Daniel E. Waite

Aneurysmal bone cyst of the jaws. Report of a case associated with fibrous dysplasia and review of the literature.

A case of aneurysmal bone cyst (ABC) of the mandible, recurring for the third time and arising in conjunction with fibrous dysplasia, is reported. A comprehensive review of the literature and analysis of over 50 cases of ABC of the jaws yielded the following results: ABCs of the jaws constitute 1.5 % of all non-odontogenic and non-epithelial cysts of the jaws, and 1.9 % of all ABCs of the skeleton. The mandible was affected in 55 % of the cases, the maxilla in 45 % of the patients. Females represented 53 % of the patients and males the remaining 47 %. Seventy-four percent of the ABCs occurred in patients 20 years old and younger. This lesion is regarded as non-neoplastic and as most likely secondary to a pre-existing bone lesion. Our review established that 21 % of the reported cases in the jaws had developed in association with various primary lesions of bone, including fibro-osseous lesions. The primary bone lesion initiates an osseous, arteriovenous fistula which, through its hemodynamic forces, creates a secondary reactive lesion, that is an aneurysmal bone cyst. We also established a recurrence rate of 26 %, based upon previously reported cases as well as our own. The treatment of choice is surgical curettage with cryosurgery and immediate packing with bone chips.

Malignant melanotic neuroectodermal tumor of infancy. A clinical, pathologic, ultrastructural and tissue culture study

The melanotic neuroectodermal tumor of infancy is an uncommon neoplasm typically of early childhood which has a predilection for the head and neck region, particularly the maxilla. Except for one previous example in the literature, this tumor has consistently behaved in a benign fashion. This study documents the clinical course and pathologic findings of a tumor which began in the maxilla of a 4‐month‐old boy, followed by a local recurrence, metastasis to a cervical lymph node and finally, widespread dissemination and death at 18 months, 24 months and 38 months, respectively. The tumor was initially composed of nests consisting of melanin‐containing cells and small dark cells. An elevated vanillylmandelic acid level was recorded during the course of the disease. At autopsy, the tumor in lymph nodes, liver, bone and soft tissues had a monotonous pattern of small dark cells similar to a conventional neuroblastoma. Previous ultrastructural studies indicate that the melanotic neuroectodermal tumor of infancy is composed of melanocytes and neuroblast‐like cells. Our case provided the unique opportunity to examine in sequence the ultrastructural and in vitro characteristics of a recurring and eventually metastasizing melanotic neuroectodermal tumor. Although the neuroblast‐like cells were initially difficult to identify by electron microscopy, a melanin‐producing cell line and a separate nonpigmented cell line were successfully isolated from various tumor explants. Various stages of melanosome development were identified in the pigmented cells from the local recurrences and in vitro. Dibutyryl cAMP accentuated the formation of pigment and dendritic development in the melanocytes and dendrites only in the small nonpigmented cells. Electron dense granules were observed in the cultured smaller cells and also in the lymph node and soft tissue metastases. Tyrosine hydroxylase activity was demonstrated in the neuroblast‐like cells. In the final biopsy and autopsy material, only the neuroblast‐like cells remained and the tumor resembled a conventional neuroblastoma.

Evaluation of collagen/hydroxylapatite for augmenting deficient alveolar ridges: A preliminary report

A multicenter study was undertaken to evaluate a new alveolar ridge augmentation material composed of purified fibrillar collagen and particulate hydroxylapatite (PFC/HA). In a study of 77 patients and 99 reconstructed ridges, this material provided superior handling properties over HA alone as evidenced by its ease of surgical placement and manipulation, and the rarity of particle migration or displacement. Moreover, the rapid development of ridge firmness and stability allowed for the loading of dentures within three to six weeks. Prosthodontist evaluations and surveys of patient satisfaction showed great satisfaction with denture fit, comfort, esthetics, speech, and ability to masticate.

Mandibular ramus anatomy as it relates to the medial osteotomy of the sagittal split ramus osteotomy

The sagittal split ramus osteotomy is probably the most frequently used procedure for correction of mandibular skeletal dentofacial deformities. Despite numerous improvements in the technique in the 30 years since the procedure was introduced, a number of troublesome complications still occur. These include unfavorable fracture during surgery, paresthesia, and relapse. The purpose of this study was to determine where fusion of the buccal and lingual cortical plates occurs in the upper mandibular ramus, as it is thought that placement of the horizontal medial osteotomy above the point of fusion (without any intervening medullary bone) may lead to unfavorable fracture during splitting. Forty-nine human mandibles were sectioned vertically at three locations perpendicular to the surface of the ramus and the occlusal plane. Measurements were made to locate vertically the point of fusion of the buccal and lingual cortical plates relative to the lingula and to the depth of the sigmoid notch. The point of fusion occurred between 7.5 and 13.3 mm above the lingula. Only 2% of mandibles had fusion at or below the level of the lingula in the anterior ramus, whereas in the posterior ramus, 6.1% of mandibles were fused at that level. At a level halfway from the lingula to the sigmoid notch, 20% of mandibles were fused in the anterior ramus, whereas in the mid- to posterior ramus, the incidence was as high as 39%. The location of the medial horizontal osteotomy should be at or just above the tip of the lingula. A higher level of cut may be associated with an increased difficulty in splitting or incidence of unfavorable fracture.

