Relationship between the presence of unerupted mandibular third molars and fractures of the mandibular condyle

Previous studies have shown that the presence of unerupted mandibular third molars predisposes the mandible to angle fractures. This study attempted to relate the presence of unerupted mandibular third molars with the incidence of condyle fractures. The authors compared the proportion of fractures in 439 patients who had unerupted third molars or no unerupted third molars. Fractures at the condylar region showed a significantly higher incidence in patients without unerupted third molars than in those patients with unerupted third molars. This study provides solid clinical evidence to suggest that the removal of unerupted mandibular third molars predisposes the mandible to condyle fractures.     

Ectopic third molar in the mandibular condyle: A review of the literature

Objectives: To evaluate the etiopathogenesis, clinical features, therapeutic options, and surgical approaches for removal of ectopic third molars in the mandibular condyle. Study design: MEDLINE search of articles published on ectopic third molars in the mandibular condyle from 1980 to 2011. 14 well-documented clinical cases from the literature were evaluated together with a new clinical case provided by the authors, representing a sample of 15 patients. Results: We found a mean age at diagnosis of 48.6 years and a higher prevalence in women. In 14 patients, associated radiolucent lesions were diagnosed on radiographic studies and confirmed histopathologically as odontogenic cysts. Clinical symptoms were pain and swelling in the jaw or preauricular region, trismus, difficulty chewing, cutaneous fistula and temporomandibular joint dysfunction. Treatment included conservative management in one case and in the other cases, surgical removal by intra- or extraoral approaches, the latter being the most common approach carried out. In most reported cases, serious complications were not outlined. Conclusions: The etiopathogenic theory involving odontogenic cysts in the displacement of third molars to the mandibular condyle seems to be the most relevant. They must be removed if they cause symptoms or are associated with cystic pathology. The surgical route must be planned according to the location and position of the ectopic third molar, and the possible morbidity associated with surgery. Key words:Third molar, ectopic tooth, condyle, mandible.     

Dentists' decisions on prophylactic removal of mandibular third molars: a 10-year follow-up study

OBJECTIVES: In recent years, several critical outcome studies concerning the prophylactic removal of mandibular third molars have been published. These would appear to motivate a more restrictive approach today as compared with 10 years ago. The aim of the present study was to examine dentists' decisions on the prophylactic removal of impacted mandibular third molars over a 10-year period. METHODS: Thirty-six cases were selected so as to represent an equal distribution of males and females, ages, angular position and degree of impaction of the molar. Twenty-six general dental practitioners (GDPs) and 10 oral surgeons judged the same cases on two occasions 10 years apart. RESULTS: Calculated for each category of dentists, there was no significant difference in the mean number of molars designated for removal between the two occasions. Two GDPs and three oral surgeons presented a higher removal rate, whereas five GDPs presented a lower removal rate on the second occasion as compared to the first one. The dentists presented a considerable interindividual variation in removal rate, between 0 and 22 molars on the first occasion and between 0 and 25 molars on the second occasion. CONCLUSION: In the decisions on prophylactic removal of mandibular third molars, there has been no change over the last 10 years towards a more noninterventionist attitude. Thus, the dentists seem not to have been influenced by the evidence that this intervention is not cost-effective.     

Impact of impacted mandibular third molars in mandibular angle and condylar fractures

Previous retrospective analyses prove that impacted mandibular third molars (M3s) increase the risk of angle fractures and decrease the risk of concomitant fractures to the condyle. The authors have attempted to verify these relationships and identify the underlying mechanism of injury. A retrospective cohort was designed for patients attending the Division of Oral and Maxillofacial Surgery from January 2001 till October 2008. The primary predictor variable was M3. The secondary predictor variables were: M3 position, classified using the Pell and Gregory system; angulation, classified using Shiller's method; and the number of visible dental roots. The outcome variables were angle and condyle fractures. Hospital charts and radiographs were used to determine and classify these variables. The study sample comprised 1102 mandibular fractures in 600 patients. For patients injured by moderate traumatic force resulting in two fractures of the mandible, the presence/absence of impacted M3s played an important role in angle/condylar fractures. Patients with impacted M3s were three times more likely to develop angle fractures and less likely to develop condylar fractures than those without impacted M3s. This study provides clinical evidence to suggest that the removal of unerupted mandibular third molars predisposes the mandible to condyle fractures.     

