Factors predictive of difficulty of mandibular third molar surgery

Rotary Instrument or Piezoelectric for the Removal of Third Molars: a Meta-Analysis

AIM

The aim of this systematic review and meta-analysis was to compare, in the lower third molar surgery, the osteotomy techniques with rotary instruments and piezoelectric motors.

METHODS

An electronic search was conducted using the following databases: Pubmed, Web of Science, and the Cochrane Oral Health Group Trials Register. Inclusion criteria were: studies in humans, randomized or nonrandomized, comparing the extraction of third molars that required osteotomy and/or odontosection with rotary instrument and osteotomy and/or odontosection with piezoelectric motor assistance. The analysis and inclusion of articles was performed by two reviewers independently. An evaluation of the quality of articles and data extraction was carried out.

RESULTS

From a total of nine hundred seventy four (974) trials, eleven articles were included in the qualitative analysis, and seven were included in the quantitative analysis. Rotary instruments were faster than the piezoelectric surgery (95 % CI 0.34 to 1.16). The piezoelectric surgery showed better results when compared with roatry instruments when trismus was assessed in 2 (95 % CI 0.65 to 1.69), 3 (95 % CI 0.63 to 1.67) and 5 (95 % CI 0.03 to 2.26) days after surgery. Seven days after surgery, there were no differences between the techniques (95 % CI (-0.022) to (-1.49)).

CONCLUSION

The piezoelectric surgery was effective in reducing pain, swelling and trismus in third molar surgery, but the same requires greater surgical time than the rotary instruments.

Cerebral analgesic response to nonsteroidal anti-inflammatory drug ibuprofen

Nonopioid agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs), are the most commonly used class of analgesics. Increasing evidence suggests that cyclooxygenase (COX) inhibition at both peripheral and central sites can contribute to the antihyperalgesic effects of NSAIDs, with the predominant clinical effect being mediated centrally. In this study, we examined the cerebral response to ibuprofen in presurgical and postsurgical states and looked at the analgesic interaction between surgical state and treatment. We used an established clinical pain model involving third molar extraction, and quantitative arterial spin labelling (ASL) imaging to measure changes in tonic/ongoing neural activity. Concurrent to the ASL scans, we presented visual analogue scales inside the scanner to evaluate the subjective experience of pain. This novel methodology was incorporated into a randomized double-blind placebo-controlled design, with an open method of drug administration. We found that independent of its antinociceptive action, ibuprofen has no effect on regional cerebral blood flow under pain-free conditions (presurgery). However, in the postsurgical state, we observed increased activation of top-down modulatory circuits, which was accompanied by decreases in the areas engaged because of ongoing pain. Our findings demonstrate that ibuprofen has a measurable analgesic response in the human brain, with the subjective effects of pain relief reflected in two distinct brain networks. The observed activation of descending modulatory circuits warrants further investigation, as this may provide new insights into the inhibitory mechanisms of analgesia that might be exploited to improve safety and efficacy in pain management.

Incidence of root canal treatment of second molars following adjacent impacted third molar extraction

Background/purpose

The aim of this study was to evaluate the incidence of requirement for root canal treatment of adjacent second molars following the surgical extraction of an impacted third molar.

Materials and methods

The dental records of 6323 consecutive patients who had impacted third molars removed surgically were evaluated and the incidence of postoperative root canal treatment requirement of adjacent second molars was determined. Patients who required root canal treatment of neighboring second molars were accepted as the study group, while the remaining patients were accepted as a control group. Sex, age at the time of the operation, localization of third molar, the depth of impaction, angulation of the tooth, and the professional experience of the surgeon performing the operation were evaluated from patient records.

Results

The incidence of requirement of root canal treatment for second molars following a neighboring impacted third molar extraction was 0.17% (11/6323) and invariably occurred in the mandible. The mean age of the study group was found to be significantly higher than the control group (31 years vs. 23 years). The years of professional experience of the surgeons was significantly lower in the study group than in the control group.

Conclusion

Although the incidence is minimal, iatrogenic subluxation injuries occurring during the surgical removal of impacted third molars can lead to pulpal complications and a requirement for root canal treatment of adjacent second molars.

The "Red Line" Conundrum: A Concept Beyond Its Expiry Date?

Introduction George Winter attempted to assess the depth and difficulty of extracting impacted mandibular wisdom molars by describing three imaginary lines drawn on an intra-oral radiograph. Of these lines, the red line is the only one which is measured and great importance is attached to its actual length. Method The authors of this short paper describe the difficulty in drawing this red line accurately through examples. Conclusion The authors believe that Winter's lines and their interpretation are only of historical value and have no place in contemporary texts on oral surgery.

Common risk factors for postoperative pain following the extraction of wisdom teeth

The extraction of third molars is a common task carried out at dental/surgery clinics. Postoperative pain is one of the two most common complications of this surgery, along with dry socket. Knowledge of the frequent risk factors of this complication is useful in determining high-risk patients, planning treatment, and preparing the patients mentally. Since the risk factors for postoperative pain have never been summarized before while the risk factors for dry socket have been highly debated, this report summarizes the literature regarding the common predictors of postextraction pain. Except for surgical difficulty and the surgeon's experience, the influences of other risk factors (age, gender and oral contraceptive use) were rather inconclusive. The case of a female gender or oral contraceptive effect might mainly be associated with estrogen levels (when it comes to dry socket), which can differ considerably from case to case. Improvement in and unification of statistical and diagnostic methods seem necessary. In addition, each risk factor was actually a combination of various independent variables, which should instead be targeted in more comprehensive studies.

