Primary Palate Reconstruction Combined With Cranio-Maxillo-Facial Fixation After Self-Inflicted Gunshot Wound Injury: Critical Incision Planning for Regional Flap Reconstruction

Self-inflicted gunshot wounds (GSW) to the palate result in complex bony and soft tissue trauma to the mid and upper face. Patients who survive these injuries are faced with significant speech and feeding difficulties. Upper and midface fractures open reduction and internal fixation (ORIF) is required for many of these patients, and consideration to incision planning is critical in order to preserve a primary option for oroantral fistula repair. The temporoparietal fascia (TPF) flap is an excellent option for primary palate repair as it is often exposed in the operative field during facial fracture ORIF and can be readily used for this purpose if its blood supply and width is not inadvertently compromised while making a temporal incision. This flap is easy to elevate, does not require any microvascular expertise, and using the TPF to reconstruct the palate injury primarily may save the patient years of wearing an obturator and/or subsequent trips to the OR for operative fistula management. In contrast to the temporalis muscle flap, this flap does not create temporal hollowing after elevation, which is a significant aesthetic complaint among patients. Proper incision planning is critical to preserve this flap as an option for palate fistula repair as the fascial layer is often incised when making coronal incisions. Primary repair of palate injuries using the TPF flap at the same time as upper facial ORIF has very little morbidity in this setting, and greatly augments patients' quality of life.

Management of After-Hours Pediatric Dental Emergencies Among Pediatric and General Dentists

Purpose: Assess how pediatric dentists (PD) and general practitioners (GP) manage after-hours pediatric dental emergencies according to perceived urgency. Methods: A survey was e-mailed to PD and GP in North Carolina. Participants responded to management of 18 cases (primary and permanent dentition) according to perceived urgency. Repeated-measures logistic regression was used to analyze factors influencing perception of clinical scenarios. Results: Response rates for PD and GP were 45.5% and 36.3%, respectively. Perceived urgency varied by clinical scenarios, dentition (primary vs. permanent), and practitioner (PD vs. GP) (P<.001). Practitioners with fewer years in practice or seeing fewer pediatric patients managed more cases as urgent. Traumatic injuries in primary dentition (intrusion, pulp exposure, palatal displacement, avulsion) were managed as more urgent by GP than PD (P<.001). Emergencies related to infection and permanent dentition were perceived similarly by PD and GP. Conclusions: Clinical scenarios highlighted disagreement in the management of after-hours pediatric dental emergencies between GP and PD, especially trauma in primary dentition. General practitioners tended to refer to an ED or see urgently, and PD tended to defer care. By identifying needs for improved education in dental trauma management, we can increase utilization of the dental home, avoiding use of overburdened EDs.

Unusual Case of Graphite Tattoo in a Pediatric Patient: Clinical Presentation and Differential Diagnosis

Graphite tattoo, a rare finding in children, is characterized by a localized blue-grey macule of variable sizes and shapes. Intraoral graphite implantation may cause this pigmentation through accidental injury with a graphite pencil. The purpose of this paper is to report an unusual case of graphite tattoo involving the anterior palate region in a seven-year-old girl. A diagnosis was made based on clinical and radiographic examinations and histopathology features. This report also highlights the importance of differential diagnosis and management of oral benign and malignant pigmented lesions in children.

Transpalatal screw traction: a simple technique for the management of sagittal fractures of the maxilla and palate

Sagittal fractures of the maxilla and palate are uncommon in clinical practice. Current methods for the management of such fractures have advantages and limitations. The authors present the simple and practical technique of bilateral transpalatal screw traction to manage this fracture type.

Fellatio-associated petechiae of the palate: report of purpuric palatal lesions developing after oral sex

Fellatio--a sexual act in which the penis is placed into the mouth of another person--can result in submucosal hemorrhage of the palate. A young woman with fellatio-associated palatal petechiae is reported and the features of irrumation-induced oral lesions of the palate are reviewed. Fellatio-associated petechiae and purpura can potentially occur in anyone who engages in receptive penile oral sex. The lesions are asymptomatic and typically appear on the soft palate. Because the fellatrix or fellator may be unaware of the etiology of the lesions or may be reluctant to provide these details of the sexual history, the clinician needs to have a high index of suspicion based on the patient's clinical presentation and collaborating history of preceding fellatio.

[Automutilation of the palate in a psychiatric patient]

A 46-year-old man with a history of alcohol abuse was referred to an oral and maxillofacial surgeon with a large necrotic wound with raised edges on the palate. After history taking, radiography and clinical assessment, together with a psychiatrist, the lesion was diagnosed as an automutilation resulting from a period of alcohol abstinence. After a period of care in a medical centre, the lesion improved quickly. Following this treatment, the patient was admitted to a psychiatric treatment centre for supplemental treatment of his addiction problems.

[Early effectiveness of combining radial forearm free flap and adjacent tissue flap in reconstruction of palatomaxillary defects]

OBJECTIVE

To investigate the method of combining radial forearm free flap and adjacent tissue flap in reconstruction of palatomaxillary defects and its effectiveness.

