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PubMed1988

Van Buchem disease: surgical treatment of the mandible.

First described in 1955, Van Buchem disease is an infrequently occurring hereditary sclerosing bone dysplasia. It is more properly called hyperostosis corticalis generalisata. The most striking feature is an unusual enlargement of the mandible with a normal dental occlusion. Skull base, spine, and pelvic bone involvement is also seen. The defect appears to be an increase in cortical bone thickness or sclerosis. The condition first appears around puberty in the autosomal recessive type and in early childhood with the autosomal dominant type. Reported here is a family with Van Buchem disease, in which surgical recontouring of the mandible was performed for one of the members. The surgery was performed by a combined intraoral/extraoral technique with good aesthetic results and minimal morbidity. A differential diagnosis and workup is also presented.

Adult↗
PubMed1997

Schwannoma of the mandible.

Schwannoma is a benign neoplasm originating from Schwann's cell. It involves neurons and axons of peripheral nerves. This tumor has a predilection for the head and neck region, and often occurs as soft tissue lesion. Intraosseous sheath tumors are rare, comprising less than 1% of all bone tumors; the mandible is the most common site. The literature reports only 30 acceptable cases of schwannoma of the mandible. We report a new case of schwannoma that is unusual in its intraosseous localization and the patient's comparatively young age.

Child↗
PubMed1998

Controlled multiplanar distraction of the mandible: device development and clinical application.

Distraction osteogenesis has been shown to be an effective method of lengthening and augmenting endochondral bone. It has also been applied effectively in the reconstruction of the membranous bones of the craniofacial skeleton. With the accumulation of clinical experience in mandibular distraction, the differences between endochondral and membranous bone distraction have become apparent, especially in the limitations of uniplanar distraction for the three-dimensional reconstruction of the deficient mandible. Distraction of the mandible in a single plane cannot satisfy fully the functional and structural requirements of the patient with malocclusion as well as deficiency of the skeletal and soft tissue. This study reports the development and clinical use of a multiplanar mandibular distraction device with the ability to achieve linear distraction (Z-plane or sagittal), angular distraction (Y-plane or vertical), and transverse distraction (X-plane or coronal). The device contains two independent gear arrangements attached to two arms that extend from the central unit. Therefore, the trajectory of the regenerated bone may be changed during the distraction process. The device also allows manipulation of the various planes of movement independent of each other. Furthermore, the rotational points for the multiplanar distraction devices are located at a single point; therefore only a single osteotomy and two pin sites are required. The multiplanar distraction device allows the surgeon to customize and contour the dimensions of the distraction process by controlling the trajectory of the translation of the regenerated bone.

Child, Preschool↗
PubMed2001

Imaging the neonatal mandible for accurate distraction osteogenesis.

The position of mandibular teeth is difficult to document in the neonatal patient. Panorex images are difficult to obtain in an uncooperative pediatric patient. The new technique presented by the authors uses computed tomographic data to create a curved, reformatted image of the mandible, and generates an image similar to a panorex image. This curved, reformatted mandibular image provides accurate visualization of the mandible and mandibular teeth. This technique allows for precise pin placement and osteotomy in distraction osteogenesis.

Humans↗
PubMed2001

Combined simultaneous distraction osteogenesis of the maxilla and mandible using a single distraction device in hemifacial microsomia.

Facial asymmetry in hemifacial microsomia can be corrected by an effective procedure of gradual distraction of the mandible. In younger children with deciduous dentition, changes in dental occlusion secondary from mandibular distraction can be easily corrected with orthodontic treatment. In older patients, mandibular elongation through distraction osteogenesis can produce good aesthetics but can create a severe alteration in occlusion requiring complex orthodontic treatment during an extended period. A Le Fort I osteotomy was performed simultaneously with mandibular corticotomy to avoid this problem. We present an 11-year-old patient with grade II hemifacial microsomia with facial asymmetry that was corrected with a combined simultaneous distraction of the maxilla and mandible using a single mandibular distraction device and an interdental splint. Excellent facial symmetry was achieved while maintaining preexisting dental occlusion.

