Is the collateral circulation pattern in the hard palate affected by cleft deformity?

OBJECTIVES: To evaluate the influence of collateral vascularization on surgical cleft palate closure and deformities. MATERIALS AND METHODS: Corrosion casting was performed using red-colored acrylic resin in twelve fresh adult cadavers with a normal hard palate. Additionally, white-colored barium sulfate was injected into a fetus with a unilateral complete cleft palate, and layer-by-layer tissue dissection was performed. Both substances were injected into the external carotid arteries. Corrosion casting involved dissolving the soft and hard tissues of the orofacial area utilizing an enzymatic solution. RESULTS: In normal palates, bilateral intraosseous infraorbital arteries formed a network in the premaxilla with the intraosseous nasopalatine- and greater palatine arteries (GPAs). The perforating GPAs anastomosed with the sphenopalatine artery sub-branches. Bilateral extraosseous GPA anastomoses penetrated the median palatine suture. Complex vascularization in the retrotuberal area was detected. In the cleft zone, anastomoses were omitted, whereas in the non-cleft zone, enlarged GPAs were distributed along the cleft edges and followed the anatomical course anteriorly to initiate the network with facial artery sub-branches. CONCLUSIONS: The anatomical subunits of the palate exhibited distinct anastomosis patterns. Despite omitted anastomoses with collateral circulation in the cleft zone, arteries maintained their anatomical pattern as seen in the normal specimen in the non-cleft zone. CLINICAL RELEVANCE: Based on the findings in normal- and cleft palates, surgeons may expect developed anastomosis patterns in the non-cleft zone. Due to the lack of microcirculation in the cleft zone, the existent anastomoses should be maintained as much as possible by the surgical technique. This applies anteriorly in the incisive canal territory, alveolar ridges, and posteriorly in the retrotuberal area.

A simple solution for vector control in vertical alveolar distraction osteogenesis.

One of the important and frequent complications in alveolar distraction osteogenesis is vectorial change of the transport segment. This report presents a simple solution for vector angulation control by placing intermaxillary fixation screws intraoperatively. Advantages of the technique are also discussed.

Micronucleus assay assessment of possible genotoxic effects in patients treated with titanium alloy endosseous implants or miniplates.

The use of titanium and its alloys (Ti-6Al-4V) for oral surgery has increased dramatically in recent years. Ti is a stable biocompatible metal suitable for oral applications and it has been used for endosseous subperiosteal implants and miniplate fixation for more than 25 years. Dental implants are typically made of Ti or Ti alloys. The alloys are potentially toxic due to release of vanadium and aluminum. We tested the possible genotoxicity of Ti alloy endosseous implants and miniplates on the oral mucosal tissues of two groups of patients: 17 patients receiving Ti miniplate and screw fixation, and 37 endosseous dental implant placement patients. Preoperative and postoperative mucogingival cell samples were collected. Genotoxicity was assessed by the micronucleus assay (MN). There were slight but not statistically significant increases in the frequencies of MN (p=0.087 and p=0.047) post-operation in both groups. In summary, neither of the applications showed genotoxicity in the oral epithelial cells of patients.

Dentoalveolar transport osteodistraction and canine distalization.

The orthodontic treatment period with extractions is prolonged in many cases because of the limited rate of biological tooth movement. An approach using transport distraction osteogenesis was designed to reduce orthodontic and orthognathic treatment time. Overall management of selected alveolar cleft cases with wide defects may also be optimized and simplified through transport distraction of a tooth-bone segment. We will discuss our experience with 73 cases, both conventional orthodontic cases and orthognathic patients, in which dentoalveolar distraction was used to reduce orthodontic treatment time and to treat wide alveolar clefts with compromised soft tissues to facilitate optimal outcome.

Response of ramus following vertical lengthening with distraction osteogenesis.

