Lingual Plate Research Articles

A 30-Year Follow-Up of Partial Removable Dental Prostheses in a University Dental School Setting.

To describe the pattern of partial removable dental prosthesis (PRDP) designs over a 30-year period in a cohort of patients from the Université de Montréal, Faculty of Dentistry and to examine the effect of this design in PRDP complaints and the required treatment in a subsample of the patients' cohort. In this retrospective descriptive study, 1380 PRDP laboratory prescriptions (1980-2009) and 131 PRDP clinical complaint forms (2006-2008) from the archives of the undergraduate prosthodontics clinic of Université de Montréal were selected. Data on type of PRDPs, design, PRDP-related complaints, and the need for treatment were collected. Descriptive statistics and bivariate statistical analyses were conducted. U-shaped (54%) and lingual plate (94%) were the most common major connectors used in the maxillary and mandibular arch, respectively. In 95% of laboratory prescriptions, circumferential clasp was the design for the retainers. Fracture of PRDP components was the most common (41%) complaint. Most of the complaints (68%) were made by PRDP wearers having natural teeth in the opposing arch. There was a significant relationship between fracture of PRDP components and having opposing natural teeth (p = 0.002). Seventy-three percent of PRDP-related complaints were manageable only by minor treatments such as repair, readjustments, and oral hygiene instructions. Changes in the design of PRDPs were noticeable at the Université de Montréal since 1980, but there has been little change in the last 20 years. Biomechanical concepts and optimum hygiene were the basic elements in the design of RDPs in this university-based dental school setting. The majority of the complaints were treated by minor treatments.

RETROSPECTIVĂ DIN LITERATURĂ PRIVIND TOPOGRAFIA CANALULUI MANDIBULAR

This study represents a review of the literature on the topography of the mandibular canal. A PubMed and MedLine search was performed alongside with a hand search of specialised books. 193 abstracts, 41 full articles and 12 books were used for the study, out of which 93 were included in the references list. The region of the mandibular body behind the first premolar contains the mandibular canal, which presents a certain trajectory in relation with the lateral teeth apices and in relation with the buccal and lingual cortical plates. The mandibular canal is considered an important anatomic landmark that can influence the success of endodontics, oral surgery procedures and implant therapy.

Ameloblastic Carcinoma of the Mandible: a Rare Case Report

Ameloblastic carcinoma is characterized by rapid, painful expansion of the jaw, unlike conventional ameloblastoma. The tumor most frequently involves the mandible. The expanding lesion causes perforation of buccal and lingual plates of the jaw and invades the surrounding soft tissue. Rapidly growing large tumor mass may cause tooth mobility. Mandibular tumor involving mental nerve leads to the paresthesia of the nerve. Maxillary tumor can produce fistula in the palate and paresthesia of infraorbital nerve. Although rare, these lesions have been known to metastasize mostly to the regional lymph nodes or lungs. Because the lesion is usually found unexpectedly after an incisional biopsy or the removal of a cyst, a guide to the differential diagnosis is usually not useful. The tumor cells resemble the cells seen in ameloblastoma, but they show cytologic atypia. Moreover, they lack the characteristic arrangement seen in ameloblastoma. Direct extensions of the tumor, lymph node involvement have been reported. A case of ameloblastic carcinoma in a 60 year old man of typical aggressiveness and extensive local destruction is reported here and its clinical, radiographical and histological features are discussed.

Comparison of Clinical and Histologic Outcomes of Zirconia Versus Titanium Implants Placed in Fresh Sockets: A 5-Month Study in Beagles.

