Validation of cone-beam computed tomography as a predictor of osteoporosis using the Klemetti classification.

This study aimed at evaluating the validity of cone-beam computed tomography (CBCT) for assessing mandibular bone quality using the Klemetti classification. The morphology of the endosteal mandibular cortex of 30 (60 hemi-mandibles) postmenopausal women between the ages of 45 and 80 years was evaluated based on the Klemetti classification in panoramic radiographs used as reference images. Afterwards, panoramic reconstruction and cross-sectional slices of CBCT examinations of these patients were analyzed and categorized according to the same classification. All the images were assessed by two oral radiologists. The McNemar-Bowker test compared the agreement between the CBCT images and the reference images. No differences were found between the diagnostic results based on panoramic radiography and panoramic reconstruction. However, the mean scores for the cross-sectional evaluation were higher, and the results, statistically different from the others. Based on the disagreement found between the panoramic radiographs and the CBCT cross-sectional slices, the Klemetti classification is not an adequate means of assessing bone quality with CBCT. On the other hand, the higher values found for the cross-sectional slices could be associated with better visibility on the CBCT images.

Validation of cone-beam computed tomography as a predictor of osteoporosis using the Klemetti classification

Abstract This study aimed at evaluating the validity of cone-beam computed tomography (CBCT) for assessing mandibular bone quality using the Klemetti classification. The morphology of the endosteal mandibular cortex of 30 (60 hemi-mandibles) postmenopausal women between the ages of 45 and 80 years was evaluated based on the Klemetti classification in panoramic radiographs used as reference images. Afterwards, panoramic reconstruction and cross-sectional slices of CBCT examinations of these patients were analyzed and categorized according to the same classification. All the images were assessed by two oral radiologists. The McNemar-Bowker test compared the agreement between the CBCT images and the reference images. No differences were found between the diagnostic results based on panoramic radiography and panoramic reconstruction. However, the mean scores for the cross-sectional evaluation were higher, and the results, statistically different from the others. Based on the disagreement found between the panoramic radiographs and the CBCT cross-sectional slices, the Klemetti classification is not an adequate means of assessing bone quality with CBCT. On the other hand, the higher values found for the cross-sectional slices could be associated with better visibility on the CBCT images.

Disease Stage and Mode of Therapy Are Important Determinants of Treatment Outcomes for Medication-Related Osteonecrosis of the Jaw.

PURPOSE: The treatment of patients with medication-related osteonecrosis of the jaw (MRONJ) is challenging. The purpose of the present study was to estimate the frequency and identify the factors associated with clinical improvement during treatment. PATIENTS AND METHODS: We designed and implemented a retrospective cohort study and enrolled a sample of subjects diagnosed with MRONJ between 2004 and 2015. The primary predictor variables were a set of heterogeneous variables grouped into the following categories: demographic (age and gender) and clinical (location of necrosis, therapy duration, medication type, disease stage, and treatment type). The primary outcome variable was the treatment outcome, defined as stable or worse and improved or healed. The descriptive, bivariate, and multiple logistic statistics were computed, and statistical significance was defined as P < .05. RESULTS: The sample included 337 subjects with a mean age of 68.9 years. Of the 337 subjects, 256 were women (76%). A total of 143 patients (42.2%) experienced spontaneous necrosis. Twenty-four (7.1%) had had exposure to targeted antiangiogenic agents. Those with stage 1 or 2 disease were more likely to have better outcomes than those with stage 3 disease (stage 1, adjusted odds ratio [OR] 3.4, P = .005; stage 2, adjusted OR 2.2, P = .03). Treatment type was a significant variable. Subjects undergoing surgery were 28 times more likely to have a positive outcome than those receiving nonoperative therapy (adjusted OR 28.7, P < .0001). CONCLUSIONS: Subjects with MRONJ who presented with less severe disease or who underwent operative treatment were most likely to have improvement or complete healing of their MRONJ-related lesions.