The effects of NICE guidelines on the management of third molar teeth

Background Third molar surgery (TMS) is probably one of the most commonly performed surgical procedures undertaken in the NHS. In 2000, the National Institute of Clinical Excellence (NICE) introduced guidelines relating to TMS. These recommended against the prophylactic removal of third molars and listed specific clinical indications for surgery. The impact of these guidelines has not been fully evaluated and this research hopes to focus the effect of these guidelines over the last ten years.Methods Using data obtained from a variety of NHS databases such as HES (Eng & Wales), the NHSBSA and data from NHS Scotland, we looked at the age range of patients requiring third molar removal and the number of patients having third molars removed in both primary and secondary care environments from 1989 to 2009. In addition we looked at the clinical indications for TMS activity in secondary care.Findings The mean age of patients increased from 25 years in 2000 to 32 years in 2010, with the modal (most common) age increasing from 26 to 29 years. After the introduction of clinical guidelines the number of patients requiring third molar removal in secondary care dropped by over 30%, however, since 2003 the number of patients has risen by 97%. There is also a significant increase in caries as an indication for third molar removal.Conclusions More patients are requiring third molar removal with an increasing number of patients having caries related to their third molars. Patients are, on average, older confirming that the removal of third molars is shifting from a young adult population group to an older adult population group. NICE guidelines did appear to have contributed to a fall in the volume of third molars removed within the NHS post 2000. However, concluding that this reduction demonstrates the success of NICE's guidance would be a premature assumption. The number of patients now requiring third molar removal is comparable to that of the mid 1990s. NICE has influenced the management of patients with third molars but this has not resulted in any reduction in the number of patients requiring third molar removal. Coding and data collection for third molars is not uniform, leading to potential misrepresentation of data. This perhaps raises the issue that an improved universal coding system is required for the NHS and that the NICE guidelines need review.     

Summary of: The effects of NICE guidelines on the management of third molar teeth

Background Third molar surgery (TMS) is probably one of the most commonly performed surgical procedures undertaken in the NHS. In 2000, the National Institute of Clinical Excellence (NICE) introduced guidelines relating to TMS. These recommended against the prophylactic removal of third molars and listed specific clinical indications for surgery. The impact of these guidelines has not been fully evaluated and this research hopes to focus the effect of these guidelines over the last ten years.Methods Using data obtained from a variety of NHS databases such as HES (Eng & Wales), the NHSBSA and data from NHS Scotland, we looked at the age range of patients requiring third molar removal and the number of patients having third molars removed in both primary and secondary care environments from 1989 to 2009. In addition we looked at the clinical indications for TMS activity in secondary care.Findings The mean age of patients increased from 25 years in 2000 to 32 years in 2010, with the modal (most common) age increasing from 26 to 29 years. After the introduction of clinical guidelines the number of patients requiring third molar removal in secondary care dropped by over 30%, however, since 2003 the number of patients has risen by 97%. There is also a significant increase in caries as an indication for third molar removal.Conclusions More patients are requiring third molar removal with an increasing number of patients having caries related to their third molars. Patients are, on average, older confirming that the removal of third molars is shifting from a young adult population group to an older adult population group. NICE guidelines did appear to have contributed to a fall in the volume of third molars removed within the NHS post 2000. However, concluding that this reduction demonstrates the success of NICE's guidance would be a premature assumption. The number of patients now requiring third molar removal is comparable to that of the mid 1990s. NICE has influenced the management of patients with third molars but this has not resulted in any reduction in the number of patients requiring third molar removal. Coding and data collection for third molars is not uniform, leading to potential misrepresentation of data. This perhaps raises the issue that an improved universal coding system is required for the NHS and that the NICE guidelines need review.     