Purpose: This study evaluated the clinical and histomorphometric results of titanium (Ti) and custom-made zirconia (Zr) implants placed into fresh extraction sockets in beagles that did not receive oral hygiene attention or a softened diet during postoperative healing. Materials and Methods: The roughness of the Ti and Zr implant surfaces was assessed by confocal microscopy. In eight beagle dogs, four implants each (two Ti and two Zr) were placed in the distal sockets of the third and fourth premolars with the implant shoulder at the bone crest and subjected to submerged healing. Standardized radiographs were taken after placement and 5 months after placement (at sacrifice). Histologic and histomorphometric measurements were performed on nondecalcified histologic sections. The main outcome measures included implant survival, bone-implant contact (BIC), and bone loss on the buccal and lingual plates. Results: Topographic analysis showed significant differences between the Zr and Ti surfaces. Roughness was higher for Ti than for Zr implants, kurtosis was close to 3 for Ti, and skewness was negative for Zr. After 5 months, the mean BIC was similar for the Zr (57.0% ± 15.2%) and Ti (56.5% ± 14.4%) implants, and the most severe bone loss site was observed on the buccal wall. The risk of failure was significantly higher for the Zr (43.8%) than for the Ti (12.5%) implants. Conclusion: The implant failure rate for the Zr implants was 3.5 times higher than that of the Ti implants. This may be partially explained by the less favorable topography of the Zr implants, which had, on average, significantly lower roughness (Ra = 0.85 ± 0.04 μm), negative skewness of the surface profile (-1.56 ± 0.27), and higher kurtosis (7.88 ± 1.99).

Multivariate assessment of site of lingual nerve

Injury to the lingual nerve can cause debilitating symptoms. The nerve lies in the retromolar region and its anatomical site can vary within patients and according to sex, age, and dentate status. To our knowledge, no previous studies have recorded its course from multiple bony landmarks and examined the association between age, dentate status, and sex, in the same sample. We dissected 30 white cadavers and took primary and secondary reference points from the internal oblique ridge. We measured the distance to the lingual nerve in sagittal, vertical, and horizontal planes, and recorded the position where the nerve was closest to the lingual plate. We dissected 46 hemimandibles (23 male, mean age 79 years, range 52–100) of which 26 were from the left side. Mean (SD) sagittal, vertical, and horizontal distances from the primary reference point were 9.29 (3.41)mm, 9.15 (3.87)mm, and 0.57 (0.56)mm, respectively. Mean (SD) vertical and horizontal distances from the secondary point were 7.79 (5.45) mm and 0.59 (0.64)mm, respectively. The proximity of the nerve to the lingual plate varied widely (range −13.00 to 15.17mm from the primary reference point). Dentate status was significant for the sagittal measurement from the primary point, and the vertical measurement from the secondary point. Differences in age, sex, or site of the contralateral nerve were not significant (n=16 pairs). Our findings suggest that the site of the nerve is consistent between and within subjects for sex and age, but not for dentate status. The association between the nerve and the lingual plate varied, which suggests that care must be taken when operating in the area.

Osteonecrosis of the mandible in a patient with lung adenocarcinoma undergoing anti‐angiogenic therapy with bevacizumab

AbstractBevacizumab is a recombinant monoclonal humanised antibody, designed to inhibit the binding ability of vascular endothelial growth factor to its receptor. Recently bevacizumab has been implemented in the treatment protocols against certain types of cancer. A 63‐year‐old Caucasian male patient with lung adenocarcinoma, presented in the OMFS clinic with a non‐healing lesion of the mucosa at the region of tooth 17 including areas of exposed bone and presence of pus along with paraesthesia, distributed to the left side of the lower lip. The patient had undergone two chemotherapy cycles including IV bevacizumab which was administered once every 3 weeks in a dose of 15 mg/kg. The radiographic examination (Orthopantomogram, ConeBeamComputedTomography) revealed cortical erosion of the lingual plate on the posterior left mandibular region with involvement of the inferior alveolar nerve. A diagnosis of stage II osteonecrosis was established that was later confirmed by the histopathological evaluation and ruled out possible bone metastases. After 2 weeks of treatment with an empiric antibiotic regimen, the necrotic lesion was removed with surgical debridement and without complications. In the 6 months follow‐up the diseased area was fully healed and the paraesthesia was improved.

Keratocystic Odontogenic Tumor (KCOT/OKC)-Clinical Guidelines for Resection.

