Metin Şençimen

Anatomical and functional aspects of ligaments between the malleus and the temporomandibular joint

The aim of this paper is to investigate the anatomical topography and the relationship between the ligaments, malleus and temporomandibular joint (TMJ) and to determine the role of these ligaments on the movement of the malleus. The malleus, incus, petrotympanic fissure (PTF), chorda tympani, anterior malleolar ligament (AML), discomallear ligament (DML), malleomandibular ligament, sphenomandibular ligament and articular disc were explored in 15 skulls. Traction and tension tests were carried out to clarify their role in malleolar movement. In 12 of the cases, two separate ligaments were connected to the anterior of the malleus, whereas a single ligament from the anterior of the malleus to the PTF was observed in 3 cases. In 12 cases, the DML united the retrodiscal tissues. In the other 3 cases, the medial and the lateral parts of the ligament were connected to the retrodiscal tissue after passing through the PTF. The thickness of the ligaments differed among specimens. When tension was applied to the DML no malleolar movement occurred, but when the AML was overstretched, significant movement was observed in 5 cadavers; little movement in 6 cadavers, and no movement in 4 cadavers. This study suggests that extreme stretching of the condyle in conjunction with the ligaments between the ossicles of the inner ear and the TMJ could be the reason for unexplained otological problems.

Histomorphometric analysis of different latency periods effect on new bone obtained by periosteal distraction: an experimental study in the rabbit model

OBJECTIVES The aim of this study was to evaluate the effects of latency period on the bone formation after periosteal distraction. For this purpose, a rabbit model was developed and histologic and histomorphometric analyses were conducted. STUDY DESIGN Periosteal distractors were custom designed and built from stainless steel. Rabbits were divided into 2 groups of 18 each according to the duration of latency period. In group 1, the latency period was 7 days, and in group 2 it was 1 day. Distraction was performed by activating the distractor 0.25 mm twice per day. A periosteal distraction of 7.0 mm was achieved after a distraction period of 10 days. Both groups were divided to 3 subgroups according to the rabbits being killed on the 15th, 30th, or 60th day of the consolidation period. Histologic and histomorphometric analyses were performed to evaluate the bone formation. RESULTS In the histologic evaluation, new bone formation was observed on the lateral side of the mandible of all the rabbits. Histomorphometric measurements revealed that the mean area of newly formed bone formation was 2.62 cm(2) in group 1 and 3.26 cm(2) in group 2. CONCLUSIONS Periosteal distraction osteogenesis is a viable method in acquired and congenital alveolar ridge defects, resulting in new bone formation. Newly formed bone can be obtained by periosteal distraction osteogenesis applying different latency periods.

Early Detection of Alterations in the Resonance Frequency Assessment of Oral Implant Stability on Various Bone Types: A Clinical Study

This study was undertaken to evaluate the relation between bone quality and alterations of implant stability quotient values measured during the initial phase of healing. Nineteen patients treated with 106 implants were included in the current study. The mean bone density of the implant recipient area was measured using Simplant 11 software incorporated in the computerized tomography (CT) machine. Mean bone density measurements were recorded in Hounsfield units. The implant recipient sites were subdivided into 5 groups according to bone quality. The numbers of the structures on the recipient site belonging to D1 and D5 types showed no statistical significance and were excluded. Standard 2-stage surgical technique was utilized to prepare the surgical sites. The implant stability quotient (ISQ) value at implant placement was recorded and did not influence the treatment procedure. The ISQ was measured by an Osstell instrument. The ISQ was further registered on the 21st and 60th days. SPSS statistical software was used for the statistical analysis. In comparison with the time of insertion, the mean values of the ISQ were decreasing for the first 21 days. However, on subsequent days, the ISQ values of all bone types have increased and on the 60th day reached the values recorded at the time of insertion. Analysis of the relation between changes in stability and bone type does not reveal statistical significance. With knowledge of the current clinical study, it can be concluded that bone quality in the recipient bone site does not effect changes in implant stability at the early stages of the osseointegration process.

Juvenile hyaline fibromatosis of the mandible with bone involvement: Report of a rare case

Juvenile hyaline fibromatosis (JHF) is a rare autosomal-recessive hereditary disease, characterized by gingival hypertrophy, flexion contractures of joints, bone lesions, hyaline deposition in the extracellular spaces of the dermis and soft tissues, stunted growth, and skin lesions such as multiple nodules, tumors and pink, pearly papules. No case of JHF with a mandibular bone involvement, exists in the literature. Bone involvement in JHF is an uncommon finding and distinct solitary lesions in the calvarial bones has been reported by some authors. A 21-year-old male patient was referred to Diyarbakir Military Hospital, Department of Dental Service. Clinical findings were consistent with a solid alveolar mass in the right mandibular premolar-molar region and displaced right mandibular molar teeth. Orthopantomographic examination showed impaction of all lower right molars in a mixed radioopaque/radiolucent area. Microscopically, increased nodular connective tissue was seen under the lobulated mucosal surfaces of the resected area. The case presented here had a localized fibrous proliferation that infiltrated bone trabeculae and caused displacement of teeth. Juvenile hyaline fibromatosis should be considered in the differential diagnosis with the other intraosseous radiolucent-patchy opaque lesions of jaw bones. Based on the clinical and histopathological findings, a diagnosis of JHF was made.

Onlay iliac bone grafting as an ancillary augmentation procedure for paranasal rejuvenation during bimaxillary surgery

OBJECTIVE The aim of this paper is to present the outcome of iliac bone block grafts used for paranasal augmentation during bimaxillary orthognathic surgery for the patient with deep concavity of canine fosse. STUDY DESIGN Preoperative evaluation of the patient, done with 3-dimensional (3D) surgical simulation software, revealed deep bony concavity of paranasal area and insufficient soft tissue improvement when Le Fort I level maxillary advancement was accomplished. The deficient sites were grafted and better profile was achieved with 3D simulation. After the leveling phase, Le Fort I advancement and mandibular setback with sagital split osteotomies were performed. Bony deficiency of paranasal regions were corrected simultaneously with autogenous iliac block grafts to obtain maximum improvement in the profile. RESULTS More satisfactory esthetic results were obtained with paranasal augmentation, and acceptable profile was provided for the patient. CONCLUSIONS Bimaxillary orthognathic surgery combined with augmentation of paranasal area is an efficient method to obtain better aesthetic outcome for patients with severe concave profile. Paranasal augmentation with iliac bone block grafting is a novel technique to ensure favorable soft tissue support and esthetic appearance of the patient.

Guided Bone Regeneration Technique Using Hyaluronic Acid in Oral Implantology

Guided bone regeneration is a term used to describe the use of the barrier membranes to enhance complete osteogenesis by preventing the rapid ingrowth of fibroblasts into a bony defect and promoting the migration of osteogenic cells from adjacent bony edges or bone marrow into the defect in an unimpeded fashion. Hyaluronic acid (HA) is a glycosaminoglycan of the general formula (C14H22NO11)n and is an essential component of the extracellular matrix in connective tissue, which is found in abun‐ dance in the alveolar environment. The most important function of HA is its involve‐ ment in tissue healing and repair. It has been shown that HA stimulates cell proliferation, migration and angiogenesis, re-epithelialization and proliferation of basal keratinocytes and reduces collagen and scar tissue formation. This text presents our clinical experiences and outcomes following HA applications in various implant surgery procedures. According to our clinical outcomes, HA is a highly promising material for improving therapeutic outcomes for oral implantology.