Dento-alveolar characteristics in adolescents born extremely preterm.

It has been shown that children born extremely preterm (EPT) often suffer from medical complications and growth restrictions in early childhood. Catchup growth diminishes these effects but the children are known to have lower weight, height, and head circumference as school children. Effects on enamel development have been shown. How this affects the dento-alveolar outcome during adolescence is not known. Forty EPT children with a gestational age (GA) of less than 29 weeks, at 12-16 years of age, and matched healthy controls born at term, with a GA of 37-43 weeks, were examined. Data from the clinical examination, dental casts, and bitewing radiographs were collected and compared. Malocclusion was noted, and dento-alveolar length, width, palatal height, and mesio-distal tooth width were measured. Medical diagnoses, neurological, and neuropsychiatric disturbances were noted at the time of the survey. The two groups were compared with an epidemiological normal reference material. The results showed no differences between the controls and reference material. Angle Class II was the most frequent malocclusion associated with morbidity, neurological, and neuropsychiatric disturbances, followed by deep bite and overjet. Three or more malocclusions were almost twice as common among the EPT children compared with the controls. Significantly smaller incisors, canines, and first molars were found. In summary, the EPT children, during adolescence, had medical aberrations as well as dento-alveolar effects opposed to the healthy children born at term. Dentists should be aware of this and treatment plans should be made in due time.

Posterior crossbite and temporomandibular disorders (TMDs): need for orthodontic treatment?

The aim of this work was to update the bibliography regarding the concept of 'temporomandibular disorder (TMD)' and 'posterior crossbite' and try to find out if there is any association between some special signs/symptoms of TMD and type of posterior crossbite. A literature search from 1970 to 2009, due to specified criterion, resulted in 14 publications that were found to be relevant for the present systematic review. An association between TMD and posterior crossbite (Yes-group) was reported as often as absence of such a relationship (No-group). The samples in the two groups showed similarities as well as differences with respect to number, gender, and age. Most articles reported only on 'presence' or 'absence' of crossbite and only few on type of crossbite opposite to a thorough account of clinical signs and symptoms of TMD. This review seems, however, to state that a functional posterior crossbite (mandibular guidance with midline deviation) is associated with headache, temporomandibular joint and muscular pain, and clicking. As evident from the discussion, such type needs orthodontic treatment to rehabilitate the asymmetric muscular activity between the crossbite and non-crossbite sides and the changed condyle/temporal relationship caused by mandibular deviation. Whether this treatment also will avoid future TMD problems can be answered only after clinical follow-up studies have been performed.

Aesthetic evaluation in subjects treated due to congenitally missing maxillary laterals. A comparison of perception in patients, parents and dentists.

The treatment of the congenitally missing maxillary lateral incisor is a challenge to the dental profession. The demand for optimal orthodontic and prosthetic treatment is high because the condition has an impact on facial aesthetic. The aims of the present study were to determine how different outcome of treatment were perceived by professionals and laypeople and to identify situations that caused dissatisfaction or satisfaction after space closure or tooth replacement. A panel of four groups (patients with missing laterals, parents to these subjects, patients with other malocclusion and general dental practitioners) were included. Sixteen cases with uni- or bilateral missing maxillary lateral incisors, treated with space closure or with prosthetic replacements were presented photographically to the panel. The prosthetic replacements included resin-bonded bridges, porcelain bonded to gold bridges and implants. The panel was asked to rate the overall appearance of the mouth, to rank up to three disturbing features and to rank the most important treatment goals in case of treatment need. An obvious difference between the panel groups was found. The general practitioners were less critical than laypeople in rating the overall appearance. Amongst dentists the tooth colour, the tooth shape and asymmetry were the most disturbing factors whilst laypeople were disturbed by colour, spacing and tooth shape. Half of the dentists did not find any treatment need whilst the corresponding figure amongst laypeople was 19 per cent.When a treatment need was confirmed the most common treatment goals amongst dentists were to change the colour or the shape of the teeth. The laypeople wanted to change the colour, the space condition or the shape of the teeth. The study has shown that professionals and laypeople are of different opinion when rating treatment outcome in cases with missing maxillary laterals. Careful planning to achieve optimal aesthetics should be performed.

Dentoalveolar development in subjects with normal occlusion. A longitudinal study between the ages of 5 and 31 years.

