Alveolar Canal Research Articles

Alteration in blood gases in cats naturally infected with Aelurostrongylus abstrusus

Four cats were presented with respiratory signs and first-stage larvae of Aelurostrongylus abstrusus were found in faecal samples. Anthelmintic treatment was given to the infected cats and venous blood gases were analysed during the treatment period. Blood gas analysis suggested hypoventilation and respiratory acidosis in infected cats. Hypoventilation may be the result of airway obstruction by adults and larvae in respiratory bronchioles and the alveolar canals. The blood gas values had returned close to the physiological range by two months after treatment. Assessment of respiratory acidosis may aid development of additional treatment methods in cats infected with A. abstrusus.

CT scan study of the mandibular nerve intra-mandibular path

It is mandatory to know the anatomic path of the mandibular nerve and its intra-mandibular connections for numerous odontology, stomatology, and maxillofacial surgical procedures. We present a computed tomography study of the mandibular nerve intra-mandibular path. The computed tomography of 14 mandibles was performed (vestibulo-lingual cross-section) and four landmarks were defined behind the mental foramen. At each landmark, we measured the distance between the alveolar canal and the two cortical layers in the vestibulo-lingual plane, and the distance between the alveolar canal and the alveolar crest, and the inferior border of the mandible in the vertical plane. In the vestibulo-lingual plane, the mandibular nerve is located close to the vestibular cortical layer, then to the lingual cortical before it exits. In the crestal plane, it is located at the superior third of the inferior border of the mandible. In spite of anatomical variability, there is a globally common path which means that the utmost caution should be taken by performing systematic imaging before undertaking any surgery close to the nerve.

Correlation of Radiographic Signs, Inferior Dental Nerve Exposure, and Deficit in Third Molar Surgery

To identify the specific radiographic signs on orthopantomograms that are positive predictors of intraoperative inferior dental nerve (IDN) exposure and postoperative IDN deficit in lower third molar surgery. A prospective clinical cohort of patients with lower third molars with specific radiographic signs showing a close proximity of the roots to the IDN who underwent total excision at our center from June 2006 to June 2008 were recruited as the study group. The prevalence of intraoperative IDN exposure and postoperative IDN deficit were recorded. The correlations between the various radiographic signs and the prevalence of IDN exposure and deficit were analyzed. The prevalence of IDN deficit in the sample was compared with an age-, gender-, and operator experience-matched control group of patients who had undergone lower third molar surgery without any of the radiographic signs present. Patients with a total of 178 lower third molars with 1 or more of the specific radiographic signs present were recruited as the study group. The prevalence of IDN deficit in the study group (5.1%) was significantly greater than that in the control group (0.56%; P = .01). In the study group, darkening of root and displacement of the inferior dental canal by the root were radiographic signs significantly related to IDN exposure (P = .001 and P = .019, respectively). Darkening of the root was the only sign significantly related to a postoperative IDN deficit (P = .016). When 2 or more radiographic signs were present, the risk of a postoperative IDN deficit was significantly increased (P = .001). Darkening of the root and displacement of the inferior dental canal by the root were positive predictors of intraoperative IDN exposure. Darkening of the root or the presence of 2 or more radiographic signs were positive predictors of a postoperative IDN deficit.

Darkening of Third Molar Roots: Panoramic Radiographic Associations With Inferior Alveolar Nerve Exposure

The aim of the present study was to examine the association between the darkening of the root on the preoperative panoramic radiograph and intraoperative inferior alveolar nerve (IAN) exposure. In the present study, 116 mandibular third molar surgical extraction cases with darkening of the third molar roots on the preoperative panoramic radiographs were selected for a case group, and 193 patients with one or more of the following "high-risk" signs, indicating a close spatial relationship between the root and dental canal, were selected for the control group: interruption of the white line, diversion of the canal, and/or narrowing of the canal. The correlation between the radiographic markers and IAN exposure was estimated using bivariate analysis. The IAN was visible in 47 (15.2%) of 309 intraoperative extractions. Darkening of the third molar roots was significantly associated with IAN exposure (P < .001). Those with both darkening and adjacent "high-risk" radiographic markers present simultaneously had a significantly greater risk of IAN exposure than those with darkening only (P < .001) or any other combination of multiple high-risk factors (P = .001). Significant differentiation between isolated darkening and darkening with both adjacent and high-risk signs seems to be essential in predicting IAN exposure.

