Normal Eruption Research Articles

A new guide using CBCT to identify the severity of maxillary canine impaction and predict the best method of intervention.

OBJECTIVE:This study aimed to test the intra and inter-rater reliability, reproducibility, and validity of a new guide called the “Cone Beam Computed Tomography-Maxillary Canine Impaction (CBCT-MCI),” designed to assess the position, severity, and predictability of the maxillary canine impaction (MCI) treatment intervention using Cone Beam Computed Tomography (CBCT).MATERIALS AND METHODS:This study is a retrospective radiographic review of 44 patients with unilateral or bilateral MCI. A total of 56 maxillary impacted canines’ CBCT radiographs were analyzed using the new CBCT-MCI guide, with each of its 10 items scored. The total scores of the 10 items were then compared to a scale to predict the best treatment intervention of MCI: normal spontaneous eruption, surgical-orthodontic traction, or surgical extraction. Radiologists and orthodontists have developed, tested, and retested the CBCT-MCI guide on the same 56 maxillary impacted canines using CBCT radiographs to check its reliability and reproducibility using the Kappa coefficient. Furthermore, the validity of this guide was tested by comparing the predicted best treatment intervention with the actual treatment administered to the assessed impacted maxillary canine using the Kappa coefficient and percentage of agreement using cross-tabulation.RESULTS:The result of this study showed significantly strong Kappa values of intra-rater agreement (k = 0.91, (P < 0.0001) and inter-rater agreement (k = 0.84, P < 0.0001). Furthermore, testing the relationship between the two MCI treatment interventions using cross-tabulation, the agreement percentages between the predicated and actual treatment plans of the assessed MCI ranged between 70% and 95.5% with a significantly strong Kappa value (k = 0.82, P < 0.0001).CONCLUSIONS:This study suggests that the CBCT-MCI guide is capable of producing accurate, reliable, and reproducible results in assessing and predicting the type of orthodontic treatment intervention of MCI in a simple, quick, and efficient way.

Management of impacted maxillary canines during orthodontic treatment: Report of two cases with 1-year follow-ups

The prevalence of impacted maxillary canines is 2%–3%. The position of the canine germ should be evaluated between 9 and 11 years of age group. In addition to the clinical examination, radiographic evaluation of the canine site will aid in gathering additional data such as the position of the canine, its relationship with the adjacent teeth, and any oral pathology associated with the site. It becomes imperative to have an early diagnosis of the ectopically positioned canine. Orthodontic considerations which include orthodontic traction for the malpositioned canine tooth along with surgical exposure assume significance, if the permanent canine is deviating from its normal eruption pathway trajectory within its specified timeline of erupting into the dental arch. The objective of reporting the following two cases is to analyze a successful 1-year follow-up outcome of an interdisciplinary, evidence-based approach in managing impacted canines in two female patients in their second decades of life.

Effect of periostin silencing on Runx2, RANKL and OPG expression in osteoblasts.

Normal tooth eruption is closely related to relevant genes and the dynamic balance between osteoblasts and osteoclasts. If secretion of RANKL and OPG by osteoblasts is disordered, relevant gene deficiencies or mutations will result in serious tooth eruption disturbances, e.g., cleidocranial dysplasia (CCD). Thus, we examined changes in Runx2, RANKL, and OPG protein expression in MC3T3-E1cells after silencing the periostin gene, thus, providing an experimental basis to study tooth eruption mechanisms. Based on previous research, cells were divided into two groups according to the virus number: the contrast group (NC group; pFU-GW-016 PSC53349-1) and the experimental group (KD group; LVpFU-GW-016PSC66473-1). Cells were infected with the lentiviral vector (multiplicity of infection = 100) and assessed by image cytometry 72 h after infection. After screening cells for the strongest gene silencing effect, Runx2, RANKL and OPG protein expression were detected by western blotting. Based on quantitative PCR, the periostin gene silencing efficiency in the KD group was over 90% (P < 0.01). After periostin gene silencing, compared with the control group, Runx2 and RANKL expression in the KD group was reduced (P < 0.01 and P < 0.05, respectively), but OPG protein expression showed no significant change (P > 0.05). The RANKL/OPG ratios in the KD group were lower than those in the NC group after periostin gene silencing (P < 0.05). Silencing periostin may reduce the expression of Runx2, suggesting that there may be asynergistic relationship between periostin and Runx2 in their effects on osteoblast differentiation, while reducing RANKL expression obviously confirms that the NF-κB (nuclear factor κB) pathway plays an important role in this process and that periostin silencing changes the underlying tendency toward bone metabolism. This method could even provide an experimental basis for using exogenous periostin protein to treat some abnormal bone metabolism diseases, as it could be used as asupplement for the treatment of tooth eruption abnormalities caused by Runx2 gene deficiencies or mutations (CCD).

