Spontaneous bone formation after mandible segmental resection in "krokodil" drug-related jaw osteonecrosis patient: case report

We report a case of a 48-year-old male patient with "krokodil" drug-related osteonecrosis of both jaws. Patient history included 1.5 years of "krokodil" use, with 8-month drug withdrawal prior to surgery. The patient was HCV positive. On the maxilla, sequestrectomy was performed. On the mandible, sequestrectomy was combined with bone resection. From ramus to ramus, segmental defect was formed, which was not reconstructed with any method. Post-operative follow-up period was 3 years and no disease recurrence was noted. On 3-year post-operative orthopantomogram, newly formed mandibular bone was found. This phenomenon shows that spontaneous bone formation is possible after mandible segmental resection in osteonecrosis patients.

The effects of systemic stress on orthodontic tooth movement

OBJECTIVES

To determine if systemic stress affects the biological reactions occurring during orthodontic tooth movement.

METHODS

Four groups of male 10 week-old Wistar rats were used. Group A animals (N=10) were restrained for one hour per day for 40 days; Group B animals (N=10) were restrained for one hour per day for three days; Group C (N=10) and Group D (N=8) animals were unrestrained. The upper left first molars in the rats in Groups A (long-term stress), B (short-term stress) and C (control) were moved mesially during the last 14 days of the experiment. The animals in Group D (N=8) were used for body weight and hormonal dosage comparisons only. They were not subjected to any stress and did not have appliances fitted. All animals were killed at 18 weeks of age and blood collected for measurement of plasma corticosterone. Tooth movement was measured with an electronic caliper. The right and left hemi-maxillae of five rats from each group were removed and the number of tartrate-resistant acid phosphatase (TRAP) positive cells, defined as osteoclasts, adjacent to the mesial roots of the upper first molars counted. The contralateral side in each animal served as the control (split-mouth design).

RESULTS

Corticosterone levels were significantly higher in the stressed groups (Groups A and B) than in the control group (Group C). Tooth movement was significantly greater in Group A (long-term stress) compared with Group B (short-term stress) and Group C (control), which did not differ from each other. There were significantly more osteoclasts in the long-term stress group than in the short-term stress and control groups.

CONCLUSION

Persistent systemic stress increases bone resorption during orthodontic tooth movement. Systemic stress may affect the rate of tooth movement during orthodontic treatment.

Three-dimensional finite elemental analysis of zygomatic implants in craniofacial structures

The objective of this study was to analyse stress distribution in craniofacial structures around zygomatic osseointegrated implants. An integrated system for Digital Imaging and Communications in Medicine (DICOM) data were utilized to create a three-dimensional model of craniofacial structures. The amount and distribution of the main stresses were compared using three-dimensional finite elemental analysis. The system allowed visual confirmation and analysis of stress distribution as well as the convenient and simple construction of a digital biomechanical model that provided details of anatomical structures in the regions of interest. Zygomatic implants with or without connected implants supporting the superstructure were compared. Stresses in severely resorbed maxillae with connected implants were not concentrated around the alveolar bone supporting the zygomatic implants. Stresses where there were no connected implants tended to be generated in the zygomatic bone, at the middle part of the zygomatic implant and at the joint of the fixture-abutment. Stress due to occlusal forces is mainly supported by the zygomatic bone, is transferred predominantly through the infrazygomatic crest, and is divided between the frontal and temporal processes of the zygomatic bone in different directions.

Tooth development included in the multifocal jaw lesions of Langerhans cell histiocytosis

Many cases demonstrating the oral manifestations of Langerhans cell histiocytosis (LCH) have been reported; however, tooth development in jaw lesions has rarely been mentioned. This paper reports the case of a 3-year-old Japanese girl with LCH suffering from multiple osteolytic lesions of the skull and jaw bones. She was referred to our paediatric clinic because of swelling of the mucogingival folds in the upper and lower primary molar regions. The patient responded well to steroid therapy and the osteolytic lesions resolved. There was an accompanying development of permanent tooth germs included in the lesions. Langerhans cell histiocytosis in children usually has a long-term clinical course and paediatric dentists should be involved with oral health care for affected patients.

