Mandibular fractures following third molar extraction. A retrospective clinical and radiological study

Automated Prediction of Extraction Difficulty and Inferior Alveolar Nerve Injury for Mandibular Third Molar Using a Deep Neural Network

Extraction of mandibular third molars is a common procedure in oral and maxillofacial surgery. There are studies that simultaneously predict the extraction difficulty of mandibular third molar and the complications that may occur. Thus, we propose a method of automatically detecting mandibular third molars in the panoramic radiographic images and predicting the extraction difficulty and likelihood of inferior alveolar nerve (IAN) injury. Our dataset consists of 4903 panoramic radiographic images acquired from various dental hospitals. Seven dentists annotated detection and classification labels. The detection model determines the mandibular third molar in the panoramic radiographic image. The region of interest (ROI) includes the detected mandibular third molar, adjacent teeth, and IAN, which is cropped in the panoramic radiographic image. The classification models use ROI as input to predict the extraction difficulty and likelihood of IAN injury. The achieved detection performance was 99.0% mAP over the intersection of union (IOU) 0.5. In addition, we achieved an 83.5% accuracy for the prediction of extraction difficulty and an 81.1% accuracy for the prediction of the likelihood of IAN injury. We demonstrated that a deep learning method can support the diagnosis for extracting the mandibular third molar.

Iatrogenic Fracture of the Lower Jaw: A Rare Complication of Lower Molar Extraction

Iatrogenic mandible fracture is a rare complication of a tooth extraction with an incidence between 0.0033-0.0034%. This study retrospectively analyzes a total of 8 patients who underwent lower molar extraction associated with mandible fracture during tooth removal in the period from April 2006 to March 2019. The assessed parameters were age and sex of patients, method of tooth extraction, side distribution of fracture, type of extracted tooth, the position of a lower third molar, presence of bone pathological lesion formed in connection with a tooth, displacement of bone fragments, and sensory impairment in the innervation area of the mental nerve. The position and impaction of the lower third molars were evaluated according to Pell and Gregory's classification and Winter's classification. One fracture was left-sided, and 7 fractures were right-sided. In 6 cases, Winter's extraction elevator was used. In 7 patients, the mandible fracture was treated surgically by performing stable osteosynthesis with the plates and screws. One patient was treated conservatively. This work analyzes the causes of iatrogenic mandible fractures and provides recommendations to reduce the risk of their occurrence.

[Biomechanical study of cystic lesions of the mandible based on a three-dimensional finite element model]

OBJECTIVE

To analyze the biomechanics of cystic lesions in the mandibular body in a three-dimensional (3D) finite element model.

METHODS

A 3D finite element model of cystic lesion of the mandibular body was constructed based on the CT images of the mandible of a healthy adult female volunteer with normal occlusion. The size of the cyst and the residual bone wall were analyzed when the lesion area approached the stress peak under certain constraints and loading conditions.

RESULTS

When the size of the cyst reached 37.63 mm×11.32 mm×21.45 mm, the maximal von Mises stress in the lesion area reached 77.295 MPa, close to the yield strength of the mandible with a risk of pathological fracture. At this point, the remaining bone thickness of the buccal and lingual sides and the lower margin of the mandible in the lesion area was 1.52 mm, 0.76 mm and 1.04 mm, respectively.

CONCLUSIONS

Residual bone mass is an important factor to affect the risk of pathological fracture after curettage of cystic lesions. A thickness as low as 1 mm of the residual bone cortex in the cystic lesion area of the mandibular body can be used as the threshold for a clinical decision on one-stage windowing decompression combined with two- stage curettage.

Comparison of comma incision with Ward's incision in third molar extraction in terms of postoperative sequel - A clinical study

Objective:

The objective of the study was to compare standard Ward's incision and comma-shaped incision and its influence on postoperative complications in surgical removal of impacted mandibular third molar.

Materials and Methods:

This was a prospective study. Fifty individuals divided into two groups with impacted mandibular third molars were recruited for the study. Twenty-five individuals were allocated to each group: a standard Ward's incision was made in Group A and a comma incision was made in Group B to reflect the mucoperiosteal flap, after which the common steps for removal of impacted third molars were followed. The postoperative parameters were recorded immediately on the postoperative days 1, 3, and 7.

Observation and Results:

The pain scores which were recorded on days 1, 3, and 7 in the surgical area with comma incisions were found to be significantly lower as compared to the pain scores in the area where standard incisions were made. Similarly, swelling was lesser with comma incision than with standard Ward's incision. There was a significant difference in mouth opening between the two incisions on day 1, but no significance was seen on days 3 and 7. All of these findings showed significant statistical differences.