Complex Composite Odontoma: A Cause of Impacted Teeth

Odontomas are one of the most common odontogenic lesions, earlier considered as mixed odontogenicneoplasms but lately have been accepted as hamartomatous malformations. They are either detectedaccidentally on radiographs or when they are a cause of impeding normal eruption of teeth. Odontomasoriginate from the odontogenic tissue and contain enamel and dentine, hence are referred to as compositelesions. They can be of two types depending on the appearance. If they have masses of calcified structuresresembling multiple miniature teeth then they are called compound odontomas and if they appear as anirregular disorganized radiopaque mass they are referred to as complex odontomas. A case if complexodontoma is reported herewith which led to impacted maxillary molar.

Dental prosthetic rehabilitation of Papillon-Lefèvre syndrome: a case report.

Papillon-Lefèvre syndrome (PLS) is a rare disorder characterized by palmar plantar hyperkeratosis and rapidly progressive periodontitis with loss of deciduous and permanent dentition at an early age. It is reported to occur in 1 to 4 individuals per million people. This case report presents highlighting features of the rare PLS in a 17-year old male who complained of discomfort while mastication and it was accompanied with symmetrical, sharply demarcated erythematous plaques involving the skin of the palms and soles, which extended to the finger joints, elbows, and knees. Along with the rough and dry skin, hyperhidrosis of lesion with a foul odor and transverse grooving of nails were noted. The past dental history revealed normal eruption of deciduous teeth followed by pre-mature mobility and shedding in 4-6 months. Permanent teeth also showed normal eruption and early shedding in the next 4-5 years. Complete edentulous maxillary and mandibular arches led to a decrease in alveolar bone and facial heights. There was no similar disorder in the patient’s family but family history revealed the consanguineous marriage of the patient’s parents.

Evaluation of the correlation between impacted canine and malocclusions

Abstract Introduction: Tooth impaction is defined as the absence of a tooth on the arch, after its normal eruption age. The main reason canines are impacted is the lack of space required for the tooth to erupt. Aim of study: The main objective of this study is to determine the types of malocclusions associated with canine impaction (Lindauer classification). A secondary objective is to establish the correlation between these parameters and identification of subjects with high risk of canine impaction based on pre-existing malocclusion. Material and methods: This study was performed on a sample of 20 patients, 9 men and 11 women. The dental casts were subject to Angle classification and various measurements such as arch perimeter, Pont’s index, sum of the mesiodistal width of the incisor and arch length were performed. The Lindauer sectorial classification was determined based on the patients’ panoramic radiography. Results: According to the data collected, the Class II /2 malocclusion is more frequent, and it is associated with the impacted canine (approximately 50%). According to the Lindauer classification higher frequency of the impacted canines was found in Sector IV. Conclusion: The diagnosis for impacted canines is often associated with Class II /2 malocclusion, and according to the Sector classification, it is often localised in Sector IV.

The effect of Ekman-Westborg and Julin trait (generalized megadontia) and localized megadontia on tooth components size and ion content.

The objective of this study is to compare size, enamel thickness and ion relative concentration in generalized megadontia (Ekman- Westborg and Julin trait) and a localized megadont upper third molar to normal teeth. The MD dimensions of permanent teeth were compared to controls. Tooth components of molars were measured from X-rays and compared to controls. The enamel and dentin relative amounts of elements of mandibular first permanent molar and deciduous canines of E-WJ trait girl, and megadont upper third molar were determined using ESD program of SEM and compared to match-paired normal teeth. The teeth of the girl diagnosed with E-WJ trait were true megadont (larger than mean ± 2SD). The ratio of enamel thickness to M-D dimension of molars of E-WJ trait and localized megadontia molars is reduced in comparison with normal similar teeth. In the enamel, carbon and silica concentrations were different in E-WJ trait teeth. The enamel thickness was reduced in the E-WJ trait and megadont molars, but the relative amount of elements in enamel and dentin was similar to normal. The megadontia is due to a very large tooth germ, as determined by the DEJ, while the ratio of enamel apposition from the total M-D dimension is reduced. Generalized megadontia, as observed in E-WJ trait, is due to large tooth germ, but the enamel thickness is similar to normal. Extractions of permanent teeth are necessary in order to allow normal eruption of teeth.

