Mandibular lengthening by external distraction: an experimental study in the rabbit

OBJECTIVE

To observe the development of bone at different times during the period of mandibular lengthening by external distraction using Ilizarov's transosseous osteosynthesis technique.

MATERIALS AND METHODS

Fifteen rabbits, 2 to 3 kg in weight, were used for this experiment. The left side of the mandible was exposed and a corticotomy was performed with a water-cooled drill. After 12 hours, distraction was started and continued 1 mm per day for 2 weeks. Plain radiography and three-phase bone scan scintigraphy were performed on the 1st, 7th, and 14th postoperative days. The mandibles were then either removed for immediate histologic evaluation or after 2, 5, or 8 weeks of postdistraction fixation.

RESULTS

Elongation of up to 11 mm was achieved. Radiographic and scintigraphic evaluation suggested a residual inflammation on the 7th day and definite ossification on the 14th day. Histologic observations of the distraction site showed a gradual change from an amorphous matrix to a fibrous matrix and, finally, an osseous-like tissue.

CONCLUSION

Bone lengthening by gradual distraction is commonly used in tubular bones. To achieve mandibular lengthening it is necessary to resolve many problems. Morphologic, radiographic, scintigraphic, and histologic observations confirm that mandibular lengthening by external distraction is possible, with the formation of new bone tissue.

Accuracy of fine needle aspiration biopsy in head and neck tumors

PURPOSE

Fine-needle aspiration biopsy (FNAB) is frequently used in the diagnosis of lesions occurring in the head and neck region. This study evaluated the correlation between the findings on FNAB and the histological findings observed after surgery.

MATERIALS AND METHODS

A review of 218 patients who underwent FNAB of a head or neck tumor was performed. Cytological reports were classified into the following diagnostic categories: negative or positive for malignant cells and unsatisfactory. False-positive, false-negative, true-positive (sensitivity), and true-negative (specificity) rates were calculated.

RESULTS

Twelve specimens did not allow an adequate diagnosis (5.5%). Among benign tumors, 96.2% of the cases were correctly diagnosed, and 3.8% were nondiagnostic specimens. Among malignant tumors, 86.4% of cases were correctly identified. There were two (3.4%) false-negatives and six (10.2%) nondiagnostic specimens, with a total false-negative rate of 13.6%.

CONCLUSIONS

Sampling errors present a minor problem with FNAB. Most nondiagnostic or incorrect specimens were caused by nonhomogenous lesions, with poor placement of the needle and an insufficient amount of aspirated material. FNAB is a useful modality for the diagnosis of head and neck masses.

Accuracy in the diagnosis of mandibular involvement by oral cancer

Cancer of the mandibular region usually has a poor prognosis; this is particularly correlated to invasion of the mandible. To reduce the consequences of poor therapeutic planning, careful preoperative assessment of bone infiltration is necessary. We have examined the records of 50 patients evaluated by clinical examination, conventional radiography, computed tomography (CT), bone scintigraphy with 99mTc and magnetic resonance imaging (MRI). The highest sensitivity (100%) was attained by scintigraphy; the highest values of specificity (96.3%) were reached by CT scan and MRI. A CT scan showed the highest predictive positive value (95.4%) and efficiency (94%), this plus MRI have good values and the associated sensitivity and efficiency are higher than when these techniques are used alone.

Intraosseous mucoepidermoid carcinoma. Report of a long-term evolution case

Primary central mucoepidermoid carcinoma (CMC) of the jaws accounts only for 2-3% of all mucoepidermoid carcinomas reported. Bhaskar in 1963 first analysed the criteria for his central origin, histology and pathogenesis. The authors report a long-term evolution case of CMC of the mandible with peculiar clinical features observed at the Department of Maxillo-Facial Surgery of the School of Medicine and Surgery of the "Federico II" University of Naples (Naples, Italy) examining histopathologic and clinical features and problems related to the treatment.

Lymph-node metastasis in squamous cell carcinoma of the lip. A retrospective analysis of 105 cases

During 1975-87, 105 patients with squamous cell carcinoma (SCC) of the lip were surgically treated. All patients underwent radical resection of the tumor. Only the patients with palpable lymph nodes had a simultaneous neck dissection. All patients were followed up for at least 5 years. Of the 80 patients without palpable lymph nodes, only three developed lymph-node metastasis. Of the 25 patients with palpable lymph nodes who underwent modified neck dissection, four had recurrence of lymph-node metastasis at a different level. The over-all 5-year survival rate was 97%. The survival rate for patients with lymph-node metastasis was 88%.

Aggressive cemento-ossifying fibroma of the jaws

The cemento-ossifying fibroma is probably the most frequent fibro-osseous lesion seen by oral pathologists. Occasionally, reports of lesions behaving in an aggressive fashion appear in the literature. At the present time, the relationship if these "aggressive" lesions to the "usual" fibromas is unclear. Two cases of "aggressive" cemento-ossifying fibroma are reported. Certainly, clinical, radiological, and histological characteristics of aggressive and usual fibromas do coincide. There are, however, diverging features warranting separation of different forms. These mild differences may be detected during preoperative assessment of the lesion, allowing a diagnosis of aggressive form to be made.

