Panoramic radiographic features that predict the development of bisphosphonate-related osteonecrosis of the jaw

Objectives

The purpose of this study was to clarify which panoramic radiographic features can predict the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ).

Methods

Participants included 24 patients treated with bisphosphonates (BP) for osteoporosis who developed osteonecrosis of the jaw (ONJ⁺ group). Controls included 179 patients treated with BP who did not have osteonecrosis (ONJ^? group) and 200 patients with no history of BP administration (unmedicated group). The mandibular cortical width, mandibular cortical index (MCI), sclerosis of trabecular bone, and thickening of the lamina dura were evaluated on panoramic radiographs.

Results

The mandibular cortical width was significantly smaller in the ONJ^– group than in the other groups. Class II MCI (semilunar defects of endosteal margin) was frequently noted on the affected and contralateral sides in the ONJ⁺ group but not in the ONJ^? or unmedicated groups. Sclerosis of the trabecular bone was significantly more frequently observed on the affected side in the ONJ⁺ group than in the other groups. Thickening of the lamina dura was observed significantly more frequently in the BP-treated groups than in the unmedicated group.

Conclusions

Class II MCI may be an indicator to predict the development of BRONJ. Sclerosis of trabecular bone was a characteristic imaging feature of BRONJ. Thickening of the lamina dura may be an imaging feature caused by BP administration.

     

Osteoporotic mandibular changes caused by type 2 diabetes mellitus: a comparative study by cone beam computed tomography imaging

Objectives

Studies on bone mineral density and fracture risk in diabetic patients have attracted interest in the last few years. This study was aimed at comparing mandibular osteoporotic changes assessed by qualitative and quantitative radiographic methods in the mandibles of type 2 diabetes mellitus patients with those of non-diabetic subjects using cone beam computed tomographic images.

Methods

This quantitative and qualitative study of mandibular bone in diabetic patients included 23 type 2 diabetes mellitus patients and an equal number of healthy subjects. Radiomorphometric measurements were performed for each subject using cone beam computed tomography images. Changes in cortical bone thickness were determined by measuring bone area. Fractal dimension analysis was applied to evaluate the trabecular structure of the bone.

Results

No statistically significant difference could be established between the type 2 diabetes mellitus group and the control group in regard to either radiomorphometric measurements or fractal dimension analysis. Quantitative assessment of mandibular bone indicated a thinning of the cortical bone, with a statistically significant difference between the type 2 diabetes mellitus patients and the healthy controls.

Conclusions

Bone condition related to diabetes involves complex pathophysiological mechanisms; thus, radiographic imaging parameters may be useful as an adjunct to clinical parameters.

     

Deterioration of teeth and alveolar bone loss due to chronic environmental high-level fluoride and low calcium exposure

Objectives

Health risks due to chronic exposure to highly fluoridated groundwater could be underestimated because fluoride might not only influence the teeth in an aesthetic manner but also seems to led to dentoalveolar structure changes. Therefore, we studied the tooth and alveolar bone structures of Dorper sheep chronically exposed to very highly fluoridated and low calcium groundwater in the Kalahari Desert in comparison to controls consuming groundwater with low fluoride and normal calcium levels within the World Health Organization (WHO) recommended range.

Materials and methods

Two flocks of Dorper ewes in Namibia were studied. Chemical analyses of water, blood and urine were performed. Mineralized tissue investigations included radiography, HR-pQCT analyses, histomorphometry, energy-dispersive X-ray spectroscopy and X-ray diffraction-analyses.

Results

Fluoride levels were significantly elevated in water, blood and urine samples in the Kalahari group compared to the low fluoride control samples. In addition to high fluoride, low calcium levels were detected in the Kalahari water. Tooth height and mandibular bone quality were significantly decreased in sheep, exposed to very high levels of fluoride and low levels of calcium in drinking water. Particularly, bone volume and cortical thickness of the mandibular bone were significantly reduced in these sheep.

Conclusions

The current study suggests that chronic environmental fluoride exposure with levels above the recommended limits in combination with low calcium uptake can cause significant attrition of teeth and a significant impaired mandibular bone quality.

Clinical relevance

In the presence of high fluoride and low calcium-associated dental changes, deterioration of the mandibular bone and a potential alveolar bone loss needs to be considered regardless whether other signs of systemic skeletal fluorosis are observed or not.

