The wisdom behind third molar extractions

Full life cycle changes of low impacted mandibular third molar associated cystic lesions and adjacent tooth root resorption: a retrospective study

OBJECTIVE

Low impacted third molars are usually asymptomatic and are often found by X-ray examination. The removal of asymptomatic low impacted third molars is one of the most controversial clinical issues in oral and maxillofacial surgery.

METHODS

In this study, 806 patients with low impacted mandibular third molars (LIMTMs) (full bony impaction) were analyzed to determine the prevalence and risk factors for cystic lesions and adjacent tooth root resorption throughout the patients' entire life cycle.

RESULTS

The results showed that the prevalence of adjacent tooth root resorption and cystic lesions was age-related, exhibiting a trend of first increasing and then decreasing; prevalence peaked at the age of 41 to 45 years old, the prevalence rates were 12.50% and 11.11% respectively. And the lowest prevalence rate was 2.86% and 2.44% in ≥ 61 group and 56- to 60-year age group respectively. Age was an independent risk factor for adjacent tooth root resorption of LIMTMs, whereas age and impaction type (especially inverted impaction) were independent risk factors for cystic lesions.

CONCLUSIONS

The full life cycle management strategy for LIMTMs may need to be individualized. Surgical removal is recommended for LIMTMs in patients younger than 41 to 45 years, especially for inverted, mesioangular, and horizontally impacted LIMTMs. LIMTMs in patients older than 41 to 45 years may be treated conservatively with regular follow-up, but surgical removal of inverted impacted LIMTMs is still recommended to avoid cyst formation.

Evaluation of the effect of extraction in comparison to distalization on the maxillary third molars in class II malocclusion: a retrospective study

OBJECTIVE

To compare the effects of first premolar extraction versus distalization on the vertical position and mesiodistal angulation of maxillary third molars (MxM3) in adolescent class II patients.

METHODS

The panoramic x-rays (OPGs) of 200 adolescent class II patients with developing MxM3s were screened. The chosen sample consisted of 2 groups: Group 1 (Distalization) comprising 48 MxM3s, and Group 2 (Extraction) comprising 50 MxM3s. The pre- and post-treatment OPGs were traced to detect the mesiodistal angulation changes of the second molars (MxM2) and MxM3s.

RESULTS

The angulation and vertical position of the MxM3s at T0 & T1 were also evaluated using Archer's classification. The distalization group presented a non-significant decrease in the mean angulation of MxM2 and MxM3 (-2.4o & -4.5o uprighting respectively). In the extraction group, both MxM2 and MxM3 presented a highly significant decrease in the mean angulation (-10.5o & -11o uprighting respectively). The angulation and vertical position change of MxM3 significantly improved in the extraction group when compared to the distalization group (P < .001).

CONCLUSION

Significant uprighting and occlusal positioning of the maxillary third molars occurred in the premolar extraction treatment group when compared to the distalization treatment group. The results of the current study highlight the importance of recognizing maxillary third molars during orthodontic treatment planning of Class II malocclusion cases.

Third molar-related knowledge, attitudes, behaviors, and medical history of 904 Chinese adults: a cross-sectional survey

This study investigated the perceptions and medical history of third molars (M3s) and assessed the prevalence of visible M3s (V-M3s) among 904 Chinese adults. The enrolled participants were interviewed to complete a structural questionnaire focused on sociodemographic information and their understanding of, attitudes toward, behaviors regarding, and medical history with respect to M3s. In addition, the number of V-M3s in the cohort was determined by oral examination. Logistic regression analysis was performed to explore the association between individuals' sociodemographic characteristics and their perception of M3s or the presence of V-M3s. The Chi-square test was used to compare the actions taken against symptomatic M3s and the corresponding outcomes among different groups divided according to respondents' sociodemographic factors. In total, 904 completed questionnaires were gathered and analyzed. Nearly half (43.9%) of the respondents knew nothing about M3s, and only 12.7% provided correct answers to all the questions asked. Male sex, older age, occupation involving physical labor, and no previous dental experience were active factors in unawareness of M3s. Male sex was also significantly associated with the presence of at least one V-M3 and negative behavior about symptomatic M3s. In terms of medical history, 192 participants reported having had at least one M3 extracted (438 in total), and 72.6% of the M3s were removed due to the presence of related symptoms or pathologies. In conclusion, the population investigated had a shortage of knowledge about M3s and adopted negative attitudes and actions about M3-related problems.

Historical aspects about third molar removal versus retention and distal surface caries in the second mandibular molar adjacent to impacted third molars

This paper provides an insight into the historical recommendations regarding removal of mandibular third molars, as set out by the Royal College of Surgeons of England and the National Institutes of Health in the USA, as well as regional guidance from the National Institute for Health and Care Excellence and the controversy that surrounds surgical removal of third molars. The influences of third molar management as it developed in the UK, the historical economic evaluations, and the available evidence base on third-molar removal versus retention are described. This article seeks to address the growing concerns regarding the increasing frequency of distal surface caries (DSC) in mandibular second molar teeth when the decay is associated with asymptomatic, partially erupted, mandibular third molars, especially when they are mesially or horizontally impacted. Lastly, we illustrate radiographs of patients affected by DSC and how guidance that has been issued by a guideline institution regarding third molar surgery, even though it is based on insufficient evidence, is perceived as a strictly compulsory clinical strategy, and has been used in clinical practice in the UK for more than 20 years.

The radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars

OBJECTIVES

The indication for removal of asymptomatic fully impacted third molars is still controversial. In this study, radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars was performed, aiming to provide a reference for clinical prophylactic extraction of these teeth.

METHODS

Patients with impacted mandibular third molars were included and the maximum width of the dental follicle around the crown was measured in horizontal, sagittal and coronal sections by cone beam computed tomography. The dental follicles were stained with haematoxylin-eosin, analysed by a pathologist and classified as normal, inflammatory or cystic. A Chi-squared test was used to analyse the association of the incidence of inflammation and cysts with the clinical variables of the impacted mandibular third molars.

RESULTS

Thirty-seven samples were normal dental follicles; 52 samples showed inflammatory infiltration with an incidence of 57.14%; 2 samples with a maximum dental follicle width of 2-3 mm were diagnosed as odontogenic cysts, and the incidence was 2.20%. There was no significant difference in the incidence of inflammatory and cystic dental follicles between males and females, or between different age groups (P > 0.05). With an increase of the maximum width of the dental follicle, there was a rise in the incidence and degree of infiltration of chronic nonspecific inflammation.

CONCLUSION

Asymptomatic impacted mandibular third molars tend to be extracted, especially for teeth with a 2-3 mm maximum width of the dental follicle on radiological examination.