The oral health status and dental treatment needs of children affected by osteogenesis imperfecta – part I

Introduction. Osteogenesis imperfecta is an inherited disorder of the connective tissue. Which in most cases, is caused by mutations in the genes encoding collagen type I. Apart from clinical features, there are characteristic dental aberrations. Aim. The purpose of this research was the assessment of the condition of teeth and therapeutic needs of children with the congenital brittle bone disease. Material and methods. The questionnaires with patient’s parents, consisting medical history and dental history were performed. The intra-oral examination included the condition of the dentition, the presence of dentinogenesis imperfecta, malocclusion, the assessment of the attrition index and dmft/DMFT index. Results. 62 patients with osteogenesis imperfecta were examined – 32 boys and 30 girls. There were normal eruption times of deciduous (48 patients – 77.42%) and permanent teeth (34 patients – 82.93%) reported in the majority of the patients with OI. In most cases bad eating and hygienic habits were observed. Dentinogenesis imperfecta in deciduous and permanent teeth was reported mostly in type III of OI. dmft/DMFT index among children with OI were low in comparison to the population studies of corresponding age groups. Conclusions. Despite bad eating and hygienic habits as well as pathological structure of dentition of patients with the congenital brittle bone disease, caries index among these children were low in comparison to the population studies of corresponding age groups.

Eruption Guidance of Horizontally Impacted Permanent First Molar with Primary Retention of Primary Second Molars: Case Reports

Tooth eruption involves a complex developmental process of tooth migration from the dental follicular origin to the final occlusion position in the oral cavity via the alveolar process. Disturbance of tooth eruption can occur at any point in a series of eruption stages; however, horizontal impaction of the mandibular first molar and primary retention of the primary mandibular second molar are rarely observed simultaneously. This study describes the treatment for two cases of horizontally impacted first molar with primary retention of primary molar. The primary retention of the primary mandibular second molar was extracted, and orthodontic traction was applied to the horizontally impacted primary mandibular first molar. Subsequently, displacement of the premolar tooth bud was improved and space regaining for eruption was achieved, guiding to normal eruption of the first molar.

A metabolomic study on the association of exposure to heavy metals in the first trimester with primary tooth eruption

BackgroundThe influence of prenatal heavy metals exposure on primary tooth eruption in humans is rarely reported. AimBased on the cohort study design, we investigated the association of exposure to 12 heavy metals in the first trimester with primary tooth eruption, and the maternal metabolisms in the first trimester which might be related to the above relationship. MethodsMaternal urine samples were collected in their first trimester, and 12 metals (Ti, V, Fe, Co, Cu, As, Se, Cd, Sn, Hg, Tl, U) were measured using the inductively coupled plasma mass spectrometry method. The maternal metabolome in the first trimester was analyzed by ultrahigh performance liquid chromatography coupled mass spectrometry based metabolomics using urine samples. The infant's first tooth eruption time and number of teeth at age one were recorded by oral examination and questionnaire. ResultsNo significant associations were observed between heavy metals exposure in the first trimester and primary tooth eruption, except for Co. The level of Co was positively associated with time of infant's first tooth eruption, and was negatively associated with the number of teeth at age one. Based on metabolomic profiling, glycine was revealed as the key mediating metabolite, which showed negative correlation with Co and opposite effect of Co in the primary tooth eruption. ConclusionsPrenatal Co exposure in the first trimester might delay the primary tooth eruption in children through the decreased glycine-disrupted dentin formation, providing the first evidence and novel insights into the control of prenatal heavy metals exposure for ensuring normal (timely) primary tooth eruption.

Cavity treatment in primary molars and malocclusion: quasi-randomised clinical trial.