METHODS

Between March 2005 and May 2010, 17 patients with palatomaxillary defects were treated. There were 11 males and 6 females with an age range of 45-74 years (mean, 62.5 years), including 1 case of benign tumor and 16 cases of malignant tumors (7 cases of squamous cell carcinoma of palate, 1 case of recurring squamous cell carcinoma of palate, 1 case of malignant melanoma of palate, 1 case of adenoid cystic carcinoma of palate, 1 case of malignant melanoma of maxilla, 1 case of ductal carcinoma of maxilla, and 4 cases of squamous cell carcinoma of maxilla). The maxillectomy defect ranged from 7.0 cm x 5.5 cm to 10.0 cm x 7.5 cm. According to Brown's classification for the maxillectomy defect, there were type II in 15 cases, type III in 2 cases. Palatomaxillary defects were repaired with radial forearm free flap and buccal fat pad in 11 cases, and with radial forearm free flap, buccal fat pad, and mandibular osteomuscular flap pedicled with temporal muscle in 6 cases. The effectiveness was evaluated after operation by observing the vitality of the flap, the functions of speech, swallowing, breath, and the facial appearance.

RESULTS

All cases were followed up 6-12 months without tumor recurrence. All flaps and skin grafts at donor sites survived. The functions of speech, swallowing, and breath were normal without obvious opening limitation. The facial appearance was satisfactory without obvious maxillofacial deformity. No enophthalmos occurred in patients with orbital floor and infraorbital rim defects. The patients had no oronasal fistula with satisfactory oral and nasal functions.

CONCLUSION

According to the type of palatomaxillary defects, it can have good early effectiveness to select combining radial forearm free flap and buccal fat pad or combining radial forearm free flap, buccal fat pad, and mandibular osteomuscular flap for repairing defects.

Successful minimally invasive management of primary maxillary central incisors after lateral luxation: a case report

Lateral luxation in primary maxillary incisors is a traumatic injury that can lead to darkening of the tooth, pulp necrosis, root resorption, and damage to the permanent teeth. Management of this kind of trauma typically includes pulpectomy or extraction in cases of root resorption. However, in young children, removal of the tooth may be psychological stressing, especially for the parents, while increased mobility can make immediate endodontic treatment difficult to perform. This article outlines a severe palatal luxation on the maxillary right central incisor treated with conservative management in a 2-year-old boy. At the one-year follow-up appointment, the surrounding bone was healthy, the roots displayed physiological resorption, the crowns showed color improvement, and there was no radiographically noticeable damage to the permanent teeth.

[Reconstruction of large through-and-through palate defects with folded free forearm flap]

OBJECTIVE

To explore the reconstruction method of large through-and-through palate defects.

METHODS

From 2003 to 2006, 7 cases of large through-and-through palate defects were reconstructed with vascularized folded free forearm flap. 8 flaps were used, including 7 free forearm flaps and 1 pectoralis major myocutaneous flap.

RESULTS

All the tissue flaps survived well except one flap necrosis because of arterial thrombosis. The appearance of reconstructed palate was acceptable, and the functions of swallowing and speech were normal or almost normal.

CONCLUSIONS

It is feasible and effective to repair large through-and-through palate defects with folded free forearm flap.

[A pitfall of AirWay Scope--an experience of distinctive airway edema after palatal laceration caused by irWay Scope]

Pentax AirWay Scope (AWS) is a new videolaryngoscope which allows indirect visualization of the vocal cords and provides a better laryngeal view compared with the conventional Macintosh laryngoscope. We report a female patient who developed distinctive upper airway edema after palatal laceration at the time of insertion of the AWS. She was scheduled for tympanoplasty. After anesthesia induction, there was technical difficulties in tracheal intubation with Macintosh laryngoscope (her Cormack grade was rated as 3), and we used the AWS, but could not obtain an appropriate view on the monitor. When the device was removed, we detected bleeding derived from the right palatal laceration. Following the aspiration of the blood, we could barely achieve tracheal intubation with a flexible fiberscope without hypoxemic episode. The upper airway including the arytenoid and vocal cords were distinctively edematous after the operation. Then, the tracheal tube was left for three days after the operation, to secure the airway until the reduction of airway edema. On the postoperative day 4, following the fibroscopic confirmation that the airway edema was reduced, the patient was extubated successfully. AWS should be used more carefully, especially at the time of insertion along the palate.

Diagnosing abuse: a systematic review of torn frenum and other intra-oral injuries

INTRODUCTION

A torn labial frenum is widely regarded as pathognomonic of abuse.

METHODS

We systematically reviewed the evidence for this, and to define other intra-oral injuries found in physical abuse. Nine studies documented abusive torn labial frena in 27 children and 24 [corrected] were fatally abused: 22 were less than 5 years old. Only a direct blow to the face was substantiated as a mechanism of injury.

