Risk factors of nerve injury during mandibular sagittal split osteotomy

There is little objective data about whether surgical technique or mandibular anatomy are a risk for inferior alveolar nerve (IAN) injury during bilateral sagittal split osteotomy (BSSO). Orthodromic sensory nerve action potentials (SNAPs) of the IAN were continuously recorded on both sides in 20 patients with mandibular retrognathia during BSSO operation. Changes in latency, amplitude, and sensory nerve conduction velocity (SNCV) at baseline and at different stages of the operation were analyzed. The SNAP latencies prolonged, the amplitudes diminished, and the SNCVs slowed down during BSSO (P = 0.0000 for all parameters). The most obvious changes occurred during surgical procedures on the medial side of the mandibular ramus. There was a clear tendency towards more disturbed IAN conduction with longer duration of these procedures (right side R = -0.529. P = 0.02; left side R = -0.605, P = 0.006). Exposure or manipulation of the IAN usually had no effect on nerve function, but the IAN conduction tended to be more disturbed in cases with nerve laceration. Low corpus height (R = 0.802, P = 0.001) and the location of the mandibular canal near the inferior border of the mandible (R = 0.52, P = 0.02) may increase the risk of IAN injury. There was no correlation between the age of the patients and the electrophysiological grade of nerve damage.     

Surgical techniques in the treatment of pleomorphic adenoma of the parotid gland: our experience and review of literature.

This paper presents a retrospective study carried out on a sample of 100 patients affected by pleomorphic adenoma of the parotid gland and treated at the Department of Maxillofacial Surgery at the University of Rome "La Sapienza" between January 1, 1989 and December 31, 1997. For the diagnosis of this neoformation, cytological tests were performed on material taken from the neoformation using fine needle aspiration and ultrasound scan. In some selected cases, a CT examination of the head and neck with medium contrast or Nuclear Magnetic Resonance (NMR) was carried out. This study sets out to examine the most suitable treatment to be followed for the removal of the pleomorphic adenoma of the parotid gland. In 56 cases the patients underwent a superficial, conservative parotidectomy. Forty one patients had a total parotidectomy with the facial nerve left intact and one patient had a total parotidectomy where the marginal mandibular nerve of the facial nerve was damaged. The remaining two patients involved in the study were suffering from a recurrent pleomorphic adenoma and in these two cases a total parotidectomy was performed where the facial nerve was killed. The removal of the cranial nerve VII in these patients proved necessary because the nerve fibers had adhered to the surrounding scar tissue of the tumor, either after previous surgery or due to repeated chronic phlogosis of the gland.     

The first appearance of Meckel's cartilage in the fetus

Meckel's cartilage plays an important role in the topographical organisation and in the differentiation of the facial structure during the embryonal and even much later during the foetal period. Our observations on serial sections carried out in two human foetuses aged 12 and 16 weeks indicate that the two dorsal (tympanic) and ventral (mandibular) branches of Meckel's cartilage are perfectly defined at 16 weeks. In the dorsal branch, the primordia of the incus and of head of the malleus are still composed on non-ossified cartilage. In the ventral branch, it is also possible to describe at 16 weeks three posterior, medial and anterior parts which are composed of cartilage. The initiating role played by the ventral part of Meckel's cartilage on the ossification of the mandible leads during the embryonal period to the formation of the mandibular primary growth center, which is therefore clearly defined in our first stage at 12 weeks. The partial fibrous evolution and the regression of the major part of the ventral branch of Meckel's cartilage only start after 16 weeks of intrauterine life.     

A study of dental staining among competitive swimmers

OBJECTIVE: To estimate the prevalence of dental stains (DS) in competitive swimmers and quantify the risk of these stains compared with sportsmen in a non-swimmers group in Castellón, Spain. METHODS: Cross-sectional and case-control designs. Between July 1996 and March 1997, 404 subjects, (171 enrolled in two clubs of competitive swimming and 233 sportsmen from two schools), were examined in order to detect and classify yellowish-brown or dark-brown stains on the facial surface of the eight incisors. Participation rates were 88.6% for swimmers, and 95.7% for sportsmen. Mean of participants' age was 12 years, range 7-22 years. Castellón has three public competition swimming pools, two of which are indoors. Two of the pools used chloride products, and the third bromine for the disinfection of water. The recommended hygiene regulations were adhered to. RESULTS: Prevalence of DS was 60.2% in swimmers and 12.9% in sportsmen (P= 0.0001). Risk factors for DS included: use of competition swimming pools, age, gender, years of competition, daily consumption of coffee, red wine, and iron supplement during the last year. Professional dental cleanliness was a protective factor. In a logistic regression analysis, the use of competition swimming pools maintained a high risk of DS, odds ratio (OR)=9.28; 95% confidence interval (CI) 5.21-16.5, adjusted by the other variables. Amongst swimmers, more than 6 h of training a week increased the risk of these stains (OR=3.51; 95% CI 1.35-9.10). CONCLUSION: The study indicated a high risk of DS in competitive swimmers.     

