Alparslan Esen

Comparison of stability of titanium and absorbable plate and screw fixation for mandibular angle fractures

OBJECTIVE The purpose of this experimental study was to compare the stability of titanium and absorbable plate and screw fixation systems for mandibular angle fractures. STUDY DESIGN Twenty-one sheep hemimandibles were used to evaluate 3 different plating techniques. The groups were fixated with a single titanium plate, a single absorbable plate and double absorbable plates. A cantilever bending biomechanical test model was used for the samples. Each group was tested with vertical forces by a servohydraulic testing unit. The displacement values in each group at each 10 N stage up to 100 N were compared using the 2-way analysis of variance test. RESULTS The displacement values for the 3 groups differed significantly (P < .05). The variance analyses showed that titanium plate placement had more favorable biomechanical behavior than others. In addition, the 2 absorbable plates group had more favorable biomechanical behavior than a single absorbable plate group but it was not significantly different at 10 to 40 N. CONCLUSION The study demonstrated that titanium plate and screw fixation system had greater resistance to occlusal loads than absorbable plate and screw systems. In addition, a second absorbable plate orientation provides a more favorable biomechanical behavior than a single absorbable plate placement.

Conservative Treatment Protocol for Keratocystic Odontogenic Tumour: a Follow-up Study of 3 Cases

ABSTRACT Background The keratocystic odontogenic tumour is classified as a developmental cyst derived from the enamel organ or from the dental lamina. The treatment of keratocystic odontogenic tumour of the jaw remains controversial. The aim of this study was to report the outcome of our conservative treatment protocol for keratocystic odontogenic tumour. Methods Three patients with different complaints referred to Oral and Maxillofacial Surgery Clinic, Faculty of Dentistry, Selçuk University. Initial biopsy was carried out in all patients and keratocystic odontogenic tumours was diagnosed subsequent to histopathological examination. The patients with keratocystic odontogenic tumours were treated by enucleation followed by open packing. This conservative treatment protocol was selected because of existing young aged patients. The average follow-up duration of the cases was 2 years. Results Out of 3 cases, 2 lesions were present in mandible and 1 lesion in maxilla. There was no evidence of recurrence during follow-up. All the cases were monitored continuously with panoramic radiographs, computed tomography and clinical evaluations. Conclusions This conservative treatment protocol for keratocystic odontogenic tumours, based on enucleation followed by open packing would be a possible choice with a view of offering low recurrence rate and low morbidity rate particularly in young patients.

Effect of 2 flap designs on postoperative pain and swelling after impacted third molar surgery

OBJECTIVE The aim of this study was to evaluate 2 flap designs (envelope and modified triangular flap) for postoperative pain and swelling after mandibular impacted third molar surgery. STUDY DESIGN Thirty patients who had symmetric bilateral fully impacted mandibular third molars were selected. Left teeth were approached with an envelope flap, and right teeth were removed using a modified triangular flap. Postoperative pain and swelling were evaluated until the seventh day by using 2 verbal rating scales. RESULTS Statistical analyses showed that there were no significant differences between the 2 incision techniques regarding postoperative pain and swelling (P > .05). CONCLUSIONS There is no significant difference between the envelope and modified triangular flap regarding postoperative pain and swelling after impacted third molar surgery.

Comparison of two different approches to the pterygomaxillary junction in Le Fort I osteotomy