RESULTS

Two studies noted accidentally torn labial frena, both from intubation. Abusive intra-oral injuries were widely distributed to the lips, gums, tongue and palate and included fractures, intrusion and extraction of the dentition, bites and contusions.

CONCLUSIONS

Current literature does not support the diagnosis of abuse based on a torn labial frenum in isolation. The intra-oral hard and soft tissue should be examined in all suspected abuse cases, and a dental opinion sought where abnormalities are found.

Evaluation of a Collagen-Glycosaminoglycan Dermal Substitute in the Dog Palate

Tissue shortage complicates surgery of cleft lip and palate. The healing of defects on the palate impairs growth of the dentoalveolar complex because of scar tissue formation. Implantation of a matrix into the wound might overcome this adverse effect. Integra with and without a silicone top layer was implanted into standardized full-thickness wounds (Ø 6 mm) in the palatal mucoperiosteum in beagle dogs. In some wounds, the silicone layer was removed after 14 days. Control wounds did not have an implant. At 2 and 4 weeks post-surgery, the wounds were assessed for epithelialization, inflammation (hematoxylin and eosin, leucocyte protein L1), number of myofibroblasts (alpha smooth muscle actin), and general histological characteristics. Wounds filled with Integra without the silicone layer showed fewer myofibroblasts and inflammatory cells than the sham wounds. Collagen fibers were more randomly orientated in these wounds than in the sham group. Wound closure was found to be retarded, and many inflammatory cells were present when Integra with silicone was implanted. The silicone layer was lost within 4 weeks in these wounds. We conclude that, in the moist oral environment, the silicone of Integra is not required. Re-epithelialization and tissue integration proceed more favorably without it. Further research in the dentoalveolar development with Integra will be conducted in a simulated cleft palate repair in the dog model.

Conventional radiographs: are they still the standard in localization of projectiles?

The penetration of air gun pellets in facial soft tissue can cause major problems during the removal of foreign bodies, although conventional radiography, computed tomography, image-guided surgical removal, and ultrasound have been applied to facilitate the procedure. It was the aim of the present case report to introduce a modified intraoperative method for the localization of air gun pellets, based on the use of radiopaque markers in conventional radiographs. A 66-year-old patient attempted to commit suicide by using an air gun. The pellet hit the right temporal region. A computed tomographic (CT) scan was acquired to localize the foreign body. The first attempt to remove the pellet through the penetrating wound failed. Because of a dislodgement of the pellet, the CT scan could no longer be used for the localization of the air gun pellet. As the air gun pellet was positioned under the zygomatic arch, ultrasound was unable to identify its position. Successful intraoperative localization of the projectile was performed after fixation of radiopaque markers to the skin in the region of the estimated localization, with conventional radiographs in 2 planes, acquired with a mobile dental x-ray device. Although the markers remained attached to the patient as reference makers, the air gun pellet was removed easily. The use of radiopaque markers in conventional radiographs in 2 planes allows fast, intraoperative localization of radiopaque foreign bodies within soft tissue. The procedure can be carried out with a conventional x-ray device that should be available in every oral and maxillofacial practice. The use of reference markers should be considered a standard procedure for the localization of radiopaque foreign bodies in the head and neck.

Ultrasonic osteotomy as a new technique in craniomaxillofacial surgery

Ultrasound osteotomy is a new surgical technique used in dentistry to section hard tissues without damaging adjacent soft tissues. It was hypothesized that this could also be useful in craniofacial and orthognathic surgery. An ultrasonic device was employed in the following craniofacial surgical procedures: 144 Le Fort I osteotomies, 140 palatal expansions after Le Fort I osteotomies and 140 bilateral sagittal osteotomies; 2 Le Fort III osteotomies for treatment of Crouzon syndrome in two patients; 12 cases of unicortical calvarial bone grafting; removal of superior orbital roof in 25 cases of craniofaciostenosis; removal of external wall of the orbit in 10 cases of orbital cavity tumour; removal of anterior and posterior walls of the frontal sinuses in four cases of orbital cavity tumour. Integrity of soft tissues and surgical time were evaluated. Functional results were good without any soft-tissue damage being observed, but the overall operative time was increased. Ultrasound osteotomy is a new technical procedure that is advantageous for bone cutting in multiple situations, with minimal to no damage in adjacent soft tissues such as brain, palatal mucosa and the inferior alveolar nerve.