A Novel Surgical Approach for Treatment of Class II Furcation Defects Using Marginal Periosteal Membrane.

OBJECTIVES: This study was designed to describe and evaluate the use of a vascularized marginal periosteal barrier membrane (MPM) harvested by a semilunar incision, alone or combined with a bone graft, in treatment of class II furcation defects in mandibular molars, compared to open flap debridement (OFD). METHODS: Thirty class II furcation defects in mandibular molars were randomly assigned into three equal groups: Group I included OFD, Group II included defects treated with MPM, and Group III consisted of defects treated with MPM after applying demineralized freeze-dried bone allograft (DFDBA). At baseline and 6-month follow-up, vertical probing depth (VPD), clinical attachment level (CAL) measurements, along with a radiographic measurement of bone height (BH), were obtained for each defect. Transmission electron microscopy (TEM) was used for further evaluation of the histological changes associated with gingival samples related to each line of treatment. RESULTS: Both Groups II and III reflected significant favorable outcomes in all the assessed parameters compared to OFD. A non-significant difference was found between both groups regarding VPD, while significant improvement in CAL and BH were detected in Group III (p ≤ 0.05). Favorable histological findings were also noticed in the test groups, with more improvement in Group III. CONCLUSION: Placement of a vascularized MPM as a barrier membrane, using a semilunar incision, demonstrated a significant improvement in both clinical and histological outcomes of class II furcation defects in lower molars. When it was combined with DFDBA, a meaningful difference was found with regard to early wound healing and gain in CAL and BH.

Retrospective analysis of osteoradionecrosis of the mandible: proposing a novel clinical classification and staging system.

Osteoradionecrosis of the jaw is a common radiation-induced complication that may be observed in oral cancer patients. Several classifications and staging systems have been proposed for osteoradionecrosis of the mandible based on clinical symptoms, radiological findings, and/or the response to diverse treatments. However, none has been universally accepted because of their individual deficiencies. The aim of this study was to introduce a new clinical classification that can be applied to the treatment of osteoradionecrosis in an easier and more acceptable way, through a retrospective analysis of patients with osteoradionecrosis of the mandible. A review was conducted of 99 patients diagnosed with osteoradionecrosis of the mandible in the study institution between 2000 and 2013. A novel classification was established on the basis of bone necrosis and soft tissue defects. A new staging system with four different stages (stage 0, stage I, stage II, and stage III) is proposed. We believe that this new classification and staging system is easier and more acceptable for clinical evaluation than previous ones.

Osteoradionecrosis of the mandible: A ten year single-center retrospective study.

BACKGROUND: Numerous factors have been associated with the development of osteoradionecrosis (ORN) of the jaws. The purpose of this study was to investigate the factors that are linked to the severity of mandibular ORN. METHODS: A retrospective study was conducted which included all ORN cases treated in the Department of Oral and Maxillofacial Surgery in Munich (LMU) between 2003 and 2012. The cases were categorized according to the necrosis stage and several variables were evaluated in order to identify possible correlation between them and the severity of the necrosis. RESULTS: A total of 115 patients with 153 osteonecrosis lesions were included in the study. Twenty-three cases were of stage I, 31 were of stage II and 99 were of stage III. The initial tumors were predominantly located in the floor of the mouth, the tongue or the pharynx. Diabetes mellitus (OR: 4.955, 95% Cl: 1.965-12.495), active smoking (OR: 13.542, 95% Cl: 2.085-87.947), excessive alcohol consumption (OR: 5.428, 95% Cl: 1.622-18.171) and dental treatment and/or local pathological conditions (OR: 0.237, 95% Cl: 0.086-0.655) were significant predictors for stage III necrosis. CONCLUSIONS: The aforementioned factors are predictive of ORN severity and can guide its prophylaxis and management.

Periodontal regeneration - furcation defects: a systematic review from the AAP Regeneration Workshop.