Summary and Conclusions:

The results of the study showed that the new comma-shaped incision design was preferable over the conventional method (Ward's incision), considering the lesser degree of postoperative complications.

Osteomyelitis of the Mandible Caused by Late Fracture following Third Molar Extraction

The common postoperative complications of the extraction of third molars are frequently reported; however, reports about osteomyelitis of the mandible caused by late fracture following third molar extraction are rare. Here, we report a case of osteomyelitis of the mandible caused by late fracture following third molar extraction. A 38-year-old Japanese man was referred to the surgery department with chief complaints of dull pain and swelling in the right masseteric region and paresthesia of his lower lip and mental region in March 2018. A family dentist removed his lower third molar in the right side in January 2018. When the patient was chewing an innards stew 23 days after the procedure, he heard a cracking sound from the right mandible. Thus, we diagnosed the patient as having osteomyelitis of the mandible caused by late fracture following third molar extraction and performed sequestrectomy and curettage under general anesthesia in April 2018. In conclusion, it is necessary to recognize the possibility that late fracture following third molar extraction can cause osteomyelitis. Furthermore, once osteomyelitis of the mandible caused by late fracture occurred, early and appropriate treatment is necessary because the osteomyelitis may progress rapidly and in some cases may result in pathological fracture.

Pathological fracture of the mandible caused by radicular cyst: A case report and literature review

RATIONALE

Pathological fracture of the mandible caused by radicular cyst is rare. This report describes a unique case of a mandibular pathological fracture caused by radicular cyst, arising from an endodontically treated molar.

PATIENT CONCERN

A 49-year-old female was referred to our department with persistent pain in left mandibular angle, accompanying with restricted mouth opening and malocclusion.

DIAGNOSE

An orthopantomograph (OPG) showed a unilocular lesion with a relatively well-defined border, and the lesion was associated with a fracture in the inferior border of the mandible.

INTERVENTION

This patient was treated through curettage of the cyst combined with open reduction and internal fixation of the fracture.

OUTCOMES

At the 1-year follow-up visit, the patient did not have any complaints, and the radiographs indicated the consolidation of the fracture without recurrence of cyst.

LESSONS

This case report highlights the routine follow-up of endodontically treated teeth in order to check for apical healing and detect the cystic change at early stages.

Stress distribution in mandibular donor site after harvesting bone grafts of various sizes from the ascending ramus of a dentate mandible by finite element analysis

PURPOSE

Harvesting bone from the ascending ramus of the mandible is a common procedure. However, mandibular fracture may occur after grafting bone blocks. This study aimed to investigate the resulting force distribution of stress and strain in the mandibular donor site after harvesting bone grafts of different sizes and various loadings.

METHODS

Finite element analysis was performed for virtual harvesting of bone blocks of nine different sizes between 15 × 20 and 25 × 30 mm and three different chewing loads (incisal, ipsilateral and contralateral). von Mises stress and first principal stress distributions were measured.

RESULTS

von Mises stress was distributed between 35.01 (10 × 15 mm graft, incisal load) and 333.25 MPa (30 × 20 mm graft ipsilateral load), whereas first principal stress distributions were between 48.27 (10 × 15 mm graft, incisal load) and 414.69 MPa (30 × 20 mm graft ipsilateral load). In general, the least stress was observed with incisal load followed by ipsilateral load and finally contralateral load. The critical value of 133 MPa was found after removing almost all grafts with a width of 20 or 30 mm.

CONCLUSIONS

Incisal loading led to less stress compared with contralateral and ipsilateral loads. Increasing graft size led to increasing weakness of the donor site. Graft width exerted a greater influence on stress development than its height.

CLINICAL RELEVANCE

Ipsilateral chewing and increasing width of the bone graft result in maximum stress in the mandibular donor side, and critical values regarding to the possibility of fractures are already to expect from a graft size of 20 × 15 mm.

Assessment of Regeneration of Bone in the Extracted Third Molar Sockets Augmented Using Xenograft (CollaPlugTN Zimmer) in Comparison with the Normal Healing on the Contralateral Side

Introduction:

Alveolar bone resorption is a significant clinical problem. Bone loss in third molar region following extraction or surgical removal not only leads to periodontal problems in second molar region but also it may lead to some serious problems like increased incidence of angle fractures. In order to reduce the risks following third molar surgery, the socket should be augmented with bone grafts. In recent days guided tissue regeneration is the most accepted and successful technique followed many authors and its efficacy has been proved.

