Glandular Odontogenic Cyst in Maxilla: A Case Series.

Glandular odontogenic cyst is rare phenomenon with 0.012% to 0.03% frequency of all jaw cysts and worldwide prevalence of 0.17%. Diagnosis of Glandular odontogenic cyst, well known for its aggressive growth potential and high rate of recurrence, is very crucial. This report presents cases of two 50-year old individuals with Glandular odontogenic cyst presenting as a radiolucent lesion of maxilla. Final diagnosis was made on the basis of histopathological features and further confirmed by immunohistochemical analysis. Keywords: histology; immunohistochemistry; odontogenic cyst.

The Status of Affected Infraorbital Nerve and Inferior Alveolar Nerve in Patients With Jaw Fibrous Dysplasia: A Clinical and Radiographic Evaluation.

The affected infraorbital nerve (IFBN) and inferior alveolar nerve (IFAN) status in patients with jaw fibrous dysplasia has not been definitely depicted. In this study, the authors try to explore the status of affected IFBN and IFAN in patients with jaw fibrous dysplasia. Ten patients with jaw fibrous dysplasia were included in this study. The complaints of numbness in the IFBA and IFAN innervated area were asked and recorded, and careful clinical examination was performed to evaluate the touch sense, pain sense, pressure sense, and temperature sense in the IFBA and IFAN innervated areas. Computed tomography scans also were performed to evaluate the imaging characteristics of affected IFBA and IFAN. The results showed that 1 patient with maxillary lesion showed complaints of slight numbness, and clinical examination showed that the patient exhibited slight insensitive in pain sense. In addition, 1 patient with mandibular lesion showed relative obvious complaints of numbness, and clinical examination showed that the patient exhibited slight insensitive in pain sense and temperature sense, but not serious. All other patients exhibited no numbness in the IFBA and IFAN innervated area. Although the position and morphology changed in some patients, all neural canal of affected IFBA or IFAN existed and showed no invasion of lesion. Taking these findings together, it further confirmed that evaluation of the function of IFBAN and IFAN is necessary for patients with jaw fibrous dysplasia, and the affected IFBAN and IFAN may should be reserved in most patients with jaw fibrous dysplasia when resecting or recontouring the lesion.

Spontaneous bone formation after mandible segmental resection in "krokodil" drug-related jaw osteonecrosis patient: case report.

We report a case of a 48-year-old male patient with "krokodil" drug-related osteonecrosis of both jaws. Patient history included 1.5 years of "krokodil" use, with 8-month drug withdrawal prior to surgery. The patient was HCV positive. On the maxilla, sequestrectomy was performed. On the mandible, sequestrectomy was combined with bone resection. From ramus to ramus, segmental defect was formed, which was not reconstructed with any method. Post-operative follow-up period was 3 years and no disease recurrence was noted. On 3-year post-operative orthopantomogram, newly formed mandibular bone was found. This phenomenon shows that spontaneous bone formation is possible after mandible segmental resection in osteonecrosis patients.

A FEM based endosteal implant simulation to determine the effect of peri-implant bone resorption on stress induced implant failure.

Although dental implants exhibit only limited failure rates, their fracture is associated to major modifications of the prosthetic treatment and complex surgery for the removal of the remaining embedded implant part. This investigation aims to assess the developing stress fields in the bone-implant interface during mastication and asses the failure modes of oral implants.In order to achieve this, a FEM model of an implant was reverse engineered and virtually loaded at the top of the crown for a force spectrum ranging from 75-225 N in a vertical, horizontal and oblique occlusal direction. The calculated stress fields were compared with clinically retrieved fractured implants with identical geometrical characteristics and the fracture modes of both cases were correlated. The developing stress patterns facilitated the interpretation of the implant failure as the maximum stresses, indicated critical values in both, lingual and buccal sides of the implant-bone interface at a certain critical level of bone resorption, in which failure occurs.

Influence of the patients’ sex, type of dental prosthesis and antagonist on residual bone resorption at the level of the premaxilla

Objectives: To analyze the height and width of the ridge at the level of the premaxilla in edentulous patients, evaluating whether the sex of the patient, type of prosthetic rehabilitation and antagonist have an influence. Material and Method: We randomly selected a total of 89 patients, having an average age of 66.21 years old. A total of 308 measurements were made, all of them at the level of the premaxilla, in the intercanine area. As dependent variables, we analyzed the patients’ sex, age and the antagonist: removable (dental) prostheses (RP), fixed(dental) prostheses (FD), natural dentition (ND). As independent variables, we measured the height and residual width in sagittal sections provided by tomographic studies using Dentascan®. Results: We observed a significantly smaller ridge in women versus in men, and in patients whose antagonist was a fixed prosthesis; whereas for the type of prosthesis, we did not observe significant differences between the two categories analyzed. Conclusions: Bone resorption at the level of the premaxilla is a variable process in which a smaller size is observed(height and width) in women and when the antagonist is a fixed prosthesis (AU)

[Bony regrowth after major erosion of the maxillary following silastic malar augmentation. Case report]. / Régénération osseuse après érosion majeure du maxillaire sur implants malaires en silicone. Cas clinique.