BACKGROUND: The aim of this review is to present the available evidence regarding the effectiveness of different regenerative approaches for the treatment of furcation defects in specific clinical scenarios compared with conventional surgical therapy to provide clinical guidelines for the therapeutic management of furcation defects and to identify priorities for future research that may advance the understanding of periodontal regenerative medicine. METHODS: A comprehensive search based on predetermined eligibility criteria was conducted to identify human original studies and systematic reviews on the topic of periodontal regeneration of furcation defects. Two reviewers independently screened the title and abstract of the entries yielded from the initial search. Subsequently, both reviewers read the full-text version of potentially eligible studies, made a final article selection, and extracted the data of the selected studies considering specific clinical scenarios. The clinical scenarios contemplated in this review included the following: 1) facial and interproximal Class I defects in maxillary molars; 2) facial and lingual Class I defects in mandibular molars; 3) facial and interproximal Class II furcation defects in maxillary molars; 4) facial and lingual Class II furcation defects in mandibular molars; 5) Class III furcation defects in maxillary molars; 6) Class III furcation defects in mandibular molars; and 7) Class I, II, or III furcation defects in maxillary premolars. Endpoints of interest included different clinical, radiographic, microbiologic, histologic, and patient-reported outcomes. RESULTS: The initial search yielded a total of 1,500 entries. The final selection consisted of 150 articles, of which six were systematic reviews, 109 were clinical trials, 27 were case series, and eight were case reports. A summary of the main findings of previously published systematic reviews and the available evidence relative to the indication of regenerative approaches for the treatment of furcation defects compared with conventional surgical therapy are presented. Given the marked methodologic heterogeneity and the wide variety of materials and techniques applied in the selected clinical trials, the conduction of a meta-analysis was not viable. CONCLUSIONS: On the basis of the reviewed evidence, the following conclusions can be drawn. 1) Periodontal regeneration has been demonstrated histologically and clinically for the treatment of maxillary facial or interproximal and mandibular facial or lingual Class II furcation defects. 2) Although periodontal regeneration has been demonstrated histologically for the treatment of mandibular Class III defects, the evidence is limited to one case report. 3) Evidence supporting regenerative therapy in maxillary Class III furcation defects in maxillary molars is limited to clinical case reports. 4) In Class I furcation defects, regenerative therapy may be beneficial in certain clinical scenarios, although most Class I furcation defects may be successfully treated with non-regenerative therapy. 5) Future research efforts should be primarily directed toward the conduction of clinical trials to test novel regenerative approaches that place emphasis primarily on patient-reported outcomes and also on histologic demonstration of periodontal regeneration. Investigators should also focus on understanding the influence that local, systemic, and technical factors may have on the outcomes of regenerative therapy in furcation defects.

Periodontal regeneration - furcation defects: a consensus report from the AAP Regeneration Workshop.