Amniotic fluid induces rapid epithelialization in the experimentally ruptured fetal mouse palate--implications for fetal wound healing

Cleft of the secondary palate is one of the most common congenital birth defects in humans. The primary cause of cleft palate formation is a failure of fusion of bilateral palatal shelves, but rupture of the once fused palate has also been suggested to take place in utero. The possibility of post-fusion rupture of the palate in humans has hardly been accepted, mainly because in all the cleft palate cases, the cleft palatal edge is always covered with intact epithelium. To verify whether the intrauterine environment of the fetus plays roles in wound healing when the once fused palate is torn apart, we artificially tore apart fetal mouse palates after fusion and cultivated them in culture medium with or without mouse or human amniotic fluid. We thereby found that the wounded palatal edge became completely covered with flattened epithelium after 36 hours in culture with amniotic fluid, but not in culture without amniotic fluid. Using histological and scanning electron microscopic analyses of the healing process, it was revealed that the epithelium covering the wound was almost exclusively derived from the adjacent nasal epithelium, but not from the oral epithelium. Such actions of amniotic fluid on the fetal wound were never simulated by exogenous epidermal growth factor (EGF), albumin, or both. In addition, the rapid epithelialization induced by amniotic fluid was not prevented by either PD168393 (an inhibitor of the EGF receptor-specific tyrosine kinase) or SB431542 (a specific inhibitor of TGFbeta receptor type I/ALK5). The present study provides new insights into the unique biological actions of amniotic fluid in the repair of injured fetal palate.

Role of secreted frizzled-related protein 1 (SFRP1) in wound healing

Wound healing is a complex cascade of events, which diminishes the size of the wound and reestablishes tissue integrity. Secreted frizzled-related protein 1 (SFRP1) contributes to the inhibition of apoptosis in fibroblast populations. We investigated the role of SFRP1 in a mouse wound-healing model; 2.0-mm excisional wounds were created in the scalp and hard palate. Healing responses were measured by histomorphometric analysis, apoptosis assay, and immunohistochemistry. Dermal wounds did not harbor SFRP1, but healed faster than palatal wounds which expressed significant levels of SFRP1. Antibody experiments aimed at blocking SFRP1 in palatal wounds resulted in promotion of wound closure, enhancement of new tissue formation, decrease of inflammatory cell infiltrate, and increase of apoptotic fibroblasts. Analysis of the present data suggests that SFRP1 may be partly responsible for the poorer healing performance of the palatal wounds compared with dermal wounds. Blocking SFRP1 results in improvement of palatal healing outcomes.

Two patterns of impalement injury to the oral cavity: Report of four cases and review of literature

Impalement injuries to the oral cavity are common, and typically resolve with minimal intervention. We encountered two distinct patterns of injury that required active intervention in four consecutive patients. The first two patients, aged 2 and 7 years, sustained injuries to the floor of mouth and subsequently developed infectious complications necessitating surgical drainage. The other two, aged 4 and 5 years, sustained injuries to the junction of the hard and soft palate, avulsing deep flaps that required repair. Neurovascular complications, despite their rarity have earned maximal discussion in the literature. We feel that traumatic lacerations and infectious complications have far more clinical relevance due to their frequency of occurrence, and should thus occupy a more prominent position in the management flow chart.

Repair of palatal bone defects using osteogenically differentiated fat-derived stem cells

BACKGROUND

Although autogenous bone grafting remains the standard in the reconstruction of bone defects, disadvantages may include limited amount of bone and donor-site morbidity. Tissue engineering approaches can potentially obviate these problems. Fat contains a population of stem cells that can be isolated and differentiated into various cell lines, including osteocytes, adipocytes, and myocytes, depending on the culture conditions. In this study, the authors used osteogenically differentiated fat-derived stem cells to repair rat palatal bone defects.

METHODS

Fat-derived stem cells were isolated, differentiated into osteocytes in osteogenic medium, and seeded onto poly-L-lactic acid scaffolds. Rat palatal bone defects were surgically made and animals divided into four groups according to the type of implant for bone repair: group I, empty defect; group II, poly-L-lactic acid without cells; group III, poly-L-lactic acid with undifferentiated fat-derived stem cells; and group IV, poly-L-lactic acid with osteogenically differentiated fat-derived stem cells. Palates were harvested at 6 or 12 weeks after implantation (n = 8 per group at each time interval). Hematoxylin and eosin staining, immunohistochemical staining for osteocalcin, and histomorphometric measurements of new bone were performed.

RESULTS

Defects in groups I, II, and III had no bone and were primarily filled with fibrous tissue. In contrast, there was substantial bone regeneration in group IV, which was statistically significant by histomorphometry compared with groups I, II, and III. Newly formed bone in group IV stained positive for osteocalcin.

CONCLUSIONS

The authors successfully reconstructed palatal bone defects using absorbable three-dimensional scaffolds seeded with osteogenically differentiated fat-derived stem cells. This study demonstrates the feasibility of reconstructing bony defects with fat-derived stem cells.

Palatal development of preterm and low birthweight infants compared to term infants -- What do we know? Part 3: discussion and conclusion

BACKGROUND

It has been hypothesized that prematurity and adjunctive neonatal care is 'a priori' a risk for disturbances of palatal and orofacial development which increases the need for later orthodontic or orthognathic treatment. As results on late consequences of prematurity are consistently contradictory, the necessity exists for a fundamental analysis of existing methodologies, confounding factors, and outcomes of studies on palatal development in preterm and low birthweight infants.

METHOD

A search of the literature was conducted based on Cochrane search strategies including sources in English, German, and French. Original data were recalculated from studies which primarily dealt with both preterm and term infants. The extracted data, especially those from non-English paper sources, were provided unfiltered in tables for comparison (Parts 1 and 2).

