mesial migration of posterior teeth³⁹. Finally, our findings showed that 16% of the prophylactic cases involved other causes, such as cheek biting or the removal of non-functioning teeth; it would surely be inappropriate to use the removal of upper wisdom teeth to justify the removal of lower third molars when the risks are proportionally greater for the latter³⁸. In our survey, three (4%) young patients presented with the complaint that their wisdom teeth were malaligned and required removal. These patients probably had an asymptomatic tooth/teeth and were informed about the impaction by their dentist. In our study, we did not report on the severity or type of impaction, as the main objective of the study was to assess our referral system. In an earlier, large, longitudinal study that evaluated the fate of maxillary and mandibular third molars over time in a population-based cohort of young adults⁴⁰, the authors concluded that the presence of a radiographically diagnosable impaction at age 18 was not a sufficient indication for the prophylactic removal of a third molar because a significant proportion of third molars do erupt fully if given time.

The vast majority of research provides evidence regarding the risks associated with the removal of the third molars, including temporary or permanent nerve damage, AO, infection and haemorrhage, as well as temporary local swelling, pain and trismus. There are also risks associated with the need for general anaesthesia in some of these procedures, including rare and unpredictable instances of death. Those patients who are referred for prophylactic surgical removal are therefore being unnecessarily exposed to the risk of a surgical procedure⁵. In a large retrospective study, the reported postoperative complication rates for mandibular and maxillary third molar extraction were 4.3% and 1.2%, respectively⁴⁰. A randomised controlled clinical trial that compared the incidence of injury to the inferior alveolar nerve (IAN) with the incidence of AO showed that nerve damage occurred after extraction in 19% of patients and that the incidence of dry socket infection was 10%⁴¹. A similar study also reported that the incidence rates of injury to the IAN and AO were 5% and 2.8%, respectively⁴². A meta-analysis of randomised controlled clinical trials reported that the incidence of alveolar and wound infections was 14.4% and 6.1%, respectively⁴³. Another study showed that AO and dry socket occurred in 25–30% of patients undergoing removal of impacted mandibular third molars⁴⁴. Less commonly reported is more severe postoperative infection, such as severe fascial space cellulitis, and this is reported even less frequently than AO, affecting approximately 2–12% of patients45., 46.. Regarding pain, third molar extraction typically causes postoperative pain of moderate to severe intensity⁴⁷ and was used as a pain model to test acute pain in a study by Moore et al.⁴⁸.

Based on the above evidence, the British NICE is unequivocal in its recommendation, which was adopted by the National Health Service: ‘The practice of prophylactic removal of pathology-free impacted third molars should be discontinued’⁵. Government-funded programmes in the USA are beginning to adopt similar policies; an example is the Healthy Kids Dental program administered by Delta Dental of Michigan. Improved education of dentists that begins in dental school, and education of the public on the reasons to avoid unnecessary extractions, are also needed¹.

There is no strong evidence to support a health benefit for the prophylactic removal of pathology-free impacted teeth⁴⁹. The conditions under which extraction is justified include non-restorable dental caries, pulpal infection, cellulitis, recurrent pericoronitis, abscesses, cysts and fractures. However, the last indication for removal was contradicted in a randomised controlled trial that investigated removal compared with retention of asymptomatic third molars in patients with mandibular angle fractures. The study specifically showed that there was no significant difference between the groups in terms of bone healing; therefore, tooth retention is justifiable in the setting of a mandibular fracture⁵⁰.

In the current study, in relation to patient preparation and awareness, the oral surgeon survey showed that 38% of the patients were referred by their dentist (from a student clinical courses or a specialist or general dentist) for consultation and possible extraction. However, it was found that 37% of the patients were not aware of the meaning of dentoalveolar surgery. Ultimately, the surgeon decided whether to retain or extract the third molar based on the patient's history and the clinical examination, and eventually, this led to more time being spent by surgeons in explaining the surgical procedure (if indicated for extraction) or the risks and benefits (if the surgeon decided to retain the tooth). The surgeons surveyed reported that it took 5–10 minutes to explain the surgical procedure in 33% of patients and more than 10 minutes in 10% of patients, which impacted the overall time taken by the surgeons to finish the surgery. It was also found that in 27% of the patients treated, the operation time was 45 minutes, but that five of the patients were rated as difficult; this issue would have been minimised if the referral system was improved. Therefore, it is part of the duties of the referring dentist to prepare the patient by briefly describing dentoalveolar surgery, explaining the possible complications and explaining that the patient can consume his or her regular meal before surgery. Alternatively, if the tooth or teeth are not appropriate for extraction, conservative treatment and regular follow-up with the dentist would be advised. In fact, it has been found that general dentists play an important role in the decision-making process for third molar management⁵¹. Moreover, patient adherence to their dentists’ recommendations to retain and monitor a third molar is high⁵¹. There is also evidence that preoperative information can lead to significant anxiety reduction among patients undergoing oral surgery⁵², and it has been shown that anxiety is related to the perception and tolerance of pain. Furthermore, patient anxiety may impair how well the practitioner's performance of delicate and complex treatment procedures, and it has been found that dentists consider dental treatment to be technically superior when dental patients experience less stress⁵³. Moreover, anxious dental patients require up to 20% more chair time than those who are calm and relaxed⁵³. In our primary survey, two (3.6%) patients developed a vasovagal attack as the main complication reported by the treating surgeons. These findings support the need to examine our referral system and to emphasise the role of the referring dentist in providing a brief explanation of surgical extraction to orient the patient before referral. Therefore, we may consider including lessons on referral as part of both the graduate student curriculum and management skill practice training.

Conclusion

At our institute, 30% of patients were referred for the extraction of asymptomatic teeth. However, only 20% of patients who were seen and managed by oral surgeons believed that the extraction of one or more teeth to prevent caries of an adjacent tooth or for orthodontic reasons was necessary. A similar multicentre study should be performed in the same region to allow us to draw more definitive conclusions. The practice of prophylactic third molar extraction occurs worldwide¹, and it is generally based on the norms of practice or local or regional standards of care, crediting each school of thought as having equal merit and ignoring scientific evidence.

The role of primary dental health personnel (referring dentists) should be emphasised, and their primary objectives should include monitoring the oral health of their patients to facilitate the detection of both caries and periodontal or pathological changes that could occur in relation to impacted third molars. Meanwhile, public awareness should be increased by conducting community health campaigns that stress the importance of regular visits to the dentist every 6 months. Emphasising the role of the primary health team should raise awareness of the need to avoid the extraction of any third molar in the absence of a pathological condition or a specific problem.

Conflict of interest

None.

Acknowledgements

We would like to acknowledge College of Dentistry Research Centre (CDRC) for their support, thanks to the charge nurses at the Oral and Maxillofacial Clinic in the GUC and BUC campuses, namely, Ms. Fatma Racam and Ms. Vicky Orah, respectively, as well as the students and our colleagues at the Dental Faculty, King Saud University, Riyadh, KSA. There was no financial support for this study.