BACKGROUND: Treatment of furcation defects is a core component of periodontal therapy. The goal of this consensus report is to critically appraise the evidence and to subsequently present interpretive conclusions regarding the effectiveness of regenerative therapy for the treatment of furcation defects and recommendations for future research in this area. METHODS: A systematic review was conducted before the consensus meeting. This review aims to evaluate and present the available evidence regarding the effectiveness of different regenerative approaches for the treatment of furcation defects in specific clinical scenarios compared with conventional surgical therapy. During the meeting, the outcomes of the systematic review, as well as other pertinent sources of evidence, were discussed by a committee of nine members. The consensus group members submitted additional material for consideration by the group in advance and at the time of the meeting. The group agreed on a comprehensive summary of the evidence and also formulated recommendations for the treatment of furcation defects via regenerative therapies and the conduction of future studies. RESULTS: Histologic proof of periodontal regeneration after the application of a combined regenerative therapy for the treatment of maxillary facial, mesial, distal, and mandibular facial or lingual Class II furcation defects has been demonstrated in several studies. Evidence of histologic periodontal regeneration in mandibular Class III defects is limited to one case report. Favorable outcomes after regenerative therapy for maxillary Class III furcation defects are limited to clinical case reports. In Class I furcation defects, regenerative therapy may be beneficial in certain clinical scenarios, although generally Class I furcation defects may be treated predictably with non-regenerative therapies. There is a paucity of data regarding quantifiable patient-reported outcomes after surgical treatment of furcation defects. CONCLUSIONS: Based on the available evidence, it was concluded that regenerative therapy is a viable option to achieve predictable outcomes for the treatment of furcation defects in certain clinical scenarios. Future research should test the efficacy of novel regenerative approaches that have the potential to enhance the effectiveness of therapy in clinical scenarios associated historically with less predictable outcomes. Additionally, future studies should place emphasis on histologic demonstration of periodontal regeneration in humans and also include validated patient-reported outcomes. CLINICAL RECOMMENDATIONS: Based on the prevailing evidence, the following clinical recommendations could be offered. 1) Periodontal regeneration has been established as a viable therapeutic option for the treatment of various furcation defects, among which Class II defects represent a highly predictable scenario. Hence, regenerative periodontal therapy should be considered before resective therapy or extraction; 2) The application of a combined therapeutic approach (i.e., barrier, bone replacement graft with or without biologics) appears to offer an advantage over monotherapeutic algorithms; 3) To achieve predictable regenerative outcomes in the treatment of furcation defects, adverse systemic and local factors should be evaluated and controlled when possible; 4) Stringent postoperative care and subsequent supportive periodontal therapy are essential to achieve sustainable long-term regenerative outcomes.

Sclerosis in bisphosphonate-related osteonecrosis of the jaws and its correlation with the clinical stages: study of 43 cases.

We analysed the degree of sclerosis in the different stages of bisphosphonate-related osteonecrosis of the jaws (BRONJ) and studied the relation between the grade of sclerosis, the clinical symptoms, and the depth of lucency. We compared 43 patients with mandibular BRONJ with a control group of 40 cases with no bony lesions. The presence of sclerotic bone, cortical irregularities, radiolucency, fragmentation or sequestration, periostitis, and narrowing of the mandibular canal were studied from computed tomographic (CT) scans using the program ImageJ 1.47v (National Institute of Health, Bethesda, USA) to measure the radiolucency, width of the cortices, and degree of sclerosis. Patients with BRONJ had more severe sclerosis than controls (p<0.01). There was also a significant difference among the different stages of BRONJ, with the highest values found in stage III (p=0.02). The degree of sclerosis differed according to sex, type of bisphosphonate, and the clinical characteristics such as pain, or suppuration, but not significantly so (p>0.05). We conclude that the degree of sclerosis increases with the clinical stage of BRONJ, and is correlated with the depth of lucency.

Is mandibular asymmetry more frequent and severe with unilateral disc displacement?

PURPOSE: To investigate the prevalence of mandibular asymmetry (MA) within the symptomatic unilateral anterior disc displacement (ADD) patients, and analyze the influence TMJ factors of the MA severity. METHODS: Patients aged under 20 years old with symptomatic unilateral ADD and asymptomatic volunteers with normal disc-condyle relationship diagnosed by magnetic resonance imaging (MRI) were included in this study. Posteroanterior cephalometric radiographs were taken to measure MA. Condylar height, disc length and disc displacement were measured by MRI. The prevalence and severity of MA were compared between the ADD and the control groups. The correlation between the severity of MA with the amount of condylar height shortage, disc deformity and distance of disc displacement were also evaluated within the ADD group. RESULTS: There were 165 cases in the unilateral ADD group, and 156 cases in the control group. One hundred and nineteen cases had MA which accounted 72.12% (119/165) in the ADD group; while in the control group, only 25.64% (40/156) exhibited MA. The mean horizontal menton deviation and condylar height shortage in the unilateral ADD group were significantly larger than that in the control group (5.62 mm vs. 4.19 mm; 3.14 mm vs. 1.32 mm, p < 0.01). The severity of MA was significantly correlated with the amount of disc displacement, disc deformity and condylar height shortage (correlation coefficient: 0.80, 0.70, and 0.82). CONCLUSION: MA is much more common and severe in young unilateral ADD patients. The severity of MA is correlated with the height of condyle and the status of the disc.

