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Variations in occlusal and space characteristics in a series of 6-18-year olds, in Ilala District, Tanzania.

This study was carried out in Ilala District, Tanzania as part of a major oral health survey. The aim of the study was to investigate the variation in different occlusal and space characteristics among children and adolescents in different age group. A total of 698 children and adolescents aged 6-18 years were examined clinically. The subjects were categorized into three age groups, 6-9 years with early mixed dentition, 10-14 years with late mixed dentition and 15-18 years with permanent dentition. The examiners were calibrated before the survey and the agreement was satisfactory. Anteroposterior relationships of the dental arches were measured according to Angle's classification. Other occlusal and space variables included overjet, overbite, openbite, crossbite, crowding, spacing, and separate determination of diastema mediale. Most of the subjects in different age groups, 93-96%, had Angle's Class I molar occlusion. Large overjet (> 5 mm) occurred in 3-5% of the subjects. Deep bite (> 5 mm) was observed in about 2% of the children in all age groups. Anterior open bite was the most prevalent occlusal anomaly in all age groups, noted in 9-13% of the subjects. Transversal occlusal anomalies were rare. More than 33% of the subjects had spacing while less than 10% had crowding of the dentition. These results indicate that using the present criteria, most 6- to 18-year olds in Ilala district have optimal sagittal occlusion and a lot of spacing. The most common occlusal anomaly was anterior openbite.

Adolescent↗

Longitudinal study of functional conditions in the masticatory system in Flemish children.

A 5-yr longitudinal study on occlusal and functional parameters has been made in 75 children aged 8-11. They were selected at random from an original group of 510 studied 5 yr earlier. The following parameters were measured: frequency of frontal open bite lateral and frontal crossbite, the attrition on molars and on front teeth, the contacts on lateral excursion, pain on condyle palpation, TMJ clicking, deviations in the opening and lateral movement, and the maximal interincisal distance. There was an increase in the percentage of deep bite and crossbite. Attrition on molars was seen in 41% and on front teeth in 13% of the children. No real pattern could be observed as a function of age. The mean maximal opening range was 43.7 mm, varying between 23 and 52 mm. Restricted opening was found in one girl. In 60% a deviation in the opening has been found. In 26% TMJ sounds were observed and 28% had pain on condyle palpation. In most of the children the symptoms were very mild to moderate. No significant correlation could be found between dysfunctional signs and occlusal parameters. The present results did not provide any conclusive answer to the tremendous increase in dysfunctional signs over this 5-yr period. The treatment need is, however, low and should not be overestimated.

Belgium↗

A simple appliance for the management of obstructive sleep apnoea--the MEDUNSA Anti-Snoring Device (MASD).

Obstructive sleep apnoea (OSA) is a breathing abnormality that occurs during sleep. It is characterised by snoring and episodes of sleep disturbance that can occur from 10 to 500 times per night causing excessive daytime exhaustion. A large tongue and a retrognathic mandible have been listed as aetiological factors. Orthodontic appliances that have been used to manage the condition are usually complicated, uncomfortable, expensive and delicate. The aim of this clinical procedure is to design a simple, inexpensive, durable and user-friendly appliance that can be used in the management of OSA. The procedure involves taking upper and lower impressions of a patient with OSA and articulating the study casts in a registered protrusive bite. Gum guards of the dental arches are then constructed and fused together in the protrusive position with a 5 to 10 mm open bite. The forward and downward advancement of the mandible caused by the appliance drags the tongue and other structures along, and thus opens the posterior pharyngeal airway during sleep. For ease of reference this appliance has been named the MEDUNSA Anti-Snoring Device (MASD) and it differs from similar appliances in that it is entirely toothborne and does not impinge on the surrounding soft tissues. The MASD was used in a patient with OSA at the MEDUNSA Oral Health Centre. Pre-treatment and post treatment airway dimensions from the lateral cephalograms confirm an increase of 50 per cent in airway size at the level of the epiglottis with a corresponding reduction in clinical symptoms. The MASD is an extremely valuable tool to dentists, orthodontists, as well as any other health professionals managing sleep-breathing abnormalities. While the MASD has been successful in this preliminary case, clinical trials are under way to further evaluate the MASD.

Adult↗

The effects of myotonic dystrophy and Duchenne muscular dystrophy on the orofacial muscles and dentofacial morphology.

