MAJOR PREDICTORS OF LATE MANDIBULAR FRACTURE IN THIRD MOLAR EXODONTIA: A REVIEW.

Albuquerque Barros 1,2 , Júlio Leal Villela Garcia 1,2 , Luciana Fortes Tosto Dias 1,2 , Diego César Marques 1,2 , Lucas Antônio de Carvalho e Silva 1,2 , Regis Manzini 2 , Andrés Santiago Quizhpi López 2 , André Gunther Lima 1,2 , Igor Mariotto Beneti 1,2 , Rogério Luiz de Araújo Vian 2,3 , Elias Naim Kassis 1,2 . 1. Unorp University Center North Paulista São José do Rio Preto – SP, Brazil. 2. Unipos Post graduate and continuing education, Street Ipiranga, 3460, São José do Rio Preto SP, Brazil 15020-040. 3. Santa Casa Hospital-Bucomaxillo Facial Traumatology CenterRibeirão Preto/SP, Brazil. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 08 April 2019 Final Accepted: 10 May 2019 Published: June 2019

374 extraction is a rare complication that may occur in the trans or postoperative period. When it occurs in the postoperative period, it is considered a late fracture [1,2].
In this context, epidemiological data reveal that the incidence of late fracture can vary from an average of 6.5 cases in 1,000 [3]. This problem may occur after two weeks of surgery and during chewing. Thus, the fracture presents a simple trait with a little displacement of the bone segments and is located in the region of the mandibular angle, which is an area of low fracture resistance due to its finer sectional area 4.
In this sense, it is possible to establish the main predictors that provoke or increase the risk of mandible fracture after third molar extraction, highlighting the age, gender, degree of impaction, angulation and volume of the dental element, presence of tumors, cysts or lesions osseous associated with the dental element and systemic diseases [5]. Patients older than 40 years of age have an increased risk of fracture due to decreased bone elasticity and hypercementosis of the impacted tooth, which leads to a greater osteotomy for exodontia [5].
Regarding gender, men tend to have greater strength during chewing in relation to women, presenting a greater risk of mandible fracture. In patients with total dentin, the risk is even higher [6]. The degree of impaction, angulation, and volume of the third molar are also important factors. The greater the impaction and angulation of the dental element, the greater the osteotomy necessary for the exodontia. Position III C teeth, according to the classification of Pell and Gregory, that is, located completely inside the mandibular branch and with occlusal surfaces below the cervical line of the second molar, and distoangulated teeth, according to the classification of Winter, have a higher risk of fracture since both require greater osteotomy [7].
In addition, preexisting bone lesions such as cysts, tumors or recurrent pericoronitis may weaken the mandible and are also important predictors [8]. Systemic diseases such as osteoporosis, significantly decrease bone density, are also another important factor. Fracture diagnosis is performed by means of imaging tests, such as panoramic radiography and presence of signs and symptoms such as pain on movement, bone crepitation, edema and ecchymosis, occlusal alteration, jaw mobility and local bleeding [9]. In some cases, it is difficult to verify the trait of the fracture only by the panoramic radiograph, being used the computed tomography to confirm the diagnosis [9].
Added to this, the report of the popping noise perceived by the patient is often the first sign of mandibular fracture after third molar exodontia, with pain and increased volume [10]. The treatment of mandibular fracture after third molar extraction is the same in cases of mandible fracture due to trauma and follows the basic principle of reduction and fixation, restoring the mandibular contour, dental occlusion and temporomandibular function [10]. Therefore, the present work aimed to present, through a literary review, the main predictors of late mandibular fracture in third molar extraction, in order to contribute important prophylaxis and treatment information to the dental literature.

Methods:-Eligibility and Study Design
A total of 34 articles were found involving Late mandibular fracture. Exodontia. Third molar. Surgery. Conventional treatment. Initially, it was held the exclusion existing title and duplications following the interest described this work. After this process, the summaries were evaluated, and a new exclusion was held. So, 17 articles were included and discussed in this study.
Experimental and clinical studies were included (case reports, retrospective, prospective, randomized trials and systematic review and meta-analysis) with qualitative and/or quantitative analysis. Initially, the keywords were determined by searching the DeCS tool (Descriptors in Health Sciences, BIREME base) and later verified and validated by MeSh system (Medical Subject Headings, the US National Library of Medicine) in order to achieve consistent search.

