Search PubMed⌕ Search

Biomedical subjects

S W Guthua

Publications and source records attributed to S W Guthua.

At least 19 recordsLinked to original sources
PubMed1998

Osteosarcoma of the maxillofacial bones in Kenyans.

Osteosarcoma (OS) is a highly malignant tumour and is the most common primary neoplasm of bone; although rare, especially in the maxillofacial skeleton. This article presents 14 Kenyan cases of OS of the maxillofacial bones seen between January 1991 and July 1997: 11 in the mandible, two in the maxilla and one in the right zygomatic arch. Patients ranged in age from one week to 50 years (Mean = 29.7), with an equal gender distribution. While pain and rapid swelling were the commonest clinical features, the radiographic and histopathological characteristics were as varied as has been described elsewhere. Generally, effective management of most of the cases was poor due to late presentation for treatment.

Adolescent↗
PubMed1996

A human MSX1 homeodomain missense mutation causes selective tooth agenesis.

We demonstrate that a mutation in the homeobox gene, MSX1, causes a common developmental anomaly, familial tooth agenesis. Genetic linkage analyses in a family with autosomal dominant agenesis of second premolars and third molars identified a locus on chromosome 4p, where the MSX1 gene resides. Sequence analyses demonstrated an Arg31Pro missense mutation in the homeodomain of MSX1 in all affected family members. Arg 31 is a highly conserved homeodomain residue that interacts with the ribose phosphate backbone of target DNA. We propose that the Arg31 Pro mutatrion comprises MSX1 interactions, and suggest that MSX1 functions are critical for normal development of specific human teeth.

Alleles↗
PubMed1995

The association between oral leukoplakia and use of tobacco, alcohol and khat based on relative risks assessment in Kenya.

A case-control study was conducted to determine the significance of tobacco, alcohol and khat (Catha edulis) chewing habits in the development of oral leukoplakia among Kenyans aged 15 yr and over. In a house-to-house survey, 85 cases and 141 controls matched for sex, age and cluster origin was identified and compared for these risk factors. Smoking unprocessed tobacco (Kiraiku) with a relative risk (RR) of 10.0 (95% confidence interval (CI) = 2.9-38.4) and smoking cigarettes (RR = 8.4; 95% CI = 4.1-17.4) were the most significant factors. While the RR associated with smoking cigarettes alone was 4.5 (95% CI = 1.9-10.8), smoking of both products (RR = 15.2) suggested probable synergy or additive effects. Oral leukoplakia in 18 cases could not be attributed to smoking tobacco. Commercial beer, wines and spirits were relatively weak, but statistically significant, risk factors. Traditional beer, khat and chilies were not significantly associated with oral leukoplakia.

Adolescent↗
PubMed1995

Management of post-traumatic temporomandibular joint ankylosis in children: case report.

Temporomandibular joint (TMJ) ankylosis is a distressing affliction that denies the victim the benefit of normal diet, careers that require normal speech and causes severe facial disfigurement that aggravates psychological stress. Opinions in current literature portray controversy in its management. Hurried clinicians take shortcuts and partially treat symptoms and often make the condition worse. Others ignore shortcomings and erroneously prescribe their preferred techniques as absolute indication to the peril of the affected children. Gap arthroplasty if applied in a growing maxillofacial skeleton as in children, causes iatrogenic arrest of facial growth. The intended correction of facial disfigurement is therefore not achieved. Early detection and immediate psychological support by excision and reconstruction of ankylosed TMJ with a costochondral graft, improves patient comfort and rehabilitation when used as a planned part of a comprehensive therapy. This paper questions prior varied opinions and discusses scientific baseline considerations in management of long standing TMJ ankylosis in children in relatively affordable circumstances.

Ankylosis↗
PubMed1995

Orofacial lesions as indicators of HIV/AIDS among dental patients in Kenya.

Despite an estimated prevalence of 3-5% of HIV infection in Kenya, little has been reported on the occurrence of oral lesions amongst the afflicted individuals. We report ten cases who presented with orofacial lesions and subsequent serological evaluation confirmed them seropositive. In the light of the numerous problems facing clinical staff in less developed countries, these findings underscore the significance of clinical identification of more probable HIV patients on the basis of orofacial signs. Continuing education with respect to HIV infection through wider dissemination of information on orofacial signs to clinical staff especially in the context of invasive care and containment of infection are recommended.

Adult↗
PubMed1995

Prevalence of oral mucosal lesions in a Kenyan population with special reference to oral leukoplakia.

