Retrospective Radiographic Survey of Unconventional Ectopic Impacted Teeth in Al-Madinah Al-Munawwarah, Saudi Arabia

OBJECTIVES: Ectopic unconventional impacted teeth are rare. These teeth erupt in an unusual direction with limited unconventional access and have increased surgical risks. AIM: This study aimed to investigate and assess the prevalence and distribution of rare ectopic impacted teeth at the Taibah University Dental College and Hospital (TUDCH), Al-Madinah Al-Munawwarah, Saudi Arabia. METHODS: The study designed through a retrospective radiographic cross-sectional survey involving the review and examination of 9000 archived digital orthopantomograms of patients who visited the (TUDCH) in the period from January 2014 to December 2019 and to analyze any associated factors. RESULTS: There were 63 ectopically impacted teeth, with an incidence of 0.7%. The age of the patients ranged from 18 to 68 years, with a mean of 32.4 ± 13 years. Regarding patient nationality, 68.3% were Saudis. The most common ectopically impacted teeth were the extra impacted premolars, with an incidence of 0.2%, followed by the inverted molars, impacted first or second molars, and buccoversion or lingoversion third molars, with incidences of 0.16%, 0.13%, and 0.12%, respectively. The mandible was affected with ectopic impaction more than the maxilla, with an incidence of 55.6%. There was no difference between the right and left sides. Impacted teeth in the sinus were the least common. CONCLUSION: The prevalence of ectopic impacted teeth was 0.7% among the surveyed patients at TUDCH, Al-Madinah Al-Munawwarah, Saudi Arabia. Hence, the oral surgeon must have readiness for such a challenging, increasing situation.

Primary molt in Gruiforms and simpler molt summary tables

Molt summary tables reveal the sequence and mode of flight-feather replacement and how these feathers are divided into independent replacement series. Tables for summarizing molt are relatively new, and the rules for generating them were first formally illustrated using data from a temperate passerine. However, this first illustration failed to address (i) species with primaries divided into more than one replacement series, (ii) species with stepwise primary replacement, which almost always involves incomplete annual replacement of the primaries, and (iii) species with incomplete annual replacement within molt series characterized by single-wave replacement. Here, we review complications that arise in developing molt summary tables for such cases and we offer solutions that remove ambiguity about the direction that molt proceeds within a replacement series and about the recognition of nodal and terminal feathers that mark the beginning and end of molt series. We use these modified molt summary tables to describe the sequence of primary replacement in four groups of Gruiform birds, a group for which primary replacement has been reported to proceed from the outermost primary toward the body, unlike most other birds. Eighty molting Grey-winged Trumpeters,Psophia crepitans,and 124 molting Limpkins,Aramus guarauna, show the sequence of primary replacement is proximal in both groups; furthermore, the primaries of trumpeters are divided into two replacement series, one beginning at the outermost primary P10, and the other beginning at P3. To further evaluate the extent of this highly unusual direction of replacement in Gruiforms, we cast the data (Stresemann & Stresemann, 1966) on primary replacement in upland rails (Rallidae) and flufftails (Sarothruridae) into molt summary tables; both also replace their primaries proximally, from outermost to innermost, suggesting that this mode of primary replacement may be characteristic of Gruiformes.