OBJECTIVE The purpose of this study was to compare the damage before and after down fracture in Le Fort I osteotomies performed with and without the separation of pterygomaxillary junction using curved osteotomes in a cadaver model. STUDY DESIGN The study sample comprised 6 cadavers aged between 55 and 70 years (mean age: 63.8 years). Three cadavers were partially edentulous, 2 cadavers still maintained a full complement of teeth and 1 cadaver was edentulous. Le Fort I osteotomy was performed on all cadavers. Pterygomaxillary osteotomies were only performed on the right sides whereas the left sides were left intact. Subsequently, the maxilla was mobilized by applying digital pressure on the anterior maxillary segment. Computed tomography scans of each specimen were obtained before surgery, after surgery-before down fracture and after down fracture to document secondary fractures. RESULTS Before the down fracture, secondary fractures were found in only 1 specimen (right side), whereas after the down fracture, secondary fractures were found in 5 specimens by CT. After the down fracture, the rate of occurrence of secondary fractures was 62% in the right side and 38% in the left side. CONCLUSION With respect to the results of the present study, the use of osteotomes for pterygomaxillary dysjunction increases the incidence of fractures in maxillary osteotomy. However, the occurrence of almost all fractures subsequent to down fracture suggests the presence of possible bony splits that could not be diagnosed by radiographic examination immediately after maxillary osteotomy may have become apparent or transformed into fractures following down fracture.

Biomechanical evaluation of malleable noncompression miniplates in mandibular angle fractures: an experimental study

The purpose of this experimental study was to test the reliability of a single malleable titanium miniplate using Champys method of fixing fractures of the mandibular angle. Eighteen sheep hemimandibles were used to evaluate 2 plating techniques. The groups were tested with either a single non-compression titanium miniplate or a single malleable titanium miniplate. A cantilever bending biomechanical test model was used for the samples. Each group was tested with vertical forces using a servohydraulic testing unit. The displacement values in each group at each 10N stage up to 90N were compared using 2-way analysis of variance (ANOVA). The displacement values for the 2 groups differed significantly (p<0.01). The variance analyses showed that the biomechanical behaviour of a single non-compression miniplate was better than that of a single malleable miniplate. The non-compression miniplate fixed by screws had greater resistance to occlusal loads than the malleable plate fixed by screws, and the malleable plate alone was not sufficient to withstand the early postoperative bite force.

The use of autogeneous mandibular bone block grafts for reconstruction of alveolar defects.

Objective: Purpose of this retrospective study was to evaluate outcomes autogenous bone block grafts obtained from mandible for different indications. The healing of the donor and recipient sites in the postoperative period, morbidity and the resorption of the graft were investigated. Patients and Methods: Twenty-nine patients grafted with mandibular bone block graft were participated in the present study. Grafting was applied in these patients for three indications; reconstruction of alveolar cleft, lateral crest augmentation before dental implantation and sinus floor augmentation. All operations were performed under local anesthesia and in some cases sedation was used as well. Results: Minimal exposure of the block graft occurred in three alveolar cleft patients. Secondary epithelization was achieved in all cleft patients with no symptoms of infection. In one patient infection was seen in donor site 1-week after the operation. The region was curetted and antibiotics administrated again. Two patients showed an infection of recipient site, after 4 weeks the grafts were removed. In all the patients, as the screw head became apparent until 1 thread, amount of the resorption were considered <1.5 mm. Conclusion: The usage of mandibular block grafts is a simple and effective treatment modality for reconstruction of different types of alveolar defects and it also reduces cost of treatment.

Clinicoradiological evaluation of dermis-fat grafts after temporomandibular joint discectomy: A retrospective study

Purpose: The aim of this study was to compare the preoperative and 1-year postoperative clinical and radiological findings of the patients after unilateral temporomandibular joint (TMJ) discectomy with inter-positional abdominal dermis-fat graft. Materials and Methods: Fourteen patients underwent unilateral discectomy and dermis-fat grafting between 2008 and 2010. Preoperative and 1-year postoperative clinical parameters such as maximum mouth openings (MMO) and lateral movements (LM) of the mandible were recorded. Additionally, preoperative and postoperative magnetic resonance imagingwas obtained to determine the duration of operated TMJs. Results: All of the 14 patients showed the improvement in mandibular mobility and function. There was a significant increase in the MMO and LM during the follow-up period. Pain levels at follow-up were significantly lower than the preoperative levels. Radiologically, the dermis-fat graft was detected within the joint or surrounding the condyle in all 14 operated joints. The graft material that was found within the joint space was mainly grey in four joints. Ten joints showed heterogeneous material composed of fat interspersed with grey tissue. Conclusion: Discectomy and dermis-fat grafting appears to be a successful surgical option regarding to the clinical parameters. However, summed degenerative changes depending on surgical operation should be retained.

