## 1 Introduction  
The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth and remains until the tooth reaches its final position in the dental arch [1; 2]. Radiographically, DF appears as a radiolucent area around the tooth; histologically, it consists of condensed ectomesenchyme that surrounds the enamel organ and the dental papilla in association to which forms the germ of the tooth [3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14]. In terms of function, DFs participate in tooth morphogenesis and directing tooth eruption through cascades of signaling pathways and different transcriptional factors [1; 2; 15].  
In oral surgery, the removal of a symptomatic impacted third molar or its prophylactic removal is one of the most commonly performed surgical procedures [11]. Indeed, third molars are the most frequently impacted teeth, and the prevalence of third molar impaction has been reported to range from 16.7% to 73% [16; 17; 18; 19; 20]. Even though it is well known that DFs around impacted teeth have the potential to develop pathological conditions, there is no conclusive agreement among clinicians about their prophylactic removal [4; 5; 6; 7; 8; 9; 10; 11; 13; 18; 11; 13; 18; 21]. Consequently, the pathological potential of impacted third molars is under continuous investigation.  
The radiographic evaluation of the DF represents the main approach used to establish its physiologic development. Indeed, the DF is considered normal when its maximum width is lower than 2.5 mm [3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 22; 23]. At present, it is increasingly common to have a pre-surgical evaluation using tridimensional radiographic exams (e.g., cone beam computer tomography, CBCT) [22; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34]. Because of the low dosage of X-rays associated with this method, it represents the foremost technique administered in pediatric patients [35; 36]. In the specific context of impacted third molars, CBCT can be more accurate than conventional two-dimensional radiographic methods in displaying the morphology of the teeth and of their related anatomical structures, as well as in the measurement of DF width [14; 22; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34]. For these reasons, CBCT has been recommended for third molar surgical planning, especially when there is the potential to provide new information that can impact clinical management decisions not offered by conventional radiography.  
Most dental practitioners discard extracted unerupted third molars rather than sending them for histopathological analysis. Consequently, there are not many studies focused on the morphology of radiographically normal DFs of impacted third molars [4; 5; 6; 7; 8; 9; 10; 11; 13; 21; 23; 37; 38; 39; 40; 41]. In addition, the lack of radiographic evidence of pathology is not a reliable indicator of the absence of disease, and the prevalence of DF tissue pathosis has been estimated to be higher than generally assumed from radiographic evaluation alone [5; 6; 23; 40]. For these reasons, we performed this case series study with the specific aim of histologically evaluating DFs from thirteen consecutive mesioangular impacted third molars that appeared normal through CBCT analysis.