Effects on the periodontium of vertical bone cutting for segmental osteotomy.

The periodontal response to vertical osteotomy was evaluated in seven males and ten females, aged 14-45 years (mean 26.8), who were scheduled for maxillary and/or mandibular segmental osteotomies. Plaque and gingival indices, pocket depth, clinical attachment level, width of attached gingiva, and osseous support were recorded from teeth adjacent to each osteotomy site prior to and from six months to three years after surgery. In each patient teeth numbers 3, 9, 13, 19, 25, and 29 were used as controls. There was no significant (P less than or equal to 0.05) difference between experimental and control teeth with respect to plaque, gingivitis, pocket depth, or clinical attachment level. Slightly decreased osseous support and width of attached gingiva were found adjacent to osteotomy sites. However, although these decreases were statistically significant (P = 0.005), they were not clinically very large. It was concluded that segmental osteotomies, in general, may be performed without producing significant changes in the periodontal structures.

Evaluation of the surgical procedure of sagittal split osteotomy of the mandibular ramus

Abstract The present article introduces a statistical analysis of a surgical procedure, bilateral sagittal split osteotomy of the mandibular rami, which was performed at the University of Minnesota Hospital. A general survey of our experience with this surgical procedure in forty-one cases is also presented.

Periodontal evaluation of canines erupted through grafted alveolar cleft defects.

Two to eight years after receiving autogenous iliac crest grafts for treatment of alveolar cleft defects, eighteen patients who had unilateral cleft palate were evaluated for their periodontal status. When cleft-associated canines were compared with contralateral control canines, no statistically significant differences were found between specific surface values for plaque index, gingival index, or probing depths. Attachment loss was found to be greater (less than 0.72 mm) on the mesio-facial, facial, and mesio-palatal surfaces of the cleft-associated canines than on the control canines. Fifty-six per cent of the cleft-associated canines required surgical exposure and 44% also required orthodontic assistance to erupt to a functional occlusion. Osseous grafting of alveolar cleft defects resulted in satisfactory clinical periodontal support for cleft-associated canines.

Pigmented neuroectodermal tumor of infancy: An example of rarely expressed malignant behavior

A 4-month-old patient presented with a melanotic neuroectodermal tumor. The tumor continued to progress and recur following each surgical intervention and the patient died at the age of 38 months, 36 months following discovery of the tumor. This article describes the clinical and pathologic features of the disease. At autopsy, the tumor resembled that of a neuroblastoma.

Tomographic evaluation of temporomandibular joints following discoplasty or placement of polytetrafluoroethylene implants

A retrospective comparison was made of tomographic change in the temporomandibular joint (TMJ) of patients who had been treated by either discoplasty or discectomy with polytetrafluoroethylene (PTFE) disc replacement. Fifty-five PTFE- and 18 discoplasty-treated joints were evaluated. More than 60% of the PTFE-treated joints showed severe, destructive osseous change, whereas none of the discoplasty joints showed such change. Histologic examination of the tissues surrounding removed PTFE implants showed a foreign body giant cell reaction. The severity of radiographic change raises questions about the propriety of PTFE as a disc replacement material.

Mandibular anatomy as it relates to rigid fixation of the sagittal ramus split osteotomy

Rigid fixation of osteotomy segments is frequently used to reduce relapse and allow for early mobilization of the mandible following the sagittal ramus split osteotomy. This study evaluated cortical bone thickness in the retromolar area of 49 human mandibles to determine if there is an advantage (in terms of cortical thickness) to placement of screws for rigid fixation at the external oblique ridge versus placement at the inferior border. The mandibles were sectioned vertically at three sites in the retromolar area, corresponding to the bone available for rigid fixation of the sagittal osteotomy. Cortical bone thickness was measured at the external oblique ridge and 5 mm above the inferior border. The buccal and lingual cortices were found to be significantly (P less than .001) thicker at the external oblique ridge than at the inferior border. This suggests that there may be an advantage in terms of stability to placement of internal fixation screws at the superior border.