External Root Resorption of Second Molars Due to Impacted Mandibular Third Molars during Orthodontic Retention

Whether there is a relationship between impaction of the third molars and the onset of crowding remains to be determined, and extraction of third molars after orthodontic treatment is left to the judgement of the practitioner. This report describes a case where a third molar caused external root resorption (ERR) of the mandibular second molar after orthodontic treatment. As ERR of the mandibular second molar was detected after non-extraction orthodontic treatment, the affected tooth was extracted and substituted with the third molar. External root resorption of the second molar occurred despite being determined as low risk given the state of the impacted third molar as observed on a panoramic radiograph obtained at the end of active treatment. The present results indicate that in cases where the mandibular third molar is present, the corpus length is short, and non-extraction treatment has been performed, it is necessary to obtain X-ray images on a regular basis or preventively extract the third molar to avoid ERR of the second molars.

Knowledge and Attitude Among the Saudi Dentists Towards Coronectomy of Impacted Mandibular Third Molars

Purpose

Compared to the complete extraction of impacted third molars that are in close proximity to the mandibular canal, the coronectomy procedure is used as an alternative, owing to its minimal risk of damaging the Inferior alveolar nerve. Despite clear coronectomy concepts mentioned in the literature, the procedure is debatable. This study aimed to assess the knowledge and attitude towards the coronectomy procedure among dentists in Saudi Arabia.

Patients and Methods

The 16 close-ended questionnaire was distributed electronically to 377 dentists over the country. It included the demographic data and the options given to their patients with complicated impacted third molars, and the number of coronectomy they have performed. The retrieved data were exported and transferred to the SPSS software program for analysis. The Chi-squared and Fisher’s exact tests were used as appropriate for comparisons. A P-value <0.05 was considered significant.

Results

Only 54 (15%) participants performed coronectomy procedure, and only 28.3% of the participants advised their patients to do coronectomy. Nearly two-thirds of the participants (71.9%) were aware of coronectomy procedures, with no significant differences (P> 0.05) between the groups. About 68.9% of the participants agreed that coronectomy aims to protect inferior alveolar nerve damage. More than 60% of participants believed that coronectomy is a reliable technique, while 40.6% of participants claimed that they were capable of deciding whether to do coronectomy or extraction. No significant differences were found between the groups concerning most of the study variables (P> 0.05).

Conclusion

Knowledge of Saudi dentists towards coronectomy is good, while their attitude is still low. More learning strategies about coronectomy should be implemented.

Changes in third molar position after Class II subdivision malocclusion treatment with asymmetric extractions

INTRODUCTION

This study aimed to assess the changes in third molars angulation and their available space after Class II subdivision malocclusion treatment with asymmetric premolar extractions.

METHODS

The sample consisted of 37 patients (17 male, 20 female and mean age 13.18 ± 1.99 years) in group 1 (Type 1 Class II subdivision) and 25 (10 male, 15 female, mean age 13.56 ± 2.46 years) in group 2 (Type 2 Class II subdivision). In group 1, extractions were performed in the two maxillary quadrants and in the Class I mandibular quadrant. In group 2, extraction was performed in the Class II maxillary quadrant. Panoramic radiographs were used to evaluate third molar angulations and their available space pre- and post-treatment. Radiographic measurements were performed with Dolphin^® Imaging 11.9. Paired t tests were used for intragroup comparison between stages and sides.

RESULTS

In Type 1, there were similar improvements in third molar angulations and increases in the space available on the extraction quadrants in the maxillary arch. In the mandibular arch, there was significantly greater improvement in angulation and greater space availability in the extraction quadrant after treatment. In Type 2, there was significantly greater improvement in angulation and available space for the maxillary third molar on the extraction quadrant. In the mandibular arch, there was a similar improvement in the available space for the third molars.

CONCLUSIONS

After treatment, both groups presented better angulation and significantly greater space for third molar eruptions on the extraction quadrants, when compared to the homologous non-extraction quadrants.

Indications of the extraction of symptomatic impacted third molars. A systematic review

Background

A literature review was made to determine when third molar (3M) extraction is recommended in symptomatic patients and when it is not recommended.

Material and Methods

A Medline (PubMed) and EMBASE search was made for articles related to indications for the extraction of 3Ms, published in the last 10 years and up until September 2018.

Results

The electronic search yielded 175 articles. After eliminating duplicates, a total of 173 articles were subjected to review of the title and abstract. Only 19 studies were finally included in the systematic review. There was a well documented increase in morbidity associated to impacted 3Ms (non-restorable caries, fracture, infection, periodontal disease, repeated pericoronitis, cysts and tumors), and in the presence of disease, extraction was considered to be indicated. The extraction of 3Ms with signs and/or symptoms of periodontal disease improved periodontal health at the distal surface of the second molar. Postoperative quality of life of patients with symptomatic 3Ms and with disease improved after surgical extraction.

Conclusions

Extraction is indicated in the presence of disease associated to an impacted 3M, whether symptomatic or not. In contrast, extraction is not indicated in the absence of infection or other associated disease conditions. Key words:Third molar, periodontal disease, periodontitis, pericoronitis, dental caries, occlusal caries, mandibular cysts, osteomyelitis, odontogenic tumor.

Prophylactic removal of impacted mandibular third molars: a systematic review and economic evaluation

BACKGROUND

Impacted third molars are third molars that are blocked, by soft tissue or bone, from fully erupting through the gum. This can cause pain and disease. The treatment options for people with impacted third molars are removal or retention with standard care. If there are pathological changes, the current National Institute for Health and Care Excellence guidance states that the impacted third molar should be removed.

OBJECTIVE

The objective of this study was to appraise the clinical effectiveness and cost-effectiveness of the prophylactic removal of impacted mandibular third molars compared with retention of, and standard care for, impacted third molars.

METHODS

Five electronic databases were searched (1999 to 29 April 2016) to identify relevant evidence [The Cochrane Library (searched 4 April 2016 and 29 April 2016), MEDLINE (searched 4 April 2016 and 29 April 2016), EMBASE (searched 4 April 2016 and 29 April 2016), EconLit (searched 4 April 2016 and 29 April 2016) and NHS Economic Evaluation Database (searched 4 April 2016)]. Studies that compared the prophylactic removal of impacted mandibular third molars with retention and standard care or studies that assessed the outcomes from either approach were included. The clinical outcomes considered were pathology associated with retention, post-operative complications following extraction and adverse effects of treatment. Cost-effectiveness outcomes included UK costs and health-related quality-of-life measures. In addition, the assessment group constructed a de novo economic model to compare the cost-effectiveness of a prophylactic removal strategy with that of retention and standard care.

