Loss of Permanent First Molars in the Mixed Dentition: Circumstances Resulting in Extraction and Requiring Orthodontic Management.

Extraction of significantly compromised permanent first molars may be indicated during the mixed dentition stage of occlusal development. The purpose of this article was to review circumstances that can result in the loss of a permanent first molar-including dental caries, molar incisor hypomineralization, eruption disturbances of permanent teeth, and failure of restorative treatment to affirm that a complete dental arch is not necessary for the existence of a functional dental arch. The extraction of permanent first molar(s) with subsequent orthodontic treatment in a young patient can be considered a cost-effective alternative to placing complex restorations that require replacement over the lifespan. Approaches to establish a functional dental arch in the event of the loss of a permanent first molar(s) are outlined. Additionally, orthodontic diagnostic and treatment principles are reviewed. Case histories are provided to illustrate the clinical management of permanent first molar extractions to achieve a functional dental arch.

Secondary trauma from occlusion and periodontitis.

OBJECTIVE: To assess the association between secondary trauma from occlusion and the severity of periodontitis. METHOD AND MATERIALS: A total of 288 subjects with chronic periodontitis of varying severity and 93 healthy subjects were included in the study. Premature and balance contacts were identified by manual palpation and visualization of occlusal contacts during clenching in habitual intercuspation and lateral or protrusive movements of the mandible. Statistical analysis was performed with Kruskal-Wallis, Mann-Whitney, and Spearman correlation tests. RESULTS: Statistically significant differences (P<.001) were found for all variables tested (ie, the total amount of trauma per patient and the number of premature and balance contacts increased significantly with the level of clinical attachment loss). The Spearman test showed a statistically significant correlation between the total amount of trauma per patient and the severity of periodontitis (P<.001). CONCLUSION: The results of this study indicate that secondary trauma from occlusion (ie, premature and balance contacts) is frequently seen in periodontally compromised patients and is positively correlated with the severity of attachment loss.

Analysis of different type of transmigrant mandibular teeth.

OBJECTIVE: Until recently, most reports about transmigration have documented that the canine is the only tooth which can migrate to the opposite side of the arch. The goal of the study was to define the transmigration of different types of teeth in people in various regions of Turkey. STUDY DESIGN: A total of 112,873 panoramic radiographic files from seven different Turkish cities were inspected. The following data were evaluated according to age, gender, number of transmigrant teeth, localization, eruption status, side, unilaterally or bilaterally and associated pathology or dental abnormalities. RESULTS: Of the 112,873 radiographs included in the study, 90 were seen to present as transmigrant in 87 patients, representing 0.079% of the sample. There were only two (0.0017%) transmigrant lateral (TML) teeth and only three (0.0026%) transmigrant premolar (TMP) teeth encountered. The mean age at the time that the transmigrant mandibular teeth were identified was 29.9 years, with a range from 10 to 66 years. Out of the 87 cases, 51 were female and 36 were male, with a male:female ratio of 1:1.41. Transmigrants were more commonly seen unilaterally (96.5%). The most frequent associated pathology was odontoma. CONCLUSIONS: Because early detection is vital to prevent complications and ensure more successful treatment, these extensive studies are crucial. In this extensive study, we indicated cases of transmigration of premolar and lateral teeth as a variant. Demographic variables and properties of all transmigrants (TM) were also presented.

Transmigrant mandibular canines.

PURPOSE: The aim of the present study was to investigate the patterns of transmigrant mandibular canines, the incidence and classification of transmigrant canines, and the associated pathology of these teeth. PATIENTS AND METHODS: This retrospective cohort study was composed of 4,500 panoramic radiographs of patients who presented to our Oral and Maxillofacial Surgery Services from January 1998 to December 2005. Panoramic radiographs were reviewed. Observations were made on the status of missing permanent mandibular canines, retained deciduous canines, side and number of transmigrant canines, gender and age of patients, and any other associated pathology. RESULTS: In the present study, a total of 15 patients had transmigrated canines-6 females (ages 13-33 years) and 9 males (ages 13-57 years). All transmigrant canines were unilateral. Two canines were impacted in the mandible enveloped in cystic lesions. The rest of the transmigrated canines were in varying stages of intraosseous travel and positioning within the mandible, with no pathological entity. CONCLUSION: The use of a panoramic radiograph is imperative and is recommended for discovering such rare malpositions. If the mandibular canine that has migrated across the mandible is associated with pathology, it may be removed. Otherwise, it should be kept under observation.