There is no clinical consensus for the treatment of Keratocystic Odontogenic Tumor (KCOT). KCOTs are regarded as benign aggressive tumors and resection is usually considered as a last option. We review the clinical indications for resection based on a case series. This is a retrospective study of patients with KCOT treated in a single unit over 17years. Eighty patients were identified, of which 12 (15%) underwent resection. The remaining 68 patients were managed by enucleation and curettage, enucleation with peripheral ostectomy, or decompression with secondary enucleation. Data extracted includes gender, age, race, location, previous treatment for the lesion, surgery and outcome/follow up. Twelve patients treated by resection were identified. The location in the ten benign resected KCOTs was either the mandibular ramus or the posterior maxilla. All mandibular KCOTs exhibited perforation of the lingual plate and involvement of the pterygoid musculature. Seven of the ten cases were recurrent KCOTs and three had no prior treatment. Two had malignant changes in the KCOT and were also resected. The primary reason for resection of KCOT was involvement of the pterygoid muscles. The presence of malignant change was a separate indication for resection.

Is cone-beam computed tomography diagnostic for anterior Stafne bone cyst: Report of a rare case

Introduction: The incidence of anterior Stafne bone cyst (lingual mandibular bone defect, static bone cyst, latent bone cyst, developmental submandibular gland defect of the mandible) has been estimated to between 0.009% and 0.3%. It is characterized by a round or ovoid, well-defined border, unilocular radiolucency. Most of anterior Stafne bone defects were located between the cuspid and the first molar, but a few cases have been reported in the incisor area. Case Report: We present a 48-year-old man with anterior Stafne bone defect in the incisor area diagnosed by using cone-beam computed tomography (CBCT). Discussion: CBCT can be a confirmatory imaging technique to detect anterior mandibular bony configurations such as Stafne bone cavity with the lingual cortical plate being spared.

An unusual case of large, destructive stafne bone cavity with computed tomography findings

Stafne bone cavity (SBC) is an asymptomatic lingual bone depression that usually described as a small oval homogenous radiolucency in the posterior mandibular region. The radiographic appearance and location of the SBC are characteristic and easily identified. The diagnosis can be confirmed by computed tomography (CT) scans, magnetic resonance (MR) imaging or sialography. This report describes a case of SBC in a 61-year-old male asymptomatic patient, presenting as a radiolucency in the left mandibular body with loss of buccal and lingual cortical plates on three-dimensional CT scan.

The prevalence of mandibular incisive nerve canal and to evaluate its average location and dimension in Indian population.

Aim:The aim of this study was to find the prevalence of the mandibular incisive canal, evaluate its location and dimensions using cone beam computer tomography (CBCT) in Indian population.Materials and Methods:CBCT scan images of 120 subjects were analyzed for the presence of the mandibular incisive canal, its location, size, and its length. The distance between the incisive canal and the buccal and lingual plate of the alveolar bone, and the distance from the canal to the inferior border of the mandible were also measured to position the canal in the mandible.Results:About 71.66% of the CBCT scans of Indian subjects examined showed the presence of the Incisive canal, of which 48.33% exhibited canals bilaterally and 23.33% showed unilateral canals. 28.33% of the subjects CBCT scans did not exhibit the presence of incisive nerve canal. The average length of the incisive canal was 10.173 mm. The average diameter of the Incisive canal in the CBCT scans was 2.578 mm. The distance from the Inferior border of the mandible to (a) the origin of the Incisive canal was 9.425 mm and (b) to the apex of the Incisive canal was 9.095 mm. The distance from the buccal cortex of the mandible to (a) the origin of the incisive canal was 1.48 mm and (b) to the apex of the incisive canal was 4.476 mm. The distance from the lingual cortex of the mandible to (a) the origin of the incisive canal was 4.464 mm and (b) to the apex of the incisive canal was 5.561 mm.Conclusion:The presence, location, and dimensions of the mandibular incisive canal are an additional required data that needs to be elicited before planning an inter-foraminal placement of implants.