RESULTS

The clinical review identified four cohort studies and nine systematic reviews. In the two studies that reported on surgical complications, no serious complications were reported. Pathological changes due to retention of asymptomatic impacted mandibular third molars were reported by three studies. In these studies, the extraction rate for retained impacted mandibular third molars varied from 5.5% to 31.4%; this variation can be explained by the differing follow-up periods (i.e. 1 and 5 years). The findings from this review are consistent with the findings from previous systematic reviews. Two published cost-effectiveness studies were identified. The authors of both studies concluded that, to their knowledge, there is currently no economic evidence to support the prophylactic removal of impacted mandibular third molars. The results generated by the assessment group's lifetime economic model indicated that the incremental cost-effectiveness ratio per quality-adjusted life-year gained for the comparison of a prophylactic removal strategy with a retention and standard care strategy is £11,741 for people aged 20 years with asymptomatic impacted mandibular third molars. The incremental cost per person associated with prophylactic extraction is £55.71, with an incremental quality-adjusted life-year gain of 0.005 per person. The base-case incremental cost-effectiveness ratio per quality-adjusted life-year gained was found to be robust when a range of sensitivity and scenario analyses were carried out.

LIMITATIONS

Limitations of the study included that no head-to-head trials comparing the effectiveness of prophylactic removal of impacted mandibular third molars with retention and standard care were identified with the assessment group model that was built on observational data. Utility data on impacted mandibular third molars and their symptoms are lacking.

CONCLUSIONS

The evidence comparing the prophylactic removal of impacted mandibular third molars with retention and standard care is very limited. However, the results from an exploratory assessment group model, which uses available evidence on symptom development and extraction rates of retained impacted mandibular third molars, suggest that prophylactic removal may be the more cost-effective strategy.

FUTURE WORK

Effectiveness evidence is lacking. Head-to-head trials comparing the prophylactic removal of trouble-free impacted mandibular third molars with retention and watchful waiting are required. If this is not possible, routine clinical data, using common definitions and outcome reporting methods, should be collected.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016037776.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 30. See the NIHR Journals Library website for further project information.

Surgical removal versus retention for the management of asymptomatic disease-free impacted wisdom teeth

BACKGROUND

Prophylactic removal of asymptomatic disease-free impacted wisdom teeth is the surgical removal of wisdom teeth in the absence of symptoms and with no evidence of local disease. Impacted wisdom teeth may be associated with pathological changes, such as pericoronitis, root resorption, gum and alveolar bone disease (periodontitis), caries and the development of cysts and tumours. When surgical removal is performed in older people, the risk of postoperative complications, pain and discomfort is increased. Other reasons to justify prophylactic removal of asymptomatic disease-free impacted third molars have included preventing late lower incisor crowding, preventing damage to adjacent structures such as the second molar or the inferior alveolar nerve, in preparation for orthognathic surgery, in preparation for radiotherapy or during procedures to treat people with trauma to the affected area. Removal of asymptomatic disease-free wisdom teeth is a common procedure, and researchers must determine whether evidence supports this practice. This review is an update of an review originally published in 2005 and previously updated in 2012 and 2016.

OBJECTIVES

To evaluate the effects of removal compared with retention (conservative management) of asymptomatic disease-free impacted wisdom teeth in adolescents and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 10 May 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2019, Issue 4), MEDLINE Ovid (1946 to 10 May 2019), and Embase Ovid (1980 to 10 May 2019). The US National Institutes of Health Trials Registry (ClinicalTrials.gov)and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. .

SELECTION CRITERIA

We included randomised controlled trials (RCTs), with no restriction on length of follow-up, comparing removal (or absence) with retention (or presence) of asymptomatic disease-free impacted wisdom teeth in adolescents or adults. We also considered quasi-RCTs and prospective cohort studies for inclusion if investigators measured outcomes with follow-up of five years or longer.

DATA COLLECTION AND ANALYSIS

Eight review authors screened search results and assessed the eligibility of studies for inclusion according to the review inclusion criteria. Eight review authors independently and in duplicate conducted the risk of bias assessments. When information was unclear, we contacted the study authors for additional information.

MAIN RESULTS

This review update includes the same two studies that were identified in our previous version of the review: one RCT with a parallel-group design, which was conducted in a dental hospital setting in the United Kingdom, and one prospective cohort study, which was conducted in the private sector in the USA. Primary outcome No eligible studies in this review reported the effects of removal compared with retention of asymptomatic disease-free impacted wisdom teeth on health-related quality of life Secondary outcomes We found only low- to very low-certainty evidence of the effects of removal compared with retention of asymptomatic disease-free impacted wisdom teeth for a limited number of secondary outcome measures. One prospective cohort study, reporting data from a subgroup of 416 healthy male participants, aged 24 to 84 years, compared the effects of the absence (previous removal or agenesis) against the presence of asymptomatic disease-free impacted wisdom teeth on periodontitis and caries associated with the distal aspect of the adjacent second molar during a follow-up period of three to over 25 years. Very low-certainty evidence suggests that the presence of asymptomatic disease-free impacted wisdom teeth may be associated with increased risk of periodontitis affecting the adjacent second molar in the long term. In the same study, which is at serious risk of bias, there is insufficient evidence to demonstrate a difference in caries risk associated with the presence or absence of impacted wisdom teeth. One RCT with 164 randomised and 77 analysed adolescent participants compared the effect of extraction with retention of asymptomatic disease-free impacted wisdom teeth on dimensional changes in the dental arch after five years. Participants (55% female) had previously undergone orthodontic treatment and had 'crowded' wisdom teeth. No evidence from this study, which was at high risk of bias, was found to suggest that removal of asymptomatic disease-free impacted wisdom teeth has a clinically significant effect on dimensional changes in the dental arch. The included studies did not measure any of our other secondary outcomes: costs, other adverse events associated with retention of asymptomatic disease-free impacted wisdom teeth (pericoronitis, root resorption, cyst formation, tumour formation, inflammation/infection) and adverse effects associated with their removal (alveolar osteitis/postoperative infection, nerve injury, damage to adjacent teeth during surgery, bleeding, osteonecrosis related to medication/radiotherapy, inflammation/infection).

AUTHORS' CONCLUSIONS

Insufficient evidence is available to determine whether asymptomatic disease-free impacted wisdom teeth should be removed or retained. Although retention of asymptomatic disease-free impacted wisdom teeth may be associated with increased risk of periodontitis affecting adjacent second molars in the long term, the evidence is very low certainty. Well-designed RCTs investigating long-term and rare effects of retention and removal of asymptomatic disease-free impacted wisdom teeth, in a representative group of individuals, are unlikely to be feasible. In their continuing absence, high quality, long-term prospective cohort studies may provide valuable evidence in the future. Given the current lack of available evidence, patient values should be considered and clinical expertise used to guide shared decision-making with people who have asymptomatic disease-free impacted wisdom teeth. If the decision is made to retain these teeth, clinical assessment at regular intervals to prevent undesirable outcomes is advisable.

