A survey of 3,874 routine full-mouth radiographs: I. A study of retained roots and teeth
ABSTRACT A comprehensive study of 3,874 routine full-mouth radiographs yielded the following findings concerning retained roots and teeth: 1.1. The incidence of retained roots discovered in routine full-mouth radiographs of all types of patients was close to 20 per cent. Twice as many roots are retained in the maxilla as in the mandible, and over six times as many are retained in posterior areas as in anterior areas.2.2. The incidence of retained roots in edentulous jaws was close to 24 per cent, and the incidence of retained and embedded teeth was 2.6 per cent.3.3. The over-all incidence of radiolucencies associated with retained roots was over 50 per cent.4.4. Of these retained roots, those exposed to the oral cavity were involved with radiolucent areas in 81 per cent of the cases, while roots lying beneath the surface or completely encased in bone had radiolucent areas around them in 20 per cent of the cases.5.5. The size of the retained root had no influence on the incidence of associated radiolucent areas.6.6. There was no difference in the numbers of radiolucencies between roots found in the maxilla and those found in the mandible, but a markedly higher incidence of involvement was noted in anterior areas as compared to posterior areas.7.7. The incidence of retained roots of deciduous teeth which remain in the jaws is extremely small (1.2 per cent).8.8. Retention of deciduous teeth occurred in one out of every sixty-three patients. The most frequently retained deciduous tooth was the maxillary cuspid.The significance of these findings is discussed, and the need for comprehensive radiographic examination of all patients is emphasized.
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ABSTRACT: OBJECTIVES: The root morphology of the maxillary first premolar differs from the other premolars by presenting a high incidence of separated roots. This study addressed the spatial conditions during root development as a possible influencing factor. Therefore, maxillary computed tomographic (CT) scans of patients with regularly erupted or impacted permanent canines were evaluated on the root morphology of the premolars. METHODS: The following parameters were retrospectively analysed in 250 maxillary CT scans (100 patients with regular erupted permanent canines, 150 patients with at least one impacted permanent canine): sex, status of the canines (erupted/impacted), position of the impacted canines (buccal/palatal; vertically inclined inside/outside the dental arch/horizontally inclined) and root morphology of the premolars. RESULTS: Of the patients, 68 % with at least one impacted canine were female; the canine was impacted palatally in 75.6 % and in a horizontally inclined position in 58.4 %. In patients with an impacted canine, the number of first and second premolars with separated roots was significantly reduced on the ipsilateral as well as on the contralateral side (all p values < 0.01). CONCLUSIONS: The present study detected an influence of maxillary canine impaction on the root morphology of all premolars, in that impaction and the associated surplus of space resulted in decreased root separation. This supports the hypothesis that root development is at least partly influenced by increased spatial conditions of the dental arch. However, root development can be regarded as a multifactorial event, influenced by space, direct mechanical interferences, as well as genetic predetermination. The retrospective nature of this observational study did not allow for conclusive differentiation between these factors. Alternatively, root separation and the mesial concavity of the first premolar may represent a path for canine eruption similar to the lateral incisor. CLINICAL RELEVANCE: A single-rooted maxillary first premolar might represent an additional risk factor for canine impaction.Clinical Oral Investigations 07/2012; · 2.20 Impact Factor
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ABSTRACT: To determine whether clinical variables associated with surgically exposed unilateral maxillary impacted canine cases are predictors for orthodontic treatment choices involving (1) extraction, (2) expansion, (3) extraction and expansion, or (4) nonextraction and nonexpansion. A retrospective study of records of 97 cases meeting the inclusion criteria with unilateral maxillary impacted canines from three private practices were reviewed for gender, age, molar classification, impaction location and angulation, and presence of pretreatment maxillary and mandibular casts and cephalograms. Maxillary and mandibular transverse dimensions and lower incisor crowding were obtained from occlusal cast images using custom computer software. Skeletal analysis and incisor angulation and position were obtained from digitized cephalometric tracings. Statistical comparisons were made to determine parameters orthodontists could use to develop an orthodontic treatment plan. Subjects with Class II end-on molars on the nonaffected side were less likely to have extraction and/or expansion. Subjects with extraction and/or expansion had decreased lower incisor to mandibular plane, available canine space, maxillary premolars, and molar transverse dimensions and an increased mandibular incisor Irregularity Index compared with nonextraction/nonexpansion subjects. Using a multiple-variable model, available canine space was the single most important predictor of extraction and/or expansion, followed by maxillary molar transverse dimension and mandibular incisor Irregularity Index. Available canine space, maxillary transverse dimension at the molars, and the mandibular incisor Irregularity Index serve as indicators for extraction and/or expansion in cases involving unilateral maxillary impacted canines requiring surgical exposure. Many of these cases are treated without extraction and/or expansion.The Angle Orthodontist 12/2011; 82(4):723-31. · 1.18 Impact Factor
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ABSTRACT: The aim of the present study is to determine the number of third molars per person, angulation, level, amount of space for eruption of third molar between ramus of mandible and second molar and the eruption status of third molar in a group of Libyan students, with different impaction patterns and agenesis of third molars. In this descriptive retrospective study, a total of 200 students (100 male and 100 female students of bachelor of dental surgery, Faculty of Dentistry, Garyounis University, Benghazi, Libya) were enrolled. Students who had complete complement of teeth within the age group 17-26 years were selected for this study, while those cases who had history of extraction of any of the teeth or who refused to give consent were excluded. Before starting the study, ethical concern from the ethical committee, IRB and informed consent from each student who underwent radiography were obtained. The results showed that 5% of third molars were congenitally missing. Approximately 93.5% of the subjects had all four third molars, 1% had two third molars and 0.5% had one third molars with 2.5% having agenesis of all third molars. Third molar agenesis showed predilection for maxilla with higher proportion in females (3%) than males (2.1%). Angular position was maximum with vertical position (5.83%), with least being horizontal impactions. Level of occlusal plane of third molar similar to that of adjacent tooth was seen in 44.74%, below the occlusal plane in 24.76%, totally impacted noted in 30%. The present study showed that 33% of the teeth were fully erupted and 66% were in various stages of eruption and 5% were congenitally missing in these students.Dental research journal 03/2012; 9(2):152-7.