Bone Wires↗
PubMed2002

Early revascularization of membranous inlay bone graft in canine mandible model.

The early revascularization of a membranous inlay bone graft in a canine mandible was investigated using bone scans and histological examinations. Eight 5-month-old mongrel dogs were used as the subjects. The inlay bone graft, a 1- x 2-cm critically sized bone, was completely separated from the lower border of the canine mandible and then refixed to the original site. Bone scans and histological examinations were performed in the first, second, third, and fourth postoperative weeks. The bone scan in the first postoperative week revealed radioisotope uptake on the margin of the grafted bone with an isotope count that was 21% of the normal bone uptake. In the second postoperative week, the radioisotope uptake in the grafted bone increased to 52% of the normal bone uptake. In the third and fourth postoperative weeks, the isotope uptakes were 111% and 124%, respectively. The histological findings in the first postoperative week showed an absence of osteoblastic activity and 6 viable blood vessels in a field magnified x 200, which was the equivalent of 25% of the vessels of the normal bone. In the second postoperative week, osteoblastic activity was noted, and the number of viable blood vessels increased to 15, that is, 63% of the vessels of the normal bone. In the third postoperative week, there was an increase in osteoblastic activity, and the number of viable blood vessels was 21, that is, 88% of the vessels of the normal bone. In the fourth postoperative week, there was a marked increase in osteoblastic activity with the number of vessels reaching 23, that is, 96% of the normal bone. In summary, revascularization of the membranous inlay bone graft began within the first week after the bone graft and thereafter gradually increased. In the third postoperative week, revascularization returned to a near-normal value compared with the value of the adjacent normal mandibular bone.

Animals↗
PubMed2003

Orthodontic-surgical treatment after posttraumatic bilateral condylectomy of the mandible in an adult patient.

A posttraumatic open bite associated with a bird face is reported. Condylectomy was indicated in relation to the plurifragmentary fracture of the condyles with limitation of mandibular movement. Condylectomies were mandatory as a result of delayed maxillofacial surgical treatment, which was related to the poor general condition of the patient after trauma. Functional disorder recovery and aesthetic deformity correction were planned by a team approach between orthodontists and maxillofacial surgeons with the support of a logopedist for the postural-related muscle problems. The main practical and theoretical problems presented by the clinical case were a result of the need to restore the occlusal relations and to avoid recurrence of open bite in this patient. The patient presented a wide alteration of muscular function and a strength fibrotic retraction with alteration in the relationship between upper and lower jaws and retrusion of the mandible associated to open bite. Orthodontic treatment was carried with no impact on the upper and lower axis, avoiding orthodontic correction of the open bite. Surgery corrected both the open bite and the bird face by means of bilateral sagittal split osteotomies. Wiring of the mandibular osteotomies and intermaxillary fixation allowed positioning of the mandibular ramus bilaterally because of the fibrosis and muscular action-related forces without resulting in a similar rotation of the mandible with the risk of recurrence. Myotherapy and logopedic support minimized the risk of recurrence, improved reduction of muscular tension with the resolution of the lip incompetence, and allowed functional recovery of mandibular movements.

Adult↗
PubMed2001

The effect of calcitonin on osseous healing in guinea pig mandible.

Calcitonin (CT) is reported to be an effective medication for the treatment of inflammatory root resorption and to be capable of stimulating osteoblast proliferation in cell culture studies. In this study the effect of CT on the healing of osseous defects was evaluated in the mandibles of guinea pigs. After raising tissue flaps two experimental cavities were created on both sides of the corpus mandible of 33 guinea pigs. CT was applied into cavities either in hydroxypropyl methycellulose (HPMC) gel or gelatin as carrier. HPMC and gelatin alone and an empty cavity were also examined as control groups. Histopathological examinations under light microscopy were performed on weeks 1, 3, and 6. At week 1 in CT+gelatin and CT+HPMC groups, prominent osteoblastic activity was observed when compared with control groups. At week 3 the presence of woven bone in the experimental cavity areas reflected the increased osteoblastic activity in all groups. At the end of week 6 woven bone was gradually replaced by osteogenic tissue undergoing remodelization with Haversian systems in all groups. It is suggested that the osseous healing of the experimental cavity was enhanced by CT application in early stages (i.e. at week 1). However there was no significant difference of osteogenic activity between the control and CT-treated groups at the end of weeks 3 and 6.