Referral patterns and the referral system for oral surgery care. Part 2: The referral system and telemedicine

OBJECTIVE: To investigate GDP opinions of the current referral system and to investigate the need and demand for telemedicine in oral surgery referrals. DESIGN: Postal questionnaire. SETTING: 400 GDPs in Greater Manchester. RESULTS: 84% participation rate. 48% were not satisfied overall with the service of their current specialist oral surgery referral site. The principal reason was the length of the waiting time for consultation and treatment. Distance for patients to travel to the specialist unit was also of concern, even though most patients (89%) travelled short distances (return journey of twelve miles or less). 23% of respondents wished to improve their ability to communicate with the oral surgeon and 70% wanted involvement in the patient consultation. Both of these requirements were more likely in younger practitioners. CONCLUSION: There is a need and demand for change in the referral system for oral surgery specialist care. Telemedicine could conceivably be one way to improve access to specialist oral surgery care.     

A study of therapeutic antibiotic prescribing in National Health Service general dental practice in England

OBJECTIVE: To study the therapeutic prescribing of antibiotics by general dental practitioners. DESIGN: A postal questionnaire of National Health Service general dental practitioners in ten English Health Authorities. SUBJECTS: General dental practitioners (1,544) contracted to provide NHS treatment in the Health Authorities of Liverpool, Wirral, Oxfordshire, Buckinghamshire, Nottingham, North Nottinghamshire, Sheffield, Newcastle, Northumberland and North Tyneside. MAIN OUTCOME MEASURES: The questionnaires were analysed and the responses to each question expressed as absolute frequencies. RESULTS: Responses to the questionnaire were received from 929 (60.1%) practitioners. More than 95% of practitioners recognised the need for prescribing antibiotics where there was evidence of spreading infection. Some practitioners (12.5%) prescribed antibiotics for acute pulpitis and (3.3%) for chronic marginal gingivitis. Antibiotics were prescribed by practitioners before drainage of acute abscesses (69%) and by 23% after drainage. Practitioners were generally not influenced by patient's expectations of receiving antibiotics (92%), but would prescribe when under pressure of time (30.3%), if they were unable to make a definitive diagnosis (47.3%), or if treatment had to be delayed (72.5%). Amoxicillin was the most frequently prescribed antibiotic used for most clinical conditions apart from pericoronitis, acute ulcerative gingivitis and dry sockets where metronidazole was the drug of choice. There was a wide variety of dosage, frequency and duration for all the antibiotics used in the treatment of acute dental infections. CONCLUSIONS: The results obtained from this questionnaire support the conclusion that the therapeutic prescribing of antibiotics in general dental practice varies widely and is suboptimal. There is a clear need for the development of prescribing guidelines and educational initiatives to encourage the rational and appropriate use of the antibiotics in National Health Service general dental practice.     

Neurinoma in the buccal mucosa

A 14-year-old girl was referred to our clinic with a problem of a painless slow growing lesion for approximately three years. MR imaging findings of lesion was "retention cyst of the salivary gland". Controversially, the histological examination of the total excised specimen was "neurinoma" and that was inconsistent with MR findings. Neural tissue tumors of the oral cavity are rare, however, this diagnosis was confirmed by surgical excision and histopathological examination. There was a rare location of the lesion as well.     

Terminology of facial morphology in the vertical dimension

Consideration of facial type plays an important role in the formulation of an orthodontic treatment plan and prognosis of treatment. Of particular importance is the vertical relationship, that is, whether an individual is long-faced (dolichofacial), or short-faced (brachyfacial). The vertical facial type provides a clue regarding the growth direction of the facial complex, and should be used with an anteroposterior classification to describe a patient's face. The potential for confusion in communicating vertical facial types exists due to the nature of the terminology in use. For example, the term dolichoprosopic as used in the Bimler analysis has an opposite meaning to the term dolichofacial. It would seem prudent that if such terminology is to be employed there should be some attempt at standardization, and at least an appreciation of the derivations of the terms, and their differences.     

Immunohistological localization of cell adhesion proteins and integrins in the periodontium.

The distribution of the cell adhesion proteins vitronectin, fibronectin, tenascin, and laminin as well as several integrin subunits, alpha 2, alpha 5, and alpha v, was studied in primate periodontal tissues. Full baboon mandibular sections were analyzed by immunohistochemical methods in order to localize the molecules studied in both soft and hard tissues. Vitronectin was associated with the connective tissue of the marginal gingiva, the periodontal ligament, as well as the endosteum and periosteum. A notable finding was the particularly high staining intensity of vitronectin in the periodontal ligament. Fibronectin was widely distributed in the periodontal connective tissue and was also localized to the pericellular matrix of osteocytes and blood vascular elements. Epithelial basement membranes stained positively for both fibronectin and tenascin. These proteins were also expressed in the periosteal and endosteal connective tissues and the periodontal ligament. The staining intensity for tenascin was higher in zones along the cementum and bone surfaces. Laminin was, characteristically, limited to basement membranes of epithelium and endothelium. The distribution of fibronectin, tenascin, and laminin is related to previous findings in other species. The localization of the several integrin alpha-subunits is also described in full baboon mandibular sections. The vitronectin receptor (alpha v) had a uniquely strong expression in osteoclasts of the alveolar bone and was found, at lesser intensity, on periodontal ligament fibroblasts. The fibronectin receptor alpha subunit, alpha 5, was also observed on osteoclasts, and, in addition, was widely distributed on fibroblasts, cementoblasts, and osteoblasts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Adenomatosis of minor salivary glands. Report of a case.

An account is given of a patient who had multiple canalicular adenomas in the upper lip and adjacent oral mucosa. A few months after these had been excised, several more tumors of the same type developed. Microscopic examination also revealed numerous tiny foci of adenomatous proliferation within otherwise normal salivary gland lobules. We suggest that this phenomenon represents a field neoplastic change although it appears to be benign.