Immediate bleeding complications in dental implants: a systematic review.

Objective: A review is made of the immediate or immediate postoperative bleeding complications in dental implants, with a view to identifying the areas of greatest bleeding risk, the causes of bleeding, the length of the implants associated with bleeding, the most frequently implicated blood vessels, and the treatments used to resolve these complications. Material and Methods: A Medline (PubMed) and Embase search was made of articles on immediate bleeding complications in dental implants published in English up until May 2014. Inclusion criteria: studies in humans subjects with severe bleeding immediately secondary to implant placement, which reported the time until the hemorrhage, the implant lenght, the possible cause of bleeding and the treatment. Exclusion criteria: patients receiving anticoagulation treatment. Results: Fifteen articles met the inclusion criteria. The area with the largest number of bleeding complications corresponded to the mandibular canine. The cause of bleeding was lingual cortical bone perforation during implant placement, with damage to the sublingual artery. The implants associated with bleeding were those measuring 15 mm in length or more. Management focused on securing the airway (with intubation or tracheostomy if necessary), with bleeding control. Conclusions: It’s important to pay special attention when the implants are placed in the mandibular anterior zone, especially if long implants are used. The most frequently cause of bleeding was the perforation of the lingual plate. Treatment involves securing the airway, with bleeding control. Key words:Hemorrhage, complications, immediate, bleeding, dental implants.

Attachment Rate of the Inferior Alveolar Nerve to Buccal Plate During Bilateral Sagittal Split Osteotomy Influences Self-Reported Sensory Impairment

This study was aimed to investigate a modified buccal osteotomy technique and whether the integrity of the lingual part of the lower border influences the attachment of the neurovascular bundle to the proximal segment of the mandible during a sagittal split osteotomy without increasing the number of bad splits. The presence of self-reported sensibility disturbance in the lower lip at the last follow-up visit was assessed. This study included 220 and 133 patients with bilateral sagittal split osteotomy undergoing the classical and the new modified buccal osteotomy techniques, respectively. In the new technique, the lower border is divided into a lingual fragment that remains incorporated in the tooth-bearing fragment and a buccal fragment that comes with the proximal fragment (buccal plate). In the classical technique, the inferior alveolar nerve was attached to the proximal segment of the mandible in more than one third of operation sites (36.36% on the right and 40.91% on the left) compared with less than one fourth of the operation sites using the new technique (9.73% on the right and 23.01% on the left). The overall figure of self-reported changed sensibility was 09.40% (12/128) in the new technique compared to 15.12% in the classical technique. We present a suitable improvement to the classical buccal osteotomy technique that allows less manipulation and injury of the inferior alveolar nerve with consequent reduction in self-reported postoperative changes in lower lip sensation

The mandibular incisive canal and its anatomical relationships: A cone beam computed tomography study.

BackgroundTo avoid postoperative injuries in the interforaminal region, presence of the Mandibular Incisive Canal (MIC), its extension and canal positioning in relation to the cortical bone and alveolar process were investigated by cone beam computed tomography (CBCT). Material and MethodsOne hundred CBCT examinations obtained by means of the i-CAT CBCT imaging system were analyzed in multiple-plane views (axial, panoramic and cross-sectional) and three-dimensional representations were performed using iCAT CBCT software. The MIC was evaluated for its presence, measurement and proximity to the buccal and lingual plates, alveolar process and inferior border of the mandible.ResultsThe MIC was visible in all (100%) CBCT images. The mean length of MIC was 9.8 ± 3.8 mm. The distances between the canal and buccal plate, as well as between the canal and lingual plate of the alveolar bone were 4.62 ± 1.41 mm and 6.25 ± 2.03 mm, respectively. The distances from the canal to the alveolar process, and to the inferior border of the mandible were 10.25 ± 2.27 mm and 7.06 ± 2.95 mm, respectively.ConclusionsDue to the high prevalence of MIC, its variation in length and distance up to the cortical bone, suggested that preoperative radiographic evaluation of the MIC must be carried out case-by-case using CBCT, which could clearly show the three-dimensional structure and adjacent structure of the MIC. Key words:Diagnosis, anatomy, cross-sectional, tomography.