处理无症状第三磨牙的循证思考

第三磨牙是最易发生阻生的牙齿,与多种病变形成有关,临床上主要的治疗方法为拔除。虽然国际上对有症状第三磨牙的拔除已达成共识,但就无症状第三磨牙是否应当预防性拔除仍存在争议。循证医学要求医生对患者的诊断和治疗必须基于当前可得到的最佳临床研究证据,以保证患者得到当前最好的治疗效果。本文通过对近年来文献中关于第三磨牙拔除适应证、无症状第三磨牙可能发生的病变以及第三磨牙拔除风险等方面的内容进行综述,以便在处理无症状第三磨牙的决策制定中作出基于证据的合理选择。     

Impacted mandibular third molars and their influence on mandibular angle and condyle fractures – A retrospective study

BackgroundPrevious retrospective analyses prove that impacted mandibular third molars (M3s) increase the risk of angle fractures and decrease the risk of concomitant fractures to the condyle.Study designA retrospective cohort was designed for patients reported to the Department of Oral and Maxillofacial Surgery from January 2011 till June 2013. The study variables are presence or absence of third molar, if it is present, their position, classified using the Pell and Gregory system; angulation, classified using Shiller's method. The outcome variables were angle and condyle fractures.Materials and methodsHospital records and panoramic radiographs were used to determine and classify these variables.The study sample comprised of 118 mandibular angle and condyle fractures in 110 patients.Database was constructed and analysed using SPSS version 10.0.ConclusionThis present retrospective study concluded that the presence of impacted third molar predisposes the angle to fracture and reduces the risk of a concomitant condylar fracture. However absence of impacted third molar increases the risk of condylar fracture. The highest incidence of angle fracture was observed in position A impacted mandibular third molars. And there is no significant relationship, concerning ramus position and angulation of impacted mandibular third molars with the angle fracture.     

Third molar management: a case against routine removal in adolescent and young adult orthodontic patients.

In the nearly two decades since the National Institutes of Health conference, controversy and uncertainty have continued with respect to the diagnosis and treatment of impacted, nondiseased third molars in adolescents and young adults. Articles published over the past 10 years have studied the issue from the vantage point of risk management. Those who favor prophylactic removal justify this action on three premises: 1. All impacted third molars are potentially pathologic; therefore, prophylactic removal reduces or eliminates risk of future disease. 2. The presence of third molars can cause late crowding. 3. Removal during adolescence and young adulthood reduces risks of operative and postoperative complications compared with older patients. Those who favor conservative management offer three counter arguments: 1. Although impacted third molars do pose a risk of a pathologic condition, the risk is relatively small in comparison with the risks of operative and postoperative complications and the costs of unnecessary removal. 2. Although some investigators have shown a statistical association of third molars and late anterior crowding, the association is not strong enough to allow prediction of patients at risk. This is due principally to the high degree of individual variability, suggesting that many other factors interact in the development of postadolescent crowding. 3. Although studies have shown that morbidity is reduced when impacted, nondiseased third molars are removed during adolescence or young adulthood, the cost-risk-benefit data do not justify routine removal. Proponents of prophylactic removal argue that the benefits outweigh the risks. Proponents of conservative management argue that the scientific evidence is inconclusive in support of prophylactic removal. Unfortunately, much of the clinical research has been flawed. This has led to contradictory interpretations that have not fully clarified the relative risks and benefits of early intervention. Untrustworthy data have served only to fuel the debate and controversy concerning proper protocols. However, careful analyses of the published research show that routine removal of impacted or unerupted, disease-free third molars cannot be justified. A case-by-case management protocol that requires monitoring development represents the consensus of most researchers in this field.     

Motives underlying food choice: dentists, porters and dietary health promotion

OBJECTIVE: To test the hypothesis that Swedish dentists schedule more mandibular third molars for prophylactic removal compared with UK dentists and oral surgeons. DESIGN: Clinical and radiographic information relating to a stratified sample of 36 disease-free mandibular third molars (equal distribution of males and females, patients' age, angular position and degree of impaction) was presented to 26 general dental practitioners (GDPs) and 10 oral surgeons in Sweden and 18 GDPs and 10 oral surgeons in Wales who were asked to decide whether or not the third molars should be removed. RESULTS: There was no evidence of any difference in mean number of molars scheduled for removal by the GDPs, but the Swedish oral surgeons scheduled significantly more third molars for removal than oral surgeons in Wales. CONCLUSION: The less interventionist approach among oral surgeons in the UK may reflect the development and application of authoritative guidelines in the UK and an extensive debate concerning appropriateness of prophylactic removal there.     

