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.

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.

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.

Distraction osteogenesis in Silver Russell syndrome to expand the mandible

Distraction osteogenesis is a method commonly used to activate bone regeneration in nonunions and osseous defects and for lengthening procedures of tubular bones. This technique involves the sectioning of a bone and the subsequent deliberate, controlled movement of the opposing sectioned edges to lengthen, widen, or reposition a bone, or all three. In this report, a patient with Silver Russell syndrome and severe mandibular hypoplasia was treated by means of distraction osteogenesis of the midsymphysis to widen the mandible in concert with sagittal-ramus osteotomies to lengthen the mandible. This treatment created significantly increased arch length in the mandible, which was necessary to facilitate the patient's orthodontic treatment. We believe this is the first reported case of distraction osteogenesis to widen the mandible with the use of a tooth-borne appliance.