Measurement of the Lingual Position of the Lower Third Molar Roots Using Cone-Beam Computed Tomography

The aim of this study was to evaluate the distance between the roots of the impacted third molars and the floor of the mouth to predict the risk of lingual root displacement during surgery. Thirty-one patients (5 men and 26 women) were evaluated for this study using cone-beam computed tomography (CBCT). The teeth were grouped according to their position on the orthopantomogram as vertical, mesioangular, horizontal, and distoangular. The distance between 2 points on the roots and lingual soft tissues was measured. The average distance between the apex of the root, which is in the most lingual position, and the lingual cortical plate was 1.03 mm. The average distance between the most lingual point on the apical half of the root, which is in closer proximity, and the lingual cortical plate was 0.65 mm. The distance between the apices and the lingual plate is very short, which allows displacement of broken roots or teeth, especially when the lingual plate is perforated.

Rehabilitación con coronas completas de metal-cerámica y prótesis parciales removibles convencionales

El tratamiento se realizó en un paciente de sexo femenino de 67 años, con buen estado de salud general, portadora de prótesis removible superior incómoda para sus funciones fisiológica y estética. Al examen presenta PPR (prótesis parcial removible) superior de marcado desgaste incisal y oclusal, soporte y retención deficiente, disminución de la DVO (dimensión vertical oclusal), pérdida de contorno facial, edentulismo superior clase II modificación 2 de Kennedy, rebordes conservados, presencia de piezas 1.7, 1.3 y 2.3; edentulismo parcial inferior clase III modificación 1, sin aditamento protésico, rebordes muy reabsorbidos, presencia de piezas 3.8, 3.4, 3.3, 3.2, 3.1, 4.1, 4.2, 4.3, 4.4, 4.5 y 4.8. Se restauró la DVO confeccionando coronas metal cerámica con islas de metal para los apoyos oclusales y brazos recíprocos en los pilares de las piezas 1.7, 3.8 y 4.5. ; y de placas linguales sobre los cíngulos de la piezas 1.3 y 2.3., de la PPR superior e inferior respectivamente. Se construye la morfología oclusal dándole over jet y over bite, desoclusión canina y protección mutua, con cúspides de 30º. Estéticamente se procedió a restablecer el contorno vestibular superior perdido, con la línea de la sonrisa específica.

Pre-operative assessment of relationship between inferior dental nerve canal and mandibular impacted third molar in Saudi population.

To study the correlation between the position of the inferior dental (ID) nerve canal and the angulation of impacted mandibular third molars using dental cone beam computed tomography (CBCT). The study considered 100 impactions in 85 patients (60 males, 25 females), for whom an initial panoramic radiographic assessment had revealed that the ID canal and the lower 3rd molar were in close proximity. A CBCT scan of each patient was carried out to assess how the ID nerve canal position influenced the class and position of impaction, angulation of impaction, and bone contact. Class I position B impactions were found in the majority of cases, where the position of the ID canal was approximate to the lingual plate and inferior to the 3rd molar (85.7%). The results were statistically significant (p=0.001). 96% of the ID canals showed bone contact. Of these, 77.1% of ID canals exhibited lingual bone contact, inferior to impaction. The results were statistically significant (p=0.001). Horizontally angulated impactions were most common in the mandible, and significantly associated with lingual and inferior positioning of the ID canal (76.2%). Our sample population most commonly exhibited horizontally angulated class I position B impactions of the mandible. The position of the ID canal significantly influenced the type of impaction and bone contact.