Additive effect of a diode laser on the antibacterial activity of 2.5% NaOCl, 2% CHX and MTAD against Enterococcus faecalis contaminating root canals: an in vitro study

This in vitro study was performed to evaluate the effect of a diode laser and common disinfectants used in combination on mono-infected dental canals. One hundred and six single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After two weeks of incubation, samples were divided into two experimental groups (n = 48) and two control groups (n = 5). In the first group, the teeth were rinsed for 5 min with either sterile saline, 2.5% NaOCl, or MTAD, or for 1 min with 2% chlorhexidine gluconate (CHX). In the other group, samples were additionally irradiated with a 810-nm diode laser at 2 W output for 5 × 5 s. Intracanal bacterial sampling was done, and the samples were plated to determine the CFU count. In the first group, 2.5% NaOCl was as effective as 2% CHX and significantly more effective than MTAD (P < 0.008). In the second group, either MTAD, 2% CHX or 2.5% NaOCl in combination with laser treatment had a similar effect. Absence of growth was seen only for MTAD plus laser treatment. Complete elimination of E. faecalis was seen only for the combination of MTAD with diode laser irradiation. Combination therapy with MTAD irrigation and diode laser irradiation, within the parameters used in this study, can be recommended as an effective treatment option for complete elimination of E. faecalis from the root canal system.

Evaluation of bifid mandibular canals with cone-beam computed tomography in a Turkish adult population: a retrospective study

Knowing the anatomic location and also variations of the mandibular canal is especially important for surgical procedures on mandible such as dental implant surgery, impacted molar extraction and sagittal split ramus osteotomy. The purpose of this study was to clarify the incidence and location of bifid mandibular canals in an adult Turkish population to avoid complications during surgical procedures. A retrospective study using cone beam CT images was performed to evaluate bifid mandibular canal in mandible of 242 patients. Both right and left sides were studied (n = 484). Axial, sagittal, cross-sectional and panoramic images were evaluated, and three-dimensional (3D) images were also reconstructed and evaluated, as necessary. The course and length of bifid mandibular canals and the superior and inferior angles between canals were measured. Bifid mandibular canals were observed in 225 (46.5%) of 484 sides examined. The most frequently encountered type of bifid canal was the forward canal (29.80%), followed by the retromolar (28.10%) the buccolingual (14.50%) and the dental canal type (8.30%). Mean lengths of bifid canals were 13.6 mm in the right side and 14.1 mm in the left side. Mean superior angles were 139° on the right and 141° on the left side, whereas mean inferior angles were 38° on the right side and 32° on the left side. No statistically significant differences were found in the lengths or angles between the right and left sides and also for gender (p < 0.05). This study, which utilized CBCT images, uncovered a higher prevalence of bifid mandibular canals than what has been reported in previous studies using conventional radiography techniques.