Alloplastic malar augmentation has become a routine procedure associated with few complications. Among them, authors have described bony erosion and resorption. The case presented here illustrates an unusual case of maxillary bone erosion after silastic malar augmentation. Implants were surgically removed and no more surgical intervention was performed. After 15 months, contrast-enhanced CT scan has showed nearly complete bony regrowth to an almost normal state. Considering resorption phenomenons following silastic chin implants, Peled et al. reported no long-term sequellae after implant removal and bony regrowth to the presurgical state after 9 months. Accordingly, we conclude that these phenomenons, even spectacular, are always reversible after implants removal and that treatment should just consist in ablation of the offending prosthetic material.

Relevant anatomic and biomechanical studies for implant possibilities on the atrophic maxilla: critical appraisal and literature review.

PURPOSE: The purpose of this review was to highlight anatomic and biomechanical aspects of atrophic maxillae for implant possibilities. MATERIALS AND METHODS: A MEDLINE electronic search of the years 1966 to 2009 was conducted with the keywords "atrophic,""resorbed,""edentulous," and "maxilla." RESULTS: Twenty papers presented the following findings: (1) previous use of a removable prosthesis is a risk factor for resorption, with flabby tissues related to the severity of resorption; (2) implants in the reconstructed maxilla (< or =5 mm) and supporting overdentures had a higher risk for bone loss based on the worse periimplant soft-tissue health observed; (3) bleeding on probing was found with pocket depths > or =5 mm in half of the zygomatic implants; (4) prevalence of bone septa is higher in atrophic maxillae, and changes on nasopalatine canal can reduce up to 44.4% of the full length of buccal bone plates; (5) female patients have less medullar bone quantity and connectivity than male patients; (6) transectioning of nutrient vessels is easier and accelerates resorption; (7) stress does not concentrate on maxillary sinus base cortical bone contiguous to trabecular bone; (8) splinted implants receive nine times less load than nonsplinted implants even under oblique loading; (9) implant stability quotient (ISQ) values for implants ranged between 60 and 65; (10) in vivo force transfer to implants is similar between fixed prostheses and overdentures; (11) inclined implants generate better biomechanical responses; (12) masticatory efficiency and bite forces improve in maxillectomized patients who receive obturators with milled bar attachments. CONCLUSION: Sound implant-supported choices for an atrophic maxilla must be made with a thorough understanding of its anatomic and biomechanical factors.

A novel animal model to study non-spontaneous bisphosphonates osteonecrosis of jaw.

The aim of this study was to evaluate a novel animal model of bisphosphonates-associated osteonecrosis, which realistically recapitulates the same pathological human condition. Five Wistar rats were given intravenous zoledronic acid 0.04 mg once a week for 5 weeks. After 2 weeks, the animals underwent the extraction of an upper molar, producing a 4 mm-diameter bone defect on the same site. After 7 weeks from the extraction, the animals were clinically examined and a bone scintigraphy was carried out. After an additional week, the rats were killed and both Computerized Tomography and histological analysis were performed. Five rats, not treated with zoledronic acid and exposed to the same surgical treatment, were used as controls. At 7 weeks after the extraction, all the rats treated with zoledronic acid showed expansion of the defect and bone exposure. These features were confirmed by bone scintigraphy. The rats of the control group demonstrated epithelialization of the bone defect and a normal uptake of the contrast medium during the scan. The Computerized Tomography scan disclosed irregularity of the cortical margin and bone destruction, which were not evident in the control group. On microscopy, the samples showed necrotic bone, loss of osteocytes and peripheral resorption without inflammatory infiltrate, while the controls showed normal bone healing. The rat treated with zoledronic acid can be considered a novel, reliable and reproducible animal model to understand better the pathophysiology of osteonecrosis of the jaw and to develop a therapeutic approach.

Electromyographic activity of masticatory muscles in women with osteoporosis.