Materials and Methods:

Based upon our clinical experience, the use of bio absorbable collagen wound dressing such as CollaPlug^TN has achieved quick healing and more primary wound coverage. Amongst the graft materials collagen is preferable due to its high biocompatibility and hemostatic ability. This study was done to assess the regeneration of bone in the extracted third molar sockets using xenograft (CollaPlug^TN-Zimmer) which was compared with the normal healing on the contra lateral side. The assessment was done to analyze post-operative healing complications and to compare the bone density formed between control site and implant site radiologically.

Conclusion:

On this basis of this study, the use of collaplugTN appears to be beneficial to the patient in postoperative wound healing and also for better bone formation. The use of this material was advantageous because of its simplicity of application cost effectiveness and availability. There is enhanced wound healing and early bone formation.

Late mandibular fracture occurring in the postoperative period after third molar removal: systematic review and analysis of 124 cases

Factors associated with the diagnosis, aetiology, and treatment of mandibular fractures occurring during the postoperative period following the removal of a lower third molar are discussed. The following databases were searched using specific key words: PubMed/MEDLINE, LILACS, Embase, and Scopus. The search yielded 124 cases. Sex, age, side, tooth position and angulation, bone impaction, relationship between the tooth and the inferior alveolar nerve, local pathological conditions, aetiology of the fracture, symptomatology, and time between surgery and fracture, as well as any displacement of the fracture and the treatment of the fracture, were evaluated. Data were tabulated and the χ² statistical test was applied (P<0.05). Male patients aged >35 years, with teeth in positions II/III and B/C, complete bony impaction, and local bone-like alterations, were found to have a higher frequency of fracture and pericoronitis (P<0.05). Late fractures generally occurred between the second and fourth postoperative weeks (P<0.05). They were generally not displaced and the typical treatment was the non-surgical approach (P<0.05). It is concluded that the risk of mandibular fracture after extraction is associated with excessive ostectomy and/or local alterations. At-risk patients should be thoroughly briefed on the importance of a proper postoperative diet.

Identifying the risk factors causing iatrogenic mandibular fractures associated with exodontia: a systemic meta-analysis of 200 cases from 1953 to 2015

PURPOSE

Iatrogenic fracture of mandible (IFM) associated with exodontia though rare, they do occur with an incidence ranging from 0.0034 to 0.0075 %. Most of the data is in the form of case reports or a small case series. This is an attempt to amass the data available in literature since the last 62 years. The purpose of this meta-analysis is to identify the etiologies and risk factors leading to IFM associated with exodontia and also the measures to minimize the complication.

METHODS

Articles published between 1953 and 2015 were searched in Medline database. Data was collected and analyzed based on age, gender, extracted tooth, status of dentition, pathological bone lesion adjacent to the tooth, type of impaction, angulation of the impacted third molar, site of fracture, side of fracture, time of fracture, and treatment of fracture.

RESULTS

A review identified 200 documented cases of IFM associated with the removal of teeth. The reasons for its occurrence found to be multifactorial with a higher incidence in the fifth decade of life with male prevalence. Risk factors more commonly identified were removal of the third molar, fully dentate patient, associated pathology, impacted tooth, angle region, left quadrant, and time interval of 3 weeks postoperatively.

CONCLUSIONS

IFM related to the removal of teeth is a rare complication. Identifying and addressing the risk factors will enable the surgeon to avoid the complication of IFM associated with exodontia.

Removal of Deeply Impacted Mandibular Molars by Sagittal Split Osteotomy

Mandibular third molars are the most common impacted teeth. Mandibular first and second molars do not share the same frequency of occurrence. In rare cases the occlusal surfaces of impacted molars are united by the same follicular space and the roots pointing in opposite direction; these are called kissing molars. In some cases, a supernumerary fourth molar can be seen as unerupted and, in this case, such a supernumerary, deeply impacted fourth molar is seen neighboring kissing molars. The extraction of deeply impacted wisdom molars from the mandible may necessitate excessive bone removal and it causes complications such as damage to the inferior alveolar nerve and iatrogenic fractures of the mandible. This case report describes the use of the sagittal split osteotomy technique to avoid extensive bone removal and protect the inferior alveolar nerve during surgical extruction of multiple impacted teeth.