RESULTS

Morphology assessment of the infant palate is subject to non-standardized visual and metrical measurements. Most methodologies are inadequate for measuring a three-dimensional shape. Several confounding factors were identified as causes contributing to disturbances of palatal and orofacial development.

CONCLUSION

Taking into account the abovementioned shortcomings, the following conclusions may be drawn for practitioners and prospective investigators of clinical studies. 1) The lack of uniformity in the anatomical nomenclature of the infant's palate underlines the need for a uniform definition. 2) Metrically, non-intubated preterm infants do not exhibit different palatal width or height compared to matched term infants up to the corrected age of three months. Beyond that age, no data on the subject are currently available. 3) Oral intubation does not invariably alter palatal morphology of preterm and low birthweight infants. 4) The findings on palatal grooving, height, and asymmetry as a consequence of orotracheal intubation up to the age of 11 years are inconsistent. 5) Metrically, the palates of orally intubated infants remain narrower posteriorly, beginning at the second deciduous molar, until the age of 11 years. Beyond that age, no data on the subject are currently available. 6) There is a definite need for further, especially metrical, longitudinal and controlled trials on palatal morphology of preterm and low birthweight infants with reliable measuring techniques. 7) None of the raised confounding factors for developmental disturbances may be excluded until evident results are presented. Thus, early orthodontic and logopedic control of formerly premature infants is recommended up to the late mixed dentition stage.

[The usage of the whole palate flap in maxillofacial surgery]

OBJECTIVE

To study the clinical effects, the merits and shortcomings of the hard palate flap in repairing postoperative defects of oral soft tissue.

METHODS

The whole-palate flap pedicled with the unilateral greater palatine artery was used to repair 25 cases of oral soft tissue defects.

RESULTS

Of the 25 cases, 22 flaps survived completely and 2 flaps survived partially. The postoperative appearance and functions were satisfactory.

CONCLUSION

Compared with other flaps, the hard palate flap is easier to harvest and use. It has reliable blood supply and does not harm the patients' appearance and function. It is one of the most desirable methods for repairing the oral soft tissue defect.

Midfacial fractures in children and adolescents: a review of 492 cases

We studied the records of children and adolescents admitted to our hospital with facial fractures between 1993 and 2002. During the 10-year period, 492 patients with 555 midfacial fractures were treated. Their ages ranged from 1 to 18 years, the peak incidence being between 16 and 18. Three-hundred and eighty (77%) were boys. The zygoma was the most commonly fractured bone (n = 286), and the hard palate the least commonly fractured (n = 6). Motor-vehicles were responsible for 272 (55%) of all fractures. Most fractures were treated by closed reduction, and only 139 (25%) were treated by observation. Complications, including unsatisfactory fracture repair and infection, were recorded in 18 (4%) and the overall mortality was 1% (n = 8).

Nasotracheal intubation: an unusual cause of palatal perforation in an insulin dependent diabetes mellitus patient

A case of palatal perforation occurring in 7-year-old girl with IDDM due to nasotracheal intubation is reported. The child, who was not previously diagnosed of IDDM, was brought to hospital in comatose stage and was put on nasotracheal tube for maintaining respiration. This paper highlights the link between IDDM and palatal perforation communicating the nasal cavity due to naso-tracheal intubation.

[A patient with Prader-Willi syndrome. Characteristics, oral consequences and treatment options]

A dentist referred a 32-year-old man with the Prader-Willi syndrome to a center for special dental care because of the poor cooperation of the patient, progressive toothwear and advanced palatal trauma. The dental problems were, among others, caused by the disto-relation (Class II-2), a poor oral hygiene, the frequency of sugar intake, oesophageal reflux and a strongly reduced salivary pH of 5.5. Treatment of the dentition was established by minimal invasive and adhesive dentistry.

Evidence for fibroblast growth factor receptors in myofibroblasts during palatal mucoperiosteal repair

Fibroblast growth factors (FGFs) regulate cell growth and differentiation and play crucial roles in the process of tissue repair and remodelling. We have previously shown that basic FGF is widely expressed at the injured site. Since the presence of FGF receptors (FGFRs) determines cellular responsiveness, we examined the localisation of FGFR1, FGFR2 and FGFR3 expression by immunohistochemistry throughout the repair of full-thickness excisional wounds up to 28 days after wounding. Strong expression of FGFR1 was observed in the nuclei of myofibroblasts, which are characterised by alpha-smooth muscle (alpha-SM) actin expression. The weak expression of FGFR2 was also observed in the nuclei of myofibroblasts. In contrast, there was no staining for FGFR3 in fibroblasts through the wound healing process. In addition, transforming growth factor-beta1 (TGF-beta1), a potential inducer of myofibroblasts, enhanced the expression of FGFR1 and FGFR2 in the nuclei of palatal fibroblasts in vitro. These findings suggest that FGFR1 and FGFR2 in myofibroblasts may be responsible for the signal transduction of FGF during the wound healing process.