Factors Influencing the Localization of Mandibular Third Molars in Twins

PURPOSE

The aim of the present study was to evaluate the genetic and environmental factors influencing the localization of mandibular third molars by analyzing the panoramic radiographs of twins. We examined the mandibular third molars of Japanese monozygotic (MZ) and dizygotic (DZ) twins recruited by the Osaka University Center for Twin Research.

MATERIALS AND METHODS

The present study included 49 pairs (98 participants) of MZ twins and 11 pairs (22 participants) of DZ twins. Using panoramic radiography, we evaluated the degree of eruption of mandibular third molars according to the height of the alveolus bone and the third molar space/crown width ratio. Using co-twin control analysis and a generalized linear mixed model, we evaluated the effects of various factors, including gender, age, body height, number of teeth, length of the lower dental arch, existence of a second molar, bruxism, and previous orthodontic therapy.

RESULTS

Body height, third molar space/crown width ratio, and length of the mandibular dental arch were related to the degree of mandibular third molar eruption and were strongly influenced by genetic factors rather than common or unique environmental factors.

CONCLUSIONS

The degree of third molar eruption was more similar among MZ twins than among DZ twins; therefore, genetic factors can be expected to have more significant influence than will environmental factors. These results can help identify the trend of third molar eruption from a young age, allowing us to advise the early extraction of mandibular third molars for patients with a short stature, narrow retromolar space, or short mandibular dental arch. In addition, if the genes that influence the degree of eruption were identified, we would be better equipped to predict an individual's risk of impaction, and indications for extraction might change.

Prophylactic extraction of non-impacted third molars: is it necessary?

BACKGROUND

The decision of removing a non-impacted 3rd molar, unlike extraction of an impacted 3rd molar, is challenging for dentists as well as patients. This study investigates the pathologies affecting second molars situated adjacent to asymptomatic non-impacted 3rd molars.

METHODS

This retrospective study included digital radiographs of 749 patients taken between April to October 2015. Panoramic radiographs were evaluated for the presence of erupted asymptomatic non-impacted 3rd molars and pathologies on adjacent second molars. The patients were reviewed according to age and gender.

RESULTS

A total of 2342 asymptomatic 3rd molars were assessed in the study based on the inclusion and exclusion criteria, and 2112 of them were found to be non-impacted. The second molars adjacent to non-impacted 3rd molars were shown to be significantly associated with distal caries (25.2%), mesial bone loss (10.5%) and total bone loss (37.2%), i.e., mesial as well as distal bone loss.

CONCLUSIONS

Pathologies of the 3rd molars and teeth adjacent to 3rd molars can occur as a result of multiple factors. Caries and periodontal disease may also occur due to the inaccessibility to maintain oral hygiene. With a regular follow-up schedule, reinforced by the dentist and good oral hygiene, several pathologies that are significantly associated with non-impacted 3rd molars can be prevented and may not require prophylactic extraction.

Is prophylactic removal of impacted mandibular third molar justified in all patients? A prospective clinical study of patients 50 years and above

BACKGROUND

The prophylactic extraction of asymptomatic impacted mandibular third molar is a contentious issue in dental practice.

OBJECTIVE

To evaluate symptomatic impacted mandibular third molars in patients 50 years and above, and determine the burden of the impaction on the adjacent second molar.

METHODS

This was a prospective clinical study over a three-year period. The diagnosis of impacted mandibular third molar and their associated pathology was made by clinical and radiological examination. The data obtained were age, sex, type of impaction, reason for surgical extraction, and the clinical condition of the adjacent second molar.

RESULTS

Patients 50 years and above were 33.4%, and those with impaction 22.8%, while the symptomatic cases were in 18.4% patients. The age of the patients ranged from 52 to 84 years with male: female ratio, 2.3:1. In all the asymptomatic impactions, the adjacent second molars were disease-free, whereas 73.6% of the adjacent second molar related to symptomatic cases were asymptomatic (P=0.001).

CONCLUSION

This study showed that 15.9% of impactions in 18.4% of patients were symptomatic and required surgical extraction, whereas the burden of impaction on the adjacent second molar was 26.4%, and these required only preventive and restorative treatments.

Relationship Between Third Mandibular Molar Angulation and Distal Cervical Caries in the Second Molar

Third lower molar partially erupted is commonly encountered in dental practice. This situation challenges clinicians with the dilemma whether to remove or to monitor it, because this molar can cause pathology of the adjacent second molar. The aim of this retrospective study is to evaluate the relationship between third mandibular molar and distal cervical caries in second molar. This retrospective study analyzed 55 digital orthopantograms of adult patients and a total number of 95 mandibular third molars were assessed for eruption status, angulation, radiographic evidence of caries or restoration in the mandibular third molar, and radiographic evidence of caries or restoration in the distal surface of the mandibular second molar. The distal cervical caries in second molar is associated with fully erupted and partially erupted wisdom molar in horizontal, mesioangular and vertical position and less with presence of caries in third molar. There are caries lesions in distal second molars in mesioangular position when adjacent third molar is caries free.

The Impact of Genetics and Environmental Factors on the Position of the Upper Third Molars

PURPOSE

The purpose of this study was to estimate the importance of heredity in the position of the upper third molars.

MATERIALS AND METHODS

Panoramic radiographs and lateral cephalograms of same-gender twins were analyzed. The determination of zygosity was performed by means of DNA tests with polymerase chain reaction for the amplification of short tandem repeats and 15 specific DNA markers. Data were estimated by the relative influence of additive genetic factors (A), nonadditive genetic factors (D), the common or shared environment (C), and unique environmental factors (E).

RESULTS

The study sample consisted of 212 twins: 80 dizygotic and 132 monozygotic twins. The genetic analysis showed that the best-fitting model for the size of the molars and their angulations was AE (additive genetic factors and unique environmental factors), in which the additive genetic factors had up to 84% influence and specific environment had up to 40%. Therefore, the ACE (additive genetic factors, common or shared environment, and unique environmental factors) model showed higher significance for the tooth eruption level. The heritability estimates were up to 59%, specific environment contributed up to 16%, and common environment reached 30%.

CONCLUSIONS

Genetic factors play a key role in the position of the upper third molars.