Animals↗
PubMed1997

Experience with segmental reconstruction of the radiated mandible with alloplastic prostheses.

Reconstruction of the mandible after radiation therapy and segmental resection is often complicated by wound breakdown, osteoradionecrosis, and crippling of the oral cavity. These complications make patient salvage after radiated oral carcinoma a high-risk endeavor. Although head and neck surgeons have improved the reliability of mandibular reconstruction with microvascular free tissue transfer, medical and oncologic issues may prohibit their application. This report presents 12 selected cases undergoing alloplastic reconstruction of the mandible and soft tissue reconstruction of the oral cavity. Although not as reliable as some reports of free tissue transfers, the results were reproducible and satisfactory in these cases, with time-efficient hospitalization and functional rehabilitation. Ten of 12 prosthetic reconstructions have been durable in this study population for as long as 36 months.

Aged↗
PubMed2001

Technetium 99m single positron emission computed tomography scanning for assessing mandible invasion in oral cavity cancer.

OBJECTIVES: To study the accuracy of single positron emission computed tomography (SPECT) scanning and compare its results to clinical examination, Panorex, and computed tomography (CT) scanning with respect to determining mandibular invasion by oral cavity and oropharyngeal cancer, and to define the role of SPECT scanning in the preoperative assessment of oromandibular cancer. STUDY DESIGN: Prospective study of 38 patients who underwent technetium 99m SPECT scanning as part of their preoperative clinical assessment for cancer at risk of invading the mandible. All patients underwent partial or segmental mandibulectomy as part of their surgical management. METHODS: A data protocol was used to tabulate patient demographics, tumor characteristics and results of preoperative tests as patients were enrolled into the study. Following surgical treatment, these data were correlated with histopathological findings. Detailed analysis was performed to assess the tabulated data. RESULTS: The SPECT scanning demonstrated an 87% overall accuracy in predicting bone invasion compared with 71% for clinical examination, CT scanning, and Panorex x-rays. The SPECT scanning was significantly more sensitive (95%) than either CT scans (55%) or Panorex x-rays (50%). Notably SPECT scanning demonstrated a considerable improvement in specificity (72%) compared with conventional radionuclide scanning. Although not as specific as CT scanning or plain films, SPECT scanning was significantly more effective in ruling out disease than was clinical examination. CONCLUSIONS: Preoperative SPECT scanning used in combination with clinical examination, CT scanning, and Panorex x-rays to assess patients at risk for mandible involvement by oral cavity cancer can improve the accuracy of predicting bone invasion and help in appropriate treatment planning so as to safely reduce the proportion of disease-free jaws resected.

Adult↗
PubMed1983

Salvage of the exposed irradiated mandible.

Maintaining the continuity of the tumor-free mandible is a priority objective in managing the patient with head and neck cancer. After review of seven patients with cutaneous or intraoral bone exposure from osteoradionecrosis of the mandible, we recommend treatment consisting of debridement of soft necrotic bone, retention of dry sclerotic bone, and coverage with well-vascularized flap tissue. Utilizing this therapeutic plan, we have preserved mandibular architecture and obtained primary healing of the wounds.

Aged↗
PubMed1984

Augmentation of the atrophic mandible with a vascularized rib graft.

A patient with a 29-year history of denture wearing had her mandible augmented with a vascularized rib graft. The rib was contoured to fit the arch of the mandible and vascularized by means of the facial arteries to the intercostal vessels. The nutrient artery was not included in the vascularized bone graft. Cortical cancellous bone chips were packed around the rib to augment the buccal surface of the rib graft. Periosteal perfusion and vascularity of the transferred rib were well documented at 1 week, 1 month, and 6 months postoperatively by radionuclide scintigraphy. It is now 24 months after surgery and the patient began wearing a denture 2 months after the rib transfer. She underwent a split-thickness skin graft vestibuloplasty and floor-of-the-mouth lowering 12 months following the rib transfer with improvement in her denture-wearing capabilities, which has remained constant for 10 months. Vertical resorption of the graft at 3 months was 10 percent, at 6 months 15 percent, and it has stabilized at 25 percent.