Use of the radial forearm flap for deep, central, midfacial defects

Six cases that required soft-tissue replacement in the central midface are presented. The greatest number of flaps were used for large defects in patients with cleft palates who had undergone multiple previous operations. Several were for palatal defects attributable to cocaine abuse, and one was used for lining in a nasal reconstruction. There were no flap losses and, on the basis of these experiences, it is concluded that this is an excellent method for providing soft tissue in these difficult situations.

[Continued physical capacity after head gunshot injury]

The human brain shows a very high density of functionally important structures. Even small lesions may therefore cause clinical symptoms. Penetrating gunshots to the head are presumed to cause immediate incapacitation by subsequent disturbance of cerebral functions. The authors discuss anatomical and functional principles of the terms action, capacity to act and incapacitation and report two illustrative cases with lack of incapacitation following gunshots to the head.

Reversed palatal perforation by upper incisors in ageing blind mole-rats (Spalax ehrenbergi)

Blind mole-rats (Spalax ehrenbergi) are fossorial solitary rodents that present striking morphological, physiological and behavioural adaptations to the subterranean environment in which they live. Previous studies have shown that mole-rats are specialised in tooth-digging. The rapid eruption-rate of their incisors has evolved to compensate for their excessive wear by excavation. Males use their incisors more than females for digging and fighting, and their rate of incisor eruption is significantly more rapid than in females. Since mole-rats use their incisors for digging throughout the year, we suggest that continuous mechanical pressure on their oral tissues concentrated at the apical sites of the upper incisors leads to cell and tissue fatigue. We provide evidence for 5 stages of palatal perforation by the upper incisors at their apical sites, with maximum perforation characterising aged males. Interspecies comparisons with 7 other fossorial and semi-fossorial rodent species, and with beavers, which expose their incisors to enormous mechanical pressure, revealed that this palatal perforation is unique to the male mole-rat. We suggest that while the fast eruption rate of incisors in the mole-rat compensates for the rapid wear resulting from digging, evolutionary adaptation to continuous tooth-digging is still ongoing, since the physical pressure of digging at the apical sites of the upper incisors leads to tissue destruction, breakage of the palatal bone and possibly to death, as a result of maxillary inflammation.

Local injection of IFN-gamma reduces the number of myofibroblasts and the collagen content in palatal wounds

Wound contraction and scar formation after cleft palate surgery impair maxillary growth and dentoalveolar development. Since myofibroblast numbers and scar formation are reduced by interferon-gamma (IFN-gamma) in the healing of dermal wounds, the hypothesis was tested that local administration of IFN-gamma reduces the numbers of myofibroblasts and the elevated amount of collagen during palatal mucoperiosteal wound healing. Standardized mucoperiosteal excision wounds were made in the palatal mucoperiosteum of young rats. Either IFN-gamma or vehicle alone (sham group) was repeatedly injected into the wound site between 4 and 29 days post-wounding. The results were compared with unmanipulated control wounds. Samples of wound tissue were prepared for biochemical and microscopic analysis. The hydroxyproline, sulfated glycosaminoglycan and DNA contents of the wound tissues were analyzed biochemically. The degree of re-epithelialization, tissue thickness, the numbers of myofibroblasts, and the amounts of elastin and collagen types I and III were evaluated on histological sections. Injection of vehicle alone affected almost all healing parameters, compared with the controls, and delayed the wound-healing process. IFN-gamma stimulated re-epithelialization and decreased the numbers of myofibroblasts when compared with vehicle-treated wounds. It also decreased the hydroxyproline and glycosaminoglycan contents of 60-day-old wound tissue, but the histological characteristics of scar tissue persisted. Therefore, IFN-gamma is able to reduce the numbers of myofibroblasts and the collagen content of scar tissue after palatal wound healing. It may be a promising pharmaceutical agent for the reduction of wound contraction and scarring after cleft palate surgery.

Free flap closure in complex congenital and acquired defects of the palate

Extensive palatal defects cause substantial morbidity, including nasal regurgitation, poor oral hygiene, loose-fitting obturators, and difficulty with speech. Microvascular techniques allow the surgeon to repair these complex defects with a one-stage reconstruction, in contrast to possible multistage local or regional flap reconstruction. In this retrospective review, the authors present their 5-year experience with free flap coverage of extensive palatal defects. From 1993 to 1998, 6 patients underwent free flap coverage of large palatal defects. The etiology of the large palatal defects included trauma (N = 1), neoplasm (N = 4), and a recurrent congenital cleft palatal fistula (N = 1). Three patients underwent osteocutaneous radial forearm flaps and 1 patient underwent a fasciocutaneous radial forearm flap. The remaining 2 patients underwent rectus abdominis muscle flaps. The ipsilateral facial artery and vein were used as the recipient vessels in all patients. There were no intraoperative complications (surgical or anesthetic). Postoperatively, 2 patients had surgical evacuation of small flap hematomas. One patient underwent revision of the fasciocutaneous flap. All flaps survived. In our experience, the benefits of free flap reconstruction of complex palatal fistulas seem to outweigh the risks of the operation, with reliable long-term results.

