Biomedical subjects

Bertil Lennartsson

Publications and source records attributed to Bertil Lennartsson.

3 recordsLinked to original sources

PubMed2005

Primary teeth in adults--a pilot study.

Remaining primary teeth are occasionally found in adults. The cause and the long-term survival may vary. The aim of this investigation was to study the occurrence and condition of primary teeth in adults in a county in Sweden. All dentists in general practice were asked to send in radiographs showing remaining primary teeth in patients aged 18 years and more. The following variables were registered: 1) age, 2) gender, 3) year of exposure of the radiograph, 4) location of the primary tooth, 5) impaction of the permanent successor, 6) fillings or caries in the primary tooth, 7) amount of root resorption and 8) infraocclusion of the primary tooth. 35 dentists contributed with radiographs from 65 subjects showing 89 retained primary teeth. The most commonly found tooth was the second primary molar in the mandible, followed by the primary canine in the maxilla. Except for maxillary molars, most of the primary teeth showed a moderate degree of root resorption. No relationship was found between the degree of root resorption and gender, fillings/caries or infraocclusion. For the mandibular primary molars, there was a statistically significant correlation between root resorption and age. The mesial root of the molar in the mandible was more affected by root resorption than the distal, and the degree of root resorption of the mesial and distal roots was found to be closely correlated. Also, the results indicated a symmetrical pattern of root resorption in bilateral cases of remaining mandibular second primary molars.

Adult↗

PubMed2002

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.

Adolescent↗

PubMed2002

Influence of mandibular protruding device on airway passages and dentofacial characteristics in obstructive sleep apnea and snoring.

The aim of the study was to evaluate the influence of a mandibular protruding device (MPD) after 2 years of nocturnal use on the upper airway and its surrounding structures. Lateral cephalograms in the upright position were taken of patients with obstructive sleep apnea (OSA) and of patients with snoring problems at the beginning of treatment and at the 2-year follow-up. Two computer programs were used to analyze the cephalograms. A total of 65 patients, 44 with OSA and 21 snorers, were analyzed. The linear distances in the pharynx had increased significantly at the 2-year follow-up; the calculated pharyngeal area had increased on average by 9% (mean, +58.3 mm(2)). The velum area had decreased (mean, -31.5 mm(2)), which accounts for about half the increase in the relative area of the pharynx. The average linear distances between the hyoid bone and the 2 reference lines, ie, nasal line (NL) and mandibular line (ML), had increased significantly. Mandibular protrusion (SNB) was slightly reduced, on average -0.4 degrees (P <.01), and the lower incisors were proclined (ILi/ML), on average +1.5 degrees (P <.05). In conclusion, nocturnal use of an MPD for 2 years increased the airway passage because of an increase in the relative area of the pharynx by a mean of 9% in OSA patients and snorers. A mandibular posterior rotation and a proclination of the lower incisors were observed but considered modest.

Adult↗