     

A morphometric analysis of the mandibular canal by cone beam computed tomography and its relevance to the sagittal split ramus osteotomy

Purpose

The aim of the present study was to morphometrically analyze the mandibular canal through the mandibular ramus by cone beam computed tomography (CBCT) and to relate the findings to performing sagittal split ramus osteotomy.

Methods

CBCT of 200 patients were analyzed. Five parameters were measured at the axial scan, from the mandibular foramen to 21 mm below it (3-mm intervals). The canal was classified according to the position within the bone marrow space. Variations were evaluated according to age, sex, side, and number of mandibular teeth.

Results/conclusions

The following measurements increased gradually towards the most inferior level of measurement: the total thickness of the mandibular ramus through the center of the mandibular canal, the width of the bone marrow space (both buccal and lingual), and the narrowest width from the mandibular canal inner cortical to the mandibular ramus external cortical. The inner diameter of the mandibular canal slightly decreased to the same direction. Concerning the mandibular canal position within the bone marrow space, the percentage of the separate type increased towards the most inferior level of measurement, and the contact and fusion types decreased. Age, number of teeth, and sex had no significant influence on the total thickness of the mandibular ramus and on the narrowest width from the mandibular canal inner cortical to the mandibular ramus external cortical.

     

Associations between mandibular symphysis form and craniofacial structures

Objectives

This study aimed to (1) analyze the relationships between mandibular symphysis characteristics (height, prominence, inclination, concavity, and convexity) and facial pattern, skeletal class, lower incisor position, and sex, and (2) determine the associations between the symphysis soft tissue dimensions and the underlying osseous structures.

Methods

Cone-beam computed tomography (CBCT) images were selected for 385 patients (206 women and 179 men). The patients were classified according to their skeletal class and vertical pattern. The lower incisor inclination (IMPA) was recorded. Twelve measurements were taken for each mandibular symphysis using Invivo5 software (Anatomage, San Jose, CA, USA).

Results

Symphyseal measurements were larger in males than in females. Skeletal Class II and III hyperdivergent patients showed the highest symphysis height values. Hypodivergent individuals showed lower symphysis convexity angles. Concavity of the symphysis was greater for Class II hyperdivergent patients. Lower incisor inclination showed a positive correlation with symphysis concavity and inclination. Moderate and weak correlations were found between hard tissue and soft tissue parameters.

Conclusions

Only a few characteristics of symphysis morphology depend on sex, incisor position, skeletal class, and vertical pattern. More significant relationships are found when the vertical pattern and skeletal class are analyzed in combination. The shape of the symphysis soft tissue is not directly correlated with the underlying skeletal structures.

     

Evaluation of the oropharynx in class I and II skeletal patterns by CBCT

Purpose

This study aimed to evaluate the dimensions of the oropharynx and its shape in the minimum cross-sectional area, in individuals with Class I and Class II skeletal patterns, using three-dimensional CBCT images.

Methods

Forty-two cone-beam computed tomography images of grown individuals were evaluated. The images were divided according to the patient’s skeletal patterns. The dimensions of the oropharyngeal airway space were determined using the Dolphin Imaging software.

Results

The volume and the minimum cross-sectional area were greater in patients with a Class I skeletal pattern, with a median difference of 5379 mm³ and 86.8 mm², respectively. The anteroposterior and lateral diameters in the minimum cross-sectional area were also higher in Class I individuals (2.3 and 6.0 mm, respectively), but the ratio between them was not different.

Conclusions

The volume and the minimum cross-sectional area of the oropharynx, as well as the anteroposterior and lateral diameters, are lower in individuals with a class II skeletal pattern than in individuals with a class I skeletal pattern. There was no difference in the shape of the oropharynx in healthy individuals with different skeletal patterns.

     

Craniofacial cephalometric morphologies in different cleft types: a retrospective cross-sectional study of 212 patients

Objective

The aim of this study was to evaluate and compare the craniofacial cephalometric morphologies among different cleft types in a Spanish population.

Methods

A retrospective cross-sectional study was carried out on 212 patients. The patients were subdivided into four groups according to their cleft types: unilateral cleft lip and palate; bilateral cleft lip and palate; cleft lip; and cleft palate. Angular and linear cephalometric measurements were taken on lateral radiographs.