The prevalence of oral leukoplakia and related lesions in a Kenyan rural population was determined in a systematic house to house survey of individuals aged 15 years and above. Among the 803 individuals examined, the following prevalence of lesions was observed: leukoedema (26%), melanosis (12.7%), leukoplakia (10.6%), palatal keratosis (6.4%), frictional keratosis (5.5%), pre-leukoplakia (4.1%), borderline leukoplakia (2.4%), cheek/lip biting (1.3%), and snuff dippers lesion (0.4%). 48.6% of the subjects had at least one of these lesions. Statistically significant preponderance was demonstrated for oralleukoplakia, palatalkeratosis, leukoedema and frictional keratosis among males and melanosis among females. With regard to clinical classification of oral leukoplakia, the prevalence was 10% for homogeneous and 0.6% for nonhomogeneous lesions. On the basis of aetiological classification; the prevalence was 8.3% for tobacco associated and 2.2% for idiopathic leukoplakia. 22.5% of leukoplakia lesions biopsied had evidence of epithelial dysplasia. In view of the premalignant potential of oral leukoplakia, our findings suggest a need for greater attention towards prevention and control of this lesion in the study community.

Adolescent↗
PubMed1994

Utilization of dental auxiliaries in private dental surgeries in Kenya.

This study was done to determine the nature of utilization of dental auxiliaries and medical emergencies in private dental surgeries in Kenya. A self administering questionnaire with pre-paid postage was mailed to 138 dentists. 27.5% responded. 81.6% used dental auxiliaries and the main reason was to improve efficiency in managing patients. 93.5% of the auxiliaries were on job trained secondary school graduates. 63.2% of the respondents delegated duties which were mainly non-clinical. 26.3% did not delegate any duties. In a descending order, the reasons for non delegation were: that it would be risky to patients, not allowed by law, they did not find it necessary and that auxiliaries were not held responsible if something went wrong. The main duties delegated to the auxiliaries were cleaning of instruments and sterilization, mixing of restorative materials and preparing amalgam. Delegation was done primarily based on auxiliaries capability to perform the procedure and meet the set standards. 57.9% indicated that they rarely encountered medical emergencies. Syncope was the commonest emergency encountered. 72.7% indicated that auxiliaries could not handle medical emergencies because they were not trained. It is concluded that most dentists did not delegate clinical duties to dental auxiliaries and medical emergencies were rare.

Adult↗
PubMed1994

Alternative technique of constructing bilateral cleft palate in late childhood: a case report and literature review.

Although great advances in treatment of oro-facial clefts have been made over the past 50 years; in developing countries, due to social stigmas and unavailability of specialised medical facilities and personnel to the majority of the population, there is an increasing incidence of patients coming late for repair of oro-facial clefts. This presents a challenge to both plastic, oral surgeons and associated specialists. The aim of the present article is to demonstrate, in the form of a case report, an alternative surgical technique that has be successful in 8 cases for the late repair of severe bilateral cleft palate utilizing locally available and affordable materials. The objective of managing patients with cleft palate in developing countries is to provide the best repair and rehabilitation with as few operations and in-patient care as possible due to limited financial resources experienced by the majority of in-patients. A multidisciplinary approach to the management of oro-facial clefts is emphasised.

Alveolar Process↗
PubMed1994

Residual facial deformity resulting from cancrum oris: a case report.

Cancrum oris cases are occasionally treated in various hospitals in Kenya. Despite this, only one case has been reported in literature. Besides, no epidemiological or treatment studies of cancrum oris has been carried out in Kenya. We report an unusual case of a 17 year old Kenyan female with oral cutaneous fistula and tissue atrophy on the left cheek following cancrum oris infection in childhood. Since most cancrum oris cases are a sequela of acute necrotizing gingivitis (ANG), prevention of cancrum oris can be achieved by early and prompt remedial measures once a diagnosis of ANG is established. Failure to do this might lead to cancrum oris with its attendant disfiguring complications some of which might be impossible to treat in developing countries where the requisite personnel is lacking or inadequate.

Adolescent↗
PubMed1994

Basal cell nevus syndrome: a case report.

A case is reported of a 13 year old Kenyan girl who presented at the Kenyatta National Hospital Dental Clinic with multiple mandibular and maxillary cysts, cutaneous lesions and mandibular prognathism. This combination of clinical and radiographic features led to a diagnosis of basal cell nevus syndrome. This paper is the first reported case of the syndrome in Kenya. The significance of thorough clinical inspection and radiographic screening of suspected cases is discussed.