The purpose of this study was to analyze the electromyographic (EMG) activity and the maximal molar bite force in women diagnosed with osteoporosis in the maxillary and mandibular regions, considering the habits and conditions that lead to development of generalized skeletal bone loss, including on face bones, can disturb the functional harmony of the stomatognathic system. Twenty-seven women with mandibular and maxillary osteoporosis and 27 healthy controls volunteered to participate in the study. A 5-channel electromyographer was used. Muscle activity was evaluated by means of EMG recordings of the masticatory musculature (masseter and temporalis muscles, bilaterally) during the following clinical conditions: rest (5 s); right and left lateral excursions (5 s); protrusion (5 s); maximal dental clenching on Parafilm (4 s) and maximal voluntary contraction (4 s). This latter clinical condition was used as the normalization factor of the sample data. It was observed that individuals with osteoporosis presented greater EMG activity when maintaining mandible posture conditions and less activity during dental clenching and when obtaining maximal molar bite force. It may be concluded that facial osteoporosis can interfere on the patterns of masticatory muscle activation and maximal bite force of the stomatognathic system.

Monostotic fibrous dysplasia: a 23-year follow-up of a patient with spontaneous bone remodeling.

Fibrous dysplasia is a benign fibro-osseous disease that affects one or more bones. Although its etiology has been defined, the mechanism of spontaneous resolution is still unclear. There is strong evidence indicating the occurrence of stabilization when bone maturation is completed. Deformities that lead to esthetic and functional disorders are observed in almost all cases. Plastic surgery is often recommended when the maxilla and mandible are involved. In the case of mild deformities, careful follow-up during skeletal growth is recommended. We describe here the 23-year follow-up of a patient with monostotic fibrous dysplasia whose disease had stabilized by 13 years of follow-up.

Electromyographic activity of masticatory muscles in women with osteoporosis

The purpose of this study was to analyze the electromyographic (EMG) activity and the maximal molar bite force in women diagnosed with osteoporosis in the maxillary and mandibular regions, considering the habits and conditions that lead to development of generalized skeletal bone loss, including on face bones, can disturb the functional harmony of the stomatognathic system. Twenty-seven women with mandibular and maxillary osteoporosis and 27 healthy controls volunteered to participate in the study. A 5-channel electromyographer was used. Muscle activity was evaluated by means of EMG recordings of the masticatory musculature (masseter and temporalis muscles, bilaterally) during the following clinical conditions: rest (5 s); right and left lateral excursions (5 s); protrusion (5 s); maximal dental clenching on Parafilm™ (4 s) and maximal voluntary contraction (4 s). This latter clinical condition was used as the normalization factor of the sample data. It was observed that individuals with osteoporosis presented greater EMG activity when maintaining mandible posture conditions and less activity during dental clenching and when obtaining maximal molar bite force. It may be concluded that facial osteoporosis can interfere on the patterns of masticatory muscle activation and maximal bite force of the stomatognathic system.

Este estudo teve como objetivo analisar a atividade eletromiográfica e a força de mordida molar máxima de indivíduos diagnosticados com osteoporose na região maxilar e mandibular, visto que os hábitos e condições que provocam o desenvolvimento de uma perda óssea generalizada no esqueleto, inclusive no esqueleto facial, podem causar distúrbios na harmonia funcional do sistema mastigatório. Vinte e sete indivíduos portadores de osteoporose na mandíbula e maxila e 27 voluntários sem a doença participaram deste estudo. Um eletromiógrafo de 5 canais foi utilizado. A avaliação da atividade muscular foi realizada por meio de registros eletromiográficos da musculatura mastigatória (músculos masseter e temporal, bilateralmente) durante as seguintes condições clínicas: Repouso (5 s); Lateralidades direita e esquerda (5 s); Protrusão (5 s); Apertamento dental máximo com parafilme (4 s) e a contração voluntária máxima (4 s), sendo que esta condição clínica foi utilizada como fator de normalização dos dados da amostra. Verificou-se que os indivíduos com osteoporose apresentaram maior atividade eletromiográfica durante a manutenção das condições posturais da mandíbula e menor atividade durante o apertamento dental e na obtenção da força de mordida molar máxima. Conclui-se que a osteoporose na região dos ossos da face pode interferir nos padrões de ativação da musculatura mastigatória e na força de mordida máxima do sistema estomatognático.

The effects of systemic stress on orthodontic tooth movement.