Atrophy↗
PubMed1991

Aesthetic augmentation of the posterior mandible.

The posterior mandible begins just behind the mental nerve and second bicuspid bilaterally, extends to the posterior edge of the ramus, and then runs superiorly to the zygomatic arch. Augmentation of the posterior mandible is possible by use of a synthetic implant that is tailored individually to each patient's specific needs. Implant plant thickness varies from 4 to 8 mm, with an average thickness of 6 mm. Careful preoperative planning is done based on an aesthetic assessment of the amount of highlighting desired, thickness of the soft tissues, and the use of life-size photographs and cephalometric and Panorex x-rays. A pattern is cut, and the implant is carved to fit the patient. Insertion of the material after careful tailoring to the individual patient's own mandibular size and configuration requires a generous posterior lower buccal sulcus incision. Antibiotic irrigation and systemic antibiotics are essential, and careful closure in two layers completes the procedure. One implant in the series extruded in a patient who had had radiation therapy, and one patient required repositioning of the implant. Otherwise, in 22 patients there were no infections or permanent morbidity. The procedure seems to be a realistic and safe one for both the youthful and aging face, as demonstrated in patients in this series, with ages varying from 16 to 40 years.

Adolescent↗
PubMed1994

The histologic analysis of distraction osteogenesis of the mandible in rabbits.

The process of bone formation in mandibular lengthening by distraction was studied in 30 rabbits. The mandible was subjected to a corticotomy, held in a neutral position for 2 weeks, and then lengthened at 0.18 mm per 12 hours for 24 days using a unilateral external fixation device (Orthofix M-100). On completion of the distraction, x-ray analysis showed that the distracted gap was filled with callus organized into three zones, namely, two sclerotic zones with a central radiolucent zone. These zones became indistinguishable from the adjacent preexisting mandible at 10 weeks after distraction. Histologically, new bone, which was formed by both intramembranous and endochondral ossification, underwent remodeling and resulted in cortical bone by 8 to 10 weeks after completion of distraction.

Animals↗
PubMed1995

Donor leg morbidity and function after fibula free flap mandible reconstruction.

The purpose of this study was to determine the donor leg morbidity and function after removal of the fibula free flap for mandible reconstruction. In the past 24 months, 29 consecutive patients underwent a total of 30 fibula free flap mandible reconstructions. A muscle-sparing technique was used to harvest the fibula flap, and the proximal 6 cm and distal 8 cm of fibula were left intact. Patients included 20 men and 9 women; their mean age was 58.8 years (range 29 to 82 years); the mean length of fibula removed was 14.5 cm (range 8 to 25 cm); osteocutaneous flaps were used in 27 patients (90 percent); and 16 patients (53 percent) required skin grafts to the donor leg. Donor leg morbidity and function were determined by patient questionnaire, physical examination, and isokinetic testing, with the opposite, unoperated leg serving as a control. Immediate postoperative morbidity occurred in 5 patients (17 percent) (infection, wound separation, or partial graft loss); none required additional surgery for donor complications. Patient questionnaires were completed by all patients at an average of 7.3 months after surgery. Patients were able to ambulate pain-free an average of 5.1 weeks (range 2 to 32 weeks) postoperatively and were all fully able to engage in all daily and recreational activities. Most (21 patients, 72 percent) were free of any donor pain, and the remainder (28 percent) had only occasional mild discomfort. Other complaints included ankle stiffness (41 percent), mild ankle instability (10 percent), and transient peroneal motor (7 percent) or sensory (28 percent) loss, which resolved in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The effects of alloplastic implant onlays on bone in the rabbit mandible.