The aim of the present study was to examine dentoalveolar development in subjects with an 'ideal' (normal) occlusion. The material comprised 436 study casts of 189 male and 247 female subjects of Swedish origin between the ages of 5 and 31 years with no history of orthodontic treatment. Tooth width, and arch length, width, and depth, as well as palatal height were measured. The data were analysed with a Student's t-test. The results verified that continuous changes of the dental arches occur from the primary until the adult period, with individual variations. This change could be interpreted as a biological migration of the dentition, resulting in anterior crowding especially in the mandible, even in subjects with congenitally missing third molars. The occlusion should be regarded as a dynamic rather than a stable interrelationship between facial structures. This natural development has to be considered in orthodontic treatment planning as well as in assessment of stability following orthodontic treatment. A continuous increase of palatal height up to adulthood seems to be an effect of a slow continuous eruption of the teeth. This finding is also of significance in explaining the infraposition of implant-supported crowns.

Roentgen-cephalometric standards for a Swedish population. A longitudinal study between the ages of 5 and 31 years.

This study was performed to establish age- and gender-specific cephalometric normative data for a Swedish population. The material comprised 469 lateral cephalograms from two groups of subjects of Swedish origin between 5 and 31 years of age. All subjects (males and females) were diagnosed as 'normal' according to specified criteria and with no history of orthodontic treatment. Lateral cephalograms and body height measurements were taken at 5, 7, 10 and 13 years of age in one group (group E) (longitudinal follow-up). The same registrations were made in the other group (group U) at 7, 10 and13 years of age (mixed longitudinal type). Those 13 year olds were re-examined at 16, 19 and 31 years of age (longitudinal follow-up). No significant differences between age groups in the two samples were found. Therefore, subjects of the same age were combined. The study is hence regarded as a longitudinal follow-up from 5 to 31 years of age. The subjects were also grouped into dental development stages to widen the applicability of the cephalometric data.The craniofacial distances were constantly larger in males than in females, while no statistical differences as regards angular measurements were seen between genders. Distances as well as angular measurements varied with the different developmental periods. The results clearly verify that facial pattern changes existed during the observation period, with a growth acceleration of most distances between the 13 and 16 year recordings.

A study of children with unilateral posterior crossbite, treated and untreated, in the deciduous dentition--occlusal and skeletal characteristics of significance in predicting the long-term outcome.

BACKGROUND AND AIM: The generally recommended treatment in children with unilateral posterior crossbite is expansion of the maxillary dental arch. The reported treatment success rate varies between 50% and 96%. The aim of the present study was to analyse whether some occlusal and skeletal characteristics could be found in the deciduous dentition of children with treatment success (including self-correction) in contrast to those showing non-correction (including relapse) in the young permanent dentition. PATIENTS AND METHOD: Two groups of children with unilateral posterior crossbite were followed from the age of 5 years up to 13 years of age. The children in one of the groups (n = 32) were treated in the deciduous dentition, while the children in the other group (n = 32) were to be treated in the late mixed or early permanent dentition. Another 25 children (5 years old) with excellent occlusion were included as controls. Results of clinical examination and biometric and cephalometric analyses, performed at the first examination (at 5 years of age), are presented for the three groups ("treated" "untreated" and controls). RESULTS AND CONCLUSIONS: Compared to the controls, asymmetry was registered in both dental arches. The crossbite side, measured to the midline, was narrower than the non-crossbite side in the upper jaw but broader in the lower jaw. Differences between upper/lower widths (at intercanine and intermolar level) seem to be of importance for correction or non-correction, both for "untreated" and "treated" children. A narrow crossbite side in the upper arch together with a broad crossbite side in the lower arch was found in non-corrected children in both groups, even among those treated with maxillary expansion, where the SNB angle was larger and the ANB angle smaller than in controls as well as in those with correction (including self-correction). Possibilities and limitations of treatment planning are discussed.

Prevalence of temporomandibular dysfunction and its association with malocclusion in children and adolescents: an epidemiologic study related to specified stages of dental development.

A sample of 4724 children (2353 girls and 2371 boys) (5-17 years old) were grouped not only by chronological age but also by stage of dental development (deciduous, early mixed, late mixed, and permanent dentition). The registrations included functional occlusion (anterior and lateral sliding, interferences), dental wear, mandibular mobility (maximal opening, deflection), and temporomandibular joint and muscular pain recorded by palpation. Headache was the only symptom of temporomandibular dysfunction (TMD) reported by the children. The results showed that one or more clinical signs were recorded in 25% of the subjects, most of them being mild in character. The prevalences increased during the developmental stages. Girls were in general more affected than boys. Significant associations were found between different signs, and TMD was associated with posterior crossbite, anterior open bite, Angle Class III malocclusion, and extreme maxillary overjet.