Evaluation of spontaneous space closure and development of permanent dentition after extraction of hypomineralized permanent first molars.

AIM: The aim of this study was to evaluate spontaneous space closure, development of the permanent dentition, and need for orthodontic treatment after extraction of permanent first molars due to severe molar-incisor hypomineralization (MIH). SUBJECTS: Twenty-seven children aged 5.6-12.7 (median 8.2) years had one to four permanent first molars extracted due to severe MIH. Each case was followed up on individual indications 3.8-8.3 (median 5.7) years after extractions. The eruption of the permanent dentition, and space closure were documented by orthopantomograms, casts, photographs, and/or bitewings. RESULTS: Fifteen children were judged to have a favourable spontaneous development of their permanent dentition without any orthodontic intervention. Seven children were or should be subjected to orthodontic treatment for other reasons registered prior to the extraction. Five children were judged to have a treatment at least caused by the extractions, but three of them abstained because of no subjective treatment need. CONCLUSION: Extraction of permanent first molars severely affected by MIH is a good treatment alternative. Favourable spontaneous space reduction and development of the permanent dentition positioning can be expected without any intervention in the majority of cases extracted prior to the eruption of the second molar.

Occlusal changes following posterior tooth loss in adults. Part 2. Clinical parameters associated with movement of teeth adjacent to the site of posterior tooth loss.

PURPOSE: Much anecdotal evidence is available on tooth positional changes following loss of an adjacent tooth, but only a few studies are available. In Part 1 of this series, supraeruption was assessed and Generalized Linear Models were made to determine the clinical parameters associated with the supraeruptive process. The models demonstrated that clinical parameters were not only associated with the extent of supraeruption, but also with the type of eruption present. This investigation of tooth positional changes adjacent to sites of posterior tooth loss attempts to provide increased understanding of the magnitude, direction, and associated features that may be helpful in decision making and treatment planning in the clinical setting. MATERIALS AND METHODS: One hundred patients with an unopposed posterior tooth, with 100 age, sex, and bone level matched controls, were drawn from patients undergoing routine restorative care at Leeds Dental Institute. Study models were scanned, and the extent of eruption, type of eruption of the unopposed tooth, the overbite, overjet, buccal occlusion, and degree of crowding in the dentition, tipping, rotation, and buccal movement of the teeth associated with the edentulous site were recorded. Generalized Linear Models were developed to examine associations between each tooth movement and patient or dental factors. RESULTS: A statistical significance in the degree of tipping of teeth both mesial and distal to the extraction site was detected between the subject and control groups. There was also a significant difference in rotation of the tooth mesial to the site. Four Generalized Linear Models were produced of the types of non-vertical movements found in teeth associated with sites of tooth loss. CONCLUSIONS: Teeth adjacent to the site of tooth loss may undergo non-vertical movements. Teeth mesial to the extraction site had a tendency to tip distally. The degree of tipping was increased in upper teeth and in subjects with a cusp-to-cusp buccal occlusion. Rotation of teeth mesial to the extraction site was more prevalent in the lower arch. Tipping of the tooth distal to the extraction site could be extreme and was found to be more prevalent in subjects with a reduced (Code 1) overbite and in the lower arch. Rotation of teeth distal to the extraction site was greater in the upper arch and was also associated with a reduced (Code 1) overbite. It also had an association with rotation of the tooth mesial to the extraction site. Models of non-vertical movement are likely to be of limited value due to overdispersion, indicating a high degree of variability within the model.

Patterns of intraosseous transmigration and ectopic eruption of bilaterally transmigrating mandibular canines: radiographic study and proposed classification.

Unilateral transmigration of mandibular canines is a rare phenomenon. Occurrence of bilateral transmigration of mandibular canines is even more rare. There are diagnostic, therapeutic, and prognostic implications in the occurrence of these transmigratory patterns. Proper understanding of the mechanisms involved in the impaction and intra-osseous movement of these teeth within the bone will help clinicians to intervene and formulate better treatment options. A review of previously reported cases of bilaterally transmigrating mandibular canines from the literature was undertaken. Five new cases are reported in this article. Classification of the bilaterally transmigrating mandibular canines is proposed for better understanding, ease of communication, and appropriate management of this aberrant migratory pattern.