BackgroundAn innovative caries treatment protocol for primary teeth, termed Ultra-Conservative Treatment (UCT), restores small cavities through the Atraumatic Restorative Treatment (ART) protocol and cleans medium to large open cavities with toothbrush and fluoride toothpaste. However, UCT-treated primary molars were found to exfoliate earlier than amalgam (CRT) and ART-restored cavities, which may lead to unacceptable loss of space for normal eruption of permanent successors. The null-hypothesis tested was that there is no difference between the three treatment protocols and the intra-arch distances, and index of orthodontic treatment need (IOTN) after 4 years.MethodsDental casts were taken at baseline (T0) and four (T4) years. The space of the premolars (D + E space), arch perimeter, anterior and total arch depth were measured using a morphometric computer programme. The presence and level of malocclusion were assessed according to the IOTN index. Dependent variables were all intra-arch distances and the IOTN while the independent variable was treatment protocol (CRT, ART and UCT). Data were analysed using linear and logistic regression.ResultsThe sample consisted of 867 pairs of casts of 272 initial 6–7-year-olds. No difference was observed between the UCT protocol and the two restorative protocols for the intra-arch variables in both maxilla and mandible over the 4 year period. There was no difference between the UCT and the CRT and ART protocols regarding the occurrence of orthodontic treatment need (malocclusion). In conclusion, the UCT treatment protocol does not differ significantly from the traditional amalgam (CRT) and ART restorative protocols with respect to intra-arch distances and malocclusion. The earlier exfoliation of UCT-treated primary molars does not lead to a worsening of the eruption pattern of permanent successors.

Mapping of supernumerary elements in patients seeking orthodontic treatment

Introduction: Dimension, number and shape alterations are frequently observed dental anomalies. Objective: The aim of this study was to map the frequency, the preferred location and the most prevalent types of supernumerary teeth, in the studied population. In addition, to assess the interference that supernumeraryteeth may cause in the ectopic eruption of the normal dental series teeth. Methods: This is an observational retrospective study. Data collection was performed by evaluation of dental records of patients treated in an orthodontic clinic. Patients‘ radiographs, photographs and gypsum dental models were analyzed and datarecorded in protocol files, by previously trained undergraduate and postgraduate students. Records from 1984 to 2019 were evaluated, and evaluation lasted two months. Data were stored in Microsoft Office Excel (version 2016) for descriptive analysis. Results: From the 920 patients’ records analyzed, 2.7% presented atleast one supernumerary tooth, with preferred location on the anterior maxillary area and mandibular parapremolar area. The most prevalent type was the supplemental tooth, with normal eruption orientation and normal alveolar location. Conclusion: The supernumerary teeth of the studied population showedlittle interference in the ectopic eruption of the normal dental series. Most of the supernumerary teeth were impacted, and, approximately one third of the supernumerary teeth showed deviated eruptions.

Pediatric Ameloblastic Fibroma: A Case Report

To highlight the potential difficulties in diagnosing neoplastic lesion of the head and neck in children within autism spectrum. Ameloblastic fibromas are a variation of odontogenic tumors that are located in the posterior mandible in 70% of cases. The tumors may be either unilocular or multilocular when observed radiographically. Ameloblastic fibromas tend to have well-defined, scalloped margins radiographically but may also be corticated. In close to 75% of all cases, an impacted tooth is associated with the lesion. Although not confined to patients who are in their first or second decades of life, ameloblastic fibromas most often arise in this population. A 9-year-old male diagnosed with autism presented with tenderness in the left mandible. The parents were able to elucidate the child's problem as tingling rather than pain. The patient was referred for histopathological diagnosis and treatment. After evaluation and biopsy, the lesion was identified as a pediatric ameloblastic fibroma. He subsequently underwent the conservative approach of marsupialization and curettage without complication. Six-month follow-up revealed no evidence of recurrence and normal eruption patterns of the succedaneous teeth in the affected area. In this specific case, the conservative approach to treatment appears to have been appropriate. This may not be the appropriate course for every case; as such, each case will have an individualized approach. Earlier recognition with careful inspection can reduce potential complications. We might be missing early diagnosis of ameloblastic fibroma and other significant orofacial neoplasms in patients who are nonverbal or nondescriptive such as those with autism. Moreover, careful inspection of radiographic and clinical signs cannot be overemphasized.

A three-dimensional analysis of primary failure of eruption in humans and mice.