Análisis de los eventos desfavorables como resultado de la atención en cirugía oral

Antecedentes: La cirugía oral es una especialidad que requiere preparación teórica y habilidad quirúrgica para efectuar los procedimientos. Durante el proceso de aprendizaje, los estudiantes, al efectuar cirugías, pueden enfrentar dificultades que dañen involuntariamente al paciente. A pesar de cumplirse los protocolos, es posible que se presenten eventos desfavorables durante la atención. Por este motivo, es necesario caracterizar y analizar dichos eventos en instituciones como una facultad de odontología para mejorar la calidad de la atención. Objetivo: Analizar los eventos desfavorables que se presentaron en el área quirúrgica de la Facultad de Odontología de la Pontificia Universidad Javeriana en un periodo de dos años. Métodos: En este estudio observacional-descriptivo se evaluaron todas las historias clínicas de pacientes atendidos entre el 1 de enero de 2014 y el 31 de diciembre de 2015, a fin de identificar y analizar los eventos desfavorables en cirugía oral. Resultados: De 1062 historias clínicas, 74 (7 %) tenían reportes de eventos desfavorables, 41 (56 %) de las cuales se tipificaron como complicaciones, 22 (30 %) como indicios de atención insegura y 11 (14 %) como eventos adversos. De ellos, 9 (82 %) fueron prevenibles y 2 (18 %) no prevenibles, todos relacionados con exodoncias. Conclusiones: Los eventos adversos en el área quirúrgica se presentaron en baja frecuencia y se relacionaron con exodoncias. Para reducir la ocurrencia de estas situaciones, es preciso realizar planeación prequirúrgica, elaborar meticulosamente las historias clínicas y, en caso de presentarse algún tipo de evento, informarlo.

The magnification in the lower third and second molar region in the digital panoramic radiographs

Background:

The aim of this study was to determine the accuracy of linear measurements of the lower third and second molar crowns in the digital panoramic radiographs and to compare them with plaster models as the calibration standard.

Materials and Methods:

The digital panoramic radiographs and plaster models of the orthodontic patients were used in the study. Standardized metal calibration gauges (MCGs) were bonded to the buccal surface of the lower molars bilaterally. Measurements in the panoramic radiographs were done using Dolphin Imaging 11.8 Premium program.

Results:

Forty-one panoramic radiographs and diagnostic plaster models of the orthodontic patients (mean age 18.45 ± 2.35) were analyzed. Eighty-two lower third molars, 82 second molars, and 82 first molars were evaluated. The magnification coefficients (MCC) calculated according to the plaster models ranged from 1.07 to 1.08. The magnification coefficients calculated according to the bonded MCG were about 1.04. The differences between the teeth groups and right-left sides were not statistically significant (P > 0.05). Spearman correlation showed a positive medium correlation between the magnification using the calibration with plaster models and metal gauges (P < 0.05).

Conclusions:

The magnification in the lower first, second, and third molars regions showed almost the same values. The calculation of magnification coefficient using bonded metal calipers was more accurate than calculation according to the plaster models, but the differences were not statistically significant. The use of the plaster models for calibration of the magnification coefficient in the good-positioned lower molars' region might be used as an alternative to the bonded MCGs.

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

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.

Clinical and pathologic features related to the impacted third molars in patients of different ages: A retrospective study in the Korean population

Background/purpose

The surgical extraction of impacted third molars (ITMs) is a common surgical procedure in dentistry. If prophylactic removal of ITMs is beneficial, however, is a still disputed issue. The aim of this study was to analysis the pathologic changes in impacted third molars (ITMs) and adjacent teeth according to patient age groups in the Korean population to determine if the prophylactic removal of ITMs is to be supported or not.

Materials and methods

A retrospective study of patients who underwent surgical extraction of impacted third molars was performed. The patients were divided into 5 groups according to their age. Each group was analyzed with respect to patients' chief complaints, specific pathologic conditions in ITMs, and the damage to adjacent teeth due to untreated ITMs.

Results

In this study, 2883 impacted third molars in 1109 patients were analyzed. The most common patients' chief complaint was pain, and the frequency of pain was significantly higher in older age groups. The frequency and severity of pathologic changes in ITMs and adjacent second molars due to ITMs were increased with advancing age.

Conclusion

Based on the results of this study, we conclude that the prophylactic removal of ITMs that have a higher probability of pathologic changes can be considered to be a reasonable treatment modality in younger patients to reduce morbidity resulting from surgical extraction compared with patients who attained advanced age.

Effect of Asymptomatic Visible Third Molars on Periodontal Health of Adjacent Second Molars: A Cross-Sectional Study

PURPOSE

Evidence that asymptomatic third molars (M3s) negatively affect their adjacent second molars (A-M2s) is limited. The present study evaluated the association between visible M3s (V-M3s) of various clinical status with the periodontal pathologic features of their A-M2s.

PATIENTS AND METHODS

Subjects with at least 1 quadrant having intact first and second molars, either with V-M3s and symptom free or without adjacent V-M3s, were enrolled in the present cross-sectional investigation. Periodontal parameters, including plaque index (PLI), bleeding on probing (BOP), probing pocket depth (PPD), and at least 1 site with a PPD of 5 mm or more (PPD5+), obtained from M2s were analyzed according to the presence or absence of V-M3s or the status of the M3s. The χ² test or t test was used to compare the mean PLI, PPD, BOP percentage, and PPD5+ percentage. The association of PPD5+ with V-M3 status was assessed using a multivariable logistic regression model (quadrant-based analysis), and variances were adjusted for clustered observations within subjects.

RESULTS

In total, 572 subjects were enrolled in the study, and 423 had at least 1 V-M3. At the in-quadrant level, the presence of a V-M3 significantly increased M2 pathologic parameters, including PLI, PPD, BOP, and PPD5+. When analyzed using a multivariate logistic regression model, impacted M3s and normally erupted M3s significantly elevated the risk of PPD5+ on their A-M2s (odds ratio 3.20 and 1.67, respectively). Other factors associated with an increased odds of PPD5+ were mandibular region and older age. Finally, the patient-matched comparison showed that the percentage of BOP and PPD5+ on M2s increased when V-M3s were present.

CONCLUSIONS

Irrespective of their status, the presence of V-M3s is a risk factor for the development of periodontal pathologic features in their A-M2s. Although the prophylactic removal of asymptomatic V-M3s remains controversial, medical decisions should be made as early as possible, because, ideally, extraction should be performed before symptom onset.