[Nasopalatine canal cyst: 4 cases and a review of the literature]

OBJECTIVES

Nasopalatine cyst (NPC) is the most common epithelial and non-odontogenic cyst arising in the maxilla. It is nevertheless generally underestimated by ENT surgeons. The purpose of our report was to provide details about the pathophysiology, diagnosis and treatment of NPC.

MATERIAL AND METHODS

Our study was based on a retrospective analysis of four cases and a review of the literature.

RESULTS

From January 2002 to March 2003, four patients (3 males and 1 female, mean age 43 Years) were treated for NPC at the ENT Department of Grenoble University hospital. One patient had received prior treatment. Symptoms were a palatine mass on the midline of the hard palate behind the central maxillary incisors in two patients, and a superior vestibular mass in the two others. Diagnosis was established on the basis of the CT-scan and histological findings. Excision was performed under general anesthesia in all four patients. Median hospital stay was four days (3-5 days). There was no post-operative complication. Median follow-up was 10 Months.

CONCLUSION

NPC is arises from embryological tIssue. It must be differentiated from radicular cyst. Diagnosis is based on radiographic and histological results. Treatment consists in enucleation. Surgical access depends on the size of the cyst and its anterior or posterior extension. Excision must be total to avoid relapse which may occur after five Years. Long-term follow-up is essential.

[The analysis of masticatory efficiency after maxillofacial prosthetic treatment for unilateral maxillary defect]

OBJECTIVE

To evaluate the clinic results of maxillofacial prosthetic treatment for unilateral maxillary defect.

METHODS

Masticatory efficiency was tested before and after maxillofacial prosthetic treatment for unilateral maxillary defect.

RESULTS

There was significant difference between one week, one month, three months after treatment and before treatment(F = 0.635, P = 0.002). Masticatory efficiency was increased by 59.98% after one month.

CONCLUSION

Maxillofacial prosthetic treatment can significantly increase the masticatory efficiency of unilateral maxillary defect. It remains stable one month later.

Marsupialization for odontogenic keratocysts: long-term follow-up analysis of the effects and changes in growth characteristics

OBJECTIVE

This study evaluated the effects of marsupialization on odontogenic keratocysts (OKCs) and its role in conjunction with enucleation and curettage.

STUDY DESIGN

Twenty-eight primary OKCs, treated by marsupialization before enucleation and curettage, were examined in this study. The effect of marsupialization and recurrence data after a follow-up period of at least 3 years were evaluated. The changes of growth characteristics during marsupialization were analyzed by means of histopathologic and immunohistochemical studies with monoclonal anti-Ki-67 antibody.

RESULTS

The effect of marsupialization was evaluated as extremely effective (64.3%), moderately effective (32.1%), and poorly effective (3.6%). In 5 lesions, the cysts disappeared macroscopically and further surgery was not done. Recurrence was observed in 6 lesions (21.4%), and there was no significant difference in recurrence rates between the lesions treated with or without marsupialization. There appeared to be a predilection for recurrence in the lesions in the mandibular ramus region and also for radiographically multilocular lesions. Microscopic examination showed substantial changes from a parakeratinized or orthokeratinized epithelium into a hyperplastic, stratified, nonkeratinizing squamous epithelium after marsupialization in many cases. There was no significant difference in labeling index between premarsupialization (20.2% +/- 12.0%) and postmarsupialization (15.3% +/- 10.3%).

CONCLUSION

Marsupialization was found to be effective as a preliminary treatment for large OKCs. This procedure does not appear to affect the recurrence tendency of OKCs, and the probable changes in growth characteristics become rather less aggressive.

Idiopathic osteosclerosis of the jaws followed through a period of 20-27 years

AIM

The aim of the present study was to examine the prevalence of idiopathic osteosclerosis (IO) in a baseline sample and to follow the patients through an extended period of time.

METHODOLOGY

The sample consisted of 210 patients treated in a dental school and having a complete series of intraoral radiographs at the time of treatment and at a follow-up 10-17 years later. A further 10 years later, 130 patients had another follow-up.

