Alternative surgical approaches for excision of dermoid cyst of the floor of mouth.

Two different treatment approaches for large dermoid cysts are presented in this article. The extraoral approach was utilized for a patient who presented to the emergency room with a respiratory problem. The intraoral approach was performed in a female patient presenting with a large swelling involving both the submental and sublingual areas, and this approach led to good esthetic results without recurrence.

Tempromandibular joint (TMJ) response to intra-articular dexamethasone injection following mechanical arthropathy: a histological study in rats.

The purpose of this study was to evaluate as well as to compare the effect of intra-articular versus intra-peritoneal injection of dexamethasone on synovitis induced by trauma to the rat's TMJ. Twenty-seven male Wister rats were included in the present study. Induced forced condylar hypermobility achieved through opening the rat's mouth manually 10 times for 10 consecutive days. Rats were randomized into three groups (3 rats in the control group, and 24 rats in both experimental groups). Group I (control group): Rats of this group were left without any treatment after induction of synovitis. Group II: Rats were injected with a single dose of 1.2 mg/kg dexamethasone intra-articularly (after 10 days). Group III: Rats were injected with a single intra-peritoneal injection of 1.2 mg/kg dexamethasone (after 10 days). Control rats were sacrificed at 6 weeks, while rats in Groups II and III were sacrificed at 1 and 6 weeks after drug injection, then joints were dissected and processed for histological study. The condylar head of the rats injected with intra-articular dexamethasone showed resorption with active osteoclastic activity, although the drug was given only once. This might be an alarming sign of the severe adverse effect(s) of the local injection of dexamethasone.

The effect of fibrin stabilizing factor (F.XIII) on healing of bone defects in normal and uncontrolled diabetic rats.

This study was undertaken to examine the effect of fibrin stabilizing factor (F.XIII) on healing of bone defects in normal and uncontrolled diabetic rats. Eighty rats were divided into two groups: group I (diabetic) and group II (non-diabetic) (40 rats each). Diabetes was induced in group I using streptozotocin. Both groups were divided into two subgroups, control and experimental (20 rats each). Bone defect was created in the mandible. Rats in the experimental subgroups were injected with F.XIII, while those of the control groups were injected with saline (F.XIII solvent). Animals were killed at varying intervals and tissue sections stained with hematoxyline and eosin and Van-Gieson stains were examined. Differences in collagen deposition and bone formation were compared in both control and experimental groups. Collagen deposition was evident and appeared more oriented in diabetic rats treated with F.XIII, and signs of bone deposition started in the experimental group earlier than in the control group. On the other hand, F.XIII did not significantly affect healing in non-diabetic rats. It is concluded from these results that F.XIII may enhance early stages of bone healing in uncontrolled diabetic rats.

Unusual presentation of tuberculosis of the head and neck region. Report of three cases.

Three cases are reported in which the diagnosis of tuberculosis has only been made following surgery for suspected salivary gland tumor, sebaceous cyst and carotid body tumour. Surgery could have been avoided if tuberculosis had been considered in the initial differential diagnosis.

Cavernous haemangioma of the submandibular salivary gland.

Salivary gland haemangioma is more common in the parotid than in any other salivary gland. Parotid haemangioma is considered to be the most common salivary gland tumour in infants, but is also occasionally encountered in adults. A case of cavernous haemangioma affecting the submandibular salivary gland in an adult woman is presented. The striking histological feature is the presence of numerous vascular channels assuming a periductal arrangement.

Preliminary investigation into the effects of electrical stimulation on mandibular distraction osteogenesis in goats.