Results

Unilateral cleft lip and palate was associated with a dolichofacial growth pattern, skeletal Class III with correct maxillary position, and lingual incisor inclination. Bilateral cleft lip and palate was associated with a mesofacial growth pattern, skeletal Class I with protruded maxillary position, and lingual incisor inclination. Cleft palate was associated with a mesofacial growth pattern, skeletal Class III with correct maxillary position, and lingual incisor inclination. Cleft lip was associated with a brachyfacial growth pattern, skeletal Class I with protruded maxillary position, lingual upper incisor inclination, and corrects lower incisor inclination. Significant correlations were observed between cleft types and their craniofacial cephalometric measurements.

Conclusions

The present information can be used for the determination of orthodontic treatment and even future orthognathic surgery planning, a requirement in most cleft patients.

     

Protocol for mandibular reconstruction with zygomatic implants (zygomatic mandibular implant)

Introduction

This study describes a modified protocol using transmandibular zygomatic implants with immediate occlusal loading for the comprehensive dental rehabilitation of previously reconstructed mandibular defects and reports preliminary results of this modified protocol.

Materials and methods

Fifteen patients (6 female and 9 male), with a mean of age 40.26 years (range 12 to 68 years), had previously undergone immediate mandibular reconstruction using either autologous bone grafting, bone transport, or microvascular free-flap reconstruction for a variety of diagnoses. Transmandibular zygomatic implants were subsequently placed, depending on the type of defect. Implant stability was evaluated by insertion torque, percussion testing, and the implant stability quotient (ISQ). The patients were rehabilitated with an immediate provisional prosthesis. All patients’ records included pre and postoperative clinical examination, radiographs, CT scan, and photographic analysis. All patients were followed for a minimum of 36 months.

Results

All patients were dentally rehabilitated immediately with functional and esthetic hybrid dentures based on either acrylic or porcelain on a metal framework. Among all cases of transmandibular zygomatic implants, the ISQ was greater than 75, which allowed immediate prosthetic loading. The zygomatic implants were considered to be successful if they were asymptomatic with no clinical mobility and no sign of infection. We have also added new indications for placement of transmandibular implants in cases of sequelae of gunshot trauma, dentoalveolar defects, and complications of orthognathic surgery, partially edentulous and/or failure of prior mandibular reconstruction.

Conclusions

The zygomatic implant is an excellent immediate loading option for mandibular dental rehabilitation among patients with mandibular defects. According to our observation, immediate occlusal loading of transmandibular zygomatic implants has a very good potential for success.

     

Mandibular war injuries caused by bullets and shell fragments: a comparative study

Purpose

Is to compare the patterns, severity, and management of the high- and low-velocity mandibular war injuries managed at Al Shaheed Gazi Al-Hariri Hospital in Baghdad Medical City, Iraq, during a 2-year period.

Methods

Forty-one patients with a history of mandibular war injuries treated by our maxillofacial team were reviewed during a period of 2 years (2015–2017). All patients were treated in the Maxillofacial Unit of the Hospital of Specialized Surgeries in Baghdad Medical City.

Results

A 2-year retrospective study evaluated 41 patients with mandibular war injuries with a total of 94 fractures (comminution represents 79.06% of the bullet injuries, while it is only 62.74% with IED injuries). Management of these injuries was varied according to the severity of the injuries and resources available. Close reduction was used in 72.72% of the linear fracture cases, whereas open technique was used in 56.6% of the comminuted fractures.

Conclusions

Bullet injuries were associated with a higher number of mandibular comminuted fractures, in addition to more extensive bone loss. While shell injuries of IED (improvised explosive devices), on the other hand, were associated with higher infection rate and more postoperative complication.

     

Clinical and radiological analysis of osteochondromas of the mandible using cone-beam computed tomography

Objectives

Osteochondroma (OC) is rare in the mandibular condyle. The radiographic appearance of this lesion is diverse. Most radiologists and surgeons agree that helical computed tomography (CT) has great diagnostic potential for OC. Cone-beam CT (CBCT) can also afford three-dimensional information, and it is widely used to evaluate oral and maxillofacial diseases. The purpose of this study was to elucidate the CBCT characteristics of OC in the mandible and increase the radiographic knowledge of mandibular OC.

Methods

The CBCT radiographs of 31 cases of mandibular OC (29 cases in the condyle and two cases in the coronoid process) were reviewed. All data were obtained from the oral radiology department of our institution from 2009 to 2014. The final diagnoses of all cases were based on pathological examination. Patient age, sex, symptoms, and radiographic findings were considered in all cases. Percentages, the t test, and the χ ² test were used for statistical analyses.