Bifid mandibular canals: cone beam computed tomography evaluation

For surgical procedures involving the posterior mandible, it is important to be familiar with the details of the bifid mandibular canal. To our knowledge, there have been no systematic studies evaluating the bifid mandibular canal using sectional imaging. The purpose of this study is to evaluate the incidence and configuration of the bifid mandibular canal using cone beam CT. 252 patients (301 mandible sides) underwent cone beam CT between October 2004 and September 2005 and were included in this study. The cone beam CT images were evaluated for the presence and configuration of the bifid mandibular canal. The patterns of bifurcation were classified into four types according to the classification of Nortjé et al (Variations in the normal anatomy of the inferior dental (mandibular) canal: a retrospective study of panoramic radiographs from 3612 routine dental patients. Br J Oral Surg 1977; 15: 55-63). The diameter of the accessory canal was classified into two categories: 50% or more and less than 50% of the diameter of the main mandibular canal. Of the 301 subjects, 47 (15.6%) demonstrated a bifid mandibular canal. They were Type I in 2, Type II in 40, Type III in 0, and Type IV in 5 cases. The diameter of the accessory canal was greater than or equal to 50% of the main canal in 23, and less than 50% in 24 cases. On the basis of the cone beam CT, a bifid mandibular canal was found in 15.6% of cases, a markedly higher proportion than found in previous reports using panoramic images. Cone beam CT is considered a suitable modality for detailed evaluation of bifid mandibular canals.

Orthokeratinized odontogenic cyst in a Hong Kong community: the clinical and radiological features

The aim was to evaluate the principal clinical and conventional radiological features of a consecutive series of cases of orthokeratinized odontogenic cyst (OOC) affecting a Hong Kong Chinese community and to determine the outcome by follow-up. All cases were accompanied by appropriate radiography and were confirmed by histopathology. The clinical and conventional radiological presentations, differential diagnoses and outcomes of follow-up of five consecutive OOCs were reviewed. There were two males and three females. All affected the posterior sextant. The mean age at first presentation was 33.5 years. The mean of their period of prior awareness was 0.11 years. Swelling was the most frequent presenting symptom. All presented as well-defined corticated radiolucencies; three were unilocular and two were multilocular and all displayed expansion. This resulted in displacement and erosion of the lower border of the mandible in one case and the downward displacement past the lower border of a lateral cortex in two others. The inferior dental canal in each mandibular case exhibited both displacement and absence. The antrum was affected in a sole maxillary case. Four patients were followed up for a mean of 8.5 years. The fifth patient discharged himself shortly after surgery. No lesions recurred. OOCs in this community displayed an expansile character, but did not recur after moderately long follow-up. The time between the prior awareness of their disease and their presentation for diagnosis and treatment was, so far, the shortest for any lesion affecting the jaw in this Hong Kong Chinese community.

Anterior Stafne bone defect mimicking a residual cyst: a case report

Stafne bone defects (SBDs) are asymptomatic lingual bone depressions of the lower jaw that are frequently caused by soft tissue inclusion. The common variant of SBDs exists at the third molar region of the mandible below the inferior dental canal and has been mostly diagnosed incidentally during routine radiographic examination. The anterior variant of a SBD (ASBD) is relatively uncommon and is located in the premolar region of the mandible. Sublingual salivary glands are thought to be responsible for ASBDs. However, other structures such as lymphoid or vascular tissues might be associated with ASBDs. In the present report, an ASBD which was mimicking a residual cyst was diagnosed with the aid of a three-dimensional CT scan. ASBDs might be confused with other odontogenic or non-odontogenic pathologies because of their location and lower occurrence rate. Advanced imaging modalities, especially CT scans, are useful to assess such lesions in order to avoid unnecessary surgery.

Proteus Syndrome: A Rare Entity

ABSTRACT The Proteus syndrome is a rare congenital hamartomatous condition that is characterized by a wide range of malformations, sometimes involving the face. Common manifestations include partial gigantism, congenital lipomas, and plantar hyperplasia. In this report, we describe a case of an 18-year-old male patient with Proteus syndrome, who had pronounced hemifacial hypertrophy, exostoses in the left parietal region, and enlargement of the inferior alveolar nerve and mandibular canal in the affected region. The dental development of the affected left mandible and maxilla was characterized by extremely premature development and eruption of the permanent teeth. The proposed multidisciplinary management of the patient and a review of literature of the Proteus patients, who exhibited manifestation in the craniofacial region is discussed in this report.