Lateral breakdown of nonendodontic origin adjacent to maxillary left incisors

CASE REPORT

A 16-year-old female presented with a labial fistula located between the central and lateral left maxillary incisors. The teeth had normal colour, responded positively to pulp testing, demonstrated negative percussion tests and had no evidence of periodontal pockets. The patient reported no history of trauma, but mentioned that she had received orthodontic treatment. Radiographic examination showed bone loss between these two teeth. Explorative surgery followed by antibiotic treatment was performed, but a fistula reappeared after 22 months. Surgical retreatment combined with antibiotic treatment resulted in gradual healing over a three-year period. No root canal treatment was performed. Aetiological considerations connected to tissue injury and inflammation are discussed. Inflammation induced disturbances in local homeostasis may possibly explain the lateral breakdown of bone. Such areas of reduced resistance may, under unfavourable conditions, be infected by blood-born pathogens. Information about such aberrant cases is important in endodontic decision making.

Myofibroblasts and matrix components in healing palatal wounds in the rat

In order to identify wound contraction and scar formation during palatal mucoperiosteal wound healing in growing rats, the temporal and spatial distribution of myofibroblasts and matrix components were determined immunohistochemically. Myofibroblasts were found in the mucosal part of the palatal wound tissue between 4 and 22 days, with the highest density at 8 days post-wounding. The number of collagen type I and type III fibers gradually increased until about 8 days postwounding, and thereafter the staining intensity of collagen type III decreased. At 60 days post-wounding there were more transversely oriented collagen type I fibers and less type III fibers and elastin present in the submucosa than in normal tissue. The results suggest that in this model wound contraction mainly takes place in the mucosa between 4 and 22 days postwounding. Furthermore, palatal wounds made in young rats heal with distinct scar tissue formation. Therefore, this model is useful to test the effects of therapies that aim to reduce wound contraction and scarring after cleft palate surgery.

Palatal mucoperiosteal wound healing in the rat

The objective of this study was to analyze the changes in tissue architecture and matrix composition during healing of palatal wounds of immature rats, and to compare this with rats of the same age that did not receive mucoperiosteal wounds. Wounds were made in the mucoperiosteum of the palate of 35-d-old rats. Samples were evaluated histologically at numerous points in time after wounding. The DNA, hydroxyproline and sulphated glycosaminoglycan contents were determined at 8, 15, 30, and 60 d post-wounding. Eight-d-old granulation tissue contained 43% less hydroxyproline, and 100% more glycosaminoglycans and cells than unwounded palatal tissue of 43-d-old rats. Sixty-d-old wounds contained 100% more DNA and 39% more hydroxyproline than unwounded tissue of 95-d-old rats. At the same time, densely packed and transversely aligned collagen fibres were present. It is concluded that palatal mucoperiosteal wounds made in 35-d-old rats heal with distinct scar tissue formation. The scar contains more collagen than non-wounded palatal tissue of rats of the same age. Therefore, this model may be of use for the development of therapies aiming to reduce palatal scarring.

A case of an electrical burn in the oral cavity of an adult

Electrical burns in the oral cavity account for 2.2% of all electrical burns and only 0.12% of all burns; thus, the incidence of electrical burns in the oral cavity is relatively low. As this type of injury occurs in the oral cavity when an individual sucks or chews on a live electrical wire, extension cord, plug, or outlet, most cases occur in toddlers or preschool children, and adult cases are extremely rare. Here we describe a case of an electrical burn in a 56-year-old man who accidentally bit the electric wire of a cleaner while carrying out repairs. Conservative treatment, without surgery, was performed. Two years after the injury, a slight scar and a small tongue deformity remain, but no functional disturbance has been observed.

Effects of TGFbeta2 on collagen synthesis in cultured normal and wounded fetal mouse palates

OBJECTIVE

It has been demonstrated in a number of models that fetal wounds heal with little or no scar. Since collagen is an integral part of the extracellular matrix in adult scar formation, we studied the synthesis and localization of collagen in an in vitro mouse palate model for fetal wound healing.

METHODS

Palates, dissected from fetal mice at 15, 16, and 17 days of gestation and from newborn mice, were cultured in medium containing serum (for 8 hours); this was followed by culture in serum-free medium (for 12 hours). One-half of the samples from each age group were wounded in the midline. All samples were placed in serum-free medium containing 20 microCi/mL 3H-proline for 8 hours. In addition, palates from 15-day gestation and from newborn mice were also incubated with transforming growth factor TGF-beta2 (10 ng/mL). Palates were washed with saline, homogenized, and radioactivity was counted. Proline uptake was calculated for each sample as counts per milligram of protein and was subjected to statistical analysis (three-way analysis of variance). Samples of the homogenate were subjected to sodium dodecyl sulfate-gel electrophoresis and Western blotting in order to determine the types of collagen that were synthesized. Immunohistochemical localization of collagen types I, III, and VI was carried out on paraffin-embedded samples from each group.