Proposal for a new staging system for osteoradionecrosis of the mandible

A new staging system for osteoradionecrosis of the mandible has been retrospectively applied to a group of 31 patients. In this system clinic radiographic signs and symptoms are incorporated in a simplified manner. For imaging purposes the use of plain radiographs such as periapical films and panoramic radiographs is recommended, mainly because of their readily availability. The presented staging system seems well reproducible, facilitating the comparison of study groups dealing with the various issues of osteoradionecrosis of the mandible. It is yet to be evaluated whether the presently proposed staging system is useful for management purposes

Leucocyte-rich and platelet-rich fibrin for the treatment of bisphosphonate-related osteonecrosis of the jaw: a prospective feasibility study.

Our aim was to assess the feasibility of using leucocyte-rich and platelet-rich fibrin (L-PRF) for the treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in a single group study. After treatment with L-PRF, the response of each patient was recorded 1 month and 4 months postoperatively. Further assessments were made of the site, stage, concentration of c-terminal crosslinked telopepide of type 1 collagen, and actinomycosis. Among the total of 34 patients, 26 (77%) showed complete resolution, 6 (18%) had delayed resolution, and 2 (6%) showed no resolution. There was a significant association between the response to treatment and the stage of BRONJ (p=0.002) but no other significant associations were detected. This study has shown that it is feasible to use L-PRF for the treatment of BRONJ, but the effectiveness cannot be judged with this study design. Randomised prospective trials are needed to confirm this.

Occurrence of spontaneous periodontal disease in the SAMP1/YitFc murine model of Crohn disease.

BACKGROUND: Oral involvement is often associated with inflammatory bowel disease (IBD). Recent evidence suggests a high incidence of periodontal disease in patients with Crohn disease (CD). To the best of the authors' knowledge, no animal model of IBD that displays associated periodontal disease was reported previously. The aim of this study is to investigate the occurrence and progression of periodontal disease in SAMP1/YitFc (SAMP) mice that spontaneously develop a CD-like ileitis. In addition, the temporal correlation between the onset and progression of periodontal disease and the onset of ileitis in SAMP mice was studied. METHODS: At different time points, SAMP and parental AKR/J (AKR) control mice were sacrificed, and mandibles were prepared for stereomicroscopy and histology. Terminal ilea were collected for histologic assessment of inflammation score. Periodontal status, i.e., alveolar bone loss (ABL) and alveolar bone crest, was examined by stereomicroscopy and histomorphometry, respectively. RESULTS: ABL increased in both strains with age. SAMP mice showed greater ABL compared with AKR mice by 12 weeks of age, with maximal differences observed at 27 weeks of age. AKR control mice did not show the same severity of periodontal disease. Interestingly, a strong positive correlation was found between ileitis severity and ABL in SAMP mice, independent of age. CONCLUSIONS: The present results demonstrate the occurrence of periodontal disease in a mouse model of progressive CD-like ileitis. In addition, the severity of periodontitis strongly correlated with the severity of ileitis, independent of age, suggesting that common pathogenic mechanisms, such as abnormal immune response and dysbiosis, may be shared between these two phenotypes.

Evaluation of periodontitis and bone loss in patients undergoing hemodialysis.