This article takes a closer view of two of the less rare myopathies, myotonic dystrophy (MyD) and Duchenne muscular dystrophy (DMD). A high prevalence of malocclusions was found among the patients affected by these diseases. The development of the malocclusions in MyD patients seems to be strongly related to the vertical aberration of their craniofacial growth due to the involvement of the masticator, muscles in association with the possibly less affected suprahyoid musculature. Thus, a new situation is established around the teeth transversely. The lowered tongue is not in a position to counterbalance the forces developed during the lowering of the mandible by the stretched facial musculature. This may affect the teeth transversely, decreasing the width of the palate and causing posterior crossbite. The lowered position of the mandible, in combination with the decreased biting forces, may permit an overeruption of the posterior teeth, with increased palatal vault height and development of anterior open bite. The development of the malocclusions in DMD patients also seems to be strongly related to the involvement of the orofacial muscles by the disease. However, the posterior crossbite is not developed owing to the narrow maxillary arch, as is the case in MyD patients. On the contrary, the posterior crossbite in DMD is due to the transversal expansion of the mandibular arch, possibly because of the decreased tonus of the masseter muscle near the molars, in combination with the enlarged hypotonic tongue and the predominance of the less affected orbicularis oris muscle.

Biomechanical Phenomena↗

[Vertical maxillo-mandibular dysmorphias due to excessive growth. Terminology, diagnosis and treatment].

The authors propose a system of terminology for vertical maxillo-mandibular dysmorphia, "long face" or rather "high face", and "hypsoprosopia" hypsomaxillia to facilitate the diagnosis and the therapeutic approach. They distinguish 3 abnormalities which are responsible, alone or in combination, for an increased height in the face: hypsomaxilla, hypsogenia and vertical anterior inter-incisive aperture (open bite), which can arise in three situations (supra erupted posterior alveolar maxillary segment, infra erupted anterior alveolar mandibular segment, exaggerated opening of the angle of the mandible or amblygonia). They present the clinical picture and the specific teleradiographic features of each abnormality, supported by cases of patients with definite dento-maxillary growth. On the basis of this classification, the authors propose a more systematized approach to the various segmental or total maxillary or mandibular osteotomies, which may be coupled or even combined with advancements or transverse movements in cases of associated dysmorphosis.

Cephalometry↗

Effects of increased vertical dimension on size of constriction port and fricative sound intelligibility.

The effect of increased vertical bite dimension on fricative sound productions was studied in five adults who wore dentures. Oral port size and sound intelligibility were evaluated at different degrees of artificially induced open bite. The data demonstrate that rapid compensatory adjustments occurred and oral port size changed minimally at all degrees of opening tested. However, in three of the subjects, sound intelligibility declined at the 6-mm opening, and in all subjects, a four-fold increase in sound distortions occurred in the edentulous state. This finding suggests the possibility that either physiological parameters are controlled more successfully than acoustical parameters or that compensatory efforts to maintain constrictor size may, under certain circumstances, adversely affect sound intelligibility.

Adult↗

Maximal contraction force and endurance of human jaw-closing muscles in isometric clenching.

Maximal unilateral bite force and endurance times from maximal bite force to the 75% and 50% levels of maximal values were recorded for 13 men and 15 women with bite openings of 10 and 14 mm. Measurements were made both from right and left molar regions and from the incisal region. Bite force values were significantly higher than previously measured in endurance tests by devices with unilateral housings. Men achieved greater bite force than women in the molar region in every trial. The general assumption that women's muscles are superior to those of men in static endurance when both are working at the same percentage of maximal voluntary contraction was not supported by this work for jaw-closing muscles. The endurance times to 75% and 50% levels of maximal bite force were shorter than could be expected from previous reports, and endurance times to the 50% level were even shorter than those reported for muscles of limbs.

Adult↗

Effect of mouth opening on bite-force discrimination.

The purpose of this study was to determine whether different extents of mouth opening affect normal subjects' (N = 24; 12 women, 12 men) ability to discriminate differences in their interincisor bite force. Three mouth openings were selected including 50, 70, and 90 percent of maximum opening for each subject. Bite force was measured using a specially designed strain gauge scale which permitted subjects to monitor visually when their biting force equalled a preset resistance. Resistance forces of 500 and 1000 gm. were selected as standards. The procedure involved the use of a modified method of constant stimuli in which each subject was presented with a series of paired resistance settings, one at a time--the first resistance setting being the standard and the second resistance was the comparator. This paired-comparisons procedure was continued until the subjects' difference limen (DL) value (the threshold of discrimination between two forces) could be established. An analysis of variance yielded no significant differences in subjects' ability to discriminate bite force as a function of mouth opening.

Adult↗

Occlusion in the primary and early mixed dentitions in a group of Tanzanian and Finnish children.

Two high and two low socioeconomic areas were selected for the Tanzanian portion of this study, with all nursery schools located in those areas included, for a subtotal of 580 children. The Finnish group was comprised of a total of 575 Caucasian children examined. The Tanzanian children (83 percent Black African, 10 percent Asian, 7 percent Arab) had fewer occlusal anomalies than the Finnish children did. Finnish children had a 13-percent incidence rate of lateral cross-bite; among African children, 8 percent showed anterior crossbite; and among the combined Asian/Arab group of children, 10 percent had an anterior open bite. African children had significantly fewer prevalences of distal bite, lateral crossbite and crowding than Finnish children did.

