Vertical Root Fracture:Diagnostic Tests Using Cone-beam CT And The Clinical Investigation Of Risk Factors

Vertical root fracture (VRF), which usually originates from the root andlongitudinally extends to the periodontal ligaments and soft tissues along the root[1],is the most severe one of the five types of the cracked tooth conundrum (craze lines,fractured cusp, cracked tooth, split tooth and vertical root fracture) defined byAmerican Association of Endodontists (AAE). The clinical symptoms andradiographic signs observed in VRF are similar to those in periodontal disease and afailed root canal treatment[2], making accurate diagnosis difficult.Because of the two-dimensional nature and the superimposition projectionartifacts, visualizing a VRF is difficult. Surgical flap may make VRF be confirmed,which is invasive. Cone beam computed tomography (CBCT) scans with features ofthree-dimensional nature, high spatial resolution and clearer image in axial slices[3],get more and more attention in the diagnosis of VRF. But whether it can be used as aroutine examination in diagnosis of VRF, and the operation need further research.Based on the literature review, this study provides a diagnostic test on the use ofCBCT with stringent standards and a clinical investigation to explore the risk factorsof VRF, to provide a reference for the diagnosis of VRF and CBCT in its detection.Part Ⅰ Literature reviewObjective Review the research status of the diagnosis of VRF by CBCT.Methods With systematic retrieval method, recalled the last ten years’(2001.03-2012.03) literatures in English and Chinese about diagnosis of VRF byCBCT in Medline, Embase,"VIP" and so on. The reliability of research methodsand results was analysis. Results A total of fifteen studies, six were clinical trial (five in Chinese, one inEnglish), and nine in vitro studies (all English). There is one paper in2007,2009and2012, and seven in2010, five in2011. The bias of clinical trial was few, butthere are still some problems on report of the results. Because of the relativelyreasonable design, all of the in vitro study performed a high reliability.Conclusions Papers on detection of VRF by CBCT were mainly published in thelast3years; High-quality clinical research was few, Laboratory studies existinsufficient of conclusions are not totally consistent and cannot simulate the in vivosituation well.Part Ⅱ Diagnostic tests using cone-beam CTObjective To compare the accuracy of CBCT scans and digital radiography (DR) fordetecting simulated VRF.Methods Twenty-seven teeth of one formalin-fixed human skull specimen(approved by Ethics Committee of the Hospital) were extracted out, inspected,decoronated and divided into2groups. The roots in experimental group wereartificially fractured and then fixed together. Roots in control group were kept intact.All teeth were placed back to the skull specimen. CBCT scans and DR wereobtained for all teeth. Two blinded groups of observers evaluated the CBCT and DRimages independently to make the diagnosis of whether fracture. Take the actuallyfracture or not as the gold standard, to evaluate the two methods and the consistencyof the observers.Results The sensitivity and specificity of the CBCT in diagnosis VRF of humanspecimens were75%and100%, and digital periapical radiographs were60.72%and84.62%, respectively. The reliability of CBCT(κ=0.743)was higher than digitalradiography(κ=0.449). The coherence of the two groups of investigators was highwith CBCT (κ=0.922) and medium with digital radiography (κ=0.611). Conclusions The results showed higher sensitivity, specificity and reliability forCBCT scans than digital radiography for detecting VRF.Part Ⅲ Clinical investigation of risk factorsObjective To investigate the characteristics and the risk factors of vertical rootfracture preliminarily.Methods Analysis relevant indicators of cases that were diagnosed as VRFunderwent surgical Extraction in the Department of Oral and Maxillofacial Surgeryof Stomatological Hospital of Jiangsu Province during Sep.2009to Mar.2012.Results79patients,44males and35females, mean age (58.48±11.26) years old,were involved.58.2%of patients delayed a month or more to visit. Patients withunilateral mastication and biting hard objects history accounted for41.8%and49.4%, respectively. VRF most occurred on the mandibular first molar (32.9%), andwas mainly the buccolingual direction (89.9%).82.3%of patients were with nohistory of periodontal treatment,50.6%of teeth were with crown, and26.6%withbackfill.67.1%of teeth had root canal treatment history, and26.6%were with post.Most of the teeth with vital pulp performed stimulate pain of thermal andspontaneous pain (88.2%), and with more obvious percussion pain. Pulpless teethoften had swollen gums, pus or sinus (74.2%), and with more severe alveolar boneabsorption and attachment loss.Conclusions The etiology of VRF was complex, may be associated with unilateralchewing, biting hard objects, bad occlusion, periodontal disease and other factors.There are differences in the clinical manifestations of vital teeth and non-vital teethwith VRF.