Results

Progressive facial asymmetry, malocclusion, and opening deviation were the most common symptoms. There was no sex-related difference in age at onset, symptoms, or tumor location. Although the mandibular OCs exhibited diverse shapes, they could be divided into two types: bony outgrowth (more common) and condylar expansion. The structures adjacent to the mandibular OC were often affected by the tumor; cortical hyperostosis of the affected glenoid fossa was found in most cases.

Conclusions

Mandibular OCs may show different growth positions encircling the condyle and exhibit varying shapes. CBCT can provide enough information for use in the diagnosis of OCs.

     

Use of a generic violet light in the surgical management of medication-related osteonecrosis of the jaws: a technical note

Purpose

Fluorescence-guided surgery has been recommended for the diagnosis of bone margins in cases of mandibular osteonecrosis. In this article, we report a case in which a generic violet light was used in order to activate bone fluorescence after the administration of tetracycline derivatives, as an alternative to a specific, more expensive equipment that is commercially available for this purpose. The patient had been using alendronate for osteoporosis, resulting in medication-related osteonecrosis of the jaws.

Methods

The treatment protocol includes preoperative administration of doxycycline and the application of a generic violet light during surgery in order to observe the fluorescence of bone in response to excitation through the light emitted by this device.

Results

With an effective visualization of the limit between healthy and devitalized bone tissue, it was possible to perform the necrotic tissue removal. The lesion regressed from stage 2 to stage 0, with no clinical or radiographic evidence of necrotic bone.

Conclusions

These results suggest the feasibility of using a generic violet light source as a low-cost alternative for fluorescence-guided surgery.

     

A Self-Retaining Lingual Flap Guarding Device During Surgical Removal of Impacted Mandibular Third Molar

Introduction

Lingual nerve damage is one of the common complications following mandibular third molar surgery. On considering the impact of lingual nerve damage on the patient’s quality of life, it is necessary to exercise caution to minimize its occurrence.

Material and methods

Although many lingual retractors are available, in this article we describe an indigenously designed lingual retractor for use in mandibular third molar surgery.

Conclusion

The indigenous lingual retractor described in this article provides advantages like clear access and excellent retention unlike conventional retractors.

     

Evaluation of retromolar canals on cone beam computerized tomography scans and digital panoramic radiographs

Purpose

The purpose of this study was to carry out morphologic and topographic analyses of retromolar canals on cone beam computerized tomography (CBCT) scans, comparing findings to others obtained from the corresponding digital panoramic radiographs.

Methods

Sixty-one CBCT scans were analysed digitally, as well as their corresponding digital panoramic radiographs. The prevalence and distribution of these canals, foramen diameters, and intraosseous communications were also evaluated.

Results

On CBCT scans, we found that 24.6% of individuals had at least one retromolar canal. The mean foramen diameter was slightly higher than 1 mm and we could not determine the intraosseous anatomical connections in most cases. The morphology and topography of the retromolar canals were not affected by gender and antimere. In addition, only 22.2% of all tomographically identified canals could be confirmed on digital panoramic radiographs (26.7% of such patients). Regarding all sample, 6.6% of individuals showed retromolar canals on digital panoramic radiographs.

Conclusion

We may consider that these structures are clinically relevant findings and, due to the low accuracy of the panoramic radiographs, high-quality tomographic exams should always be asked for presurgical treatment planning.

     

Radiographic study of mandibular third molars: evaluation of the position and root anatomy in Brazilian population

Objectives

The root anatomy and position of mandibular third molars are important factors in assessing the level of difficulty of surgical removal procedures. In this light, this study aims to identify the most frequent position and the root anatomy of mandibular third molars.

Methods

The study sample comprised 1205 mandibular third molars from 710 panoramic radiographs evaluated. Regarding the position, all of them were based on Pell and Gregory’s and Winter’s classifications. The root anatomy was classified according to the type and number of roots, as well as the presence of laceration, fusion, or divergence. Gender and the quadrant were also considered. Following an interexaminer analysis, a statistical analysis was performed using the Kappa test.

Results

The results showed that the IA (40.3%) and mesioangular (53.8%) position was predominant in mandibular third molars. Regarding the anatomy, the most common were two roots (98.3%), of the conical simple type (88.9%), with absence of laceration (89.2%), divergence (84%), and fusion (80%).

Conclusion

The present study showed that the most prevalent mandibular third molar type in Brazilian patients was the IA and mesioangular position, with simple root anatomy. The result of this study can assist oral surgeons to better plan and assess the level of difficulty of surgical removal procedures.