Child↗

Need for interceptive intervention for malocclusion in 6-year-old Finnish children.

The need for interceptive intervention for malocclusion was studied in a sample of 839 Finnish children aged 6 years. The children had participated in an organized preventive orthodontic program, and nearly 10% of them had received preventive or interceptive orthodontic treatment at the age of 3-5 years (stage I of the preventive orthodontic program of the author). Orthodontic intervention was estimated to be needed for 5.9% of the children due to crossbite of the permanent central incisors, to crossbite or scissors-bite of the permanent first molars, to ectopic eruption of the permanent first molars, to numerical variation of the permanent incisors, or to functional open bite. The need for further inspection in order to follow-up development of the dentition was noted in 2.7% of the children. The indications occasioning this consideration were initial severe crowding, extreme incisal overjet, and early loss of the primary mandibular canines. The relatively low prevalence rates seemed to indicate advantageous results of the preventive and interceptive orthodontic measures.

Child↗

Distribution by age and sex of functional disturbances and diseases of the stomatognathic system in 7-18 year olds.

The investigation consisted of 749 randomly selected subjects between 7-18 years of age. The subjects were interviewed for symptoms and oral parafunctions and examined clinically for occlusal interferences, malocclusions and signs of functional disturbances and diseases in the stomatognathic system. The group with one or more symptoms indicated no sex difference but the symptoms showed a gradual increase with age. Recurrent headaches were evenly distributed between the ages, but more commonly reported among girls in the age range 7-14 years. Clickings increased by age and some sex differences were found in the age distribution. Grinding and clenching showed a negative correlation with age. Boys reported clenching more often than girls between 7-14 years of age. Lip-cheek-biting and nailbiting were frequently reported in all ages. Girls in the age group of 15-18 years reported lip-cheek-biting more often than boys of the same age group; who on the other hand reported nailbiting more often. A correlation was found between thumbsucking and anterior open bite.

Adolescent↗

[Findings in the main developmental stages of the bite in dysgnathic patients].

In this study dental plaster casts of 31 male and 45 female subjects were measured using the Berlin measurement system and evaluated with the aid of a computer. The parameters of subjects with class III malocclusion, crossbite, open bite and class II/1 malocclusion were compared. The changes were studied longitudinally in the main developmental stages, namely the deciduous, mixed and permanent dentitions. Significant differences were found also following treatment between the malocclusion groups.

Child↗

Clinical findings in the stomatognathic system for individuals with rheumatoid arthritis and osteoarthrosis.

A group of 123 individuals with rheumatoid arthritis (RA group) and 28 individuals with osteoarthrosis (OA group) were compared with 52 individuals without general joint symptoms (C group). The individuals in the RA and OA groups constituted 35% and 14%, respectively, of all individuals with RA and OA at the Rheumatism Hospital in Strängnäs, Sweden, during the period of investigation. All individuals answered a questionnaire concerning subjective symptoms from the stomatognathic system and general joint symptoms and were given a clinical examination comprising the temporomandibular joint (TMJ), masticatory muscles, mandibular mobility, and occlusion. Most signs of disorder in the stomatognathic system were more frequent and more severe in the RA and OA groups than in the C group. The clinical signs were of a similar character in the RA and OA groups, but the individuals in the RA and OA groups had less occlusal support, more occlusal interferences, greater distance between RP and IP, and less vertical overbite than the C group. Anterior open bite was found with higher frequency and severity in the RA and OA groups than in the C group and was correlated to clinical dysfunction score and reduced maximum mouth opening capacity.

Adult↗

Identification of cases requiring orthodontic treatment. A longitudinal study.

The present paper is a report on the second part of a longitudinal study dealing with the identification of children requiring orthodontic treatment. The series consisted of 200 children selected at random. The children were first examined at the age of 7 and next time at the age of 10. At the second examination 38% were found not to need any orthodontic treatment, while it was considered necessary to follow the occlusal development in 19%, and 43% were found to need treatment. The treatment need was urgent in 17%, moderate in 16% and slight in 10%. The re-examination of the untreated children at the age of 10 offered a possibility of checking the orthodontic prognosis made at the age of 7. It was concluded that only children showing cross bites and severe Class II malocclusions can reliably be selected for treatment at the age of 7. At this age misjudgements can be made with regard to dental arch crowding, open bite, deep bite, overjet and distal occlusion. Furthermore, it was concluded that a final decision concerning the need of orthodontic treatment cannot always be made even in 10-year-old children. The study will be continued by examinations at the ages of 12 and 14.

Child↗

Management of posttraumatic malocclusion caused by condylar process fractures.

