Macroglossia: a review of the condition and a new classification

In studying macroglossia, no one has described normal tongue size or applied direct measurement to the pathologically enlarged tongue. Since macroglossia is primarily a condition that requires treatment on a symptomatic basis, definition of the problem in clinical terms is the most useful form for the practitioner. Based on published reports and our clinical experience, a classification scheme for macroglossia has been formulated. The concept of true macroglossia and relative macroglossia form a framework that categorizes acquired and congenital forms of tongue enlargement. True macroglossia exists when histologic abnormalities correlate with the clinical findings of tongue enlargement. Vascular malformations, muscular enlargement, and tumors are the most common forms of true macroglossia. Relative macroglossia includes those cases of apparent tongue enlargement in which the histology does not provide a pathologic explanation. Down's syndrome is a commonly quoted cause for tongue enlargement and is a form of relative macroglossia. The development of this classification system establishes an approach and common terminology on which therapy, research, and communication can be based.     

A model for fetal cleft lip repair in lambs.

Fetal wounds heal without inflammation and scar formation. This phenomenon may, in the future, be applicable to human cleft lip and palate repair. However, extensive experimental work must first be done to document the benefits of in utero repair. We developed a large animal model for creation and repair of a complete cleft lip and alveolus using fetal lambs. The cleft lip and alveolus deformity was created in eight 75-day-gestation fetuses (term = 145 days) and either repaired in three layers or left unrepaired. There were four sham-operated fetuses, and all animals were alive at harvest. Repaired, unrepaired, and control fetuses were harvested at 7, 14, 21, and 70 days following surgery. The unrepaired fetuses demonstrated a complete cleft lip and alveolus with an oronasal fistula. The maxilla was asymmetrical, with the greater segment deviated toward the cleft and with decreased anterior maxillary width. In contrast, repaired cleft lip and alveolus animals showed no scar, normal thickness of the lip, and a symmetrical maxilla. Histologic analysis of the repaired wounds showed evidence of tissue regeneration without scar formation. The results of this preliminary study indicate that the fetal lamb cleft lip and alveolus model is technically feasible with an excellent survival rate. Healing occurs without scar formation. In the repaired animals, the maxilla was symmetrical. This model will be used to document facial growth following in utero repair of a cleft lip and alveolus.     

Analysis and treatment of hemifacial microsomia

Our experience over the past 25 years leads us to conclude that hemifacial microsomia is a progressive skeletal and soft-tissue deformity with the earliest skeletal manifestations in the mandible. We find that not only does the mandibular asymmetry become worse with time, but as the contralateral side grows, the deformed mandible also increases ipsilateral secondary deformation of the maxilla, nose, and orbit. We also find that there is virtually no "catch up" growth on the affected side of the face and that these patients always become more deformed with age. The psychological problems also increase with time and progression of the facial deformity. Based on our experience with correction of end-stage deformities, we now treat these patients at the earliest possible age, as determined by the patient's skeletal classification. We treat the mandible first in the hope that this repositioning in a more physiologic position will unlock the growth potential of the adjacent structures, minimize secondary deformity, and improve function and appearance to the greater benefit of the skeletal and psychological growth of the patient.     

Smooth-muscle tumors of the oral cavity

Smooth muscle tumors of the oral cavity are rare. The world literature revealed 80 leiomyomas and 21 leiomyosarcomas. We presented one new case of each lesion in this report and discussed diagnostic and treatment considerations and prognosis. Treatment recommendations for leiomyoma and leiomyosarcoma require an en bloc excision with at least 1-cm margins of normal tissue. Both lesions may look alike clinically and may not even be definitively differentiated histologically; therefore, a follow-up period of 5 years is suggested.     

Distraction osteogenesis of the porcine mandible: histomorphometric evaluation of bone