Evaluation of discectomy and dermis-fat grafting on the contralateral side.

Purpose We investigated the effects of unilateral discectomy with an abdominal dermis–fat graft of the temporomandibular joint (TMJ) on the contralateral side. Patients and Methods A total of 14 patients who underwent unilateral TMJ discectomy and dermis–fat grafting for severe internal derangement in 2009 and 2010 were included. Clinical parameters, such as maximum mouth opening and lateral movements of the mandible, were recorded preoperatively and at 1 year postoperatively. Preoperative and 1-year postoperative magnetic resonance imaging was conducted to determine the duration of the operated and unoperated TMJs. Results and Conclusions All 14 patients showed improvement in the mandibular mobility and function. However, postsurgical disc displacement without reduction was observed on the unoperated TMJ in 1 patient. Another patient complained of crepitus on the operated TMJ. Primary occlusal contact on the operated side of occlusion was observed in 2 other patients. Maximum mouth opening and measured lateral movements had increased in all patients at 1 year after the operation.

Evaluation of strain values of critical anatomic regions for two different pterygomaxillary approaches in Le Fort I osteotomy: an experimental study

Background The purpose of this experimental study was to measure stresses both on the pterygoid plates and the skull base following two different pterygomaxillary approaches in Le Fort I osteotomy. Material and Methods The prepared skull models were randomly divided into 2 groups of 7. In the first group (A), the pterygomaxillary area was left intact. In the second group (B), pterygomaxillary separation was performed with a fine bur. The stresses were measured by using strain gauges. These strain gauges were attached to 6 different anatomical sites. The skull models were mounted on a servo-hydraulic testing unit. Each model was then subjected to a continuous linear tension until a plastic deformation was seen. Results The statistical analyses showed that there were no significant differences (p >.05) between the 2 groups regarding the strain values. Moreover, no statistical differences (p >.05) were found between the two groups in terms of maximum applied forces. Conclusions Considering the clinical conditions, the present study shows that when Le Fort I osteotomy performed without pterygomaxillary separation, there is no significant stress on the skull base during the downfracture. Moreover, it is considered that there is no need for an excessive force applied to perform downfracture in Le Fort osteotomies without pterygomaxillary separation. Key words:Le Fort I, osteotomy, strain, base of skull, pterygoid process.

Biomechanical evaluation of different fixation systems after Le Fort I osteotomy in polyurethane models of unilateral clefts

We compared the stability of three different titanium plate-and-screw fixation systems after Le Fort I osteotomy in polyurethane models of unilateral clefts. Thirty-six models were divided into 3 groups. In the first group, we adapted standard Plates 1mm thick with 2.0mm screws and placed them bilaterally on the zygomatic buttress and the piriform rim. In the second group, we did the same and added Plates 0.6mm thick with 1.6mm screws between the standard 2mm miniplates on both sides. In the last group, we placed Plates 1.4mm thick with 2.0mm screws bilaterally on the maxillary zygomatic buttress and piriform rim. Each group was tested in the inferosuperior (IS) and anteroposterior (AP) directions with a servo-hydraulic testing unit. In the IS direction, displacement values were not significantly different up to 80N, but between 80 and 210N, those in the 2×1.4mm group were better. In the AP direction, displacement values were not significantly different up to 40N, but between 40 and 180N, they were better in the standard with 1.6×0.6mm group and the 2×1.4mm group. When normal biting forces (90 - 260N) in the postoperative period are considered, the greatest resistance to occlusal loads was seen in the 2×1.4mm group. In the others, the biomechanical properties were better in the AP direction.