Reverse Intra-oral Periapical Radiography For Mandibular Posterior Teeth

Aims: To satisfy the newly reverse modified intra-oral periapical projection, in order to reduce the pa-tient discomfort and eliminate gagging reflex during periapical radiography of the lower posterior teeth. Materials and methods: Twenty voluntaries patients have been used in this research aged between 20-25 years, each patient subjected for two intra-oral periapical radiographic examinations for lower posterior teeth (premolars and molars). The first radiographic exami-nation has been made with ordinary principles of intra-oral periapical radiographic projec-tion, while the second radiograph has been made with reverse modified principles of intra-oral periapical radiographic projection. Five independent examiners (two oral radiographer, oral surgeon, oral diagnosis and oral medicine), rated the two radiographic images obtained from both radiographic examination methods. Image quality was assessed by rating the visi-bility of five anatomical landmarks: tooth structures identification (enamel, dentin and root can-al system), bone trabiculation, mental foramen borders, inferior dental canal borders and lamina du-ra. Results: The data collected from the evaluation of the radiographic images obtained from both radiographic projections were analyzed by paired samples chi-square test, which shown no significant difference (P>0.05) in image quality obtained from both techniques for five selected structures. The bone trabeculae and the lamina dura given higher rating of total score with ordinary technique (54, 49 points respectively) when compared with reverse radi-ographic technique (47, 41 points respectively). The highest percentage of unrecognized shadow of mental foramen and the inferior dental canal with use of ordinary radiographic technique (40%, 30% respectively), while the other examined anatomic structures (tooth structure, bone trabeculae and lamina dura) can be identified clearly with both radiographic techniques. Higher percentage of gag reflex and pain discomfort was observed with ordinary technique projection (45%, 40% respectively) in comparison with reverse technique projec-tion (0%, 5% respectively). Conclusion: the reverse intra-oral periapical radiographic technique can be used accurately in the radiographic projection of the mandibular posterior teeth; with minimal pain discomforted and with eliminated gagging reflex initiation.

An unusual case of acute onset lower lip numbness

An 84-year-old Caucasian woman was referred by her primary care dentist to the authors' department with progressive lower lip numbness of 2 months' duration initially noticed by the patient during toothbrushing. The paraesthesia was initially intermittent but became permanent within 1 month. The patient had not sustained any injury to the jaws and no dental treatment had been provided before symptoms started. A course of empirical antibiotics had no impact. She was previously diagnosed with hypertension, ischaemic heart disease and atrial fibrillation for which she was prescribed lisinopril, valsartan, atorvastatin, digoxin and warfarin. She had no known allergies. She was a non-smoker and drank alcohol occasionally. She was the main carer for her husband who suffers from multiple sclerosis. Clinical examination revealed reduced sensation to light touch and pinprick in the distribution of the left mental nerve. No other cranial nerve abnormalities were noted. Apart from mild tenderness in the left buccal sulcus opposite the lower left first premolar and a polyp-like lesion on the lower left lip, no other intraoral abnormalities were found. Initial blood tests including full blood count, haematinics, liver and renal function, glucose, erythrocyte sedimentation rate and bone profile were performed to rule out possible systemic causes of mental paraesthesia and were unremarkable. A panoramic radiograph (Figure 1) showed generalized osteoporosis with a loss of the lower border cortex and inferior dental canal outlines bilaterally. Subsequent magnetic resonance imaging (Figure 2) revealed extensive T1 areas of low marrow signal throughout the skull vault, skull base, cervical vertebrae and the clavicles with the entire left side of mandible showing reduced T1 signal in keeping with mandibular marrow replacement. The appearances were consistent with extensive bone metastatic disease with marrow infiltration of the left side of the mandible involving the mental nerve. Further blood tests revealed normal immunoglobulins and absence of paraprotein. Oncological referral and further investigation including chest X-ray, whole body computed tomography scan and bone marrow aspiration and trephine confirmed a diagnosis of follicular lymphoma.