BACKGROUND: Chronic kidney disease has been a worldwide public health challenge and also a risk factor for oral health. The objectives of this study are to investigate the periodontal status in Chinese patients undergoing hemodialysis (HD) and assess periodontal bone loss (BL) using cone-beam computerized tomography (CBCT). METHODS: The patients in the HD and control groups received periodontal and CBCT examinations in the same period. Age, sex, and HD details were obtained from a hospital database. Periodontal status was evaluated using the community periodontal index (CPI) and clinical attachment loss (AL). Periodontal BL was measured by the distance from the cemento-enamel junction to the alveolar crest using CBCT. The distance between the furcation upper and lower boundaries was considered the furcation defect. RESULTS: One hundred two patients undergoing HD and 204 control patients were enrolled. As for the demographic data and number of remaining teeth for each patient, there was no significant difference between HD and control groups. The CPI and AL showed statistical differences (P <0.001). The results of periodontal BL indicated that the patients undergoing HD had significantly more BL at their mandibular first premolars and first molars than did patients in the control group (P <0.01) at every site except the disto-buccal one (P <0.05). As for the furcation defects, the distance for the patients undergoing HD was nearly double that of the patients in the control group (P <0.001). CONCLUSION: Compared with the generally healthy population, periodontitis and periodontal BL were significantly more severe in the Chinese patients undergoing HD.

Staging of osteonecrosis of the jaw requires computed tomography for accurate definition of the extent of bony disease.

Management of osteonecrosis of the jaw associated with antiresorptive agents is challenging, and outcomes are unpredictable. The severity of disease is the main guide to management, and can help to predict prognosis. Most available staging systems for osteonecrosis, including the widely-used American Association of Oral and Maxillofacial Surgeons (AAOMS) system, classify severity on the basis of clinical and radiographic findings. However, clinical inspection and radiography are limited in their ability to identify the extent of necrotic bone disease compared with computed tomography (CT). We have organised a large multicentre retrospective study (known as MISSION) to investigate the agreement between the AAOMS staging system and the extent of osteonecrosis of the jaw (focal compared with diffuse involvement of bone) as detected on CT. We studied 799 patients with detailed clinical phenotyping who had CT images taken. Features of diffuse bone disease were identified on CT within all AAOMS stages (20%, 8%, 48%, and 24% of patients in stages 0, 1, 2, and 3, respectively). Of the patients classified as stage 0, 110/192 (57%) had diffuse disease on CT, and about 1 in 3 with CT evidence of diffuse bone disease was misclassified by the AAOMS system as having stages 0 and 1 osteonecrosis. In addition, more than a third of patients with AAOMS stage 2 (142/405, 35%) had focal bone disease on CT. We conclude that the AAOMS staging system does not correctly identify the extent of bony disease in patients with osteonecrosis of the jaw.

Outcomes of osseous free flap reconstruction in stage III bisphosphonate-related osteonecrosis of the jaw: systematic review and a new case series.

INTRODUCTION: There is currently no gold standard for the treatment of Stage III bisphosphonate-related osteonecrosis of the jaw (BRONJ). The question remains whether osseous reconstruction can offer an additional gain in outcome given the theoretical risk of non-union at the resection margins and recurrence in the osseous free flap. The objective was to conduct a systematic review of articles describing outcomes of osseous microsurgical reconstruction in cases of BRONJ with a minimum follow-up of 12 months, and to present the long-term outcomes of a new case series of three patients. MATERIAL AND METHODS: A multi-database QUORUM-based single-reviewer systematic review identified eight papers that fulfilled the selection criteria. There are only case series and case reports available (Level 4 of the Oxford Evidence-based medicine scale). A total of 31 patients were analysed including the cases described in this article. CONCLUSION: The limited overall rate of non-union at the resection margins and the 6.5% recurrence rate of BRONJ in the transplant counters the theoretical objections and advocates for considering osseous free flap reconstruction in the treatment of refractory BRONJ Stage III lesions. However, additional data derived from larger case series or case-control studies are imperative to support this hypothesis.

Changing trends and the role of medical management on the outcome of patients treated for osteoradionecrosis of the mandible: experience from a regional head and neck unit.