RESULTS

There were no significant differences in proline uptake between wounded mouse palates and nonwounded mouse palates at any age, and there was no histological evidence of regeneration of the palate at the site of the wound. Proline uptake was significantly greater in untreated wounded palates at 15 days' gestation than it was in newborns. After treatment with TGF-beta2, proline uptake was significantly greater in both wounded and nonwounded palates in the newborn group and had no effect on collagen synthesis in palates from 15-day gestation animals. Collagen types I and III were localized in histological specimens using immunohistochemistry and on nitrocellulose using Western blotting. No type VI collagen was demonstrated by Western blotting, but it was localized around blood vessels and on basement membranes using immunohistochemistry.

CONCLUSION

Treatment with TGF-beta2 significantly increased collagen synthesis, as assessed by 3H-proline uptake, in cultured palates from newborn mice as compared with palates from untreated newborn mice and from both treated and untreated palates of 15-day gestation mice. These data suggest a differential response to TGF-beta2 by mouse palates as a function of fetal development.

Central palatal burns associated with the eating of microwaved pizzas

Burns of the oral mucosa can be caused by heat, cold, radiation, electricity and mechanical or chemical stimuli. Acids, alkalis and salts can cause considerable damage to the oral mucosa, membranes and lips. Most damage is found in the oropharynx, besides the pharynx and tonsils, the alveolar mucosa of the tongue and the masticatory mucosa of the palate or gingiva show localized or diffused damage. The clinical appearance depends on the severity of the tissue damage and the destructive properties and mode of application of the causative agent. We present an illustrative case of central palatal burn associated with the eating of microwaved pizzas and discuss similar mechanisms of injury.

Effects of interferons on proliferation and collagen synthesis of rat palatal wound fibroblasts

The purpose was to select drugs that specifically reduce collagen synthesis by palatal granulation fibroblasts without affecting their proliferation. Granulation fibroblasts were obtained from 8-day-old palatal mucoperiosteal wounds and normal fibroblasts from palatal tissue of unwounded rats. Cultured cells were treated with interferon-alpha2b, interferon-beta and interferon-gamma (0, 100, 1000, and 10000 U/ml). Cell proliferation was measured by [3H]thymidine incorporation. Collagen synthesis and non-collagenous protein synthesis were determined from the incorporation of [3H]proline. None of the interferons significantly inhibited the proliferation of either type of fibroblasts. Interferon-alpha2b had no effect on the variables studied at the dosages used. Interferon-beta reduced collagen synthesis of granulation fibroblasts without affecting their non-collagenous protein synthesis or protein synthesis by normal fibroblasts. Interferon-gamma reduced collagen synthesis of both types of fibroblast and the non-collagenous protein synthesis of granulation fibroblasts. These data show that interferon-beta specifically reduces collagen synthesis by oral granulation fibroblasts without affecting normal palatal fibroblasts.

Z-plasty closure of the donor defect of the radial forearm free flap

The radial forearm is a popular free flap site for reconstruction of head and neck defects, because of its abundant, pliable, skin component and an available, extended, vascular pedicle. In addition, vascularized composite flaps, including a segment of radius, can be designed for skeletal stabilization. The donor-site defect can involve various complications, including loss of skin graft, unsatisfactory appearance, numbness, and radial fracture. Recent advances in reducing donor-site defect problems have included the use of rotation skin flaps, local muscle rotation, and soft-tissue expansion; however, each of these has its own limitations. Two cases are presented in which radial forearm donor site defects, measuring less than 4 cm x6 cm, were primarily closed successfully with z-plasties based on the longitudinal skin incision. Each patient has regained preoperative mobility, and prompt primary healing was achieved without complications.

A management strategy for palatal fractures: a 12-year review

Fractures of the palate are frequently associated with the more common and well-described Le Fort fractures. Palatal fractures may present diagnostic and exposure challenges and, if not satisfactorily treated, will result in occlusal problems after surgery. From 1986 through 1998, 116 complex maxillary fractures were treated at the authors' center. Among these, 13 patients were diagnosed with fracture of the palate. Patients with gunshot wounds to the face were excluded from the present study. Open reduction and internal fixation of the palatal fractures were achieved through elevation of the entire palatal mucoperiosteal flap to avoid late hardware exposure. This paper presents a unique approach to visualizing the whole bony palatal surface for accurate reduction and internal fixation of fractures.

Internal jugular vein thrombosis in a child due to a 'pencil point injury' of the palate

Penetrating trauma of the soft and hard palate are common in children and have been termed 'pencil point injuries.' Although such injuries are usually minor, the English literature has reported over 25 cases complicated by thrombosis of the internal carotid artery. We describe an unusual case of a 6 year old girl who presented with fever, cervical swelling and torticollis, following a pencil point injury. Physical examination and CT scan confirmed the diagnosis of internal jugular vein thrombosis (IJVT). The management of pencil point injuries and IJVT in children is reviewed and the possible mechanisms of IJVT in the case described here, are discussed.