Anatomical and radiographic study of the mandibular retromolar canal

Background/purpose

As the demand for surgical procedure in the retromolar area of the mandible has been increasing, the identification of the retromolar foramen (RMF) and canal involving the retromolar triangle (RMT) has become an issue of clinical concern. We examined the shape of the RMT, incidence of the RMF, and intraosseous trajectory of the retromolar canal (RMC).

Materials and methods

A total of 118 sides of dry mandibles, 22 sides of mandibles of 13 cadavers, and cone-beam computed tomography (CT) images of 100 patients were examined. Micro-CT data of 13 cadavers were reconstructed using imaging analysis software for the presence of an RMC. RMCs were classified into three types according to the courses. The width and location of the RMCs were evaluated.

Results

The shape of the RMT was classified into three categories, with the most common type being the triangular type (81.4%). Forty-seven retromolar foramina (33.6%) were observed in 140 sides of mandibles. The horizontal distances from the RMF to the second and third molars were 12.1 ± 3.3 mm and 5.8 ± 3.6 mm (mean ± standard deviation), respectively, and the distance from the mandibular foramen to the arising point of the RMC and the vertical distance from the RMF to the mandibular canal were 21.5 ± 11.2 mm and 15.3 ± 4.6 mm, respectively.

Conclusion

This study used various methods to obtain precise anatomical data on the RMT, foramen, and canal in Koreans. The reported findings may be helpful for the clinical management of patients.

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.

Spontaneous fractures of the mandible concept & treatment strategy

Background

Spontaneous fractures of the mandible dispose a surgical challenge in comparisons to fractures caused by trauma due to several complicating factors. Additionally: controversies exist concerning the terminology of the field.

Material and Methods

We conducted a retrospective study of all patients with mandibular fractures, with exclusion of fractures of the coronoid process and the alveolar process, treated at the Department of Oral and Maxillofacial Surgery, Aalborg University Hospital, Denmark between February 2003 and February 2013. Data collected from the medical records included sex, age, cause of fracture, site of fracture, and treatment.

Results

We identified 517 patients with 684 mandible fractures. Twenty-five of these were spontaneous fractures and 659 fractures were of traumatic origin. Condylar fractures rarely occur spontaneously, but constitute the majority of the traumatic fractures. Excluding these fractures from the analysis, we found a non-surgical approach in 14 of 24 (58%) of the spontaneous fractures and 110 of 376 (29%) of the traumatic fractures. This was statistically significant.

Conclusions

We found a statistical significant difference in favor of non-surgical approach in spontaneous fractures and we discussed the treatment challenges of these fractures. We addressed the terminological controversies regarding pathological fractures, and suggested the term spontaneous fractures denoting a fracture occurring during normal jaw function being either pathological or non-pathological.

Key words:Mandibular fractures, spontaneous fractures, pathological fractures, traumatic fractures, treatment.

Surgical extraction of impacted teeth in elderly patients. A retrospective analysis of perioperative complications - the experience of a single institution

OBJECTIVE

The aim of this retrospective study was to investigate the most frequent complications and assess their overall rate associated with the surgical extraction of impacted teeth in an elderly patient population.

BACKGROUND

Oral health needs of the elders are often associated with surgical procedures for the creation of appropriate conditions for any further prosthetic treatment. One such process is the removal of severely decayed, fractured or impacted teeth detrimental to the fit or appearance of dentures. While broken and decayed teeth leave little doubt for their removal, impacted teeth divide opinion, some extreme regarding their prophylactic removal and the appropriate age for the procedure.

MATERIAL AND METHODS

Material was selected from the archives of an Out-Patient Dental Surgery Clinic of the Regional Centre of Dentistry in Szczecin, from 2002 to 2013. The database was independently screened by two investigators according to inclusion and exclusion criteria. After selection process, all included records were screened using a data extraction form to obtain the necessary data.

RESULTS

The total number of impacted teeth was 73, of which 29% were partially impacted. The overall complication rate was 24.6%. The most common complications were as follows: haematoma, nerve disturbances and local infections.

CONCLUSION

Surgical extraction in patients above 60 years of age is fraught with a high risk of possible complications.

Four osteotomy methods with piezosurgery to remove complicated mandibular third molars: a retrospective study

PURPOSE

Piezosurgery has been used widely in oral and maxillofacial surgery, but there has been no report systematically describing an osteotomy method with piezosurgery for complicated mandibular third molar removal. The aim of this study was to introduce 4 osteotomy methods using piezosurgery and evaluate their effects.