Mesial force from unerupted third molars

Erupting mandibular third molars are implicated as a cause of anterior crowding of mandibular teeth. The goal of this two-part investigation was to measure the mesial force exerted by unerupted mandibular third molars. We hypothesized that such a force increases the tightness of all proximal posterior tooth contacts mesial to the mandibular second molar, and that surgical removal of third molars relieves the tightness by eliminating this force. The contact tightness between mandibular posterior teeth was measured bilaterally in 20 patients with bilateral unerupted mandibular third molars, immediately before and after unilateral removal of a third molar. We found unexpectedly that mean proximal tightness decreased bilaterally in all contacts that were measured after unilateral removal of a third molar, and we did not detect a mesial force exerted by unerupted third molars. We suspected that this bilateral relief of contact tightness resulted from placing the patients in a supine position for surgery. The second part of the experiment was conducted to determine the effects of postural change on proximal contact tightness where no surgery had been performed. For ten subjects we discovered a mean decrease in the tightness of all mandibular posterior contacts 2 hours after the patient had been moved from an upright to a supine position. The greatest mean decrease (-32%, p less than 0.0001) was found at the most posterior tooth contact. We conclude that surgical removal of unerupted mandibular third molars does not significantly reduce proximal contact tightness, but that simple movement from an upright to a supine position relieves such tightness dramatically.(ABSTRACT TRUNCATED AT 250 WORDS)     

Periodontal healing after mandibular third molar surgery--A comparison of distolingual alveolectomy and tooth division techniques

The purpose of this study was to compare the periodontal healing of mandibular second molars after the removal of impacted mandibular third molars using distolingual alveolectomy and tooth division techniques. A total of 120 consecutive healthy patients who presented with bilaterally impacted mandibular third molars were included in this study. The same operator removed the impacted third molars on both sides in all patients. The third molar on one side was removed by distolingual alveolectomy using a chisel, whereas the contralateral tooth was removed by the tooth division technique using burs. Attachment level, periodontal pocket depth and bone healing distal to the mandibular second molars were assessed at 7 days, 3 months and 6 months after surgery. The results showed better periodontal healing and bone healing when distolingual alveolectomy was employed, especially in the removal of deeply impacted mandibular third molars.     

Influence of cone beam computed tomography versus panoramic radiography on the surgical technique of third molar removal: a systematic review

Panoramic radiography is the standard imaging method for preoperative assessment before lower third molar removal. However, oral surgeons have been using cone beam computed tomography (CBCT) as an additional tool to assess detailed preoperative data, as it provides cross-sectional images. The aim of this systematic review was to determine whether the use of CBCT and the additional information provided modifies the preoperative assessment of lower third molar removal when compared to panoramic radiography and consequently results in a different surgical approach. A search of the PubMed, Embase, Web of Science, Science Direct, and Scopus electronic databases was performed on 30 June 2018, which retrieved 196 records without duplicates. The grey literature was also searched to include any other paper that might meet the eligibility criteria, which resulted in an additional five records. Among these papers, five met all of the eligibility criteria. These five studies included a total of 289 individuals and a total sample of 311 teeth. The findings showed that three-dimensional imaging does not change the surgical approach when compared to panoramic radiography; however it is considered a useful imaging method to understand the relationship between the lower third molars and the mandibular canal.     

Extractions of impacted mandibular wisdom teeth in the presence of acute infection.

The removal of 720 impacted mandibular third molars in the presence of acute pericoronitis, employing as atraumatic an operative technique as possible, did not give rise to serious complications, such as osteomyelitis, brain abscess, septicemia or facial space abscess. The results have been compared with a control group of 1,000 impacted mandibular third molars extracted without presence of acute infection.     