RESULTS

Sixteen of the 210 patients were found to have IO, mostly in the mandibular molar and premolar regions. Fourteen had one lesion, one had two lesions and one had three lesions. The mean age of these patients was 47 years as compared to 44 years for the rest of the patient group. No sex predilection was found. At the first follow-up, one lesion had disappeared, one had reduced in size and one new lesion appeared. At the second follow-up, eight patients with IO could be re-examined. Two lesions, unchanged at the first follow-up, had reduced in size and two new lesions appeared. In the area of the new lesions, residual roots were observed in the earlier radiographs.

CONCLUSION

Our findings support the theory that IO lesions should be considered anatomical variants. In some cases, however, a local aetiological agent may cause development of structures with an identical appearance.

Hypothalamic-pituitary-adrenal axis activation by experimental periodontal disease in rats

Organisms respond to inflammatory conditions by mounting a co-ordinated complex series of adaptive responses involving the immune, nervous and endocrine systems that are aimed at restoring the homeostatic balance. We have recently shown in a rat model that inappropriate hypothalamic-pituitary-adrenal (HPA) axis regulation and a subsequent inability to mount a suitable glucocorticoid response to gingival inflammation may influence susceptibility to periodontal disease. This study was designed to investigate whether ligature- and bacterial lipopolysaccharide (LPS)-induced inflammation in the gingival connective tissues may activate this physiological axis, and to further explore the significance of HPA regulation in periodontal disease. Experimental periodontal disease was induced in major histocompatibility complex (MHC)-identical but HPA low (LEW) and high (F344) responding rat strains. We tested (1) whether ongoing periodontal disease activates the HPA axis as measured by corticosterone levels, and (2) whether genetic differences in HPA regulation modulate periodontal disease progression. In the F344 strain. the periodontal tissue destruction was more severe. This observation was associated with a significant increase of corticosterone levels in F344 rats only. Addition of LPS at the gingival inflammatory site led to a further increase of corticosterone levels and disease severity in F344 rats. These findings illustrate a positive feedback loop between the HPA axis and periodontal disease: the disease activates the HPA axis, and a genetically determined high HPA responsivity further increases disease susceptibility.

Orthodontic tooth movement enhances bone healing of surgical bony defects in rats

BACKGROUND

The question of whether the repair of an alveolar bony defect can be enhanced by orthodontic tooth movement was addressed.

METHODS

Alveolar bone defects were created in 52 Wistar male rats anterior to both maxillary first molars. After 1 week of healing, orthodontic protraction was applied for 2 weeks on the right side, resulting in mesial tipping and displacement movement. Subsequently, a retention appliance was inserted for 1 week. The left side served as the untreated (control) group. Vital bone staining (procion brilliant red H-8) was administered before and after orthodontic traction. Histomorphometric analysis was performed on 62 hemimaxillae using UV confocal microscopy and an imaging program. The total area of the bony defect was divided into 4 equal quadrants, and the area of bony apposition in each quadrant was measured.

RESULTS

The total area of bony apposition was 6.5-fold larger in the treated (26.41 x 10(4) +/- 28.92 x 10(4) microm2) than in the control group (4.07 x 10(4) +/- 2.82 x 10(4) microm2), approaching statistical significance (P = 0.065). The treated occlusal quadrants demonstrated highly significant (P= 0.010), greater bone apposition compared to the control group (13.8-fold) and to the treated apical quadrants (P= 0.04, 5-fold).

CONCLUSIONS

This study confirms that orthodontic tooth movement is a stimulating factor of bone apposition. A conversion in the repair pattern of the bony defect from apicoocclusal in the control group (no tooth movement) to occlusoapical in the treated group (with tooth movement) further supports the linkage between tooth movement and enhanced bone deposition. Clinical implication suggests incorporation of orthodontic tooth movement in regenerative therapy.

