Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2018-02-14, 12:02:22 | version 1.38.0
P r o x i m i t y o f m a n d i b u l a r f i r s t a n d s e c o n d m o l a r s t o I A C Fig. 12 Fig. 12 Schematic representation of differences in distance estimated with the respective 2-D and 3-D imaging modality. Table 2 Overview of the distance between the apices of mandibular first and second molars (data considered for meta-analysis). concluded that the distance was smaller in the groups aged 16–25 years and 56–65 years com- pared with other age groups.8 Previous studies have confirmed that the distance between the apices and the mandibular canal increased with eruption of mandibular teeth.11 Kawashima et al. showed that there was increased bone growth after eruption of teeth and/or inferior migration of the IAC with age in both sexes.1 R a c e Levine studied an American population and found that white patients on average had a lower distance between the buccal aspect of the canal and the outer buccal and superior cor- tical plates of the mandible.12 They concluded that, in order to minimize the risk of IAN injury, these variables should be considered when plan- ning mandibular osteotomies or using mono- cortical plates. Hiremath et al. found that the distance from the IAN to the apices of first and second molars ranged from 0.00 to 14.71 mm in general,6 and Adigüzel et al. found it to be 4.1–5.1 mm.8 Chrcanovic found the distance from the IAN to first and second molars to be less than 6 mm.13 Bürklein et al. showed that the distance from the IAN to first molars to be 4.9 mm, to second molars to be 3.1 mm and to third molars to be 2.6 mm.7 Chong et al. demonstrated that the distance between the anatomical apex and the IAN was less than 3 mm.2 Al-Jandan et al. showed that the horizontal distance at the level of the apex and the IAC area at the second molar was 4 mm greater than at the first molar.14 Alves et al. found that the distance of second and third molars from the mandibular canal was less than 1 mm.15 Littner et al. suggested that the man- dibular canal was located 3.5–5.4 mm.11 Denio et al.’s study of dry mandibles concluded that the distance from second molars to the IAN was 3.7 mm and from first molars was 6.9 mm on 2-D radiographs.8, 16–18 Basically, there are three important pro- cesses that influence the development of the craniofacial bones: size increase, remodeling and displacement. The first two processes occur simultaneously by a combination of bone resorption and displacement. The last one results in the displacement of all the bones away from each other to undergo a size increase. The remodeling and displacement processes change and vary according to age, sex and race. These changes will have impact on the location of the IAC/IAN with respect to the apices of mandib- ular first and second molars. Q u a l i t y o f e v i d e n c e The data in the first instance were derived from secondary data and the studies used varying methodologies to estimate the distance from the apices of the mandibular first and second molars to the IAC. Hence, the results obtained should be interpreted with caution. 54 Volume 3 | Issue 4/2017 Journal of Oral Science & Rehabilitation