Primary failure of eruption (PFE) is a genetic disorder exhibiting the cessation of tooth eruption. Loss-of-function mutations in parathyroid hormone (PTH)/parathyroid hormone-related peptide (PTHrP) receptor (PTH/PTHrP receptor, PPR) were reported as the underlying cause of this disorder in humans. We showed in a PFE mouse model that PTHrP-PPR signaling is responsible for normal dental follicle cell differentiation and tooth eruption. However, the mechanism underlying the eruption defect in PFE remains undefined. In this descriptive study, we aim to chronologically observe tooth eruption and root formation of mouse PFE molars through 3D microCT analyses. Two individuals with PFE were recruited at Showa University. A mouse PFE model was generated by deleting PPR specifically in PTHrP-expressing dental follicle and divided into three groups, PPRfl/fl ;R26RtdTomato/+ (Control), PTHrP-creER;PPRfl/+ ;R26RtdTomato/+ (cHet), and PTHrP-creER;PRRfl/fl ;R26RtdTomato/+ (cKO). Images from human PFE subjects were acquired by CBCT. All groups of mouse samples were studied at postnatal days 14, 25, 91, and 182 after a tamoxifen pulse at P3, and superimposition of 3D microCT images among three groups was rendered. Mouse and human PFE molars exhibited a similar presentation in the 3D CT analyses. The quantitative analysis in mice demonstrated a statistically significant decrease in the eruption height of cKO first and second molars compared to other groups after postnatal day 25. Additionally, cKO molars demonstrated significantly shortened roots with dilacerations associated with the reduced interradicular bone height. Mouse PFE molars erupt at a much slower rate compared to normal molars, associated with shortened and dilacerated roots and defective interradicular bones.

Fiatalkori hydantion terápia okozta ínyfibrózis kombinált parodontális sebészi-ortodonciai kezelése - Esetismertetés és irodalmi összefoglalás

A közlemény célja bemutatni egy hidantoin származékkal kezelt 14 éves kislány súlyos ínyhiperpláziás esetét, teljeskörű parodontális és fogszabályozó kezelésének menetét és eredményét, valamint áttekinteni a gyógyszer okozta ínymegnagyobbodások feltételezett patomechanizmusának irodalmát.Az ínymegnagyobbodás gyakori mellékhatása több krónikusan alkalmazott gyógyszernek. Korábban gyakori volt epi-lepsziás gyermekek hidantoin származékok okozta fibrotikus ínymegnagyobbodása, viszont a terápiás protokollok változása következtében az utóbbi években már alig találkozhatunk ilyen fiatal epilepsziás pácienssel. Ezért tartjuk érdemesnek egy hidantoin származékkal kezelt epilepsziás kislány esetének bemutatását, ahol a közel 6 éves komplex parodontális és fogszabályozó kezeléssel sikerült visszaadni a kislány életkedvét, önbecsülését és javítani pszichés állapotát.Esetismertetés: Egy 14 éves epilepsziás leánygyermek 2013-ban jelentkezett súlyos, mind a két állcsontra kiterjedő, homogén, fibrotikus ínymegnagyobbodással. A nagyrohamos epilepszia miatt a gyermek nyolcéves kora óta szedett hidantoin származékokat. A jelentős ínyduzzanat korlátozta a fogak előtörését, jelentős fonációs zavart okozott, valamint lelkileg is megterhelte a kis pácienst. Helyi érzéstelenítésben a maxilla frontális szextánsában, apicálisan elcsúsztatott lebenytechnikával laterálisan, illetve a mandibulán belső fordított gingivectómiával több lépésben távolítottuk el a fibrotikus ínytömeget. Mivel a megnagyobbodott íny jelentős mértékben zavarta a fogak előtörését, és a gyermeknek Angle II típusú szkeletális ortodonciai rendellenessége volt, a sebészi fázist követően a két felső caninus buccalis ektópiás pozícióját bimaxilláris direktbond készülékkel korrigáltuk, és közel hároméves fogszabályozó kezelést követően, az akkor már 19. életévébe lépő fiatal fogászati-parodontális státusa, okklúziója teljesen rendeződött.

Biological Effects of Anti-RANKL Antibody and Zoledronic Acid on Growth and Tooth Eruption in Growing Mice

The anti-bone resorptive drugs denosumab, an anti-human-RANKL antibody, and zoledronic acid (ZOL), a nitrogen-containing bisphosphonate, have recently been applied for treatment of pediatric patients with bone diseases, though details regarding their effects in growing children have yet to be fully elucidated. In the present study, we administered these anti-resorptive drugs to mice from the age of 1 week and continued once-weekly injections for a total of 7 times. Mice that received the anti-RANKL antibody displayed normal growth and tooth eruption, though osteopetrotic bone volume gain in long and alveolar bones was noted, while there were nearly no osteoclasts and a normal of number osteoblasts observed. In contrast, ZOL significantly delayed body growth, tooth root formation, and tooth eruption, with increased osteoclast and decreased osteoblast numbers. These findings suggest regulation of tooth eruption via osteoblast differentiation by some types of anti-resorptive drugs.