This study is a retrospective review of treatment outcomes of osteoradionecrosis (ORN) of the mandible with specific reference to the evolving role of medical management with pentoxifylline, tocopherol, and doxycycline. We reviewed the presentation and management of 71 patients treated for ORN of the mandible at the regional head and neck unit during a 15-year period to January 2011, and categorised them into three grades using the Notani classification: grade I (n=28), grade II (n=16), and grade III (n=27). Twelve patients with grade I ORN, 3 with grade II, and 10 with grade III, were prescribed medical treatment. Of these, three with grade I, and two with grade II ORN were cured, and progression of the disease had halted and there was satisfactory control of symptoms in eight with grade I and four with grade III disease. Patients who failed to respond to conservative treatment were further analysed for the need for free flap reconstruction. Medical management was introduced as a standard treatment in January 2006. Of the 39 patients diagnosed before this, 20 (51%) required resection and free flap reconstruction compared with only 8/32 (25%) after it had been introduced.

A simple evaluation method for early detection of bisphosphonate-related osteonecrosis of the mandible using computed tomography.

OBJECTIVES: The aim of this study was to establish a simple method for the early detection of bisphosphonate-related osteonecrosis of the jaw (BRONJ) using computed tomography (CT). MATERIALS AND METHODS: CT images of the mandible were obtained from a total of 20 patients with BRONJ and 20 control subjects. BRONJ was classified into 2 groups, with bone exposure (Stage 1-3 BRONJ) or without (Stage 0 BRONJ). In each patient, 15 transaxial CT images were selected and 30 configured regions of interest (ROI) were identified. The ANOVA test was applied to test the relationship between the severity of systemic risk factors. RESULTS: Regarding the local status of the mandible, significant differences were observed among the Stage 0 BRONJ, Stage 1-3 BRONJ, non-BRONJ and control groups in the cancellous bone CT radiodensity values, but there were no significant differences between the Stage 0 and Stage 1-3 BRONJ groups. In the cortical bone widths, significant differences were observed only between BRONJ and the controls. CONCLUSIONS: Measuring cancellous bone CT radiodensity value has the potential to be a simple and quantitative method to detect the early stages of BRONJ.

A classification system for conditions causing condylar hyperplasia.

A classification system was developed to place patients with condylar hyperplasia (CH) into categories based on histology, clinical and imaging characteristics, effects on the jaws and facial structures, and rate of occurrence. Four major categories were defined. CH type 1 is an accelerated and prolonged growth aberration of the "normal" mandibular condylar growth mechanism, causing a predominantly horizontal growth vector, resulting in prognathism that can occur bilaterally (CH type 1A) or unilaterally (CH type 1B). CH type 2 refers to enlargement of the mandibular condyle caused by an osteochondroma, resulting in predominantly unilateral vertical overgrowth and elongation of the mandible and face. One of the forms has predominantly a vertical growth vector and condylar enlargement, but without exophytic tumor extensions (type 2A), whereas the other primary form grows vertically but develops horizontal exophytic tumor growth off of the condyle (CH type 2B). CH type 3 includes other rare, benign tumors and CH type 4 includes malignant conditions that originate in the mandibular condyle causing enlargement. The order of classification is based on occurrence rates and type of pathology, where CH type 1A is the most commonly occurring form and CH type 4 is the rarest. This classification system for CH pathology should help the clinician understand the nature of the pathology, progression if untreated, recommended ages for surgical intervention to minimize adverse effects on subsequent facial growth and development in younger patients, and the surgical protocols to comprehensively and predictably treat these conditions.

Proposal for a new staging system for osteoradionecrosis of the mandible.

A new staging system for osteoradionecrosis of the mandible has been retrospectively applied to a group of 31 patients. In this system clinicoradiographic signs and symptoms are incorporated in a simplified manner. For imaging purposes the use of plain radiographs such as periapical films and panoramic radiographs is recommended, mainly because of their readily availability. The presented staging system seems well reproducible, facilitating the comparison of study groups dealing with the various issues of osteoradionecrosis of the mandible. It is yet to be evaluated whether the presently proposed staging system is useful for management purposes.