Craniofacial distraction osteogenesis (DO) was found to be a procedure with low preoperative and postoperative morbidity. Direct current electrical stimulation is used clinically to treat different orthopaedic problems. It provided a significant increase in new-bone formation, and a higher mechanical strength of healing. The purpose of this study was to test the effect of electric current on distraction osteogenesis and to establish the best period to apply an electric current during the different distraction phases. Twelve healthy adult goats were subjected to a vertical osteotomy in the symphyseal area. A distraction device was fixed to the bone. Animals were divided into two groups, Group I (three goats) and group II (nine goats). In group I, the device was activated 1mm per day for 10 days; while in group II, the device was activated 1mm per day for 10 days with the application of direct electric current stimulation of 10 microA either during the first 3 days of latency in a continuous mode (ESL group), or during the first 3 days of the activation period in a continuous mode (ESA group); or during the first 3 days of the consolidation period in a continuous mode (ESC group). After the activation period was completed, the distraction device left in place for additional 15 days for bone consolidation in all animals. Animals were then sacrificed, the mandible was harvested, and the distracted areas were removed and processed for mechanical and histological studies. The results of this study suggested that direct current electrical stimulation display synergism on mandibular distraction when this stimulation applied to the distraction zone during activation or consolidation periods.

The use of the pedicled buccal fat pad (BFP) and palatal rotating flaps in closure of oroantral communication and palatal defects.

The use of the buccal fat (BFP) and palatal rotating flaps for the closure of oro-antral communication and reconstruction of palatal defects was compared clinically. The BFP proved to be consistently successful in closing oro-antral fistulae and palatal defects resulting from tumour resection, preserving the normal anatomical architecture of the oral mucosa. No denuded area requiring secondary granulation was required as in the case of palatal flaps. In addition, no facial disfigurement was observed on the operated side. BFP is considered a reliable, convenient method for closure of palatal defects and closure of oro-antral communication. It can also be considered as a reliable back-up procedure in the event of failure of other techniques.

Leukotriene B4 and oral cancer.

The quantitation of leukotriene B4 (LTB4) in induced squamous cell carcinoma (SCC) of the Syrian hamster cheek pouch and histologically proven human oral SCC was investigated by a combination of reverse phase-high performance liquid chromatography (RP-HPLC) and radioimmunoassay (RIA). Healthy tissue obtained from these same patients and animals treated with vehicle alone were used as controls. From both animal and human studies our results show a 10 to 30 fold increase in the levels of LTB4 found in tumour compared to control tissue. Furthermore, this dihydroxy acid was not detected in the mucosal tissue of normal subjects undergoing routine surgery. Since LTB4 is a potent inflammatory mediator and modulator of immune responses, its presence at biologically active concentrations in human squamous cell carcinoma suggests a possible role in the pathogenesis of head and neck cancer.

Congenital fusion of the maxilla and mandible (congenital bony syngnathia).

A rare case of syngnathia (maxillomandibular fusion) is described in a 2-year-old boy who presented from a rural area of Saudi Arabia. The child had the problem since birth and had undergone two surgical attempts to release the fusion at another institution but both had failed and recurrence occurred. In the authors' institute, the patient underwent two separate surgical procedures at the age of 2 and 3 years. Both procedures were followed by a period of aggressive physiotherapy, but the patient presented with re-fusion of the mandible and the maxilla 1 year after the first operation and 5 months after the second operation. It was decided to defer treatment until puberty. The cause of the relapse may be the high osteogenic potential because of his youth or the failure of the parents to maintain the active physiotherapy protocol because they live in a rural area and close follow-up was difficult. A possible genetic predisposition for bone formation at this site should be investigated.

Squamous cell carcinoma and keratoacanthoma of the lower lip associated with "Goza" and "Shisha" smoking.

BACKGROUND: A positive correlation between lip and buccal cancers and pipe smoking has been suggested. Various types of crude and manufactured tobacco products are consumed by smoking, chewing, and snuff dipping habits. 'Shisha" and 'Goza' smoking are widely practiced in the Middle East. The 'hubble-bubble' method and apparatus are used. These smoking habits are hazardous to health, causing obstructive lung disease, and may be important predisposing factors for the development of oral cancers. CASE REPORTS: Two cases of squamous cell carcinoma and a case of keratoacanthoma localized to the lower lip are presented in well-known 'Shisha' and 'Goza" smokers. CONCLUSIONS: "Shisha" and 'Goza' smoking have adverse effects on general health and may predispose to oral cancer. An extensive epidemiological study should be performed to determine whether this type of smoking habit is associated with a statistically increased incidence of squamous cell carcinoma and keratoacanthoma of the lips.