Effect of occlusal pressure on the histopathological changes in denture supporting tissues

Histopathological changes in the denture supporting tissues in relation to the occlusal pressure exerted through an experimental denture base were studied. An experimental denture, which prescribed the occlusal pressure by the amount of subsidence of the denture base (100, 50 and 13 microns), was constructed for the palate of the molar region of rat. Histopathological changes caused by the occlusal pressure were observed, and the intensity of the pressure was also estimated. In the 100 microns subsidence group, compression of epithelium and lamina propria mucosae, inflammatory change and bone resorption were caused by the occlusal pressure. In the 50 microns subsidence group, compression of epithelium and lamina propria mucosae and bone resorption were observed, while in the 13 microns subsidence group, no evidence of inflammatory change and bone resorption were observed. The epithelium and lamina propria mucosae recovered histopathologically depending on the gradual decrease of the occlusal pressure resulting from bone resorption, whereas no quantitative recovery of the resorbed bone tissue was observed in the 100 and 50 microns subsidence groups. From the results observed in this study, a high correlation was observed between the histopathological changes under a denture base and the intensity of the occlusal pressure, and the possibility of the existence of the threshold for bone resorption induced by occlusal pressure was suggested.

Etiologic aspects and orthodontic treatment of unilateral localized arrested tooth-development combined with hearing loss

In this study a case has been presented involving localized, arrested maxillary tooth development, asymmetric maxillary development, and unilateral loss of hearing. No similar case seems to have been described before. The orthodontic treatment comprised extraction of four permanent tooth germs in the maxilla and autotransplantation of mandibular teeth, followed by the use of fixed orthodontic appliances and a one-unit bridge restoration. Etiologic aspects are discussed. It is suggested that a severe attack of mumps that involved massive swelling of the parotid glands immediately after chicken pox and measles at the age of 4 to 5 years, may have resulted in a neurologic reduction of hearing and arrested tooth development. The teeth in which root development in relation to mumps does not appear to have been reported previously, whereas hearing loss after mumps has been reported. In the search for verification of this possible connection, children with arrested tooth development should be examined for reduction of hearing, and children with hearing loss after mumps ought to have their dental development checked.

Resistance of the maxillary ridge to occlusal trauma

Histories and clinical evaluations were obtained from 230 postmenopausal women aged 48 to 56 years to determine whether the alveolar height in the edentulous anterior region of the maxillae is adversely affected by the presence of mandibular incisors. Many of these women lost their teeth in early adulthood. When all subjects were included, the height of the ridge in the anterior region of the maxillae was not significantly altered by presence of mandibular incisors. When the ridge height was compared among those who had been edentate in the maxillae for less than 30 years, the difference between dentate and edentate subjects was significant. This study indicates that the alveolar ridges in the anterior region of the maxillae where teeth were extracted early in life during the rapid phase of bone metabolism are less disposed to bite trauma caused by the presence of the mandibular incisors than are individuals who lost their teeth in middle or old age.

Animal model for evaluating the effect of systemic estrogen deficiency on residual ridge resorption

The rate of resorption of residual ridges after tooth extraction varies among subjects. Despite many human studies, the etiologic factors of severe forms of resorption of residual ridges are unknown and probably multifactorial. To facilitate investigations of resorption of residual ridges, it is preferable to use an animal model with a dentoalveolar component similar to that of human beings. This study developed a rapid, nonhuman primate model in which one could measure resorption of residual ridges at the most critical period, with the least amount of time, minimal operation, and the least interference with normal nutrition. Three female Macaca fascicularis monkeys, 7 to 9 years old, were selected for simple extraction of four maxillary incisors, four mandibular incisors, and two mandibular canines. Lateral cephalographs were taken at weeks 0, 1, 2 to 3, 5 to 6, 8 to 9, 11 to 12, and 26 to 28 after extraction with a newly constructed cephalostat that allowed easy reproducibility of animal placement in the prone position. Height and area measurements were made of maxillary and mandibular anterior residual ridges in the superimposed cephalographs. Sequential mean bone loss data produced bone loss curves similar to those observed in humans. One animal underwent ovariectomy. The plasma levels of both estrogen and progesterone decreased over 25 days and stayed below the detection limits thereafter. Tooth extraction was done 4 weeks after the ovariectomy and the bone resorption pattern was able to be observed longitudinally with the newly established monkey cephalostat. The results indicated that Macaca fascicularis need not be sacrificed when used in longitudinal studies of resorption of residual ridges in a relatively short period of experimental time. This model can provide an excellent opportunity to investigate a causal relationship between the rate of resorption of residual ridges and predisposing systemic factors such as estrogen deficiency.