MATERIALS AND METHODS

A retrospective study was conducted of patients with a complicated impacted mandibular third molar requiring extraction. The predictor variable was the extraction technique. Four osteotomy methods using piezosurgery were tested according to different impaction types: method 1 involved complete bone removal; method 2 involved segmental bone removal; method 3 involved bone removal combined with tooth splitting; and method 4 involved block bone removal. Outcome variables were success rate, operative time, major complications (including nerve injury, mandible fracture, severe hematoma, or severe edema), and serious pyogenic infection. Data were analyzed using descriptive statistics.

RESULTS

The study was composed of 55 patients with 74 complicated impacted mandibular third molars. All impacted mandibular third molars were removed successfully. The average surgical time was 15 minutes (range, 8 to 26 minutes). Thirty-eight molars (51.4%) were extracted by method 1, 18 molars (24.3%) by method 2, 12 molars (16.2%) by method 3, and 6 molars (8.1%) by method 4. Two cases (2.7%) developed postoperative infections and recovered within 1 week using drainage and antibiotic administration.

CONCLUSION

The 4 osteotomy methods with piezosurgery provide effective ways of removing complicated impacted mandibular third molars.

Iatrogenic mandibular fracture associated with third molar removal after mandibular angle osteotectomy

The extraction of mandibular third molars is a common dental procedure. The complications include hemorrhage, pain, dental fracture, the displacement of teeth or fragments, iatrogenic damage or luxation of the second molar, neurologic injuries, soft tissue damage, subcutaneous emphysema, trismus, swelling, infection, and iatrogenic mandibular fracture. Fracture of the angle of the mandible associated with third molar removal is a rare but severe complication. This article describes a case of mandibular angle fracture associated with third molar extraction after mandibular angle osteotectomy, including a brief review of the literature. The removal of the mandibular angle and the outer cortex of the mandible, especially the external oblique ridge, may contribute to the bone fracture. We conclude that the extraction of the lower third molar must be before the removal of the mandibular angle, and a soft diet for at least 4 weeks postoperatively is essential to prevent late mandible fracture.

Theoretical efficacy of preventive measures for pathologic fracture after surgical removal of mandibular lesions based on a three-dimensional finite element analysis

PURPOSE

Pathologic fracture of the mandible after removal of a lesion historically has been a clinical problem. The present study aimed to evaluate mandibular strength after removal of a lesion and to illustrate the theoretical efficacy of preventive measures against pathologic fracture based on a 3-dimensional finite element (FE) analysis.

MATERIALS AND METHODS

A computed tomographic (CT)-based FE model of the mandible of a patient with a dentigerous cyst including a third molar was constructed. Using this model, the decrease of mandibular strength after virtual removal of the lesion was analyzed. The effect of the decrease of occlusal force and reinforcement by a miniplate was analyzed using a simple FE model of the mandible. Based on these analyses, removal of the cyst with the third molar was performed with a decrease of occlusal force and reinforcement by a miniplate. The validity of these procedures was analyzed using a CT-based FE model constructed after surgery.

RESULTS

The von Mises stress in a CT-based FE model after virtual removal of the cyst with the third molar was markedly greater than that in the original FE model. In the analysis using a simple FE model, the stress around the fenestrated area was decreased after premolar loading compared with that after molar loading. In addition, miniplate placement around the fenestrated area markedly decreased the stress. Based on these results, the cast crowns of the first and second molars were removed and the fenestrated area of the mandible was reinforced with a 1.5-mm locking miniplate in the actual surgery. The von Mises stress in the fenestrated area was decreased and primarily borne by the miniplate in the analysis of a CT-based FE model constructed after surgery.

CONCLUSION

The present study illustrated the theoretical efficacy of plate application for the decrease of stress on the mandible after surgical removal of a cyst including a third molar based on a simulation by FE analysis.

Does the Relationship between Retained Mandibular Third Molar and Mandibular Angle Fracture Exist? An Assessment of Three Possible Causes

The objective of this study is to discuss problems associated with dental retention through three clinical cases of mandible fractures related to the presence of retained lower third molars, emphasizing the possibility of mandible fractures resulting from this or from the extraction procedure. The three evaluated patients had a fracture in the mandible angle. The third molars were present in all the cases, as was the relationship of the fracture with the teeth. After evaluating the three cases and reviewing literature, it is believed that the presence of the retained lower third molars and the surgical procedures for their extraction increase the risk of mandible angle fractures.