     

Extraordinarily favorable recovery from unilateral condylar fracture in a 4-year-old girl

Introduction

Management of condylar fractures in children is especially important. If not properly treated, these fractures may lead to serious problems, such as ankylosis of the temporomandibular joint. This article describes an extraordinarily favorable recovery after conservative treatment of a unilateral condylar fracture in a 4-year-old girl.

Case presentation

A 4-year-old Japanese girl was referred to our institution with a right mandibular condylar fracture caused by a fall. In this article, we report the 2-year follow-up of this case by clinical and radiological evaluations after conservative treatment, highlighting the strategy used.

Conclusions

The outcomes throughout the 2-year follow-up and the remodeling process of the condyle observed on panoramic radiographs and computed tomographic images proved the suitability of the conservative treatment.

     

Reconstruction of tooth-bearing portion of mandible using polyglactin 910 sutures for internal fixation in the third-world: functional and cosmetic outcome

Background

This study analyzed the cosmetic and functional outcome of cases involving reconstruction of tooth-bearing portion of the lower jaw, using a polyglactin 910 suture for fixation.

Patients and method

This prospective intervention study documented the treatment outcome in 25 consecutive adult patients, who underwent immediate mandibular reconstruction following segmental resection of tooth-bearing portion of mandible. Cortico-cancellous bone graft was taken from the inner table of iliac bone, sparing the crest. Use of post-surgical inter-maxillary fixation was avoided.

Results

Twenty-five patients were recruited for the study. Seventeen were males and eight were females. Their ages ranged from 18 to 50 years, with a mean of 30.0 years. Average length of grafted bone was 9.8 cm. Following surgery, all 25 (100%) patients were judged to have satisfactory facial symmetry. One (4.0 %) had altered dental occlusion. Twenty-five (100%) had satisfactory bone union. All of the patients claimed to masticate satisfactorily. Assessment was carried out at the last post-operative follow-up visit for each patient who ranged between 22 and 83 months.

Conclusion

Use of polyglactin 910 suture material for fixation in mandibular reconstruction following segmental resection of tooth-bearing portion has proven to be a cosmetic and functional success. It may serve as alternative for those among whom conventional treatment methods may be contraindicated. This method of bone fixation may serve as a reliable and much cheaper alternative in low-income countries.

Level of evidence

Level IV, therapeutic study.

     

Superolateral Dislocation of Bilateral Intact Mandibular Condyles: A Rare Case Series

Background and Purpose

The dislocation of mandibular condyle is a clinical condition in which the head of condyle has been displaced out of the glenoid fossa. Complete dislocation of the mandibular condyle can occur in anterior, posterior, lateral and superior direction. Among these dislocations, bilateral superolateral dislocation of mandibular condyles is quite rare and often misdiagnosed. Because of its rare occurrence and unusual clinical course, the best treatment is debatable.

Patients and Method

We present the first case series of true bilateral superolateral dislocation of intact mandibular condyles (Type 2B) without fracturing the Zygomatic arch, associated with symphysis fracture.

Conclusion

This article intends to provide information regarding the possible biomechanics and management of bilateral superolateral dislocation of mandibular condyles associated with symphysis fracture.

     

Mandibular Reconstruction: Overview

Introduction

Mandibular reconstruction has changed significantly over the years and continues to evolve with the introduction of newer technologies and techniques.

Purpose

This article reviews the history of oromandibular reconstruction, biomechanics of mandible, summarizes the reconstruction options available for mandible with defect classification, goals in reconstruction, the various donor sites, current reconstructive options, dental rehabilitation and persistent associated problems.

Summary

Oromandibular reconstruction, although a challenge for the head and neck reconstructive surgeon, is now reliable and highly successful with excellent long-term functional and aesthetic outcomes with the use of autogenous bone grafts and current reconstructive options. The ideal reconstruction would provide a solid arch to articulate with the upper jaw, restoring swallowing speech, mastication, and esthetics. Autogenous vascularized bone grafts in combination with microsurgical techniques have revolutionized mandibular reconstruction in oral cancer surgery. Current trends in mandibular reconstruction aim to achieve reestablishment of a viable mandible of proper form and maxillary mandibular relationship while decreasing the need for invasive autogenous graft procurement. However the optimal reconstruction of mandibular defects is still controversial in regards to reconstructive options which include the donor site selection, timing of surgery and method of reconstruction.