2014 Jan-Mar; Vol 5, No 1
Graft-Free Sinus Augmentation Procedure: a Literature Review
J Oral Maxillofac Res 2014 (Jan-Mar);5(1):e1
Objectives: The restoration of edentulous posterior maxilla with dental implants is challenging due to a deficient posterior alveolar ridge. Over the last decade an advance in the graftless bone augmentation procedures had occurred where the space left beneath the Schneiderian membrane is filled with blood clot in order to produce bone formation. The aim of present article is to review the scientific literature with respect to bone formation in the sinus, after membrane elevation procedure, without using any bone substitutes.
Material and Methods: A comprehensive review of the current literature was conducted according to the PRISMA guidelines by accessing the NCBI PubMed database. The articles were searched from 1993 to 2013. English language articles with minimum one year patient follow-up and radiological and/or histological diagnostics of newly formed bone were included. Articles were excluded, if usage of bone graft or bone substitutes and/or usage of osteotome has been made during sinus lift operation.
Results: A total of 19 studies were included: 2 studies were related to the sinus membrane’s osteogenic potential, 3 to the histological evidence of bone formation in monkeys and humans, 12 to the radiologic evidence of bone gain, and 2 to the space-maintaining management. 100% of the reviewed articles presented with increased bone formation and high implant survival rates resulting from the graft-free technique.
Conclusions: It is clearly shown in the review that the potential of the maxillary sinus to heal and to form new bone without bone grafts or substitutes is of high nature.
Keywords: bone formation; dental implants; maxillary sinus floor augmentation; Schneiderian membrane.
Comparative Study of Skeletal Stability between Postoperative Skeletal Intermaxillary Fixation and No Skeletal Fixation after Bilateral Sagittal Split Ramus Osteotomy: an 18 Months Retrospective Study
J Oral Maxillofac Res 2014 (Jan-Mar);5(1):e2
Objectives: The purpose of the present study was to evaluate skeletal stability after mandibular advancement with bilateral sagittal split osteotomy.
Material and Methods: Twenty-six patients underwent single-jaw bilateral sagittal split osteotomy (BSSO) to correct skeletal Class II malocclusion. One group (n = 13) were treated postoperatively with skeletal elastic intermaxillary fixation (IMF) while the other group (n = 13) where threated without skeletal elastic IMF.
Results: The mean advancement at B-point and Pog in the skeletal elastic IMF group was 6.44 mm and 7.22 mm, respectively. Relapse at follow-up at B-point was -0.74 mm and -0.29 mm at Pog. The mean advancement at B-point and Pog in the no skeletal elastic IMF group was 6.30 mm and 6.45 mm, respectively. Relapse at follow-up at B-point was -0.97 mm and -0.86 mm at Pog. There was no statistical significant (P > 0.05) difference between the skeletal IMF group and the no skeletal group regarding advancement nor relapse at B-point or Pog.
Conclusions: Bilateral sagittal split osteotomy is characterized as a stable treatment to correct Class II malocclusion. This study demonstrated no difference of relapse between the skeletal intermaxillary fixation group and the no skeletal intermaxillary fixation group. Because of selection-bias and the reduced number of patients it still remains inconclusive whether to recommend skeletal intermaxillary fixation or not in the prevention of relapse after mandibular advancement.
Keywords: mandibular advancement; maxillomandibular fixation; orthognatic surgery; relapse; sagittal split ramus osteotomy; skeletal fixation.
Endoplasmic Reticulum Stress-Associated Chaperones, Bip/GRP78 and Calnexin are Overexpressed in Keratocystic Odontogenic Tumours
J Oral Maxillofac Res 2014 (Jan-Mar);5(1):e3
Objectives: Odontogenic keratocysts (OKCs) are developmental cysts that have been reclassified according World Health Organization (WHO), to keratocystic odontogenic tumours (KCOTs), a term that better reflects their neoplastic nature. The aim of present study is to evaluate the induction of stress of the endoplasmic reticulum and execution of the resulting unfolded protein response in keratinocystic odontogenic tumours.
Material and Methods: We analyzed by immunohistochemistry the expression of the chaperones BiP/GRP78 and calnexin in 24 cases of KCOTs. As controls, we have used 9 cases of periapical or radicular cysts (PACs) and 5 cases of Fibromas (FBs). The PACs and the FBs were included in the analysis, as PACs are the most common type of inflammatory odontogenic cysts of and FBs, as lesions of the connective tissue with unaffected epithelium.
Results: Analysis revealed a strong association between both BiP/GRP78 and calnexin expression and KCOTs: 18 out of 24 (75%) KCOTs expressed BiP/GRP78 as opposed to 1 out of 9 (13%) PACs, and none of 5 FBs evaluated (P < 0.001, x2-test). Calnexin was expressed in 11 out of 24 KCOTs (46%) but only one out of 9 (13%) PACs, and none of the 5 FBs analyzed (P < 0.001, x2-test).