At-home laser treatment of oral neuronal disorders: Case reports

The neuronal disorders occurring in the oral district are mainly anaesthesia, paraesthesia, hypoesthesia and hyperaesthesia and they may occur frequently after surgical procedures. Medical treatment depends on degree of severity of the nerve injury but, in every case, it must be immediately carried out to reduce immune inflammatory reaction. The aim of this report is to investigate the effectiveness in the recovery of the peripheral nerve lesions of a new laser device recently proposed by the commerce that, due to its reduced size and to be a class I laser according the ANSI classification, may be used at home by the patient himself. Three different cases were treated with this "at-home approach": complete resolution of symptomatology was obtained after laser treatment with a good compliance for the patient and without reporting any side effect. Key words:Laser, biomodulation, low level laser therapy, oral neuronal disorders, at-home treatment, paresthesia.

The effect of first and second premolar extractions on third molars: A retrospective longitudinal study

OBJECTIVES

To analyse the effect of first and second premolar extractions on eruption space for upper and lower third molars and on third molar position and angulation during orthodontic treatment.

METHODS

The sample consisted of 296 patients of which 218 patients were orthodontically treated without extraction and 78 patients with extraction of first or second premolars. The eruption space for third molars was measured on pre- and posttreatment lateral cephalograms, whereas the angulation, vertical position, the relation with the mandibular canal and the mineralization status of third molars were evaluated using pre- and posttreatment panoramic radiographs. All data were statistically analyzed.

RESULTS

The increase in eruption space and the change in vertical position of upper and lower third molars significantly differed between patients treated with and without premolar extractions, whereas the change in angulation, relationship with the mandibular canal and mineralization status of the third molars did not significantly differ between patients treated with and without premolar extractions.

CONCLUSIONS

The retromolar space and the position of third molars significantly change during orthodontic treatment in growing patients. Premolar extractions have a positive influence on the eruption space and vertical position of third molars, whereas they do not influence the angular changes of third molars. Due to the retrospective character of the study, these conclusions should be carefully considered. Further prospective research is necessary for better insights into this complex topic.

CLINICAL SIGNIFICANCE

This study stresses the importance of considering the possible effects of orthodontic treatment on third molars during treatment planning.

Implications of Vertebrate Craniodental Evo-Devo for Human Oral Health

Highly processed diets eaten by postindustrial modern human populations coincide with higher frequencies of third molar impaction, malocclusion, and temporomandibular joint disorders that affect millions of people worldwide each year. Current treatments address symptoms, not causes, because the multifactorial etiologies of these three concerns mask which factors incline certain people to malocclusion, impaction, and/or joint issues. Deep scientific curiosity about the origins of jaws and dentitions continues to yield rich insights about the developmental genetic mechanisms that underpin healthy craniodental morphogenesis and integration. Mounting evidence from evolution and development (Evo-Devo) studies suggests that function is another mechanism important to healthy craniodental integration and fit. Starting as early as weaning, softer diets and thus lower bite forces appear to relax or disrupt integration of oral tissues, alter development and growth, and catalyze impaction, malocclusion, and jaw joint disorders. How developing oral tissues respond to bite forces remains poorly understood, but biomechanical feedback seems to alter balances of local bone resorption and deposition at the tooth-bone interface as well as affect tempos and amounts of facial outgrowth. Also, behavioral changes in jaw function and parafunction contribute to degeneration and pain in joint articular cartilages and masticatory muscles. The developmental genetic contribution to craniodental misfits and disorders is undeniable but still unclear; however, at present, human diet and jaw function remain important and much more actionable clinical targets. New Evo-Devo studies are needed to explain how function interfaces with craniodental phenotypic plasticity, variation, and evolvability to yield a spectrum of healthy and mismatched dentitions and jaws.

Surgical removal versus retention for the management of asymptomatic disease-free impacted wisdom teeth

BACKGROUND

Prophylactic removal of asymptomatic disease-free impacted wisdom teeth is surgical removal of wisdom teeth in the absence of symptoms and with no evidence of local disease. Impacted wisdom teeth may be associated with pathological changes, such as pericoronitis, root resorption, gum and alveolar bone disease (periodontitis), caries and the development of cysts and tumours. When surgical removal is carried out in older people, the risk of postoperative complications, pain and discomfort is increased. Other reasons to justify prophylactic removal of asymptomatic disease-free impacted third molars have included preventing late lower incisor crowding, preventing damage to adjacent structures such as the second molar or the inferior alveolar nerve, in preparation for orthognathic surgery, in preparation for radiotherapy or during procedures to treat people with trauma to the affected area. Removal of asymptomatic disease-free wisdom teeth is a common procedure, and researchers must determine whether evidence supports this practice. This review is an update of an existing review published in 2012.

OBJECTIVES

To evaluate the effects of removal compared with retention (conservative management) of asymptomatic disease-free impacted wisdom teeth in adolescents and adults.

SEARCH METHODS

We searched the following electronic databases: Cochrane Oral Health's Trials Register (to 24 May 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 4), MEDLINE Ovid (1946 to 24 May 2016) and Embase Ovid (1980 to 24 May 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing and unpublished studies to 24 May 2016. We imposed no restrictions on language or date of publication in our search of electronic databases.

SELECTION CRITERIA

Studies comparing removal (or absence) with retention (or presence) of asymptomatic disease-free impacted wisdom teeth in adolescents or adults. We included randomised controlled trials (RCTs) with no restriction on length of follow-up, if available. We considered quasi-RCTs and prospective cohort studies for inclusion if investigators measured outcomes with follow-up of five years or longer.

DATA COLLECTION AND ANALYSIS

Eight review authors screened search results and assessed the eligibility of studies for inclusion according to the review inclusion criteria. Eight review authors independently conducted risk of bias assessments in duplicate. When information was unclear, we contacted study authors for additional information.

MAIN RESULTS

This review includes two studies. The previous review included one RCT with a parallel-group design, which was conducted in a dental hospital setting in the United Kingdom; our new search for this update identified one prospective cohort study conducted in the private sector in the USA. Primary outcome No eligible studies in this review reported the effects of removal compared with retention of asymptomatic disease-free impacted wisdom teeth on health-related quality of life Secondary outcomes We found only low to very low quality evidence of the effects of removal compared with retention of asymptomatic disease-free impacted wisdom teeth for a limited number of secondary outcome measures.One prospective cohort study, reporting data from a subgroup of 416 healthy male participants, aged 24 to 84 years, compared the effect of the absence (previous removal or agenesis) against the presence of asymptomatic disease-free impacted wisdom teeth on periodontitis and caries associated with the distal of the adjacent second molar during a follow-up period of three to over 25 years. Very low quality evidence suggests that the presence of asymptomatic disease-free impacted wisdom teeth may be associated with increased risk of periodontitis affecting the adjacent second molar in the long term. In the same study, which is at serious risk of bias, there is insufficient evidence to demonstrate a difference in caries risk associated with the presence or absence of impacted wisdom teeth.One RCT with 164 randomised and 77 analysed adolescent participants compared the effect of extraction with retention of asymptomatic disease-free impacted wisdom teeth on dimensional changes in the dental arch after five years. Participants (55% female) had previously undergone orthodontic treatment and had 'crowded' wisdom teeth. No evidence from this study, which was at high risk of bias, was found to suggest that removal of asymptomatic disease-free impacted wisdom teeth has a clinically significant effect on dimensional changes in the dental arch.The included studies did not measure our other secondary outcomes: costs, other adverse events associated with retention of asymptomatic disease-free impacted wisdom teeth (pericoronitis, root resorption, cyst formation, tumour formation, inflammation/infection) and adverse effects associated with their removal (alveolar osteitis/postoperative infection, nerve injury, damage to adjacent teeth during surgery, bleeding, osteonecrosis related to medication/radiotherapy, inflammation/infection).