Importance of Clinical and Radiological Parameters in Assessment of Surgical Difficulty in Removal of Impacted Mandibular 3rd Molars: A New Index

OBJECTIVE

The aim of the study is to assess the clinical and radiological factors that increase the surgical difficulty in removal of mandibular impacted 3rd molar and design a new difficulty predictive index.

METHODS

The data was collected from 100 patients with impacted mandibular 3rd molar who presented to Department of Oral and Maxillofacial Surgery, K.L.E's Institute of Dental Sciences. Clinical and radiological parameters included in the New Index were noted. The tooth was then removed under local anesthesia and time taken for the removal was noted. The Pederson Index, New Index and time taken were co-related using kappa statistical analysis.

RESULTS

The kappa agreement between Pederson Index and time taken was 66.50 % (0.2231) whereas between New Index and time was 89 % (0.7177) indicating that New Index is a better predictor of the difficulty.

CONCLUSION

The New Index is a reliable tool in predicting the difficulty in the removal of mandibular impacted third molar.

A simple score for evaluation of the complexity of third-molar extractions

OBJECTIVES

This article proposes a simple preoperative score to evaluate the complexity of tooth extractions of the third mandibular molar and to estimate the time involved.

STUDY DESIGN

We consider 11 factors (demographic, anatomic, and radiologic) that favor the surgery and that can be identified through standard clinical and radiologic examinations. The number of favorable factors (NFF) relative to each patient constitutes his/her score. The analysis of 1500 extractions performed by various surgeons with experience from 2 to 25 years evidences a quadratic inverse correlation between NFF and the time required for the surgery.

RESULTS

The shape of the time distribution suggests the existence of 3 major classes of patients characterized by time of 4 to 10 minutes, 11 to 20 minutes, and 21 to 40 minutes. The corresponding NFF brackets, as identified by their frequency distributions and validated by the receiver operating characteristic curve method, are 5 to 11 (mean [SD], 6.8 [1.6]), 2 to 4 (3.3 [1.3]), and 0 to 1 (0.8 [1.0]), respectively.

CONCLUSIONS

Our results show the good performance of this score as a predictor of the surgical time and its applicability in daily practice regardless of operator experience, background, and level of surgical ability.

Patient anxiety and surgical difficulty in impacted lower third molar extractions: a prospective cohort study

Encountering patients who are fearful and anxious is common in dental practice and these factors can increase the complexity of dental procedures. A prospective cohort study was performed to assess whether patient anxiety influences the difficulty of impacted lower third molar extraction and to identify other predictive factors of surgical difficulty; 102 extractions done under local anaesthesia were assessed. Several preoperative variables were recorded (demographic, anatomical, and surgical) and patient anxiety was assessed through the use of various questionnaires. Extraction difficulty was measured using the operation time (OT) and a 100-mm visual analogue scale (difficulty VAS) completed by the surgeon. Patients with deep impacted third molars that required bone removal and tooth sectioning showed higher levels of preoperative anxiety. Significant correlations were found between questionnaire scores and the surgical difficulty (OT and difficulty VAS). OT was also related to age, depth of impaction, third molar angulations, proximity of the third molar roots to the mandibular canal, hard and soft tissue coverage, and the need to perform an ostectomy and tooth sectioning. Impacted lower third molar extraction is significantly more difficult in anxious patients. Other demographic, radiological, and surgical factors were also found to be significantly related to the surgical difficulty.

Wisdom tooth--complications in extraction

The purpose of this study is to analyze the incidence of complications in a group of 171 patients in whom extractions of impacted mandibular third molar have been performed by two oral surgeons between the period April 2010 and March 2012. This retrospective study comprises evaluation of 270 impacted mandibular third molars which were classified into two groups A and B on the basis of procedure of osteotomy only and osteotomy and odontotomy both respectively. Total no of complications reported were 40 (14.81%). Maximum no of cases reported alveolar osteitis (AO) (11.11%) while other complications reported root tip fractures (2.22%), lingual nerve parasthesia and TMJ problems (each 0.74%) in descending frequency. Conclusion drawn is that the risk of complications in extractions of impacted mandibular third molars always exists, and extractions associated with both osteotomy and odontotomy are associated with higher risk of complications.

Prevalence of missing and impacted third molars in adults aged 25 years and above

PURPOSE

The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above.

MATERIALS AND METHODS

The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars.

RESULTS

A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars.

CONCLUSION

The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health.

Effect of age, sex and level of surgical difficulty on inflammatory complications after third molar surgery

BACKGROUND

Patients' factors such as age and sex and surgical variables such as level of difficulty have been linked with surgical outcome in third molar surgery. The aim of this study was to determine the effect of these variables on inflammatory complications in patients undergoing third molar surgery.