Stafne bone cavity: An unusual case with involvement of the buccal and lingual mandibular plates

Lingual mandibular bone defects, also known as Stafne bone cavity (SC), are unilateral asymptomatic radiolucencies, generally seen in the mandibular angle, below the inferior alveolar canal. Although panoramic radiographies normally offer enough information to make a correct diagnosis, additional studies are often required, especially in atypical cases. The present report describes an atypical presentation of a Stafne’s bone cavity in a 78 years-old male patient. In this particular case, an asymptomatic and radiolucid lesion was observed during a routine dental examination. The computed tomography (CT) showed an involvement of both lingual and buccal mandibular plates producing a tunnel-like lesion. No history of mandibular trauma or surgery was refered. An additional magnetic resonance imaging (MRI) was made to discard submandibular gland pathology and to confirm the diagnosis. Since SC is asymptomatic and nonprogressive, a conservative approach based in clinical and radiological follow-ups was considered to be the most suitable treatment option. Key words:Stafne bone cavity, lingual mandibular bone defect, case report.

Impact of orthodontic decompensation on bone insertion.

There has always been concern in determining the relationship between orthodontic tooth movement and the consequent biological costs to the periodontium and tooth root. The possibility of evaluating the tooth and bone morphology by CBCT allows more accurate analysis of qualitative and quantitative aspects of these processes. This paper presents a case report of a 20-year-old male patient with Class III malocclusion and hyperdivergent facial pattern, who was surgically treated. A significant amount of labial movement of mandibular incisors was performed during orthodontic treatment before surgery. CBCT was used for evaluation of buccal and lingual bone plates before and after tooth decompensation. The changes in the bone insertion level of maxillary and mandibular incisors in the present case encourage a reflection on the treatment protocol in individuals with dentoskeletal discrepancies.

Ameloblastic carcinoma: Report of a rare case

Ameloblastic carcinoma is a rare odontogenic tumor exhibiting histological evidence of malignancy in the primary or recurrent tumor. It is characterized by rapid, painful expansion of the jaw, unlike conventional ameloblastomas. The tumor most frequently involves the mandible. The expanding lesion causes perforation of the buccal and lingual plates of the jaw and invades the surrounding soft tissue. Rapidly growing large tumor mass may cause tooth mobility. A mandibular tumor involving the mental nerve leads to paresthesia of the nerve. A maxillary tumor can produce a fistula in the palate and paresthesia of the infraorbital nerve. Most ameloblastic carcinomas are presumed to have arisen de novo with a few cases of malignant transformation of ameloblastomas. Although rare, these lesions have been known to metastasize, mostly to the regional lymph nodes or lungs. A case of ameloblastic carcinoma in a 60-year-old man is reported here and its clinical, radiological and histological features are discussed.

Particulate bone matrix usage for alveolar bone conservation

Different filling materials have been used in an attempt to repair bone loss situations. Objective: The present study aimed to examine the effect of a bone matrix in post-extraction remodelling of the alveolar bone, and to perform a histomorphometric analysis of the residual alveolar ridges in Wistar rats.Material and Methods: Both rat first lower molars were extracted and the right alveoli were filled with particles of a bone matrix with mineral components (MO-UNC) (experimental group, EG). The left alveoli were used as a control group (CG). The animals were sacrificed at 0 hrs, 15, 30 and 60 days after extraction, and the samples were processed. Histological sections were made at the level of the mesial alveolus of the first lower molar.Repair of the alveoli was histologically evaluated and a histomorphometric study of total alveolar volume (TAV), height of the buccal plate (Bh), height of the lingual plate (Lh) and percentage of osseointegration (OI) of the particles was performed to compare the residual ridges of CG with those of the EG. Statistical analysis of the data was performed. Results: In the cases of the experimental group, newly-formed bone tissue was identified around the MO-UNC particles (osseointegration). Histomorphometric data indicate that, at 60 days post-extraction, TAV was significantly greater for EG when compared with CG (p<0.05) and the percentage of osseointegration of the particles increased as a function of time (57.6 %, 90.5% y 95.5%, for EG at 15, 30 y 60 days respectively). Conclusions: The bone matrix (MO-UNC) evaluated in this study is an osteoconductive material that prevents the collapse of post-extraction alveolar bone.