AUTHORS' CONCLUSIONS

Insufficient evidence is available to determine whether or not asymptomatic disease-free impacted wisdom teeth should be removed. Although asymptomatic disease-free impacted wisdom teeth may be associated with increased risk of periodontitis affecting adjacent second molars in the long term, the evidence is of very low quality. Well-designed RCTs investigating long-term and rare effects of retention and removal of asymptomatic disease-free impacted wisdom teeth, in a representative group of individuals, are unlikely to be feasible. In their continuing absence, high quality, long-term prospective cohort studies may provide valuable evidence in the future. Given the lack of available evidence, patient values should be considered and clinical expertise used to guide shared decision making with patients who have asymptomatic disease-free impacted wisdom teeth. If the decision is made to retain asymptomatic disease-free impacted wisdom teeth, clinical assessment at regular intervals to prevent undesirable outcomes is advisable.

Impacted Mandibular Third Molars: A Retrospective Study of 1198 Cases to Assess Indications for Surgical Removal, and Correlation with Age, Sex and Type of Impaction-A Single Institutional Experience

AIM

To study the incidence of mandibular third molar impaction in relation to type and side of impaction, age and sex of patients and indications for its surgical removal through data collected from a single institute over a period of 3 and half years.

METHODS

The records of 1198 patients who underwent the surgical removal of impacted mandibular third molars were reviewed retrospectively. Records were divided into groups according to sex, age, type and side of impaction. Radiographs were studied to determine angular position of impacted mandible third molar.

RESULTS

We found that there was a high incidence of mesioangular lower third molar impaction (33.97 %), highest number of patients were found in 15-30 years of age group (48.33 %), a left side (56.93 %) was more commonly involved, female predominance (63.44 %) was observed and recurrent pericoronitis (33.81 %) was the most common indication.

CONCLUSION

Awareness of the indications for surgical removal of impacted mandibular third molar to the patients will help to avoid future risk of complications and morbidity associated with the same. This will not only help in saving time and money but also prevents the psychological trauma associated with delayed treatment. Removal of only symptomatic IMTM seems to be the logical choice in view of financial constraint in developing countries like India but at the same time early removal offers freedom from future complications in selected cases. So surgeons should apply a meticulous approach in selecting the patients for SRIMTM.

The quality of information on the Internet on orthodontic retainer wear: a cross-sectional study

OBJECTIVES

The objectives of this study were to assess the accessibility, usability, reliability and quality of information on the Internet written for the lay public about orthodontic retainers, and to elucidate the different retention protocols encouraged.

DESIGN

A cross-sectional, observational study.

SETTING

Online, using a computer connected to the Internet in Australia.

METHODS

Two search terms; 'orthodontic retainer' and 'how long should someone wear a retainer after their braces are removed?' were entered alternatively into five search engines. Twenty results for each search term per search engine that fulfilled the inclusion criteria were evaluated in terms of accessibility, usability, reliability and quality of information using the LIDA and DISCERN instruments, ensuring there were no internal or cross-search engine duplicates. Any information about frequency and duration of retainer wear was also collected.

RESULTS

Two hundred different websites were identified and assessed. The median overall LIDA score was 72%, corresponding to a moderate quality level. The median total DISCERN score was 47%. Twenty-two websites recommended patients adhere to the specific protocol prescribed to them by their practitioner. There were 45 (22.5%) and 28 (14%) websites advising indefinite use of removable and bonded retainers respectively.

CONCLUSIONS

Information about retainers on the Internet is easily accessible and usable, though the quality of the content is generally of a moderate level. However, the information is not always accurate and reliable. Both full-time and part-time wear of removable retainers was suggested over greatly varying time periods. Indefinite wear of removable and bonded retainers was also advocated.

Predictors of Third Molar Impaction

The objective of this meta-analysis was to evaluate the prevalence of third molar (M3) impaction worldwide in individuals ≥17 y, from either sex, who had undergone oral radiography and presented with no orofacial syndromes or defects. We performed a literature search using PubMed, ISI Web of Science, and Google Scholar and retrieved English and non-English articles from any period for review. We included studies reporting M3 impaction prevalence based on radiographic examination. Risk of bias was assessed regarding individuals with craniofacial syndromes, prior extraction of permanent teeth, multiple effect size estimates, and studies conflating lack of eruption with impaction. Our search yielded 49 studies involving 83,484 individuals. Worldwide M3 impaction prevalence was found to be 24.40% (95% confidence interval [95% CI]: 18.97% to 30.80%). The odds of M3 impaction in the mandible were 57.58% (95% CI: 43.3% to 68.3%, P < 0.0001) higher than in the maxilla, but we did not detect any difference in the odds of impaction between men and women (18.62%, 95% CI: –4.9% to 48.0%, P = 0.12). Mesioangular impaction was most common (41.17%, 95% CI: 33.8% to 49.0%), followed by vertical (25.55%, 95% CI: 20.0% to 32.0%), distoangular (12.17%, 95% CI: 9.1% to 16.0%), and horizontal (11.06%, 95% CI: 8.3% to 14.6%). Impaction of 1 (42.71%, 95% CI: 30.0% to 56.5%) or 2 (29.64%, 95% CI: 19.5% to 42.3%) M3s was much more common than 3 (12.04%, 95% CI: 7.2% to 19.3%) or 4 (8.74%, 95% CI: 5.2% to 14.5%). There were small differences among impaction prevalence depending on geographic region ( F test, P = 0.049). Selection bias was evident because individuals had to undergo radiographic examination to be included in the analysis. The subgroup analysis by sex was underpowered. Worldwide M3 impaction prevalence is lower than previously reported. The percentage of individuals with impacted M3s is much smaller than the percentage that undergoes clinical treatment for M3 problems.