Étude tomodensitométrique du trajet intra-mandibulaire du nerf alvéolaire inférieur

It is mandatory to know the anatomic path of the lower alveolar nerve and its intramandibular connections for numerous odontology, stomatology, and maxillofacial surgeries. We present a computed tomography study of the lower alveolar nerve intramandibular path. The computed tomography of 14 mandibles was performed (vestibulolingual cross-section) and four landmarks were defined behind the mental foramen. At each landmark we measured the distance between the alveolar canal and the two cortical layers in the vestibulolingual plane, and the distance between the alveolar canal and the alveolar crest, and the inferior border of the mandible in the vertical plane. In the vestibulolingual plane, the alveolar nerve is located close to the vestibular cortical layer, then to the lingual cortical before it exits. In the crestal plane, it is located at the superior third of the inferior border of the mandible. In spite of anatomical variability, there is a globally common path which must lead to the greatest caution by performing systematic imaging before any surgery close to the nerve.

Implant radiography and radiology

The practitioner placing dental implants has many options with respect to pre-implant radiographic assessment of the jaws. The advantages and disadvantages of the imaging modalities currently available for pre-implant imaging are discussed in some detail. Intra-oral and extra-oral radiographs are generally low dose but the information provided is limited as the images are not three-dimensional. Tomography is three-dimensional, but the image quality is highly variable. Computed tomography (CT) has been the gold standard for many years as the information provided is three-dimensional and generally very accurate. However, CT examinations are expensive and deliver a relatively high radiation dose to the patient. The latest imaging modality introduced is cone beam volumetric tomography (CBVT) and this technology is very promising with regard to pre-implant imaging. CBVT generally delivers a lower dose to the patient than CT and provides reasonably sharp images with three-dimensional information. A comparison between CT and CBVT is provided. Magnetic resonance imaging is showing some promise, but the examinations are not readily available, generally expensive and bone is not well imaged. Magnetic resonance imaging is excellent for demonstrating soft tissues and therefore may be of great use in identifying the inferior dental nerve and vessels. All of the above technology is of little value if the information required is not obtained and so information is also provided on imaging of some of the vital structures. Of particular interest is the inferior dental canal, incisive canals of the mandible, genial foramina and canals, maxillary sinus and the incisive canal and foramen of the maxilla.

Leukaemic infiltration of the mandible in a young girl

This report presents a case of leukaemic infiltration of the mandible in a 10-year-old female of Sudanese extraction. The patient was in remission from acute lymphoblastic leukaemia when she presented with pain localized to the alveolar ridge overlying the unerupted lower right second permanent molar. Two days later, she developed right inferior alveolar nerve paraesthesia. Radiographic imaging demonstrated cortical line absence around the developing lower right second and third permanent molars, and distal displacement of the lower right third molar. In addition, the cortical outline of the right inferior dental canal lacked clarity. Biopsy confirmed leukaemia recurrence demonstrating the Philadelphia chromosome. Tailored chemotherapy was commenced, and a bone marrow transplant was carried out 12 weeks later. At 6-month dental review, the patient remained exceptionally well with no bone pain and normal sensation in the right lower lip. The importance of regular and long-term dental examination of patients with leukaemia is discussed.

Cemento-ossifying fibroma occurring in an elderly patient. A case report and a review of literature.

Cemento-ossifying fibromas (COF) are benign lesions affecting the jaws and other craniofacial bones. They commonly affect adults between the third and fourth decade of life. Radiographically, they appear as well-defined unilocular or multilocular intraosseous masses, commonly in the premolar/molar region of the mandible. The lesion is invariably encapsulated and of mixed radiolucent densities. The tumour may grow quite extensively, thus the term aggressive is some times applied. Their clinical, radiographical and histopathological features and those of fibro-osseous lesions are overlapping and may cause confusion in classification, diagnosis, and treatment. The histopathology is composed of fibrous tissues with calcified structures resembling bone or cementum. Surgical enucleation or resection is the treatment of choice. They are insensitive to radiotherapy and recurrences are uncommon. This case report presents a case of COF in 70 years old female patient that was asymptomatic. Clinically, there was an expansion of the buccal plate but not the lingual plate of the right mandible. The covering mucosa was normal and there was no tenderness or paraesthesia. Radiographically, the lesion extends superio-inferiory from the alveolar ridge to the area of inferior dental canal and mesiodistally from the premolar region to the retro-molar area. The lesion was of mixed radiolucent densities. The patient was followed up periodically for 5 years without any treatment. The patient continued to be asymptomatic with minimum changes. Occurrence of cemento-ossifying fibroma in patients over 60 years of age is unusual and had not been reported. The clinical, radiographic, histopathology and literature review are discussed.