OBJECTIVES: To determine if systemic stress affects the biological reactions occurring during orthodontic tooth movement. METHODS: Four groups of male 10 week-old Wistar rats were used. Group A animals (N=10) were restrained for one hour per day for 40 days; Group B animals (N=10) were restrained for one hour per day for three days; Group C (N=10) and Group D (N=8) animals were unrestrained. The upper left first molars in the rats in Groups A (long-term stress), B (short-term stress) and C (control) were moved mesially during the last 14 days of the experiment. The animals in Group D (N=8) were used for body weight and hormonal dosage comparisons only. They were not subjected to any stress and did not have appliances fitted. All animals were killed at 18 weeks of age and blood collected for measurement of plasma corticosterone. Tooth movement was measured with an electronic caliper. The right and left hemi-maxillae of five rats from each group were removed and the number of tartrate-resistant acid phosphatase (TRAP) positive cells, defined as osteoclasts, adjacent to the mesial roots of the upper first molars counted. The contralateral side in each animal served as the control (split-mouth design). RESULTS: Corticosterone levels were significantly higher in the stressed groups (Groups A and B) than in the control group (Group C). Tooth movement was significantly greater in Group A (long-term stress) compared with Group B (short-term stress) and Group C (control), which did not differ from each other. There were significantly more osteoclasts in the long-term stress group than in the short-term stress and control groups. CONCLUSION: Persistent systemic stress increases bone resorption during orthodontic tooth movement. Systemic stress may affect the rate of tooth movement during orthodontic treatment.

Natural frequency analysis of tooth stability under various simulated types and degrees of alveolar vertical bone loss.

The aim of this study was to test natural teeth stability under various simulated types and degrees of alveolar vertical bone loss, as well as to assess the role that the surrounding bone played for maintaining tooth stability. A three-dimensional finite element model of the human maxillary central incisor with surrounding tissue, including periodontal ligament, enamel, dentin, pulp, and alveolar bone, was established. One side and multiple vertical bone loss were simulated by means of decreasing the surrounding bone level apically from the cemento-enamel junction in 1 mm steps incrementally downward for 10 mm. Natural frequency values of the incisor model with various types and degrees of bone loss were then calculated. The results showed that, with one-sided bone resorption, the model with labial bone loss had the lowest natural frequency decreasing rates (8.2 per cent). On the other hand, in cases of multiple bone loss, vertical bone resorption at the mesial and distal sides had more negative effects on tooth stability compared to vertical bone losses on facial and lingual sides. These findings suggest that the natural frequency method may be a useful, auxiliary clinical tool for diagnosis of vertical periodontal diseases.

Treatment with tacrolimus enhances alveolar bone formation and decreases osteoclast number in the maxillae: a histomorphometric and ultrastructural study in rats.

Recent studies have suggested that tacrolimus monotherapy is a beneficial therapeutic alternative for the normalization of cyclosporin-induced bone loss in animal models and humans. The mechanism accounting for this action is unclear at present. In the present study, we attempted to determine the effect of tacrolimus monotherapy on alveolar bone using histological, histomorphometric and transmission electron microscopy (TEM). Groups of rats (n=10 each) were treated with either tacrolimus (1mg/kg/day, s.c.) or drug vehicle for 60 days. Fragments containing maxillary molars were processed for light microscopy to investigate the alveolar bone volume, trabecular separation, number of osteoclasts and osteoblasts, and transmission electron microscopy to investigate their ultrastructural basic phenotype. Treatment with tacrolimus monotherapy during 60 days may induce increases in alveolar bone volume (BV/TV,%; P<0.05) and a non-significant decrease in trabecular separation (Tb.Sp,mm; P>0.05), represented by a decrease in osteoclast number (N.Oc/BS; P<0.05) and maintenance of osteoblast number (N.Ob/BS; P>0.05). Osteoblasts were often observed as a continuous layer of active cells on the bone surface. Osteoclasts appeared to be detached from the resorbed bone surface, which was often filled by active osteoblasts and collagen-rich matrix. Moreover, osteoclasts in the treated group were frequently observed as inactive cells (without ruffled border, clear zone and detached from the bone surface). Within the limits of the present study, we conclude that tacrolimus leads to an increase in alveolar bone formation, which probably exerts action on osteoclasts. Tacrolimus could, therefore, play a crucial role in the control of both early osteoclast differentiations from precursors, as well as in functional activation.

Three-dimensional finite elemental analysis of zygomatic implants in craniofacial structures.