METHODS

Patients referred to our institution for surgical extraction of their impacted lower third molar between January 2007 and December 2008 were the subjects of the study. Patients' demographics as well as types of impaction, indication and level of difficulty based on Pederson criteria were obtained. Post operative pain, swelling and mouth opening limitation were evaluated at day 1, day 2, day 3, day 5 and 1 week after the surgery and analyzed. A p value of less than 0.05 was considered significant.

RESULTS

A total of 150 patients aged 16-38 years (25.9 ± 4.47) met the inclusion criteria. Male accounted for 66 (44.0 %) while females were 84 (56.0 %), giving male to female ratio of 1:1.3. Age, sex and difficulty index had no effect on pain and trismus throughout the periods of postoperative evaluation (p > 0.05). Postoperative swelling was not affected by gender but patients above 25 years who had high scores of difficulty index had more facial swelling.

CONCLUSION

The results of this study shows that age, gender and the level of surgical difficulty have no effect on pain and mouth opening limitation after third molar surgery.

Removal of impacted mandibular third molars using an inward fragmentation technique (IFT) - Method and first results

PURPOSE

Conventional surgical extraction of impacted mandibular third molars (M3M) requires a lateral flap reflection in conjunction with lateral bone removal for outward mobilization of the tooth. The aim of this report is to outline a novel inward fragmentation technique (IFT) in conjunction with an occlusal miniflap approach to reduce the amount of bone removal to a minimum.

PATIENTS AND METHODS

Seventeen consecutive patients (7 men and 10 women; mean age 24.4 years, range 18-36 years) required the extraction of 21-impacted M3M with a close relationship to the inferior alveolar nerve (IAN). Occlusal miniflaps were used and only occlusal bone removal was performed to expose the M3M under endoscopic vision. A central space-making cavity was created followed by inward fragmentation and mobilization of the crown and subsequent root removal through the space created.

RESULTS

20 of 21 sites healed uneventfully, one late infection was observed, no permanent neurosensory lesion occurred. The mean preoperative buccal bone height was 15.5 (11-18) mm and the postoperative buccal bone height 14.7 (11-17) mm. On the 2nd day, the mean swelling level was 1.38 (0-2) on a 4 point scale, the pain level was 2.30 (0-5) on a 10 cm VAS, mean pain duration was 2.04 days.

CONCLUSION

An inward fragmentation technique allows preservation of >90% of the buccal bone height adjacent to mandibular third molars and may reduce postoperative morbidity without raising the risk of IAN lesions.

Role of patients' demographic characteristics and spatial orientation in predicting operative difficulty of impacted mandibular third molar

BACKGROUND

The influence of patient factors such as age, sex, weight, body mass index (BMI) and spatial orientation on operative difficulty of impacted mandibular third molar (M3) surgery is a subject of controversy in the literature.

AIM

To assess the risk indicators of operative difficulty of mandibular third molar surgery at our institution.

SUBJECTS AND METHODS

A descriptive cross-sectional study involving patients that presented for wisdom tooth extraction between January 2010 and December 2011. The correlation between patients' factors such as age, sex, weight, height, BMI, radiographic spatial relationship of the impacted tooth and operation time was determined with Spearman's rank correlation coefficient. Statistically significant variables were selected for multiple regression analysis to determine which factors contribute most to operative difficulty of M3. P value was set at 0.05. Statistical analysis used SPSS 17.0.

RESULTS

Only patients' age and radiographic spatial relationship showed a statistically significant correlation with operation time (P = 0.038 and 0.008, respectively). Linear regression analysis of patients' age and angulation of M3 showed that both contribute 44.8% risk of increased operation time (regression coefficient = 0.448), with M3 angulation contributing more significantly to increase in operation time (P = 0.001) than increasing age of the patient (P = 0.005).

CONCLUSIONS

Findings from this study have shown that increasing age of the patient and the angulation of M3 impaction increases the risk of operative difficulty of the impacted M3 significantly.

Prediction of postoperative facial swelling, pain and trismus following third molar surgery based on preoperative variables

Objective: This paper investigates the relationship between preoperative findings and short-term outcome in third molar surgery. Study design: A prospective study was carried out involving 80 patients who required 160 surgical extractions of impacted mandibular third molars between January 2009 and December 2010. All extractions were performed under local anesthesia by the same dental surgeon. Swelling and maximal inter-incisor distance were measured at 48 h and on the 7th day postoperatively. Mean visual analogue pain scores were determined at four different time periods. Results: One-hundred eight (67.5%) of the 160 extractions were performed on male subjects and 52 (32.5%) were performed on female subjects. Median age was 22.46 years. The amount of facial swelling varied depending on gender and operating time. Trismus varied depending on gender, operating time and tooth sectioning. The influence of age, gender and operating time varied depending on the pain evaluation period (p < 0.05). Conclusions: Short-term outcomes of third molar operations (swelling, trismus and pain) differ depending on the patients’ characteristics (age, gender and body mass index). Moreover, surgery characteristics such as operating time and tooth sectioning were also associated with postoperative variables.

Key words:Third molar extraction, pain, swelling, trismus, postoperative findings, prediction.