Periodontal conditions of teeth presenting pathologic migration

O objetivo deste estudo foi avaliar as condições clínicas periodontais de dentes anteriores com migração patológica (MDP) em pacientes com periodontite crônica generalizada e comparar a severidade de destruição periodontal entre dentes migrados e não-migrados. Foram selecionados 32 pacientes, de ambos os sexos, apresentando média de idade de 46,0 anos (± 11,6), com perda clínica de inserção em dentes anteriores e presença de algum tipo de MDP, a saber: vestibularização, diastema, inclinação proximal, giroversão ou extrusão. Os parâmetros avaliados foram a perda clínica de inserção (PIC) e o percentual de perda óssea radiográfica (PO). Os resultados mostraram, em média, uma PIC de 5,50 mm (± 2,20 mm) e uma PO de 41,90% (± 15,40%) do comprimento radicular, em 115 dentes selecionados. Os tipos mais freqüentes de migração foram vestibularização (34,80%) e presença de diastemas (27,00%). A extrusão foi a menos freqüente (4,30%). Maiores valores de PO e PIC foram registrados nos dentes com extrusão (59,44% e 8,42 mm) e vestibularização (45,17% e 6,07 mm). Esses valores de PO foram superiores aos observados nos dentes com giroversão ou inclinação proximal (p < 0,05 - Kruskal-Wallis). A PIC não apresentou diferenças significativas entre os diferentes tipos de migração (p = 0,11). Constatou-se que os dentes anteriores com MDP apresentaram maior PIC e PO (5,1 mm e 40%) quando comparados aos não-migrados (4,1 mm e 31%). Pôde-se concluir também que o tipo de MDP mais prevalente foi a vestibularização, que esteve relacionada a maiores níveis de perda óssea.

Primary molars in severe infraocclusion: a retrospective study.

UNLABELLED: The term severe infraocclusion is used to describe teeth located at the level of or below the alveolar crest and is rare. AIM: The aims of the study were to evaluate the influence of age of diagnosis and treatment on the outcome of the successors of primary molars with severe infraocclusion and to propose a treatment protocol based on the age of diagnosis. METHODS: A retrospective study of patients with primary molars in severe infraocclusion (PMSI) in the period 1987-2001 was carried out. Parameters assessed were age, sex, degree of infraocclusion based on radiographs, altered position of adjacent and successor teeth and treatment outcome. RESULTS: The sample comprised 19 patients with 23 cases of PMSI, all were second primary molars (47.8% maxillary and 52.2% mandibular). Migration of the neighbouring tooth was present in 51.5% of cases. The PMSI treatment was by extraction in all cases, a space maintainer was fitted and remained in place until the eruption of the successor. The outcome was favourable in 82.6% of cases. CONCLUSION: Successful treatment of PMSI depends on prompt diagnosis and appropriate treatment and follow-up of the cases. The earlier the age of detection, the more favourable the outcome.

A cephalometric study of the effect of extraction of lower first permanent molars.

The sample consisted of 28 patients (16 female: 12 male) from the records of the Orthodontic Department for whom the extraction of both lower first permanent molars was considered due to caries. The age ranged from 8-14 years (mean age 12.4). A cephalometric radiograph was taken prior to the extraction and after a mean of 18 months. No other treatment was done during the observation period. The radiographs were traced arid digitized using the GeLa program. A total of 16 points were digitized yielding 19 measurements (7 angular and 12 linear). The data were analyzed using 't' test and Pearson Correlation Coefficients in SPSS PC and compared to a control group matched for age and sex. Results showed that on average, the lower second molar moved forwards 5.9 mm. On average there was no change in angulation of the incisors to the bases. There was no significant change in the vertical relations of the jaws save that caused by normal growth and development. A significant correlation was found between the change in overbite and original overbite (r = -0.55, P < 0.01), the change in Li/A-Pog (r = 0.41, P < 0.05) and the change in facial proportions (r = -0.59, P < 0.001). The change in overjet was correlated with the change in Li/A-Pog (r = 0.58, P < 0.001) and change in Li/mand (r = -0.55, P < 0.01). The extraction of the lower first molars results in deepening of the overbite on average, but has no effect on the anterior facial height or any other vertical relationship. However, the increase in overbite is associated with lingual positioning of the lower incisor and the change in facial proportions. The change in overjet is related to lingual positioning and retroclination of the lower incisors.