Aerodynamic estimates of induced anterior orifice openings in human subjects

This study first examined the accuracy of pressure-flow area estimates of experimental openings in anterior palatal obturators of three adult subjects. Second, we evaluated pressure-flow measures of the same experimental openings using a model. Results indicated that percent error in orifice estimates was slightly higher for induced openings in human subjects (13%) versus those in the model (11%). Results for our human subjects were similar to those reported by previous investigators.

Effects of primary alveolar bone grafting on maxillofacial development in the rabbit

Unilateral maxillary clefts were created in 4-week-old rabbits by removing premaxillary-maxillary sutures. Four groups, five animals per group, were formed. Control animals (Group I, no clefts) helped determine normal values for facial growth. In Group II the clefts were unrepaired. In Group III each had a rib graft harvested and placed into the alveolar defect only. In Group IV the cleft was completely grafted with multiple ribs to the nose. At six months postoperatively skeletons of all animals were directly measured and an orthogonal coordinate analysis compared maxillary and palatal growth among groups. Greatest deviations in growth were seen when the entire cleft was grafted; shortened maxillary development and nasal deflection to the clefted side occurred. Unrepaired clefts and grafts limited to the alveolus had maxillofacial development similar to that in unoperated controls. The location of grafts in clefts in infancy appears critical to avoid retarded maxillary growth.

Maxillary distal-extension removable partial denture abutments with reduced periodontal support

An in vitro study that used photoelastic models compared stress distribution characteristics of three maxillary, bilateral, distal-extension removable partial denture designs when the abutments were subjected to a progressive loss of periodontal support. One design used I-bar retention, a second design used a semiprecision, spring-loaded plunger attachment, and a third design used the ERA attachment. Both attachment designs were tested with and without splinted abutments. The ERA design was also tested with and without supporting rests and included light and heavy retention elements. Periodontal support loss up to 35%, a 60/40 crown-to-root ratio, resulted in increased stress concentrations. The ERA design with supporting rests, light retention elements, and splinted abutments compared very favorably with the I-bar retained design on nonsplinted abutments.

Maxillary bone resorption in patients with mandibular implant-supported overdentures or fixed prostheses

For several years, implant-supported overdentures have been used with excellent results in rehabilitation of the edentulous mandible. The effect on the antagonistic jaw bone resorption however, has not yet been evaluated. The aim of this study was to examine on orthopantomograms the anterior and posterior maxillary ridge resorption in three groups of patients with different mandibular prosthetic reconstructions: (1) overdentures supported by two implants, (2) fixed prostheses supported by four to six implants, and (3) complete dentures. The results indicated a more pronounced annual bone resorption in complete denture wearers compared to patients with implant-supported overdentures. A limited but continuing bone resorption was observed for the patients with implant-supported overdentures, and a slightly higher annual bone resorption occurred in the implant-supported fixed prosthesis group.

Craniofacial fibrous dysplasia showing marked involution postoperatively

There have been few reports in the literature concerning the long-term prognosis of fibrous dysplasia. We reported here a boy with craniofacial fibrous dysplasia, which showed marked involution at the end of his puberty.

Guided tissue regeneration in the treatment of infrabony defects on maxillary premolars. A pilot study

The present study evaluated clinically and radiographically the short-term results of the healing of infrabony defects at maxillary premolars treated according to guided tissue regeneration (GTR). 9 patients with bilateral presence of infrabony defects with or without furcation involvements at maxillary premolars were selected. At baseline assessments of plaque and gingival indices, bleeding, probing pocket depth and attachment level, and furcation measurements were recorded. Conventional radiographs were obtained in a way that assured a reproducible projection geometry. One premolar was randomly treated with GTR and the contralateral with open debridement. Clinical and radiographic examinations were performed again 6 months postoperatively. The bone tissue changes were assessed by means of conventional radiographs and subtraction images. Sites treated by both procedures demonstrated an improvement of gingival conditions and a reduction of pocket depths. A statistically significant attachment gain was obtained for the test (mean 1.2 mm), but not for the control sites (mean 0.6 mm). The differences, though, were not significant between the test and control sites. Limited improvement in furcation closure was recorded. The radiographic examination demonstrated loss of bone tissue in four sites treated with GTR. The findings suggest that the regeneration of the periodontal soft and bone tissues was not significantly enhanced with the GTR therapy.