Third molars and dental crowding: different opinions of orthodontists and oral surgeons among Italian practitioners

BACKGROUND

The role of third molars as a cause of incisor crowding, especially in the lower arch, continues to be controversial. The aim of this work is to compare opinions of Italian oral surgeons and orthodontists on this topic.

METHODS

One hundred ninety-three Italian practitioners of the Society of Orthodontics (SIDO) and the Italian Society of Oral Surgery (SICOI) were asked to fill out an online questionnaire made up of six questions. Practitioners were asked to express their opinion on the relation between upper and lower third molar eruption and anterior crowding.

RESULTS

One hundred sixty-six members of both societies completed the online research survey; response rate (RR) was 86%. There were no statistically significant differences between the two groups (P > 0.005). Both agree not to believe that third molars create a force responsible for anterior crowding in the upper (82.5% orthodontists, 83.8% surgeons) and in the lower arch (52.6% orthodontists, 63.8% surgeons). Both agree also not to consider the upper (89.7% orthodontists, 82.1% surgeons) and lower (58.8% orthodontists, 63.2% surgeons) third molar extraction useful to prevent crowding.

CONCLUSIONS

Italian orthodontists and oral surgeons have the same opinion on the role of the third molar in causing anterior crowding. The majority of both groups of clinicians do not consider their preventive extraction useful in order to prevent anterior crowding.

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.

Factors influencing lingual nerve paraesthesia following third molar surgery: a prospective clinical study

BACKGROUND AND OBJECTIVES

The purpose of this prospective study was to evaluate the incidence and various risk factors influencing the sensory deficit in case of lingual nerve injury (LNI) in individuals whose impacted mandibular third molars are surgically removed under local anesthesia.

MATERIALS AND METHODS

The study was based on the data collected prospectively from a random group of 100 patients who underwent surgical removal of bony impacted lower third molar in a dental hospital. Details of the patient, reason for extraction, type of impaction, method of surgery and signs and symptoms of nerve injury are recorded. Neurosensory testing was done to evaluate the LNI at 1 week, 1 months, 3 months and 6 months interval. Comparison was carried out using Chi square test. For all tests a P < 0.05 was considered significant.

RESULTS

The incidence of LNI was 4 % and of temporary in nature which recovered well within 6 months postoperatively. The age of the patient above 26 years, lingual flap retraction, depth of impaction (red line ≥10 mm) and duration of surgery above 30 min were the significant factors for causing LNI.

CONCLUSIONS

The age of the patient, depth of impaction, lingual flap retraction and longer duration of surgery are significant risk factors for LNI during mandibular third molar surgery. Greater care should be taken to avoid the morbidity and patients should be informed well ahead about the probable complications.

Surgical removal versus retention for the management of asymptomatic impacted wisdom teeth

BACKGROUND

The prophylactic removal of asymptomatic impacted wisdom teeth is defined as the (surgical) removal of wisdom teeth in the absence of local disease. Impacted wisdom teeth may be associated with pathological changes, such as inflammation of the gums around the tooth, root resorption, gum and alveolar bone disease, damage to the adjacent teeth and the development of cysts and tumours. Other reasons to justify prophylactic removal have been to prevent late incisor crowding. When surgical removal is carried out in older patients, following the development of symptoms, the risk of postoperative complications, pain and discomfort increases. Nevertheless, in most developed countries prophylactic removal of trouble-free wisdom teeth, either impacted or fully erupted, has long been considered as 'appropriate care' and is a very common procedure. There is a need to determine whether there is evidence to support this practice.

OBJECTIVES

To evaluate the effects of prophylactic removal of asymptomatic impacted wisdom teeth in adolescents and adults compared with the retention (conservative management) of these wisdom teeth.

SEARCH METHODS

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 30 March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1950 to 30 March 2012), and EMBASE via OVID (1980 to 30 March 2012). There were no restrictions on language or date of publication.

SELECTION CRITERIA

All randomised controlled trials (RCTs) on adolescents and adults comparing the effect of prophylactic removal of asymptomatic impacted wisdom teeth with no-treatment (retention).

DATA COLLECTION AND ANALYSIS

Six review authors screened the results of the search and assessed whether trials met the inclusion criteria for the review. Data extraction and risk of bias assessment were conducted in duplicate and independently by six review authors. Where information was unclear, authors of studies were contacted for additional information.

MAIN RESULTS

No RCTs were identified that compared the removal of asymptomatic wisdom teeth with retention and reported quality of life. One RCT on adolescents was identified that compared the removal of impacted mandibular wisdom teeth with retention and only examined the effect on late lower incisor crowding. This study at high risk of bias provided no evidence that extraction of wisdom teeth had an effect on lower incisor crowding over 5 years.

AUTHORS' CONCLUSIONS

Insufficient evidence was found to support or refute routine prophylactic removal of asymptomatic impacted wisdom teeth in adults. A single trial comparing removal versus retention found no evidence of a difference on late lower incisor crowding at 5 years, however no other relevant outcomes were measured.Watchful monitoring of asymptomatic third molar teeth may be a more prudent strategy.

Maxillary tuberosity fracture: a life-threatening haemorrhage following simple exodontia

Maxillary tuberosity fracture is a potential complication of routine exodontia of posterior maxillary teeth. On rare occasions, such a complication can result in torrential haemorrhage due to the close proximity of significant vessels to the area. We present a case of life-threatening haemorrhage complicating a tuberosity fracture during simple extraction of a maxillary posterior tooth. The local anatomy of the region is discussed and we provide guidelines for general dental practitioners for the management of the complication of a tuberosity fracture during routine exodontia.

Recovery after third-molar surgery: the effects of age and sex

INTRODUCTION

In this study, we assessed the effects of age and sex on quality-of-life recovery after third-molar surgery.

METHODS

Healthy subjects scheduled for removal of third molars were recruited at multiple sites for this study. Each patient was given a condition-specific instrument to be completed each postsurgery day for 14 days. Lifestyle and oral-function recovery were assessed by using a 5-point Likert-type scale. Recovery was defined as the number of days until the patient reported no or little trouble. Recovery from pain was defined as the number of days until no medications were taken. For each quality-of-life item, a Cox regression analysis was performed to assess the effects of age and sex on recovery after controlling for surgical-procedure variables.

RESULTS

Nine hundred fifty-eight subjects treated at 9 academic centers and 12 community practices were enrolled. Except for ability to open the mouth, recovery for all quality-of-life items for those 21 years or older significantly (P < 0.02) lagged behind recovery for younger subjects. Recovery for female subjects was significantly longer than for male subjects for all outcomes (P < 0.01).

CONCLUSIONS

Patients older than 21 and those who are female should be informed before removal of all 4 third molars that their oral function, lifestyle, and pain recovery will be prolonged compared with those who are younger and male.