Perineural invasion of the lower alveolar nerve by oral cancer: a follow-up study of 12 cases

Twelve previously untreated cases of oral cancer with perineural infiltration were studied retrospectively. Age, sex, site, clinical stage and outcome were evaluated. Management of the neoplasm in each case involved surgical removal and six patients required adjuvant radiotherapy. The most frequent site was the lip. At the time of diagnosis, five patients had sensory complaints and palpable lymphadenopathy was observed in three patients. The 5-year crude survival rate was 16.7%. In the cases with postoperative assessment of perineural infiltration, a median survival time of 30.8 months was observed; while in the case of preoperative assessment of nerve infiltration, extensive surgery was performed with a consequent median survival time of 44.5 months. The perineural infiltration of the lower alveolar nerve is more common (6.3%) than is generally thought. This frequency is due to the relationship with the lower lip and the mandibular region. In carcinoma of the lip, spread is generally limited to 10-15 mm along the lower alveolar nerve. In carcinoma of the mandibular region, spread is entirely dependent on the location of the tumour; the absence of clinical fixation to the bone and the small size of the carcinoma does not preclude the possibility of bone involvement. Neurological symptoms should be evaluated carefully, and a radiographic investigation of the nerve canal is mandatory.

Surgical management of the neck in squamous cell carcinoma of the floor of the mouth

Nodal involvement in squamous cell carcinoma considerably lowers survival rate. Despite its importance, neck management has still not been adequately explored. The Authors have retrospectively reviewed the records of 112 cases. Unilateral N+ were treated with a homolateral therapeutic and a controlateral prophylactic neck dissection; bilateral N+ were treated with a bilateral therapeutic neck dissection. On first observation the majority of cases (66.1%) were T1-2, N+ patients accounted for 45.5%. Among N- patients, 21.3% of occult nodal metastases were observed. The 5-year survival rate was 52.7%. With N+ lesions, a radical neck dissection should be performed; the dissection should be performed bilaterally. With N- lesions a prophylactic modified radical neck dissection is recommended in T2-4 lesions.

Accuracy in the diagnosis of parotid tumours

Parotid lesions are often not easily classified. Important information is gathered by conventional and instrumental investigation. But these data are often insufficient to make a correct diagnosis. The authors have compared these techniques. In particular, they have evaluated their accuracy in identification of site and histology. 60 patients with parotid tumours underwent the same instrumental diagnostic techniques (echography, sialography, computed tomography and fine needle aspiration biopsy). In regard to the identification of the site, the highest percentage was achieved by computed tomography (98%). Echotomography has shown an accuracy of 83%, and sialography 87%. Fine needle aspiration biopsy has allowed the definition of the histiotype in 98% of cases. Computed tomography, echotomography and sialography have not allowed the definition of histiotype in malignant tumours, but in the case of benign tumours computed tomography has permitted a diagnosis in 29 cases (57% of benign tumours). Echotomography and sialography in 25 (49%) and 26 cases (51%), respectively.

Detection of latero-cervical metastases from oral cancer

In squamous cell carcinoma of the oral cavity, the presence of nodal metastases greatly influences prognosis. The evaluation of regional lymph nodal involvement is crucial in the correct management of these neoplasms. The records of 45 patients with oral cancer were reviewed retrospectively to evaluate the accuracy and prognostic value of the techniques used to detect lymph node metastasis in the neck (clinical examination, echo-colour-Doppler, computed tomography and magnetic resonance imaging). Echo-colour-Doppler was the most accurate procedure with a predictive positive value of 95.6% and the lowest false-negative rate. Therefore, a diagnostic preoperative study must include echo-colour-Doppler preferably associated with computed tomography to achieve the greatest diagnostic accuracy.

Surgical therapy of parotid hemangiomas

The goal of this review is to define the clinical characteristics of parotid hemangiomas in children and outline their therapeutic management. The records of 42 pediatric patients with hemangiomas were reviewed; 10 required surgical treatment. Two cases of temporary postoperative facial nerve palsy were observed. Treatment was commonly delayed, and there is a significant likelihood of spontaneous regression. The indications for surgical intervention are an increase in tumor size, rapid tumor growth, failure of tumor size to decrease and hemorrhage into the lesion.