Metastatic breast carcinoma discovered in a dentigerous cyst — a case report

This paper reports a patient with a history of breast cancer, who presented with altered sensation to the right lower lip and chin. An orthopantomogram showed a probable dentigerous cyst associated with an unerupted lower wisdom tooth, which was closely related to the inferior dental canal. The tooth and cyst were enucleated under general anaesthesia. The subsequent histopathology report concluded that the cyst contained metastatic adenocarcinoma from a primary breast tumour.

Third molar evaluation with cone-beam computerized tomography

Precise 3-dimensional localization of impacted mandibular third molars relative to the inferior dental canal (IDC) is critical to clinical management and surgical outcomes. Recently introduced dental 3-D volumetric imaging systems coupled with semi-automatic modeling techniques allows 3-D visualization of the IDC and the third-molar. Six impacted third molar sites were imaged with various 3-D volumetric imaging systems (NewTom 9000, Morita Accuitomo and Hitachi Mercuray). The spatial relationship of six impacted third-molars were visualized using imaging data obtained from these units. An interactive virtual model of a proposed third molar surgical site including the third molar and the inferior dental canal was developed.

Bioactive Calcium Phosphate Material for Dental Endodontic Treatment. Root Apical Deposition.

An injectable bone substitute (IBS) made of a suspension of Calcium phosphate ceramic was used to filled dental root canal after removing of canal pulp. The aim of this study was to verify the ability of calcium phosphate ceramic suspension to fill the apical zone of teeth ex vivo (n=40) and in vivo in a sheep model (n=8). The results showed that injection is possible with a good level of BCP granules at the end of the root dental canal with extracted tooth. In vivo, the presence of blood pressure due to the pulpectomy is a negative parameter to allow a good filling. The scanning electron microscopy revealed mineral formation at the apex level with mineral tissue conduction between the BCP granules but only one tooth showed a good apical filling with a good sealing. The sealing of the apex seems to depend of the amount of BCP granules. Other experiments with other animal models closer to a Human model have to be performed before human trials.

The Relationship of the Inferior Dental Canal to the Roots of Impacted Mandibular Third Molars in Jordanian Population

The aim of this study was to evaluate the topographic relationship between the inferior dental canals (IDCs) and the roots of impacted mandibular third molars. Preoperative orthopantomograms (OPGs) were examined and the proximity of the IDC to the roots of impacted mandibular third molars was categorized into the following: groups: superimposition, adjacent, perforation, grooving, notching, or none. The categories notching, grooving, and perforation were regrouped together and called the true relationship between the IDC and the root apices. The type of impaction, age, and sex of the patient were also noted. The positional category of 96.1% of the radiographs with bilateral impactions was identical on both sides of the mandible. Out of 2526 impacted mandibular third molars examined, 1146 (45.3%) belonged to the superimposition category, 663 (26.2%) were adjacent, 312 (12.3%) showed grooving, 78 (3.08%) showed notching, and 9 (0.35%) were actually perforating the IDC. The results showed 15.7% of the total cases were in true relationship with the IDC. There was a significant association (p = 0.000) between patient's age and true relationship. Identical positional relationship of the bilateral impacted third molars to the IDC was noted in 96.1% of the radiographs. The position of the IDC in relation to the roots of impacted third molars varied according to the patient's age.