Vertical lengthening of the mandibular ramus is considered to be one of the least stable surgical procedures in the management of musculoskeletal maxillofacial deformities. The aim of this study was to evaluate the response of the mandibular ramus following vertical lengthening by means of distraction osteogenesis. This study included eight non-syndromic adult patients with temporomandibular joint ankylosis. The vertical height deficiency of the mandibular ramus and the ramus/condyle unit on the affected side were simultaneously reconstructed by transportation of a bone segment using distraction osteogenesis following gap arthroplasty. Lateral and posteroanterior (PA) cephalograms taken postoperatively before active distraction, at the completion of distraction and 6, 12, 24 months after distraction, were compared to evaluate the changes of the ramus height. In all cases the vertical ramus and ramus/condyle unit height loss were successfully reconstructed by distraction osteogenesis. There was no relapse in the amount of height gained by distraction osteogenesis at the 24 months follow-up review (p>0.05). Acute one stage vertical lengthening of the mandibular ramus is considered to be one of the least stable musculoskeletal procedures with relapse being a significant adverse outcome. In this clinical study gradual vertical lengthening of the ramus through ramus/condyle unit distraction osteogenesis has maintained the initial vertical ramus height gained for 24 months.

Methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis of the mandible.

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of Staphylococcus that is resistant to certain antibiotics, such as methicillin, oxacillin, penicillin, and amoxicillin. This nosocomial pathogen has become a great threat in hospitals globally. Up to 40% of the normal population carries S. aureus in the anterior nares, and this rate is often higher in hospitalized patients and their attendants. This case report presents a patient with serious MRSA osteomyelitis of the mandible demonstrating purulent discharge. The patient failed to recover despite prolonged postoperative treatment and the administration of several antibiotics. There was a resulting nonunion along with chronic MRSA infection. The treatment protocol involved a multimodal approach with parenteral clindamycin infusion, local rifampicin irrigation, and intermaxillary fixation of the jaws.

Long-term results of arthrocentesis in degenerative temporomandibular disorders.

OBJECTIVES: Long-term efficacy of arthrocentesis was investigated in patients with degenerative temporomandibular disorder (TMD) in this clinical study. STUDY DESIGN: Twenty-two joints of 15 patients with degenerative TMD were included as the study group, and 16 joints of 10 patients served as the control group. Arthrocentesis procedures in upper joint spaces were performed. The study group patients' mean follow-up period was 36.7 +/- 18.7 months, whereas the control group were kept for an average 9.9 +/- 2.8 months. Results were statistically compared using 1-way repeated analysis of variance and t test. RESULTS: Pretreatment maximal interincisal opening increased significantly from 33.6 +/- 6.0 mm to 37.8 +/- 6.0 mm in the study group. Pretreatment pain and crepitus scores decreased significantly from 71.0 +/- 6.6 to 27.0 +/- 16 and 0.73 +/- 0.4 to 0.6 +/- 0.5, respectively, in the study group. CONCLUSIONS: Arthrocentesis was found to be a useful method for the treatment of degenerative TMDs, and the outcomes of treatment provide long-term cure for degenerative temporomandibular joints.

Histomorphometric evaluation of the effects of zoledronic acid on mandibular distraction osteogenesis in rabbits.

PURPOSE: To assess the effect of systemic administration of zoledronic acid (ZA) on mineralization of newly formed bone and to determine strain-related osteoporosis on surrounding bone during lengthening of immature rabbit mandible. MATERIALS AND METHODS: Eighteen New Zealand white rabbits were divided randomly into 2 groups, and bone lengthening was carried out in the left portion of the mandible through distraction osteogenesis with a rate of 0.5 mm every 12 hours for 5 days. The experimental group was administered 0.1 mg/kg ZA intravenously. The control group was given saline infusion only during operation. All animals were sacrificed at the end of the 28-day consolidation period. The mandibles of all animals were removed and regenerate was evaluated. Osteoblasts, osteoclasts, collagen fibers, and fibroblasts were marked within 0.1-mm(2) area and newly formed bone area was measured within 0.5-mm(2) area. All data were analyzed using Mann-Whitney U test. RESULTS: Although irregular bone destruction spots were seen in the control group, the experimental group showed regular ossification areas and significant difference between osteoblast and osteoclast numbers (P < .05). In the regenerate zone, there was considerable difference between the 2 groups in terms of osteoblast, osteoclast, and collagen amounts (P < .05). Additionally, newly formed bone areas and fibroblast count were higher in experimental group. CONCLUSIONS: The results of this study showed that ZA had positive effects on the new bone formation, which may potentially shorten the consolidation period.