The objective of this study was to analyse stress distribution in craniofacial structures around zygomatic osseointegrated implants. An integrated system for Digital Imaging and Communications in Medicine (DICOM) data were utilized to create a three-dimensional model of craniofacial structures. The amount and distribution of the main stresses were compared using three-dimensional finite elemental analysis. The system allowed visual confirmation and analysis of stress distribution as well as the convenient and simple construction of a digital biomechanical model that provided details of anatomical structures in the regions of interest. Zygomatic implants with or without connected implants supporting the superstructure were compared. Stresses in severely resorbed maxillae with connected implants were not concentrated around the alveolar bone supporting the zygomatic implants. Stresses where there were no connected implants tended to be generated in the zygomatic bone, at the middle part of the zygomatic implant and at the joint of the fixture-abutment. Stress due to occlusal forces is mainly supported by the zygomatic bone, is transferred predominantly through the infrazygomatic crest, and is divided between the frontal and temporal processes of the zygomatic bone in different directions.

Tooth development included in the multifocal jaw lesions of Langerhans cell histiocytosis.

Many cases demonstrating the oral manifestations of Langerhans cell histiocytosis (LCH) have been reported; however, tooth development in jaw lesions has rarely been mentioned. This paper reports the case of a 3-year-old Japanese girl with LCH suffering from multiple osteolytic lesions of the skull and jaw bones. She was referred to our paediatric clinic because of swelling of the mucogingival folds in the upper and lower primary molar regions. The patient responded well to steroid therapy and the osteolytic lesions resolved. There was an accompanying development of permanent tooth germs included in the lesions. Langerhans cell histiocytosis in children usually has a long-term clinical course and paediatric dentists should be involved with oral health care for affected patients.

[Nasopalatine canal cyst: 4 cases and a review of the literature]. / Kyste du canal nasopalatin. A propos de 4 cas, revue de la littérature.

OBJECTIVES: Nasopalatine cyst (NPC) is the most common epithelial and non-odontogenic cyst arising in the maxilla. It is nevertheless generally underestimated by ENT surgeons. The purpose of our report was to provide details about the pathophysiology, diagnosis and treatment of NPC. MATERIAL AND METHODS: Our study was based on a retrospective analysis of four cases and a review of the literature. RESULTS: From January 2002 to March 2003, four patients (3 males and 1 female, mean age 43 Years) were treated for NPC at the ENT Department of Grenoble University hospital. One patient had received prior treatment. Symptoms were a palatine mass on the midline of the hard palate behind the central maxillary incisors in two patients, and a superior vestibular mass in the two others. Diagnosis was established on the basis of the CT-scan and histological findings. Excision was performed under general anesthesia in all four patients. Median hospital stay was four days (3-5 days). There was no post-operative complication. Median follow-up was 10 Months. CONCLUSION: NPC is arises from embryological tIssue. It must be differentiated from radicular cyst. Diagnosis is based on radiographic and histological results. Treatment consists in enucleation. Surgical access depends on the size of the cyst and its anterior or posterior extension. Excision must be total to avoid relapse which may occur after five Years. Long-term follow-up is essential.

[The analysis of masticatory efficiency after maxillofacial prosthetic treatment for unilateral maxillary defect].

OBJECTIVE: To evaluate the clinic results of maxillofacial prosthetic treatment for unilateral maxillary defect. METHODS: Masticatory efficiency was tested before and after maxillofacial prosthetic treatment for unilateral maxillary defect. RESULTS: There was significant difference between one week, one month, three months after treatment and before treatment(F = 0.635, P = 0.002). Masticatory efficiency was increased by 59.98% after one month. CONCLUSION: Maxillofacial prosthetic treatment can significantly increase the masticatory efficiency of unilateral maxillary defect. It remains stable one month later.

Idiopathic osteosclerosis of the jaws followed through a period of 20-27 years.

AIM: The aim of the present study was to examine the prevalence of idiopathic osteosclerosis (IO) in a baseline sample and to follow the patients through an extended period of time. METHODOLOGY: The sample consisted of 210 patients treated in a dental school and having a complete series of intraoral radiographs at the time of treatment and at a follow-up 10-17 years later. A further 10 years later, 130 patients had another follow-up. RESULTS: Sixteen of the 210 patients were found to have IO, mostly in the mandibular molar and premolar regions. Fourteen had one lesion, one had two lesions and one had three lesions. The mean age of these patients was 47 years as compared to 44 years for the rest of the patient group. No sex predilection was found. At the first follow-up, one lesion had disappeared, one had reduced in size and one new lesion appeared. At the second follow-up, eight patients with IO could be re-examined. Two lesions, unchanged at the first follow-up, had reduced in size and two new lesions appeared. In the area of the new lesions, residual roots were observed in the earlier radiographs. CONCLUSION: Our findings support the theory that IO lesions should be considered anatomical variants. In some cases, however, a local aetiological agent may cause development of structures with an identical appearance.