Pathological (late) fractures of the mandibular angle after lower third molar removal: a case series

Introduction

Pathological (late) fracture of the mandibular angle after third molar surgery is very rare (0.005% of third molar removals). There are 94 cases reported in the literature; cases associated with osseous pathologies such as osteomyelitis or any local and systemic diseases that may compromise mandibular bone strength have not been included. We describe three new cases of pathological (late) fracture of the mandibular angle after third molar surgery.

Case presentations

The first patient was a 27-year-old Caucasian man who had undergone surgical removal of a 3.8, mesioangular variety, class II-C third molar 20 days before admission to our clinic. The fracture of his left mandibular angle, complete and composed, occurred during chewing. The second patient was a 32-year-old Caucasian man. He had undergone surgical removal of a 3.8, mesioangular variety, class II-B third molar 22 days before his admission. The fracture, which occurred during mastication, was studied by computed tomography that showed reparative tissue in the fracture site. The third patient was a 36-year-old Caucasian man who had undergone surgical removal of a 3.8, vertical variety, class II-C third molar 25 days before the observation. In this case the fracture of his mandibular angle was oblique (unfavorable), complete and composed. The fracture had occurred during chewing. We studied the fracture by optical projection tomography and computed tomography.

All of the surgical removals of the 3.8 third molars, performed by the patients’ dentists who had more than 10 years of experience, were difficult. We treated the fractures with open surgical reduction, internal fixation by titanium miniplates and intermaxillary elastic fixation removed after 6 weeks.

Conclusions

The literature indicates that the risk of pathological (late) fracture of the mandibular angle after third molar surgery for total inclusions (class II-III, type C) is twice that of partial inclusions due to the necessity of ostectomies more generous than those for partial inclusions. Other important factors are the anatomy of the teeth and the features of the teeth roots. These fractures predominantly occur in patients who are older than 25 years. The highest incidence (67.8% of cases) is found in the second and third week postsurgery. We emphasize that before the third molar surgery it is extremely important to always provide adequate instructions to the patient in order to avoid early masticatory loads and prevent this rare event.

Pathological mandibular fractures: a review of the literature of the last two decades

Pathological mandibular fractures are rare, accounting for fewer than 2% of all fractures of the mandible. They could be defined as fractures that occur in regions where bone has been weakened by an underlying pathological process. Pathological fractures usually may follow surgical interventions such as third molar removal or implant placement, result from regions of osteomyelitis, osteoradionecrosis, and bisphosphonate-related osteonecrosis of the jaw, occur because of idiopathic reasons or be facilitated by cystic lesions, benign, malignant, or metastatic tumors. Pathological mandibular fractures may be challenging to treat because of their different etiology and peculiar local and general conditions, often requiring a more rigid fixation. In patients with poor medical conditions, simpler and more limited options may be preferred.

Mandibular angle fractures during third molar removal: a report of two cases

Although fracture of the tooth during surgical removal is common, mandibular fracture during lower third molar removal is an unusual and major complication. Possible aetiologies are age, gender, the position of the tooth, uncontrolled excessive force applied, insufficient surgical experience and improper instrumentation. Symptoms can vary widely and treatment options range from prescription of a soft diet to surgical treatment by open reduction and internal fixation. We present two cases of the treatment and follow-up of fracture of the angle region of the mandible during removal.

Effect of lower third molars on the incidence of mandibular angle and condylar fractures

PURPOSE

Numerous previous studies already have proven that mandibles with a third molar are significantly more susceptible to angle fracture by external force. Similarly, other data suggest that the absence of a third molar increases the risk of condylar fracture, while concurrently decreasing the risk of angular fracture. We attempt to characterize the effect of a third molar on the incidence of mandibular angle and condylar fractures.

METHODS

This retrospective study reviews data from 385 patients, all of whom were seen in our clinics between February 2006 and November 2009. All data were collected from clinical examination notes and panoramic radiographs, with third-molar state evaluated by the Pell and Gregory classification system.

RESULTS

Our results mirror those of previous studies. The incidence of mandibular angle fracture was significantly greater on sides with a third molar, whereas the condylar fracture rate significantly increased in mandibles lacking a third molar or without a fully erupted third molar. The rate of symphysis and mandibular angle fracture was also high in cases of multiple comorbid fractures.

CONCLUSIONS

Both the presence and the state of the lower third molar affect the risk of future mandibular angle and condylar fracture.