Is Pederson Index a True Predictive Difficulty Index for Impacted Mandibular Third Molar Surgery? A Meta-analysis

The aim of this meta-analysis was to find out the clinical reliability of Pederson index in assessing the difficulty of surgery for impacted mandibular 3rd molar. The relevant articles were selected by Hand search and electronic media (Medline, Pubmed, Embase Cochrane library, ISI web of science) from Jan 2000 to Dec 2010. All the relevant articles were properly screened and findings were extracted from the articles. Pederson index had shown low sensitivity and specificity in predicting the difficulty of surgery for impacted mandibular 3rd molar. Positive and negative likelihood ratio had also shown the unreliability of Pederson index. The meta-analysis of the current literature concluded that Pederson index is not a reliable test to predict the surgical difficulty of impacted mandibular 3rd molar.

Long-term treatment with alendronate increases the surgical difficulty during simple exodontias - an in vivo observation in Holtzman rats

Background

Atraumatic teeth extractions protocols are highly encouraged in patients taking bisphosphonates (Bps) to reduce surgical trauma and, consequently, the risk of jaws osteonecrosis development. In this way, this paper aims to report the findings of increased surgical difficulty during simple exodontias in animals treated with bisphosphonates.

Methods

Sixty male Holtzman rats were randomly distributed into three groups of 20 animals and received daily subcutaneous administration of 1 mg/kg (AL1) or 3 mg/kg (AL3) of alendronate or saline solution (CTL). After 60 days of drug therapy all animals were submitted to first lower molars extractions under general anesthesia. Operatory surgical time and the frequency of teeth fractures were measured as principal outcomes and indicators of surgical difficulty degree.

Results

Animals treated with alendronate (AL1 and AL3) were associated to higher operatory times and increased frequency of teeth fractures compared to match controls.

Conclusions

The bisphosphonate therapy may be associated with an increased surgical difficulty and trauma following simple exodontias protocols, which is considered a critical issue when it comes to osteonecrosis development.

Evaluation of the agreement by examiners according to classifications of third molars

OBJECTIVES

This study recorded and evaluated the intra- and inter-group agreement degree by different examiners for the classification of lower third molars according to both the Winter's and Pell & Gregory's systems.

STUDY DESIGN

An observational and cross-sectional study was realized with forty lower third molars analyzed from twenty digital panoramic radiographs. Four examiner groups (undergraduates, maxillofacial surgeons, oral radiologists and clinical dentists) from Aracaju, Sergipe, Brazil, classified them in relation to angulation, class and position. The variance test (ANOVA) was applied in the examiner findings with significance level of p<0.05 and confidence intervals of 95%.

RESULTS

Intra- and inter-group agreement was observed in Winter's classification system among all examiners. Pell & Gregory's classification system showed an average intra-group agreement and a statistical significant difference to position variable in inter-group analysis with greater disagreement to the clinical dentists group (p<0.05).

CONCLUSIONS

High reproducibility was associated to Winter's classification, whereas the system proposed by Pell & Gregory did not demonstrate appropriate levels of reliability.

Accuracy of angular measurements and assessment of distortion in the mandibular third molar region on panoramic radiographs

OBJECTIVE

The objective of this study was to examine distortion on panoramic radiographs by assessing the accuracy of angular measurements in the mandibular third molar region on panoramic radiographs using computed tomography (CT).

METHODS

Images from patients referred to a radiology practice for low-dose CT scans of their lower third molars were used in this study. The angle between the long axes of the second and third molars was assessed on panoramic radiographs and the corresponding CT images. Apparent tilting of the tooth across the arch on the panoramic image and the bucco-lingual inclination on CT were also recorded and compared.

RESULTS

Eighty-eight patients had 163 mandibular third molars. The mean difference between the panoramic measurements and the CT measurements was -1.44 degrees, indicating that on the panoramic radiograph the third molar appeared less mesially inclined on average. This pattern was present in most cases, but in 64 cases the third molar appeared more mesially inclined on the panoramic radiograph. It was not possible to predict the direction of the discrepancy based on the radiographic findings. The discrepancy between the 2 measurements was greater if the third molar appeared tilted across the arch on the panoramic image, and tilted teeth showed a higher bucco-lingual inclination on reformatted CT images.

CONCLUSIONS

Distortions inherent in panoramic imaging because of projection geometry produce discrepancies in the angular measurements in the mandibular third molar regions on panoramic radiographs. Interpretation of third molar angulation from panoramic radiographs is often unreliable and may not accurately reflect the true orientation of the tooth. Apparent tilting of the tooth across the arch on the panoramic radiograph exacerbates the problem and appears to correlate with the bucco-lingual inclination of the third molar as visualized on reformatted CT images.

Effect of age, impaction types and operative time on inflammatory tissue reactions following lower third molar surgery

BACKGROUND

Postoperative mobidity following third molar surgery is affected by a number of factors. The study of these factors is essential for effective planning and limitation of morbidity. The aim of this study was to determine the effect of age, type of impaction and operative time on immediate postoperative tissue reactions following mandibular third molar surgery.

METHODS

Consecutive patients with impacted mandibular third molar teeth were studied. All the third molars were classified according to Winter's classification. Surgical extraction was performed on all the patients by a single surgeon under local anaesthesia. The operation time was determined by the time lapse between incision and completion of suturing. Postoperative pain, swelling and trismus were evaluated.