The relative importance of the factors that contribute to the bone erosion seen underlying alloplastic implants remains unknown. This study was designed to examine the effects of different alloplastic onlays on the mandible in a rabbit animal model. Three alloplastic materials (soft solid silicone, methyl methacrylate, and porous polyethylene) were examined to determine the importance of implant composition in bone resorption. Thin (1.5-mm) and thick (6-mm) onlays were used to determine the relative importance of implant thickness. Fluorescent markers were administered at different time intervals to evaluate the patterns of new bone formation. A total of 96 implants placed on the mandibles of 16 animals were examined grossly, histologically, and under fluorescent microscopy after 12 and 24 weeks. The frequency and degree of bone erosion were related both to the type of alloplast and to the thickness of the implant. Silicone implants were associated with the greatest amount of bone resorption (p < 0.01). Thicker silicone implants were associated with a greater degree of thinning (p < 0.05). Bone resorption beneath the implants was documented by the presence of osteoclasts actively eroding bone and by changes in the normal patterns of the fluorescent markers. Both the thin methyl methacrylate and the thin porous polyethylene implants had a low incidence of bone thinning. The thick methyl methacrylate implants caused more erosion than the thin implants of the same material, although this was less than the silicone groups. Increasing the thickness of porous polyethylene implants did not adversely affect the underlying bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

Free fibula flap mandible reconstruction for oral obstruction secondary to giant fibrous dysplasia.

Fibrous dysplasia is a disorder of bone that may be associated with endocrinopathies and skin pigmentation. The pathologic, proliferative expansion and distortion of the skeleton is of unknown etiology. Craniofacial involvement that includes the mandible can exhibit gigantic disproportions and dysfunction. Treatment has evolved to include more aggressive strategies of resection and sophisticated reconstructive techniques. The reported case is noteworthy for the unrelenting growth of craniofacial fibrous dysplasia in an adult female with endocrinopathies, progressing to oral obstruction that required urgent treatment utilizing immediate free bone-flap reconstruction. The free fibula flap was employed to restore mandibular continuity after palliative subtotal mandibulectomy. Bony healing to dysplastic tissue occurred in the remaining mandibular segment. This case illustrates that fibrous dysplasia has the capacity for virulent regrowth subsequent to conservative resection. Defects following radical surgery for giant fibrous dysplasia of the mandible can be reconstructed with a microsurgical bone-flap technique.

Adult↗
PubMed1996

Alteration in facial sensibility in adolescents following sagittal split and chin osteotomies of the mandible.

Static two-point discrimination, pressure, and vibratory threshold values were measured bilaterally at standard coordinates in the area of the face innervated by the mental nerve in 115 adolescents (230 nerves). The patients were divided into four groups: normal adolescents who had not undergone any orthognathic surgery (group I controls, n = 134 nerves, mean age 18 years, SD = 3), those 1 year after undergoing bilateral sagittal split osteotomies of the mandible (group II, n = 14 nerves, mean age 19 years, SD = 2), those 1 year after undergoing an osteoplastic genioplasty (group III, n = 40, mean age 19 years, SD = 3), and those 1 year after undergoing a combination of bilateral sagittal split osteotomies and an osteoplastic genioplasty (group IV, n = 42 nerves, mean age 19 years, SD = 3). Subjective residual numbness at the 1 year postoperative interval was reported by 2 of 7 patients in group II, 2 of 20 patients in group III, and 14 of 21 patients (67 percent) in group IV. Long-term subjective numbness involved only the chin skin in 16 of 18 patients experiencing residual numbness and was perceived as problematic in the remaining 2 (group IV) patients whose subjective numbness also was measured objectively in the chin, lower lip (mucosa and skin), and gingiva. Objectively, the mean threshold values of the three sensory modalities tested were higher in group IV patients than in the remaining groups at all coordinates tested, but significant differences (p < 0.05) were found only between the mean two-point discrimination of group IV patients and the control group in the region of the chin skin. The high percentage of patients documented to have subjective and objective sensory disturbance after undergoing a combination of sagittal split osteotomies of the mandible and an osteoplastic genioplasty (group IV) may be explained by the "double crush syndrome."

Adolescent↗