Iatrogenic mandibular fracture associated with third molar removal

Third molar extraction is one of the most common procedures performed in oral and maxillofacial surgery units. It is sometimes accompanied by complications such as alveolar osteitis, secondary infection, hemorrhage, dysesthesia and, most severely, iatrogenic fracture. This article describes two mandibular angle fractures that occurred in two patients during the surgical extraction of one erupted and one unerupted third molar, including a brief review of the literature.

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.

Complications of third molar surgery

This article addresses the incidence of specific complications and, where possible, offers a preventive or management strategy. Injuries of the inferior alveolar and lingual nerves are significant issues that are discussed separately in this text. Surgical removal of third molars is often associated with postoperative pain, swelling, and trismus. Factors thought to influence the incidence of complications after third molar removal include age, gender, medical history, oral contraceptives, presence of pericoronitis, poor oral hygiene, smoking, type of impaction, relationship of third molar to the inferior alveolar nerve, surgical time, surgical technique, surgeon experience, use of perioperative antibiotics, use of topical antiseptics, use of intra-socket medications, and anesthetic technique. Complications that are discussed further include alveolar osteitis, postoperative infection, hemorrhage, oro-antral communication, damage to adjacent teeth, displaced teeth, and fractures.

Review of flap design influence on the health of the periodontium after mandibular third molar surgery

The purpose of this study is to review the effect of flap design in terms of periodontal status of the preceding second molar after lower third molar surgery. Impacted lower third molar surgery may result in periodontal complications on the distal surface of the adjacent second molar. Flap design that is used during impacted third molar surgery is important to prevent those complications. Several different flap techniques, mainly envelope, triangular (vertical) flaps, and their modifications have been developed to minimize those complications. Each technique has some advantages as well as disadvantages. It is also reported that the selection of a flap design does not seem to have a lasting effect on the health of periodontal tissue. The effect of the type of flap used for lower third molar surgery on the periodontal status of the second molar, as well as the factors that may influence this outcome, has been uncertain. The decision to use on one or the other of the flaps should be based on surgeon's preference.

Do pathologies associated with impacted lower third molars justify prophylactic removal? A critical review of the literature

Surgical removal of impacted lower third molars is widely carried out in general dental practice and in many institutional clinics. Despite the fact that there are well established indications for the removal of impacted lower third molars, prophylactic removal of these teeth is still being universally practiced. Some reports have estimated that the proportion of impacted third molars that are removed when no clinically sound justification for surgery is present is between 18% and 50.7%. Justifications for prophylactic surgery include the need to minimize the risk of disease (cysts and tumors) development, reduction of the risk of mandibular angle fracture, increased difficulty of surgery with age, and that third molars have no definite role in the mouth. This article critically examines the literature regarding the relationship between impacted lower wisdom teeth, cysts and tumor development, and mandibular fractures.

Separation of the buccal cortical plate for removal of the deeply impacted mandibular molars

We describe the case of 26-year-old patient who is apprehensive for any possible sequelae of the deeply impacted teeth. This case shows that separation of the buccal plate can have availability to remove deeply impacted molars with less any possible complications than those of sagittal split osteotomy.

Mandibular fracture 2 weeks after third molar extraction

This case report describes mandibular fracture after the surgical extraction of fully erupted lower third molar of a 53-year-old healthy male patient. The fracture occurred 15 days after the extraction while chewing. The fracture line extended from the apex of the mesiobuccal root socket to the inferior border of the mandible. Follow-up of the patient was agreed as the patient was not willing to carry on further treatment. Bony union was observed radiologically 3 months later.

Pathological mandibular fractures following third molar removal

Seventeen patients, who presented mandibular fractures following third molar removal, were treated in the Department of Oral and Maxillofacial Surgery at the University Hospital Freiburg between 2000 and 2004. Clinical and radiological data were analysed to evaluate the possible risk of fracture following third molar removal. Our data show an increased rate of pathological mandibular fractures in males over 40 years of age, following removal of a difficult lower wisdom tooth with a high retention grade that necessitated bone removal. Fourteen out of 17 fractures occurred postoperatively. In six cases, no fracture was visible in radiographs during the primary investigation. Pathological mandibular fractures were typically located anterior to the mandibular angle (n=15). We recommend informing patients about possible risks and, in selective cases, a soft diet for up to 4 weeks after the operation. A cracking noise reported by the patient is the most important indication of a fracture. If, initially, the fracture is radiologically undetectable, we recommend the use of radiological controls.

Clinical evaluation of the effects of radiographic distortion on the position and classification of mandibular third molars

OBJECTIVE

Panoramic radiographs are routinely employed for surgical planning of unerupted third molars. The objective of this study was to evaluate distortions in the position of mandibular third molars on panoramic radiographs.