RESULTS

There were 120 patients with an age range of 19-42 years. Patients in the age range of 35-42 years recorded a lower pain score (p = 0.5) on day 1. The mouth opening was much better in the lower age group on day 2 and 5 (p = 0.007 and p = 0.01 respectively). Pain, swelling and trismus increased with increasing operative time. Distoangular impaction was significantly associated with higher VAS score on day 1 and 2 (p = 0.01, 0.0, 04). Distoangular and horizontal impaction are associated with a higher degree of swelling and reduced mouth opening on postoperative review days. Vertical impaction was associated with the least degree of facial swelling and best mouth opening.

CONCLUSIONS

Increasing operating time and advancing age are associated with more postoperative morbidity, likewise distoangular and horizontal impaction types.

Necessity of 3D visualization for the removal of lower wisdom teeth: required sample size to prove non-inferiority of panoramic radiography compared to CBCT

The availability of cone beam computed tomography (CBCT) and the numbers of CBCT scans rise constantly, increasing the radiation burden to the patient. A growing discussion is noticeable if a CBCT scan prior to the surgical removal of wisdom teeth may be indicated. We aimed to confirm non-inferiority with respect to damage of the inferior alveolar nerve in patients diagnosed by panoramic radiography compared to CBCT in a prospective randomized controlled multicentre trial. Sample size (number of required third molar removals) was calculated for the study and control groups as 183,474 comparing temporary and 649,036 comparing permanent neurosensory disturbances of the inferior alveolar nerve. Modifying parameter values resulted in sample sizes ranging from 39,584 to 245,724 respectively 140,024 to 869,250. To conduct a clinical study to prove a potential benefit from CBCT scans prior to surgical removal of lower wisdom teeth with respect to the most important parameter, i.e., nerval damage, is almost impossible due to the very large sample sizes required. This fact vice versa indicates that CBCT scans should only be performed in high risk wisdom tooth removals.

Beyond patient reported pain: perfusion magnetic resonance imaging demonstrates reproducible cerebral representation of ongoing post-surgical pain

Development of treatments for acute and chronic pain conditions remains a challenge, with an unmet need for improved sensitivity and reproducibility in measuring pain in patients. Here we used pulsed-continuous arterial spin-labelling [pCASL], a relatively novel perfusion magnetic-resonance imaging technique, in conjunction with a commonly-used post-surgical model, to measure changes in regional cerebral blood flow [rCBF] associated with the experience of being in ongoing pain. We demonstrate repeatable, reproducible assessment of ongoing pain that is independent of patient self-report. In a cross-over trial design, 16 participants requiring bilateral removal of lower-jaw third molars underwent pain-free pre-surgical pCASL scans. Following extraction of either left or right tooth, repeat scans were acquired during post-operative ongoing pain. When pain-free following surgical recovery, the pre/post-surgical scanning procedure was repeated for the remaining tooth. Voxelwise statistical comparison of pre and post-surgical scans was performed to reveal rCBF changes representing ongoing pain. In addition, rCBF values in predefined pain and control brain regions were obtained. rCBF increases (5–10%) representing post-surgical ongoing pain were identified bilaterally in a network including primary and secondary somatosensory, insula and cingulate cortices, thalamus, amygdala, hippocampus, midbrain and brainstem (including trigeminal ganglion and principal-sensory nucleus), but not in a control region in visual cortex. rCBF changes were reproducible, with no rCBF differences identified across scans within-session or between post-surgical pain sessions. This is the first report of the cerebral representation of ongoing post-surgical pain without the need for exogenous tracers. Regions of rCBF increases are plausibly associated with pain and the technique is reproducible, providing an attractive proposition for testing interventions for on-going pain that do not rely solely on patient self-report. Our findings have the potential to improve our understanding of the cerebral representation of persistent painful conditions, leading to improved identification of specific patient sub-types and implementation of mechanism-based treatments.

Preliminary results of a study comparing conventional radiography with phase-contrast radiography for assessing root morphology of mandibular third molars

OBJECTIVES

The aim of this study was to evaluate the usefulness of phase-contrast radiography for assessing root morphology of mandibular third molars in comparison with conventional radiography.

METHODS

We studied 37 extracted mandibular third molars. One oral surgeon compared the number of roots and root curvature of the extracted teeth on conventional radiographs with those on phase-contrast images.

RESULTS

The number of roots and root curvature on conventional images differed significantly from those on phase-contrast images.

CONCLUSIONS

Our results suggest the possibility that phase-contrast radiography is more useful than conventional radiography for assessing the root morphology of mandibular third molars.

Considerations of mandibular angle fractures during and after surgery for removal of third molars: a review of the literature

BACKGROUND

Angle fractures are quite common considering that the angle of the mandible forms an area of lower resistance which contains a thicker upper border, a thin basilar bone, and the presence of an impacted mandibular third molar. Common complications of mandibular third molar surgery include alveolar osteitis (dry socket), secondary infection, nerve dysfunction, and hemorrhage. Reports of mandibular fracture during and after third molar removal are uncommon.

PURPOSE

The purpose of this paper is to discuss the risk and predisposing factors that should be analyzed regarding the possibility of immediate and late mandibular angle fractures and their need for surgical treatment as a means through which to remove impacted molars. This study is based on a thorough review of the literature as well as on one immediate and one late mandibular angle fracture as described by the authors' own personal experience.