PURPOSE: The aim of the study was to evaluate the results of orthognathic surgery in cases with posttraumatic malocclusion as a long-term complication of condylar process fractures. PATIENTS AND METHODS: A retrospective study on 21 patients with posttraumatic malocclusions attributable to condylar process fractures was performed. In group I, 15 patients were treated for asymmetric malocclusion with unilateral or bilateral mandibular ramus osteotomies. In group II, six patients were treated for anterior open bit with either a Le Fort I osteotomy (n=5) or a bilateral ramus osteotomy (n=1). All patients had clinical and radiographic follow-up for at least 1 year. RESULTS: Stable dental and cephalometric results were obtained in all patients except the one in group II who was treated with bilateral sagittal split osteotomies. In two cases, both in the asymmetric group, minor occlusal interferences had to be treated by equilibration in the early postoperative period. CONCLUSIONS: Orthognathic surgery is a predictable and stable method for the treatment of posttraumatic malocclusion due to condylar process fractures. Maxillary orthognathic surgery is successful in correcting symmetric anterior open bites due to bilateral condylar process fractures. Because posttraumatic malocclusion is a rare complication after closed treatment of condylar process fractures, and it can be treated satisfactorily using orthognathic surgery, routine open reduction and fixation of condylar process fractures is not indicated to prevent posttraumatic malocclusion.

Adolescent↗

Patterns and significance of bite wounds in Eurasian otters (Lutra lutra) in southern and south-west England.

Postmortem examinations were carried out on 379 otters found dead in southern and south-west England between 1988 and 2003. Most (81 per cent) were road casualties, but many had open bite wounds and in some cases these had proved fatal. Mortality was strongly seasonal and was positively correlated with night length. Although numbers decreased in the summer months, the prevalence of bite wounds in adults was highest in late summer. The number of otters examined annually and the prevalence of bite wounds increased markedly during the study period, and in 2003 more than half the otters of both sexes had recent bite wounds. The majority of the bites were considered to have been caused by other otters, but some were thought to have been inflicted by American mink (Mustela vison). Bites to cubs were mostly caused by domestic dogs. The overall mortality due to bite wounds was approximately 10 per cent.

Animals↗

Dental and facial characteristics of patients with juvenile idiopathic arthritis.

OBJECTIVE: It has been shown that the temporomandibular joint is frequently affected by juvenile idiopathic arthritis, and this degenerative disease, which may occur during facial growth, results in severe mandibular dysfunction. However, there are no studies that correlate oral health (tooth decay and gingival diseases) and temporomandibular joint dysfunction in patients with juvenile idiopathic arthritis. The aim of this study is to evaluate the oral and facial characteristics of the patients with juvenile idiopathic arthritis treated in a large teaching hospital. METHOD: Thirty-six patients with juvenile idiopathic arthritis (26 female and 10 male) underwent a systematic clinical evaluation of their dental, oral, and facial structures (DMFT index, plaque and gingival bleeding index, dental relationship, facial profile, and Helkimo's index). The control group was composed of 13 healthy children. RESULTS: The mean age of the patients with juvenile idiopathic arthritis was 10.8 years; convex facial profile was present in 12 juvenile idiopathic arthritis patients, and class II molar relation was present in 12 (P =.032). The indexes of plaque and gingival bleeding were significant in juvenile idiopathic arthritis patients with a higher number of superior limbs joints involved (P =.055). Anterior open bite (5) and temporomandibular joint noise (8) were present in the juvenile idiopathic arthritis group. Of the group in this sample, 94% (P =.017) had temporomandibular joint dysfunction, 80% had decreased mandibular opening (P = 0.0002), and mandibular mobility was severely impaired in 33% (P =.015). CONCLUSION: This study confirms that patients with juvenile idiopathic arthritis a) have a high incidence of mandibular dysfunction that can be attributed to the direct effect of the disease in the temporomandibular joint and b) have a higher incidence of gingival disease that can be considered a secondary effect of juvenile idiopathic arthritis on oral health.

Adolescent↗

[A clinical study of the changes of condylar position in class division 2 deep-bite patients after orthodontic treatment].

OBJECTIVE: To observe the effects of orthodontic treatment on the changes of condylar position in Class division 2 deep-bite patients. METHODS: 11 patients with Class division 2 deep-bite malocclusion were orthodontically treated, the changes of condylar position were evaluated by means of 3D-CT and Sam-diagnostic articulator. RESULTS: With the increase of inclination of upper incisors and opening bite, there were statistically significant changes of condylar longitudinal distance and condylar height in both sides, and retruded contact position-intercuspal position(RCP-ICP) discrepancy was significantly reduced. CONCLUSION: The condylar position in division 2 deep-bite patients could be orthodontically changed, moving anterior-inferiorly and approaching RCP.

Adolescent↗