Incidence of root canal treatment of second molars following adjacent impacted third molar extraction.

BACKGROUND/PURPOSE: The aim of this study was to evaluate the incidence of requirement for root canal treatment of adjacent second molars following the surgical extraction of an impacted third molar. MATERIALS AND METHODS: The dental records of 6323 consecutive patients who had impacted third molars removed surgically were evaluated and the incidence of postoperative root canal treatment requirement of adjacent second molars was determined. Patients who required root canal treatment of neighboring second molars were accepted as the study group, while the remaining patients were accepted as a control group. Sex, age at the time of the operation, localization of third molar, the depth of impaction, angulation of the tooth, and the professional experience of the surgeon performing the operation were evaluated from patient records. RESULTS: The incidence of requirement of root canal treatment for second molars following a neighboring impacted third molar extraction was 0.17% (11/6323) and invariably occurred in the mandible. The mean age of the study group was found to be significantly higher than the control group (31 years vs. 23 years). The years of professional experience of the surgeons was significantly lower in the study group than in the control group. CONCLUSION: Although the incidence is minimal, iatrogenic subluxation injuries occurring during the surgical removal of impacted third molars can lead to pulpal complications and a requirement for root canal treatment of adjacent second molars.

Comparative evaluation of simultaneous maxillary sinus floor elevation and implant placement with residual bone heights greater or less than 5 mm.

PURPOSE: Implants can be inserted simultaneously during sinus floor elevation (SFE), or 6 months later, for posterior maxillary rehabilitation. The residual bone height (RBH) is a major factor that affects the type of surgical procedure that will be performed. The aim of this study was to compare the survival rates of implants inserted during one-stage SFE with two different RBHs (< 5 mm and ≥ 5 mm). MATERIALS AND METHODS: This study consisted of implants inserted into an RBH of either < 5 mm or ≥ 5 mm, and the survival of the implants was assessed according to the clinical symptoms of the patients: pain or tenderness during function (or spontaneously), mobility, depth of probing, exudation history, and radiographic bone loss at the final follow-up appointment. The survival rates of the two groups were statistically compared using the Fisher exact test. RESULTS: Fifty-nine consecutive patients (29 women and 30 men) undergoing a one-stage sinus elevation procedure simultaneously with implant insertion were included in this study. Fifty-one implants were placed in the study group (RBH: 1 to 4.9 mm), and 31 implants were placed in the control group (RBH: 5 to 8 mm). The survival rate of the implants in the study group was 94.2% at the 5.4-year follow-up and 95.8% in the control group at the 7.9-year follow-up. There was no statistically significant difference between the groups in terms of the implant survival rate (P = .785). CONCLUSION: The results of this study suggest that SFE with simultaneous implant placement in patients with an RBH < 5 mm can be accomplished, and that the survival rate is similar to that of the one-stage SFE protocol with an RBH of > 5 mm.

Is the incidence of temporomandibular disorder increased in polycystic ovary syndrome?

The prevalence of temporomandibular disorders is higher among women than men (ratio 3:1 -9:1). Polycystic ovary syndrome(PCOS) is the most common endocrine disorder in women, which is characterised by chronic low-grade inflammation and excess of androgenic hormones that lead to metabolic aberrations and ovarian dysfunction. Increased activities of various matrix metalloproteinases (particularly MMP-2 and 9) in the serum of these patients has been reported, and it has been hypothesised that high activities of MMP may contribute to loss of matrix and chronic inflammation of the fibrocartilage in temporomandibular disorders. Our aim was to evaluate the incidence of temopormandibular dysfunction in women with PCOS compared with an age-matched, disease-free, control group. We studied 50 patients with previously diagnosed PCOS and 50 volunteers who had normal menstrual cycles. We made a comprehensive clinical examination of the temporomandibular joint (TMJ) and muscles of mastication in both groups and recorded the Visual Analogue Scores (VAS) for pain. There were significant differences (p<0.001) in the incidence of temporomandibular disorders (n=43 (86%) in the PCOS group compared with n=12 24% in the control group), muscle tenderness(n=32 (64%) in the PCOS group compared with n=14 (28%) in the control group) and pain in the TMJ (mean (SD) VAS 2.9 (2.61) compared with 0.3 (1.56). We confirm the higher incidence and severity of disorders of the TMJ in patients with PCOS and suspect that chronic low-grade inflammation may play a part in the aetiology of the disease.