CONCLUSIONS

The danger of an immediate jaw fracture can be avoided by means of proper instrumentation and by refraining from excessive force on the bone. The tooth should be sectioned in such a way as to minimize the extent of bone removal and force caused by instrumentation. The danger of a late jaw fracture can be avoided by precise diagnosis in cases of patients over 25 years of age, particularly men, whose tooth roots are superimposed on or adjacent to the inferior alveolar canal on a panoramic image, any local pathology and systemic disease or medications which may impair bone strength, and patients who present bruxism and are active athletes.

Mastication and late mandibular fracture after surgery of impacted third molars associated with no gross pathology

PURPOSE

This study was undertaken with the null hypothesis that in patients, fully denate or with 1 or 2 teeth missing and older than 25 years, mastication does not affect late mandibular fracture after surgical removal of impacted third molars (M3s) associated with no gross pathology.

MATERIALS AND METHODS

Five hundred sixty patients, fully dentate or with 1 or 2 teeth missing and older than 25 years who had no gross pathology associated with their impacted lower M3s, were recruited in this study. They were operated on under local anesthesia using a standard technique and randomly assigned into 2 groups for nonroutine (NR group) and routine (R group) postoperative instructions. In the NR group, patients were postoperatively educated in the possibility of mandibular fracture and were given an emphasis on the necessity of limiting mastication to a soft diet for 4 weeks. In the R group, patients were given no such education or emphasis. Patients were followed up for 2 months, and data concerning patients' age and gender; tooth position, angulation, and depth; date and site of surgery; and occurrence of late mandibular fracture were recorded and statistically analyzed. A value of P less than .05 was considered statistically significant.

RESULTS

In no patient group was there a late mandibular fracture recorded. All patients completed the follow-up period, and most of the R group patients had normal eating habits 10 to 14 days after surgery. In no patient group was there a statistically significant difference in relation to gender (P = .735), site of surgery (P = .552), class horizontal space available (P = .427), class highest portion of the M3 crown (P = .424), angulations of the teeth (P = .925), and severity of impaction (P = .445).

CONCLUSIONS

In patients, fully dentate or with 1 or 2 teeth missing and older than 25 years who have no jawbone atrophy and no systemic problems that may impair bone strength, mastication seems not to affect late mandibular fracture after surgical removal of impacted M3s associated with no gross pathology. The remote possible risk of the late fracture shown in our patients indicates the need for no special precautions.

Assessment of difficulty in third molar surgery--a systematic review

PURPOSE

The aim of this review was to identify the most important variables that determine surgical difficulty of impacted third molar extractions by their consistent showing in previous studies.

MATERIALS AND METHODS

Electronic library search for current evidence in the world literature was conducted, and relevant articles were selected, scrutinized, and the findings were compared.

RESULTS

Seven articles were most relevant, and the results of the comparison of the selected articles showed that demographic variable, age; operative variables: surgeon procedure type and number of teeth extracted; and ratiographic variable, depth angulation; and root morphology, are the most consistent determinants of difficulty.

CONCLUSION

Current evidence is in support of 3 categoreis of variables strongly associated with surgical diffulty of impacted third molars. The most important variables in each of these categories have been identified.

Factors influencing the prophylactic removal of asymptomatic impacted lower third molars

The aim of this study was to analyse factors indicating prophylactic removal of impacted lower third molars, and how they, and possibly surgeon experience, influence the therapeutic decision-making process. A descriptive observational study was made of 40 asymptomatic impacted lower third molars. Orthopantomographs were scanned and presented to four professionals with different degrees of surgical experience. The examiners received information relating to patient age and sex, molar inclination and degree of impaction, and expressed their opinion on the necessity for teeth removal. There was a statistically significant relationship between examiner decision and the estimated probability of pathology if the molars were not removed (P<0.05). The degree of influence on the decision to extract was in decreasing order: estimated risk of complications, inclination of molar, age, degree of impaction and patient sex. No statistically significant differences (P>0.05) were observed between residents and trainers in terms of the decision to remove or estimated risk of complications. The management approach adopted by oral surgeons regarding the removal of asymptomatic impacted lower third molars depends upon the perceived risk of complications if such teeth are not removed, other factors being secondary. The surgical experience of the professional does not seem to influence treatment decision.

Assessment of factors associated with surgical difficulty in impacted mandibular third molar extraction

PURPOSE

The aim of this prospective study was to investigate radiologic and clinical factors associated with increased difficulty in the removal of impacted mandibular third molars. We also aimed to form an index to measure the difficulty of removal of the impacted molars preoperatively.

PATIENTS AND METHODS

A total of 87 patients who required 90 surgical extractions of impacted mandibular third molars from November 2003 to May 2004 were involved in the study. Radiologic and clinical data were taken preoperatively. All extractions were performed under local anesthesia by a single operator. Surgical difficulty was measured by the total intervention time.

RESULTS

Increased surgical difficulty was associated with increasing age and body mass index. It was also associated with the curvature of roots of the impacted tooth and the depth from point of elevation (P < .05).

CONCLUSION

Both clinical and radiologic variables are important in predicting surgical difficulty in impacted mandibular third molar extractions.