MATERIALS AND METHODS

Panoramic radiographs of 14 patients with indication for extraction of the mandibular third molars were used. Transurgical impressions of the crowns of the teeth to be extracted and adjacent second molars (n=19) were achieved with addition silicone and poured with type IV plaster for comparison of the inclinations of the third molars on the radiographs and study casts.

RESULTS

There was a mean difference of -5.37 degrees between the position of the third molar on the panoramic radiograph and on the study cast (standard deviation 1.46, P<0.05, Student's t-test).

CONCLUSION

There is distortion in the position of teeth on the panoramic radiograph, which may influence the surgical planning; however, this does not invalidate it as the main tool for diagnosis and surgical planning of mandibular third molars.

Removal of a deeply impacted mandibular third molar through a sagittal split ramus osteotomy approach

We describe the case of a 48-year-old man who, after a 5-year history of recurrent infection and intermittent trismus associated with a deeply impacted lower right third molar tooth, presented to the accident and emergency department with severely limited mouth opening, extensive facial swelling and pyrexia. The lower right third molar was later removed successfully through a sagittal split ramus osteotomy approach. This case shows that the sagittal split osteotomy continues to have a valuable role in the removal of deeply impacted lower third molars, particularly when they are in close proximity to the inferior alveolar nerve.

Impacted tooth in mandibular fracture line: treatment with closed reduction

PURPOSE

Most mandibular fractures occur because of blunt trauma. In some cases, the mandible can be weakened by the presence of an unerupted or impacted tooth. The fate of this tooth in the fracture line and its effects on bone healing remain an important outcome event.

MATERIALS AND METHODS

In this study, we analyzed the records of 117 patients with a total of 121 fractures having an unerupted tooth remaining in the fracture line who were treated and followed by the Dental Faculty of Ankara University between 1986 and 1996. All were open fractures, and none of the patients had a history of an acute inflammatory episode related to the unerupted tooth before the injury. Intermaxillary fixation was used in all cases.

RESULTS

Three of the patients subsequently required open reduction with internal fixation. The unerupted tooth was not extracted in any patient. The fixation was maintained for an average of 45 days and followed up for 3 months. No complications were encountered.

CONCLUSION

According to these results, we suggest that asymptomatic impacted teeth in the fracture line of uncomplicated mandible fractures do not cause delayed healing when treated with closed reduction.

Marginal flap versus paramarginal flap in impacted third molar surgery: a prospective study

OBJECTIVE

A clinical prospective study was carried out to compare 2 flap designs-marginal and paramarginal-that are used during impacted third molar surgery.

MATERIALS AND METHODS

Twenty-seven healthy patients (ages 17 to 31 years) who underwent surgical removal of 4 impacted third molars, including 54 lower and 54 upper, were included. A marginal flap was used in 1 randomly chosen half of the jaw, and a paramarginal flap was used in the other half. The influence of these flaps on wound healing, periodontal pocket depth of the adjacent second molar, pain, trismus, and swelling was studied.

RESULTS

Wound dehiscences developed in 8 paramarginal flap cases, whereas none occurred with the use of a marginal flap. The buccal and distal probing depths of the adjacent second molar were significantly bigger in marginal flaps at 5 and 10 days after surgery. However, the probing depth was similar with the use of both techniques at 3 months. Pain, trismus, and swelling were similar with both techniques.

CONCLUSIONS

We found no advantages to the use of a paramarginal flap instead of a traditional marginal flap for removing impacted third molars.

Immediate and late mandibular fractures after third molar removal

PURPOSE

In this retrospective study, we analyzed immediate and late mandibular fractures after impacted lower third molar surgery.

PATIENTS AND METHODS

One hundred fifty oral and maxillofacial surgeons in the north of- France were questioned about their experience with intraoperative and late mandibular fracture after third molar surgery. Cases were examined clinically and radiographically.

RESULTS

Thirty-seven fractures were reported in about 750,000 extractions (incidence of 0.0049%). Only 27 cases could be precisely described: 17 intraoperative and 10 late fractures. The patients were 19 to 75 years of age, with an average age of 37 years for intraoperative fractures and 47 years for late fractures. All grades of tooth impaction were included. Only 2 patients did not have full dentition.

CONCLUSIONS

The major incidence of immediate and late mandible fractures occurs in patients older than over 25 years. Men may be more likely to have late fractures (8 of 10 cases).