Bilateral bifid mandibular condyle: case report and literature review

Bifid mandibular condyle is an infrequent and normally asymptomatic morphological alteration of the mandibular condyle. Although the underlying cause is not clear, a number of theories have been proposed, including teratogenic effects in the embryo, vascular alterations during condyle development, and condylar remodeling following fracture. Since Schier first described this anomaly in 1948 in live individuals, further cases have been documented in the literature. We present a new case of bilateral bifid condyle. The disorder was asymptomatic and constituted a casual finding in a young male presenting for the surgical extraction of two impacted molars.     

Distal cervical caries in the mandibular second molar: an indication for the prophylactic removal of the third molar?

AIMS: Distal cervical caries (DCC) in mandibular second molar teeth are responsible for the removal of up to 5% of all mandibular third molars. Our aim was to identify the clinical features of these patients. METHODS: We evaluated the records of 100 patients who had 122 mandibular third molars removed because of distal cervical caries in the second molar. RESULTS: Eighty-two percent of third molars had a mesial angulation of between 40 degrees and 80 degrees. The peak age for removal of third molars was 5 years later than in other studies and patients had better dental health than average. The incidence of distal cervical caries DCC has been shown to increase with age. CONCLUSION: Distal cervical caries is a late phenomenon and has been reported only in association with impacted third molars. The early or prophylactic removal of a partially erupted mesio-angular third molar could prevent distal cervical caries forming in the mandibular second molar.     

Unerupted lower third molars and their influence on fractures of the mandibular angle and condyle

Our aim was to assess the influence of the presence and state of impaction of mandibular third molars on the incidence of fractures of the mandibular angle and condyle. We designed a retrospective study of patients who presented for the treatment of mandibular fractures from January 2006 to April 2011. The independent variables were the presence and degree of impaction of lower third molars, and the outcome variables were the incidence of fractures of the mandibular angle and condyle. The information was acquired from hospital records and panoramic radiographs. Personal data included age, sex, mechanism of injuries, and number of fractures of the mandibular angle and condyle. We studied 110 fractures of the mandibular condyle and 80 of the angle. The incidence of fractures of the mandibular angle was higher in the group with incompletely erupted third molars (37/80, p < 0.001) and that of condylar fractures was higher in the group without (67/110, p < 0.001). An incompletely erupted third molar reduces the risk of condylar fractures and increases the risk of fractures of the mandibular angle.     

Lingual flap retraction for third molar removal.

PURPOSE: Lingual nerve damage following lower third molar surgery remains a clinical problem. The traditional approach in the United States has been a buccal approach avoiding exposure or surgery on the lingual side of the crest of the ridge. An alternative technique is to deliberately expose the lingual tissues and retract the lingual nerve lingually before tooth removal. This study reports a trial of this technique. MATERIALS AND METHODS: Patients had removal of their lower third molars carried out using a technique that raises a lingual flap in addition to a buccal flap and places a specially designed lingual retractor to ensure that the lingual nerve is held out of the surgical field. This technique was used in cases where the crown of the tooth had to be sectioned or when distal bone needed to be removed. RESULTS: Two hundred fifty patients were treated by this method. There were 4 cases of transient lingual paresthesia, presumably caused by traction pressure from the retractor. Three of these cases were mild and resolved within 3 weeks. The fourth case had more profound paresthesia, but still resolved within 2 months. There were no cases of permanent nerve damage, and in many cases removal of the third molar was simplified by the superior access. CONCLUSION: Lingual retraction for third molar removal improves access to the surgical site and can simplify third molar removal. In this prospective study there were no cases of permanent lingual nerve injury.     

New considerations in the treatment of compromised third molars

Management of asymptomatic malposed third molars is a controversial topic. As a result, many malposed or mildly pathologic third molars are not removed. Historical pro and con arguments regarding removal centered around cost and the aspects of the surgical removal itself. Current epidemiology and medical advances address issues not considered before. There is a large growth of the aging population (over 40 years). More and more of these elderly patients are requiring third molar removal. Over a five-year period, 1997-2002, the incidence almost doubled to 17.9 percent. This age category is known to be high risk for third molar surgery. An equally or higher risk is the rapidly growing number of patients seeking third molar surgery who are moderately severely medically compromised. This paper reviews how this lack of consensus results in delayed removal of malposed third molars in this population. Preventive dental concepts, removing compromised third molars earlier, would eliminate the high risk to this aging population.