Distraction osteogenesis is a technique for skeletal lengthening that exploits the body's innate capacity for bone formation in response to tension forces on the repair callus. The authors developed a distraction osteogenesis model with a semiburied device in the Yucatan minipig mandible because of similarities between human and porcine mandibular anatomy, temporomandibular function, chewing patterns, and bone turnover rates. The purpose of this study was to measure histomorphometric bone fill after different latency periods, rates of distraction, and duration of neutral fixation in the minipig mandible. In addition, the relationship between histomorphometric bone fill and clinical stability was investigated. Mandibular osteotomies in 20 female Yucatan minipigs weighing 25 to 30 kg were distracted with modified semiburied distraction devices. Variables included 0-day or 4-day latency; 1-mm, 2-mm, or 4-mm daily distraction rates; gap size of 7 or 12 mm; and evaluation after neutral fixation for various lengths of time. Specimens were fixed in 2% paraformaldehyde, pH 7.4, before being embedded in methylmethacrylate. Sections were prepared from the region just below the inferior alveolar canal. The area of new bone formation within the gap was measured and expressed as a percentage of the total area of the distraction gap. Bone fill ranged from 0 to 100 percent. A pilot study with 7-mm advancements showed similar bone fill with 0-day or 4-day latency, but with poor reproducibility. Mandibles that were distracted to 12 mm at 1 mm per day exhibited nearly complete bone fill, either with 0-day latency (average, 93 percent) or 4-day latency (average, 100 percent). Mandibles that had been distracted for 3 days at 4 mm per day showed moderate osteogenesis and clinical stability with increasing time of neutral fixation. Bone fill was significantly correlated with clinical stability (Spearman r = 0.801, p = 0.001). Histological examination showed exuberant periosteal osteogenesis in distracted mandibles, even in those that showed poor bone fill and clinical stability. Thus, the periosteum appears to be a major source of new bone formation. These results show that osteogenesis was nearly complete with 1 mm per day and 0-day or 4-day latency. These results are consistent with the authors' previously reported clinical and radiographic observations that a latency period is not necessary for successful healing of the mandibular distraction osteogenesis wound.     

Dietary opportunism,resource partitioning,and consumption of coffee berry borers by five species of migratory wood warblers (Parulidae) wintering in Jamaican shade coffee plantations

Diets reflect important ecological interactions, but are challenging to quantify for foliage‐gleaning birds. We used regurgitated stomach samples from five primarily insectivorous species of long‐distance migrant warblers (Parulidae) wintering in two moderate‐elevation shade coffee farms in Jamaica to assess both foraging opportunism and prey resource partitioning. Our results, based primarily on 6120 prey items in 80 stomach samples collected during a one‐week period in March 2000, confirm opportunism. The diets of all five warblers, including American Redstarts (Setophaga ruticilla), Black‐and‐White Warblers (Mniotilta varia), Black‐throated Blue Warblers (S. caerulescens), Northern Parulas (S. americana), and Prairie Warblers (S. discolor), overlapped strongly based on consumption of the same prey types, even many of the same prey species (4 of 10 interspecific overlaps >0.9, range = 0.74–0.97). Moreover, all five species fed on similarly small, often patchily distributed prey, including coffee berry borers (Hypothenemus hampei; Coleoptera, Curculionidae). Nonetheless, permutational multivariate analysis of variance also revealed that the diets of these species differed significantly, primarily with respect to prey mobility (winged vs. sessile); American Redstarts fed on the most mobile prey, and Northern Parulas on the least mobile prey and a relatively restricted set of prey taxa compared to the other four species of warblers. Overall, our results suggest both dietary opportunism consistent with a migratory life‐history, and interspecific resource partitioning consistent with differences in morphology and foraging behavior during a food‐limited season. Having provided evidence of the three necessary conditions, namely intraspecific competition, resource limitation, and interspecific overlap in resource use, the results of our study, in combination with those of other studies, also provide evidence of interspecific competition among wintering migrant insectivores. We thus argue that diffuse interspecific exploitative food competition may be more important than previously recognized.     

Surgical correction of hemifacial microsomia in the growing child

This is a follow-up study of 20 children who had surgical correction of hemifacial microsomia in an effort to improve facial growth and minimize secondary distortion. In group 1 (skeletal types I and IIA), 10 children underwent elongation and lengthening of the mandible. In group 2 (skeletal types IIB and III), 10 children had total construction of a new temporomandibular joint and mandibular ramus with rib grafts and costochondral junction. In both groups, an open bite was created on the affected side to provide space for tooth eruption and downward growth of the middle face. The mean follow-up was 50.9 months (18 to 117 months) in group 1 and 45 months (18 to 50 months) in group 2. Analysis of our early results showed that all patients have had downward growth of the midface on the affected side. All five patients in group 1, followed to complete closure of the surgically created open bite, have maintained a level occlusal plane. In group 2, the one patient followed to completion of facial growth continues to have a level occlusal plane and facial symmetry. Appropriately timed mandibular construction and/or elongation in children with hemifacial microsomia is safe and effective. There is a decrease in secondary deformity on the affected side, and the eventual overall facial growth is optimized. Some group 2 children will need secondary elongation and augmentation of the mandible. Nevertheless, this study demonstrates that early mandibular correction may obviate the need for maxillary and orbital procedures in adulthood.