Prevalence of otologic complaints in patients with temporomandibular disorder.

The prevalence and rank of order of 4 otologic complaints in 200 temporomandibular disorder (TMD) patients, as well as the relationship between the complaints and TMD subgroups, were investigated and compared with an asymptomatic control group. No subjective otologic complaints were reported by 45 (22.5%) TMD patients; the remaining 155 (77.5%) patients had at least 1 otologic complaint. Otalgia, tinnitus, vertigo, and hearing loss were reported by 63.6%, 59.1%, 50%, and 36.4%, respectively, of the subjects with myofascial pain and dysfunction; by 46.1%, 44.2%, 32.5%, and 22% of the patients with internal derangement; and by 62.5%, 45.8%, 41.6%, and 20.8% of the patients with both myofascial pain and dysfunction and internal derangement. However, the incidence of otalgia (8%), tinnitus (26%), vertigo (14%), and hearing loss (14%) was found to be lower for the control group. Statistically, the control group had fewer otologic complaints. Patients in the TMD groups had high incidences of otologic complaints compared with the control subjects without TMD signs or symptoms. Aural symptoms in patients with internal derangement or myofascial pain and dysfunction, or their combination, were nonspecific.

Histomorphometric evaluation of short-term changes in masseter muscle after lengthening the rabbit mandible by distraction osteogenesis.

PURPOSE: Structural changes in muscles may affect the process during and after distraction osteogenesis (DO) of the mandible. However, the response of the masticatory muscles is still not well defined after gradual lengthening of the mandible. In this experimental study, short-term structural changes in masseter muscles of the rabbits are evaluated after mandibular DO. MATERIALS AND METHODS: Left mandibles of 10 New Zealand rabbits were lengthened by DO for 7 days in the rate of 1 mm/day. Mandibles of all animals were removed at the end of the consolidation period. Muscle biopsy samples of distracted and contralateral sides were histopathologically investigated, and histomorphometric results were statistically analyzed. RESULTS: Atrophy, hypertrophy, regeneration, and concomitant mild interstitial edema and fibrosis were found more evident in experimental side biopsy samples 30 days after distraction. Histomorphometric analysis revealed a statistically significant decrease in the mean regions of masseter muscle fibers of the distracted sides compared with the control sides (P <.05). CONCLUSION: This experimental study showed that the structure of masseter muscle is influenced during and shortly after mandibular distraction osteogenesis. Atrophic changes of the ipsilateral masseter muscles may be regarded as regenerative response that occurs during and shortly after distraction period.

Dentoalveolar distraction osteogenesis for rapid orthodontic canine retraction.

PURPOSE: We present a technique to reduce the overall orthodontic treatment time by means of dentoalveolar distraction osteogenesis. PATIENTS AND METHODS: Eleven patients who were planned to undergo orthodontic treatment with bilateral first premolar extractions and subsequent bilateral canine tooth distalization underwent osteotomy around the canine tooth. The first premolar was extracted, and the buccal bone was carefully removed. After wound closure, a special orthopedic device was mounted and cemented to the first molar and canine teeth. Distraction was started the same day at the rate of 0.4 mm twice a day and continued until adequate movement of the canine teeth was achieved. The device was then removed, and orthodontic therapy was continued with fixed appliances. RESULTS: The distraction rate and the device were well tolerated by all of patients. No anchorage loss in the second premolar and first molar teeth, root resorption, dental ankylosis, discoloration, or loss of vitality was detected. CONCLUSION: The concept of distraction osteogenesis for rapid orthodontic tooth movement is promising and feasible for clinical practice.