Adolescent↗
PubMed1994

Replacement therapy utilising autotransplanted wisdom teeth.

Loss of 1st and 2nd molars among adolescents due to dental caries is not uncommon in developing countries. Whilst their replacement is indicated, conventional methods of treatment, namely, bridging and dentures are in most cases inaccessible because of prohibitive cost. Given that it is in the same age group that diagnosis of unfavourably embedded wisdom teeth becomes feasible, autotransplantation of the latter to replace the unsalvageable 1st and 2nd molars could be an alternative treatment. Available literature suggests a success rate of over 82% based on follow-up studies of over ten years. Observations at the Dental School Clinic of the University of Nairobi, Kenya, indicate that the time it takes the transplant to 'take' and assume its functional position is 4 to 8 weeks and 2.5 to 3.5 months respectively. Since the method is relatively straightforward, we are of the view that training undergraduates and practising dental surgeons in this technique should enhance utilisation of otherwise "useless" teeth to replace the lost 1st and 2nd molars in occlusal rehabilitation.

Adolescent↗
PubMed1993

Radiation dose as a factor in the choice of routine pre-operative dental radiographs.

Radiation doses received by patients during dental x-ray examinations were measured in 95 patients referred to the X-ray Department of the Teaching Dental Hospital, University of Nairobi. The mean skin dose for single periapical films was 5.96 milligray (596 millirads) with the bitewing view recording a mean dose of 5.57 milligray (mGy). During a 14-film full-mouth periapical survey, mean doses ranged from 10.3-16.2 mGy for the upper jaw and 10.1-13.5 mGy for the lower jaw, respectively, depending on the region of dentition. In these full-mouth examinations, the distribution of skin dose over different parts of the dentition showed a characteristic pattern which may be explained by the overlap of radiation fields in the aggregated series of exposure. Orthopantomography recorded lower mean skin doses of 3.26 mGy in the molar region and 2.67 mGy at the posterior midline at the level of the 2nd cervical vertebra. The relative merits of intra-oral radiography versus orthopantomography are discussed, with radiation dosage as one of the factors to be considered. Some observations are made on measures to reduce patient dose.

Decision Making↗
PubMed1992

A retrospective study of characteristics of impacted mandibular wisdom teeth in 110 patients treated in Nairobi, Kenya.

Analysis of 110 records of patients who presented with impacted mandibular 3rd molars was carried out to determine the frequency of occurrence of unilateral and bilateral impactions and their characteristics. 68.2% of the patients had bilateral impactions. Among the patients with bilateral impactions, 72% had mesioangular impaction occurring either bilaterally or in combination with other types of impaction. Furthermore, 38.7% mesioangular impactions were observed on the right and left sides in the patients with bilateral impactions. Among the patients with unilateral impactions 40.2% presented with mesioangular impaction, while 25.7% presented with distoangular impactions. While these observations support the general consensus regarding aetiology of mandibular 3rd molar impactions as being tooth-tissue discrepancy, the possible influence of other factors is suggested.

Adult↗
PubMed1992

Coping with embedded mandibular wisdom teeth in developing countries.

Despite low incidence of embedded mandibular wisdom teeth (third molars) among dental patients in developing countries (less than 100/1,000), the unfavourable patients:dentist ratios, the limited resources and low levels of public awareness render them an important problem to operators in these countries. Since the effectiveness with which they are removed largely depends on the age with respect to the stage of root formation, bone resilience and relationship with adjacent anatomical structures, and the dexterity of the operator, whenever possible, early removal is recommended. To minimise occurrence of non-operative complications that are costly to manage, primary health care workers have a vital role to play in raising levels of awareness and early referral for further evaluation. In view of the risks involved in the removal of these teeth and the small number of trained oral surgeons, continuing education to the dental practitioners, could improve their efficiency in the management of this condition.

Developing Countries↗
PubMed1991

Ameloblastoma after surgical removal of an impacted mandibular molar. A case report.

A case of an ameloblastoma diagnosed about 3 1/2 years after removal of an impacted mandibular 3rd molar is presented. The pre-operative radiographs, though poor in quality, showed an ill-defined radiolucency in relation to the tooth. This feature was not apparent to the examiners at the time of first presentation. Despite unfavourable working conditions in developing countries, a high level of suspicion should be maintained to avoid serious sequelae at a later stage.

Adult↗