Pederson scale fails to predict how difficult it will be to extract lower third molars

We report a consecutive series of 105 extractions of impacted lower third molars, in each of which operative difficulty was predicted preoperatively using the Pederson scale (radiographic appearance of the anatomical position of the lower third molar), and postoperative difficulty was scored with a modified version of the Parant scale (operative manoeuvres that were needed for extraction of the third molar). Preoperative classification as "difficult" on the Pederson scale was not an accurate predictor of true difficulty (postoperative classification as "difficult" on the modified Parant scale). There was no significant association between the Pederson score and duration of operation, but high Parant scores were significantly associated with longer operations. We suggest that scales for the prediction of operative difficulty in the extraction of impacted lower third molars should take into account factors other than the anatomical position of the tooth.

Correlation between a patient-centred outcome score and surgical skill in oral surgery

Our aim was to find out whether scores derived from a patient-centred outcome questionnaire correlated with the skill of the surgeon as assessed by a trainer. We found a relatively poor correlation after removal of a third mandibular molar, probably because outcome scores incorporate other measures, including patients' perceptions, anaesthesia, clarity of explanations and instructions, apart from surgical skill. The experience of the surgeon and the length of operation also influenced the results. The correlation was closest (i.e. higher levels of skill produced milder symptoms) when the operation was under local anaesthesia, probably because the surgeon's skill, behaviour, and attitude were visible to the patient throughout, and other team members had a less prominent role. In future, it may be more appropriate to assess the performance of the whole surgical team, rather than the surgeon alone.

Efficacy of low level laser therapy on neurosensory recovery after injury to the inferior alveolar nerve

BACKGROUND

The most severe complication after the removal of mandibular third molars is injury to the inferior alveolar nerve or the lingual nerve. These complications are rather uncommon (0.4% to 8.4%) and most of them are transient. However, some of them persist for longer than 6 months, which can leave various degrees of long-term permanent disability. While several methods such as pharmacologic therapy, microneurosurgery, autogenous and alloplastic grafting can be used for the treatment of long-standing sensory aberrations in the inferior alveolar nerve, there are few reports regarding low level laser treatment. This paper reports the effects of low level laser therapy in 4 patients with longstanding sensory nerve impairment following mandibular third molar surgery.

METHODS

Four female patients had complaints of paresthesia and dysesthesia of the lip, chin and gingiva, and buccal regions. Each patient had undergone mandibular third molar surgery at least 1 year before. All patients were treated with low level laser therapy. Clinical neurosensory tests (the brush stroke directional discrimination test, 2-point discrimination test, and a subjective assessment of neurosensory function using a visual analog scale) were used before and after treatment, and the responses were plotted over time.

RESULTS

When the neurosensory assessment scores after treatment with LLL therapy were compared with the baseline values prior to treatment, there was a significant acceleration in the time course, as well as in the magnitude, of neurosensory return. The VAS analysis revealed progressive improvement over time.

CONCLUSION

Low level laser therapy seemed to be conducive to the reduction of long-standing sensory nerve impairment following third molar surgery. Further studies are worthwhile regarding the clinical application of this treatment modality.

Indications for and anticipated difficulty of third molar surgery: A comparison between a dental hospital and a specialist high street practice

OBJECTIVE

To investigate the indications for and anticipated difficulty of third molar surgery between two different referral settings.

DESIGN

A prospective study involving completion of a proforma pre- and post-operatively.

SETTING

A dental teaching hospital and a specialist surgical dentistry practice in 2003.

SUBJECTS AND METHODS

Patients referred for the assessment of their third molars were recruited. Details of the clinical and radiographical assessment for each patient were recorded pre-operatively and the extent of surgery required post-operatively.

RESULTS

The main indication for referral for third molar extraction was pericoronitis in both centres. A larger number of patients were assessed and treated in a shorter period of time at the surgical dentist compared with the dental hospital. The surgical dentist was accurate in his assessment of the difficulty of surgery 96% of the time compared with 66% for the dental hospital staff.

CONCLUSIONS

This study highlights the benefits for patients in being treated by a surgical dentist. As dental students require exposure to surgical dentistry in order to attain a level of competence, a reduction in the number of patients being referred to dental hospitals may impact upon students' ability to both assess and perform surgical procedures. This may mean that undergraduates will be less able to fulfil the recommendations of the General Dental Council. An outreach programme for final year dental students to surgical dentistry practices would benefit all concerned.

How well do clinicians estimate third molar extraction difficulty?

PURPOSE

The goals of this study were to measure surgeons abilities to estimate third molar (M3) extraction difficulty and to identify variables associated with errors in estimates of difficulty.

MATERIALS AND METHODS

To address our research purpose, we implemented a prospective cohort study and enrolled a sample of surgeons who remove M3s. Predictor variables were categorized as either surgeon or subject specific. The primary outcome variable was the error in estimating operative difficulty. Preoperative and postoperative estimates of difficulty were obtained using a 100-mm visual analogue scale. Error was defined as the difference between preoperative and postoperative estimates of extraction difficulty. Appropriate univariate, bivariate, and multivariate statistics were computed.