Management of bisphosphonate-related osteonecrosis of the jaw with a platelet-rich fibrin membrane: technical report.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a challenging complication resulting from the long-term application of bisphosphonates. In most cases, BRONJ occurs after a surgical procedure involving the jawbone. Currently, the management of BRONJ remains controversial, and there is no definitive treatment other than palliative methods. Platelet-rich fibrin (PRF) represents a relatively new biotechnology for the stimulation and acceleration of tissue healing and bone regeneration. This technical note describes the total closure of moderate bone exposure in persistent BRONJ in 2 weeks with a double-layer PRF membrane. PRF may stimulate gingival healing and act as a barrier membrane between the alveolar bone and the oral cavity. PRF may offer a fast, easy, and effective alternative method for the closure of bone exposure in BRONJ.

Change in inferior sclera exposure following Le Fort I osteotomy in patients with midfacial retrognathia.

PURPOSE: For facial esthetic reasons, no sclera should be exposed above or below the irises when the head of a patient who has a normal skeletal pattern is in a neutral position and the eyelids are in a relaxed position. This study evaluated the decrease in sclera exposure after maxillary advancement or impaction in patients with midfacial hypoplasia. PATIENTS AND METHODS: Forty-seven consecutive patients (24 male, 23 female) who underwent Le Fort I osteotomy were included. The patients were divided into 2 groups according to type of maxillary movement: group I underwent maxillary advancement (n = 23) and group II underwent maxillary advancement and impaction surgery (n = 24). Standardized preoperative and 6-month postoperative photographs of the frontal view of patients were evaluated using Adobe Photoshop CS5. The proportion of inferior sclera exposure to eye height was determined, and the proportional difference between the preoperative and postoperative orbital views was statistically analyzed. RESULTS: The proportion of inferior sclera exposure to eye height decreased by a ratio of 0.07 (P = .001) in the right and left eyes of the 47 patients, with an average maxillary advancement of 6.1 mm. The proportion of inferior sclera exposure to eye height of the right and left eyes decreased from 0.1 to 0.02 and from 0.09 to 0.02, respectively, in group I (P = .001). The proportion of inferior sclera exposure to eye height decreased in group II by a ratio of 0.06 in the right and left eyes (P = .001). CONCLUSION: Inferior sclera exposure in patients with midfacial hypoplasia and retrognathia decreases significantly in accordance with the change in the lower eyelid position after maxillary advancement or impaction surgeries.

The extent of chin ptosis and lower incisor exposure changes following the osseous genioplasties.

The incision and dissection of the mentalis muscles are inevitable to access the osteotomy line during genial surgery. As the mentalis muscles elevate the central lower lip and support the lip vertically, inadvertent scarring or lengthening of these muscles may lead to lip incompetence and may increase the lower incisor exposure (LIE) that will cause an unaesthetic result. The aim of this study was to evaluate the extent of lip ptosis, LIE, and other soft-tissue changes following different types of osseous genioplasty procedures.Twenty-nine patients (18 females, 11 males) were included in this study. Patients were classified into 3 groups with respect to their genial movement type as genial setback (n = 10), genial advancement (n = 10), and vertical reduction (n = 9). Preoperative and postoperative lateral cephalograms were analyzed to evaluate the horizontal and vertical soft-tissue changes of the lower lip and chin in the 3 genioplasty groups. The statistical evaluations were performed with regression analysis. The mean increase in the LIE was 1.88 mm. Lower incisor exposure and soft-tissue thickness at pogonion were increased significantly in all patients (P < 0.05). Statistically significant differences for lower lip length and vertical position of soft-tissue supramentale values were detected in patients who underwent vertical reduction genioplasty (P < 0.05). Genioplasty procedures requiring the mentalis muscle release cause a 1.88-mm increase in LIE. Vertical positional alterations of the lower lip were especially observed following the vertical reduction genioplasty. Clinician should be aware of this consequence in the course of treatment planning.

Maxillomandibular fixation screws for early removal of hardware and correction of lingual tilting in alveolar distraction osteogenesis.

Alveolar distraction osteogenesis is a well-known technique used for the management of deficient alveolar ridges. Vector control of the transport segment is the main problem during distraction. This article describes a new technique for early removal of distractor and correction of tilted transport segment in partially edentulous patients.

Comparison of stability of resorbable and titanium fixation systems by finite element analysis after maxillary advancement surgery.

In this study, three-dimensional modeling and finite element analysis were used to evaluate and compare the stability of Le Fort I osteotomy fixed with titanium and resorbable fixation systems under molar and incisor bite forces. A three-dimensional model of 5-mm advanced hemimaxilla was generated. Contact analyses between the upper and lower segments were prescribed. Two L-plates were inserted on this model via simulation. Displacement, principal stresses, and principal elastic strains were evaluated under 44-N, 125-N incisor and, 250-N molar bite forces. These results suggest that Le Fort I osteotomies fixed with titanium miniplates and screws were stable under all tested forces. However, in resorbable group, under incisor bite forces greater than 44 N, there is a great risk of plate fracture, screw deformation, and/or failure.