Literature Review and Discussion:-
The late fracture occurs in the first two weeks of the surgical procedure. Some authors have reported an occurrence in the first four weeks [1]. However, fractures are more common in the fifth postoperative week [1]. Chewing presented the highest incidence and prevalence of mandibular fracture cause after third molar extraction, reported by the authors. It is important to guide the patient who presents the risk factors for fracture in relation to diet [1][2][3][4][5].

A. Identification
Additional records identified through other sources (n = 2) Records identified through database searching (n = 32) Records after duplicates removed (n =34)

B. Screening
Full-text articles excluded, with reasons (n =11) Full-text articles assessed for eligibility (n = 17)

C. Eligibility
Studies included in qualitative synthesis (n =17)

D. Included
Studies included in quantitative synthesis (Systematic Review) (n =17)

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In addition, in cases requiring extensive vestibular osteotomy, low bone mass in the mandibular basal portion, lingual teeth, and presence of associated osteolytic lesions, it is recommended to maintain a pasty diet for an extended period of time ranging from three to four weeks, according to the literature [6][7][8].
There are still no reports of late mandibular fracture after third molar extraction in the literature with Stafne bone cyst, with the most frequent lesions being dentigerous and radicular cyst 9,10. In other studies, half of the fractures occurred had associated cystic lesions, and most of the cases analyzed by Grau-Manclús (2011) were related to cysts or pericoronal capillary thickening of impacted third molars [11]. However, the longer the time of impacting the tooth, the greater the risk of developing cysts. In addition, over time there is greater retention of the dental element, decrease in bone density, contributing to the increase of the mandibular fragility and the risk of fracture [12][13][14].
In this context, exodontia is indicated in patients under 25 years of age, since after that age the incidence of complications is higher [15]. Conservative treatment or surgical treatment is indicated for treating mandibular fracture [16]. However, with the advent of rigid internal fixation techniques, the surgical treatment of the fracture through the use of plaques has been the treatment of choice and is superior to the conservative, since it provides a more stable reduction. The conservative treatment consists in the accomplishment of several techniques described by Ivy, Gilmer, and use of Erich bar and is maintained for 45 days. Skeletal blockade can also be performed through the use of screws and is indicated in cases in which the patient presents comorbidity [16].
A recent study reported a case of late mandibular fracture due to the extraction of third molars and highlights the clinical, ethical and legal aspects inherent to this surgical complication. The female patient underwent a surgical procedure to extract the third right lower third molar. Two days after surgery, the patient reported pain and altered the occlusion on the right side of the mandible [1]. After the clinical and radiographic reexamination, the diagnosis of late mandibular fracture was established. A second surgery, under general anesthesia, was performed to fix the mandibular bone. The fractured parts were reduced and secured with locking plate systems and 2mm bolts following the principles of load sharing. The masticatory function presented an optimal performance at 7 and 21 days after surgery. Complete bone healing was observed within 1 year of follow-up. Thus, surgical planning and appropriate techniques should be performed [1].
Still another study presented the predictors associated with the diagnosis, etiology, and treatment of mandibular fractures that occur during the postoperative period, after the removal of a lower third molar. This study evaluated 124 patients, involving the predictors of sex, age, position and dental angulation, bone impaction, relationship between the tooth and inferior alveolar nerve, local pathological conditions, fracture etiology, symptomatology and time between surgery and fracture, as well as any fracture displacement and fracture treatment were evaluated [17]. As a result, male patients aged> 35 years, with teeth in positions II/III and B/C, complete bone impingement and local bone-like alterations, presented a higher frequency of fracture and pericoronaritis (p<0.05). Late fractures usually 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). Therefore, the risk of mandibular fracture after extraction is associated with excessive ostectomy and/or local changes [17].

Conclusion:-
The present study showed the importance of identifying the main predictors of late fracture in the pre-and postoperative period, orienting the patient in the postoperative period regarding the diet for a prolonged period as a form of prevention. It has also been demonstrated that the best form of treatment of the late fracture is surgical, but in cases of comorbidity conservative treatment can be performed.