RESULTS

The sample was composed of 15 surgeons who operated on 82 subjects having 250 M3s (53.2% mandibular) extracted. The mean level of surgical experience was 8.8 +/- 11.1 years. The mean age of the subjects was 26.2 +/- 10.7 years; 57.3% were female; and 72.0% were white. The mean preoperative and postoperative estimates of difficulty were 44.3 +/- 23.4 and 39.6 +/- 24.7 mm, respectively. The mean absolute and actual differences between preoperative and postoperative estimates were 15.7 +/- 13.6 and 4.8 +/- 20.2 mm, respectively. We identified several demographic and anatomic variables statistically associated ( P < or = .05) with error in estimating difficulty.

CONCLUSIONS

Our models indicate that errors in the estimates of difficulty were related to demographic (age, gender, ethnicity, snoring) and anatomic (cheek flexibility, mouth opening) variables, with little or no dependence on radiographic variables or surgical experience.

Risk factors for third molar extraction difficulty

PURPOSE

The purpose of this study was to measure the difficulty of third molar (M3) extractions and to identify demographic, anatomic, and operative variables associated with extraction difficulty.

MATERIALS AND METHODS

To address the research purpose, we implemented a prospective cohort study and enrolled a sample composed of patients presenting for M3 removal. Predictor variables were categorized as demographic, anatomic, and operative. The primary outcome variable was difficulty of extraction, measured as extraction time per tooth. The secondary outcome variable was the surgeons postoperative estimate of M3 extraction difficulty, measured on a 100-mm visual analog scale (VAS). Appropriate univariate, bivariate, and multivariate statistics were computed.

RESULTS

The sample was composed of 82 subjects, having 250 M3s (53.2% mandibular) extracted, with a mean age of 26.2 +/- 10.7 years; 57.3% were female, 72.0% were white. The mean operating time per M3 extraction was 6.9 +/- 7.6 minutes. The mean estimate of difficulty was 39.6 +/- 24.7 mm and was significantly correlated (r = 0.68) with extraction time (P < .01). Surgical experience, M3 location (maxillary versus mandibular), procedure type, tooth position, number of teeth extracted, and tooth morphology were statistically associated (P < or = .05) with extraction time in a multivariate model.

CONCLUSION

Our model indicates that the difficulty of M3 extractions is governed primarily by anatomic and operative factors with minimal influence from demographic factors.

Clinical postoperative findings after removal of impacted mandibular third molars: prediction of postoperative facial swelling and pain based on preoperative variables

PURPOSE

This paper is intended as an investigation of the relationship between preoperative findings and short-term outcome in third molar surgery.

MATERIAL AND METHODS

We assessed 153 consecutive surgical extractions of mandibular third molars performed in 140 patients between April 1998 and March 2001.

RESULTS

Fifty-four (35%) of the 153 extractions were performed in male subjects and 99 (65%) in female subjects. The median age was 27 years. The amount of facial swelling varied depending on age and sex. Severe pain was associated with depth and preoperative index of difficulty. Average pain was associated with preoperative index of difficulty.

CONCLUSION

In conclusion, we consider that the short-term outcomes of third molar operations (swelling and pain) differ depending on patients' characteristics (age and sex) and preoperative index of difficulty. Further mega-trial studies of the association between preoperative findings and short-term outcome will help to elucidate the true nature and magnitude of the association.

Mandibular third molar removal: Risk indicators for extended operation time, postoperative pain, and complications

OBJECTIVES

The aim of this study was to identify risk indicators for extended operation time and postoperative complications after removal of mandibular third molars.

STUDY DESIGN

There were 388 molars included in the study. The teeth were removed using the buccal approach under local anesthesia. Four hours postoperatively the patient recorded his or her pain perception on a visual analogue scale (VAS). After surgery a surgeon recorded parameters regarding the tooth and if the mandibular nerve had been visible during the operation. One week postoperatively the postoperative pain and complications were recorded. Logistic regression models were made to identify risk indicators for extended operation time, postoperative pain, and complications.

RESULTS

Females were at higher risk for postoperative pain and dry socket than males. Older patients were at higher risk for extended operation time than younger patients. Radiographically fully impacted molars increased the risk of postoperative general infection. If the nerve was visible during surgery there was a higher risk of a high VAS score, postoperative pain, and general infection than if the nerve had not been visible.

CONCLUSION

Several indicators were found to increase the risk of postoperative complications, but a visible alveolar inferior nerve during the operation was repeatedly found to be the highest single risk indicator.

Types, frequencies, and risk factors for complications after third molar extraction

OBJECTIVES

The study objective was to identify the types, frequency, and risk factors for complications after third molar (M3) extractions.

STUDY DESIGN

This retrospective cohort study consisted of patients who had 1 or more M3s removed between 1996 and 2001. Risk factors were grouped into demographic, general health, anatomic, and operative. Outcome variables were operative or inflammatory complications. Data were analyzed using descriptive, bivariate, and multivariate statistics.

RESULTS

The study sample was composed of 583 patients (57.0% male) with a mean age of 26.4 +/- 8.4 years. The overall complication rate was 4.6%. Increasing age, a positive medical history, and the position of the M3 relative to the inferior alveolar nerve were associated with an increased risk for complications.

CONCLUSION

While age, medical history, and M3 anatomy cannot be altered directly, these factors may be modified indirectly, resulting in a potential decrease for postoperative complications.