Serial observation of asymmetry in the growing face

Three children suffering from facial asymmetry were observed annually using facial stereophotogrammetry before, during, and after their general skeletal adolescent growth spurt. Stereophotogrammetry allows accurate three-dimensional measurements between identifiable facial landmarks. Five pairs of bilateral parameters connecting external canthi and angles of the mouth to alae and tip of nose, and to each other, allowed a positive sign (right-side larger) or a negative (left-side larger) assessment of parameter asymmetry. Their total, taking sign into account, assessed mid-facial asymmetry. Serial observation showed that: (1) in patient no. 1 suffering from post-traumatic condylar hypoplasia, the facial asymmetry resolved; (2) in patient no. 2 suffering from unilateral facial hypoplasia, the asymmetry, which was severe, reduced with adolescence, but did not resolve; (3) in patient no. 3 suffering from fibro-osseous dysplasia of left maxilla, the asymmetry was reduced by surgery, but the full effects of the surgery were not measurable until over 1 year after operation; subsequently, the asymmetry began to increase again.

The effect of corticosteroid-induced osteoporosis on orthodontic tooth movement

The purpose of this research was to study the effect of corticosteroid-induced osteoporosis on orthodontic tooth movement and relapse. Sixteen 3-month-old New Zealand white rabbits were divided into four equal groups, two treatment and two control. All treatment rabbits were administered daily injections of 15 mg/kg cortisone acetate for 4 days before and during the experimental period. An orthodontic appliance delivering a mesial force of 4 ounces was placed on the maxillary left first molar of all animals. For all groups, measurements of active tooth movement were made after 4, 7, 11, and 14 days. For two of the groups, appliances were removed on day 14, and additional measurements of relapse were made through day 21. With the use of radiodensitometric readings of the humerus bone and histology of the maxilla, osteoporosis was demonstrated in the treatment animals. Mean incremental and cumulative active tooth movement was three to four times greater (p < 0.0001) in the treatment rabbits than in the controls. The treatment group in which relapse was measured demonstrated 100% relapse on day 18, whereas the control group relapsed at a much lesser rate through day 21 and never achieved 100% relapse. Histologic findings appeared to support tooth movement results. In conclusion, the results of this study indicate that rabbits subjected to corticosteroid-induced osteoporosis undergo significantly more rapid orthodontic tooth movement and subsequent relapse than control animals.

Dentigerous cyst--an attempt to ascertain the normal eruption of involved tooth in child patient

Dentigerous Cyst, in a young patient, located in the right palatal region, extending from 61 to 55, limited to the right side of mid-palatine suture and treated by marsupialization with post operative follow-up of 6 months has been reported. The involved permanent tooth (21) entrapped in the cyst was not extracted and found to erupt in normal direction.

Orofacial functions in patients with congenital and acquired maxillary defects: a fluoroscopic study

By means of videofluoroscopic recordings, chewing, swallowing and speech were monitored in nine patients with congenital and acquired maxillary defects. All of them were rehabilitated with a maxillary obturator prosthesis. The defective region was seldom used for chewing. No leakage between the obturator and surrounding tissue was observed, either for solids or for liquids. All of the prosthetic reconstructions were surprisingly stable during function. In the phonetic analysis, speech production was judged to be restored almost to normal. Videofluoroscopy may be valuable as a complement to other functional diagnostic procedures, and for the evaluation and improvement of rehabilitation with an obturator prosthesis.