Conclusions: Study results imply that induction of endoplasmic reticulum stress maybe of diagnostic value in keratocystic odontogenic tumours characterization. In addition to recent findings suggesting that endoplasmic reticulum stress plays a causative role in keratinization of epithelia, pharmacological interference with the execution of the unfolded protein response should be considered for the management of keratocystic odontogenic tumours.
Keywords: dental tissue neoplasms; endoplasmic reticulum stress; GRP78 protein; molecular chaperone; phosphoprotein pp90.
Factors Affecting the Formation, Severity and Location of White Spot Lesions during Orthodontic Treatment with Fixed Appliances
J Oral Maxillofac Res 2014 (Jan-Mar);5(1):e4
Objectives: The purpose of the present study was to investigate factors affecting the formation, severity and location of white spot lesions in patients completing fixed appliance therapy.
Material and Methods: A total of 45 patients (19 males and 26 females, mean age 15.81 years, standard deviation 2.89 years) attending consecutively Aberdeen Dental Hospital (ADH) between January and June 2013 to have their fixed appliances removed were given a questionnaire to elicit information regarding their dental care and diet. They were then examined clinically as well as their pre-treatment photographs to record treatment data and white spot lesion (WSL) location and severity using a modified version of Universal Visual Scale for Smooth Surfaces (UniViSS Smooth). Absolute risk (AR) and risk ratios (RR) were also calculated.
Results: The incidence of at least one WSL observed in patients was 42%, with males displaying a higher incidence than females. The highest incidence of WSLs was recorded on the maxillary canines and lateral incisors, and on the maxillary and mandibular premolars and first molars. The gingival areas of the maxillary and mandibular teeth were the most affected surfaces. Significant (P < 0.05) relationships were found between the presence of WSLs and the following factors: poor oral hygiene (OH), males, increased treatment length, lack of use of fluoride supplements, use of carbonated soft drinks and/or fruit juices and the use of sugary foods. Poor OH posed the highest risk of developing WSL (RR = 8.55).
Conclusions: 42% of patients have developed white spot lesions during fixed appliance therapy. Various contributing risk factors were identified with the greatest risk posed by a poor oral hygiene.
Keywords: dental white spot; fluoride; orthodontic wires; orthodontic brackets; risk factors; teeth.
Endodontic Management of a Mandibular First Molar with Four Canals in a Distal Root by Using Cone-Beam Computed Tomography: a Case Report
J Oral Maxillofac Res 2014 (Jan-Mar);5(1):e5
Background: Aberrations in the root canal anatomy are clinically challenging for clinicians. Mandibular first molars usually have 2 roots and 3 or 4 canals, but various combinations may exist. A distal root with three canals is rare and its incidence in literature is about 0.2 - 3%. As a diagnostic tool, cone-beam computed tomography (CBCT) may be a better choice for diagnosis of extra roots or canals comparing to conventional radiography.
Methods: An endodontic management of a mandibular first molar with six canals was performed. CBCT was used to confirm the diagnosis and to understand the morphology of the canals.
Results: Evaluation of the axial and coronal slices of CBCT images confirmed the presence of 2 roots and 6 canals. The distal root had four distinct root canal orifices with two apical foramens, being described as type XIV canal configuration.
Conclusions: Dentists should be aware of unexpected canal morphology when performing endodontic treatment. The present case demonstrated the use of CBCT in diagnosis and negotiation of extra canals in a mandibular first molar.
Keywords: anatomy; cone-beam computed tomography; molar; tooth root; tooth canal.
Long-Term Symptoms Onset and Heterotopic Bone Formation around a Total Temporomandibular Joint Prosthesis: a Case Report
J Oral Maxillofac Res 2014 (Jan-Mar);5(1):e6
Background: The literature on total alloplastic temporomandibular joint (TMJ) reconstructions is encouraging, and studies on total alloplastic TMJ replacements outcomes showed acceptable improvements in terms of both pain levels and jaw function. Nevertheless, some adverse events, such as heterotopic bone formation around the implanted prosthesis, may occur. In consideration of that, the present manuscript describes a case of heterotopic bone formation around a total temporomandibular joint prosthesis, which occurred several years after the implant.
Methods: The present manuscript describes a case of heterotopic bone formation around a total TMJ prosthesis, which occurred several years after the implant in patients, who previously underwent multiple failed TMJ surgeries.
Results: Ten years after the surgical TMJ replacement to solve an ankylotic bone block, the patient came to our attention again referring a progressive limitation in mouth opening. A computerized tomography showed evidence of marked heterotopic bone formation in the medial aspects of the joint, where a new-born ankylotic block occupied most part of the gap created by resecting the coronoid process at the time of the TMJ prosthesis insertion.
Conclusions: Despite this adverse event has been sometimes described in the literature, this is the first case in which its occurrence happened several years after the temporomandibular joint replacement. It can be suggested that an accurate assessment of pre-operative risk factors for re-ankylosis (e.g., patients with multiple failed temporomandibular joint surgeries) and within-intervention prevention (e.g., strategies to keep the bone interfaces around the implant separated) should be better standardized and define in future studies.
Keywords: ankylosis; heterotopic ossification; temporomandibular joint; temporomandibular joint disc; temporomandibular joint disorders.