Surgical management of the neck in squamous cell carcinoma of the tongue

If the nodes are involved, survival of patients with squamous cell carcinoma of the tongue is considerably reduced. Surgery remains the treatment of choice and, to define its role, we have reviewed 82 consecutive cases. Sixty-two cases (76%) were T1-2, and 46 patients (56%) had involved nodes. The cervical region II was the most often involved (n=26). Occult nodal metastases were present in 12 cases. The extent of nodal spread and prognosis varies according to whether the body or the base of the tongue is involved. Lesions of the base with involved node should be treated by a selective posterolateral neck dissection, whilst in the case of a lesion of the body of the tongue, the dissection should be selective anterolateral. In lesions of the base, when there are no nodes involved, a prophylactic selective posterolateral neck dissection is recommended, whilst in the case of the lesions of the body, selective supraomohyoid neck dissection in T2-4 lesions is recommended.

Hemangiomas of the maxillofacial area. Usefulness of 99Tcm-labelled red cell scintigraphy

Recent work reports the usefulness of radionuclides in the study of hepatic hemangiomas. In particular, 99Tcm-red blood cell (RBC) scintigraphy is useful to evaluate the vascularization and to plan the therapy. The aim of this paper is to confirm the usefulness of 99Tcm-RBC scans in the detection and follow-up of maxillofacial hemangiomas. Results using this technique in a selected group of patients with maxillofacial hemangiomas are reported.

Swelling of the floor of the mouth: a clinical dilemma

Swelling of the floor of the mouth is sometime difficult to diagnose clinically. Lithiasis and neoplasm are the most frequent causes of intraoral swelling. Also after plain radiology and computed tomography the diagnosis is often dubious. A case of swelling of the floor of the mouth due to an adenoid cystic carcinoma of the sublingual gland is reported.

[Benign parotid lymphoepithelial cysts associated with HIV infection]

HIV infections are often related with lymphoepithelial benign cysts of the parotid gland; these lesions are uncommon and other salivary glands are rarely involved. The diagnosis, often difficult, is based on imaging techniques, like computed tomography, and pathologic techniques, like fine needle aspiration biopsy. The therapeutic approach can be performed by simple aspiration, surgical resection, pharmacotherapy, or radiotherapy. Three cases of HIV-related lymphoepithelial benign cysts of the parotid gland observed at the Department of Maxillofacial Surgery of the "Federico II" University of Naples and at the Department of Oral and Maxillofacial Surgery of "La Paz" Hospital of the Universitad Autonoma of Madrid are described.

Indication for neck dissection in carcinoma of the parotid gland. Our experience on 39 cases

In cases of parotid carcinoma, the percentage of cervical metastases, at the time of first observation is 18%. Consequently, the evaluation of the grade of lymphatic involvement is very important in order to plan a correct therapy. The authors underline the important role that neck dissection has in the treatment of these tumours. There are different points of view on neck dissection in cases of malignant parotid tumours. While there is no doubt with regard to indications on neck dissection in N + patients, the problem does exist for N-patients. The Authors have analyzed 39 patients with malignant parotid tumours observed at the Department of Maxillo-Facial Surgery of the "Federico II" University of Naples.

Cervical metastases from pulmonary epidermoid carcinoma

A patient with a right latero-cervical swelling of three-months history was observed. Fine needle aspiration biopsy showed the presence of metastases of epidermoid carcinoma moderately differentiated. No signs or symptoms of head and neck neoplasm were presents. After instrumental evaluation the primary neoplasm was localised at the left lung and metastases were also localised in the right submandibular gland. Although metastases from pulmonary epidermoid carcinoma are normally bloodborne, in this case lymphatic metastases involving cervical areas were present, probably secondarily the submandibular involvement.

[Pathological fractures of the mandible caused by cancer of the oral cavity]

The pathological fracture of the mandible is a rare and undesirable consequence of cancerous bone invasion. This study investigates the retrospective incidence of this phenomenon in diagnosed cases of squamous cell carcinoma of the mandibular region, and reviews the methods of treatment used. A total of 194 patients with squamous cell carcinoma of the mandibular region were observed. Only six cases of pathological fractures were found. The treatment was conditioned by the need to eliminate the tumor, and was carried out in different methods according to the individual cases. This study underlines the importance of both knowing various techniques and collaborating with other specialists in treating the fracture.

Morbidity by plating in maxillofacial surgery

BACKGROUND

Aim of this paper is to define the behaviour of osteosynthesis plates in maxillofacial area and to determine when to remove them.

METHODS

The records of 123 patients treated with osteosynthesis plates were retrospectively assessed. Each case had a follow-up of not less than 5 years. Removal as a consequence of poor surgery was excluded from the study.

RESULTS

Osteosynthesis occurred in the mandible in 198 cases and in the upper maxilla in 146 cases, with a further 23 cases treated by plating in other sites. Plates were removed in 21 cases; the most frequent cause of removal was infection (13 sites) followed by nerve palsy and dehiscence.

CONCLUSIONS

Infections are without doubt the main cause of plate removal. In orthognathic patients, infections occurred less frequently, nevertheless they remain the main complication. Dysesthesia, along with infections, are the most frequent cause of removal. Plate exposure very rarely are reduction and fixation lost; thus the removal of the plate can be delayed.