Blood flow in jaw bones affected by chronic osteomyelitis

In order to study circulatory changes throughout the course of chronic osteomyelitis of the jaws, blood flow in bone affected by osteomyelitis was assessed in 14 patients, by means of laser Doppler flowmetry (LDF). The difference in perfusion between the osteomyelitic bone and corresponding sites on the opposite healthy jaw was evaluated. The patients were classified into two groups according to the clinical activity of their disease. A significantly reduced bone blood flow was recorded in the jaw during non-active stages, while an increased flow was associated with the initial stage of disease and the inflammatory exacerbations. No pre-existing vascular disorders were discovered prior to the development of this disease. However, a long standing local inflammation of the jaw bone was associated with a persistent reduction in blood flow. In 12 healthy subjects, blood flow in the left jaw was found not to be statistically different to that in the right jaw.

Conservative approach to unerupted teeth within cystic lesions in Gorlin's syndrome

The unerupted maxillary canine is the tooth that most commonly requires surgical exposure and guided eruption. The orthodontic specialist must be aware that delayed eruption is caused, sometimes, by serious pathologic conditions such as cystic or neoplastic malformation. A case of a 12-year-old girl who suffered from Gorlin's syndrome (nevoid basal cell carcinoma syndrome) is presented. Her symptoms were multiple jaw keratocysts, skeletal anomalies, and cleft lip and palate. Some authors advocate an aggressive surgical approach to jaw keratocysts because of their tendency to recur, thus sacrificing those teeth associated with them. Our view is that in young patients with Gorlin's syndrome, an attempt should be made to preserve permanent teeth, especially those vital for a normal growth pattern of the jaws. Therefore we recommend a conservative surgical approach, enabling guided eruption of unerupted teeth associated with cystic lesions in patients with Gorlin's syndrome.

The tongue flap: placement and fixation for closure of postpalatoplasty fistulae

A tongue flap is frequently used for closure of fistulae following cleft palate repair. Early tongue flap dehiscence is a troublesome complication. While the tongue flap is a very effective means of functionally obliterating the transpalatal oronasal opening, the final appearance of the repair leaves much to be desired. More often than not, the tongue tissue appears bulky and unnatural in the roof of the mouth. A method is described that overcomes the problem of flap detachment during the early postoperative period by suspending and supporting the tongue pedicle with a palatal sling. On peroral view, the repaired area has a better appearance when the tongue flap lines the nasal side rather than the oral side as in conventional procedures.

Serious circulatory disturbance after Le Fort I osteotomy. A case report

Severe impairment of the blood supply occurred in a patient who underwent a Le Fort I type osteotomy in which the fragment was displaced in a cranio-dorsal direction. Necrosis with sequestration of the torus palatinus present and some permanent parodontal damage ensued. Alternative procedures and management of developing circulatory impairment during surgery are discussed.

The primordial cyst (odontogenic keratocyst): its tumour-like characteristics and behaviour

The clinical behaviour of primordial cysts frequently mimics that of benign tumours. They are characterised by aggressive growth and a tendency to recur following surgical treatment. Displacement of teeth, resorption of the roots of teeth, 'seeding' of the cyst into soft tissue and pathological fracture of the mandible exemplify this behaviour. These features are described and fully illustrated by examples from a series of 60 cases. The results of various surgical procedures are evaluated.

A comparative study of the clinical and histological features of recurrent and non-recurrent odontogenic keratocysts

The clinical features of 44 recurrent odontogenic keratocysts were compared with those of 228 single non-recurrent keratocysts which had been followed for 5 or more years. Histological comparisons were made with 44 non-recurrent cysts matched for age, sex and site. There were no significant differences in the age, sex and site between patients with recurrent and non-recurrent cysts. There were no significant histological differences except for a greater amount of inflammation in the non-recurrent cysts. It is suggested that operative factors have a major influence on the likelihood of recurrence.

Diffuse, increased radiodensity of the maxilla and mandible

The case presented here demonstrates the radiographic changes characteristic of osteopetrosis; and in conjunction with normal laboratory findings, the diagnosis is confirmed. Of particular interest is the lack of history of bone fractures or infection, in view of multiple previous extractions. Practitioners must be careful not to assume that such a history implies immunity to complications. Once the diagnosis of osteopetrosis has been made, treatment for all patients should be directed toward restoration and retention of teeth with emphasis on excellent oral hygiene.