PRECOCIOUS SECONDARY DENTITION: A CASE REPORT

Chronology of human dentition possesses high variations and deviation from normal eruption timing. However, a significant deviation from routine observations might indicate a need to evaluate patient’s general health and development. This is because tooth eruption is influenced by multiple factors such as genetics, gender, socioeconomic status, craniofacial morphology, systemic diseases, and various syndromes. Presented here is an extremely rare case of early eruption of permanent canines and premolars in an 8-year-old male child. Although the number of such cases is very limited, the clinician should process adequate knowledge and should be vigilant to identify such cases.

Developmental origin, functional maintenance and genetic rescue of osteoclasts

Osteoclasts are multinucleated giant cells that resorb bone, ensuring development and continuous remodelling of the skeleton and the bone marrow haematopoietic niche. Defective osteoclast activity leads to osteopetrosis and bone marrow failure1–9, whereas excess activity can contribute to bone loss and osteoporosis10. Osteopetrosis can be partially treated by bone marrow transplantation in humans and mice11–18, consistent with a haematopoietic origin of osteoclasts13,16,19 and studies that suggest that they develop by fusion of monocytic precursors derived from haematopoietic stem cells in the presence of CSF1 and RANK ligand1,20. However, the developmental origin and lifespan of osteoclasts, and the mechanisms that ensure maintenance of osteoclast function throughout life in vivo remain largely unexplored. Here we report that osteoclasts that colonize fetal ossification centres originate from embryonic erythro-myeloid progenitors21,22. These erythro-myeloid progenitor-derived osteoclasts are required for normal bone development and tooth eruption. Yet, timely transfusion of haematopoietic-stem-cell-derived monocytic cells in newborn mice is sufficient to rescue bone development in early-onset autosomal recessive osteopetrosis. We also found that the postnatal maintenance of osteoclasts, bone mass and the bone marrow cavity involve iterative fusion of circulating blood monocytic cells with long-lived osteoclast syncytia. As a consequence, parabiosis or transfusion of monocytic cells results in long-term gene transfer in osteoclasts in the absence of haematopoietic-stem-cell chimerism, and can rescue an adult-onset osteopetrotic phenotype caused by cathepsin K deficiency23,24. In sum, our results identify the developmental origin of osteoclasts and a mechanism that controls their maintenance in bones after birth. These data suggest strategies to rescue osteoclast deficiency in osteopetrosis and to modulate osteoclast activity in vivo. Multinucleated osteoclasts required for normal bone development and tooth eruption in the mouse originate from embryonic erythro-myeloid progenitors and are maintained after birth by fusion with circulating monocytes.

Early orthognathic approach combined with SABG for congenital dentofacial deformity-A rare case report

Early orthognathic approach combined with SABG for congenital dentofacial deformity-A rare case report - IJODR- Print ISSN No: - 2581-9356 Online ISSN No:- 2581-9364 Article DOI No:- 10.18231/j.ijodr.2019.008, IP Indian Journal of Orthodontics and Dentofacial Research-IP Indian J Orthod Dentofacial Res

Relationship of Mandibular Ramus Dimensions to Lower Third Molar Impaction.

Objectives The aim of this study was to investigate the mandibular ramus features that could contribute to the etiology of mandibular third molar impaction. Materials and Methods Two hundred and forty subjects were divided into two groups: impacted group: 115 subjects presented with an impacted mandibular third molar, and control group: 125 subjects with the normal mandibular third molar eruption. Digital panoramic radiographs were used, and four angular and twelve linear measurements were done. Comparisons between groups were done using Student's t -test. Pearson correlation and linear regression tests were used to assess the degree of relationship between retromolar space and mandibular measurements. Results Control group showed significant greater measurements in most of the variables, whereas the impacted group showed significant larger gonial angle and larger inclination of lower posterior teeth than the control group. Significant correlations were found between retromolar space and coronoid height, ramal heights, ramus notch depths, the inclination of lower posterior teeth, and retromolar space/3M width ratio in both groups. Conclusion The present study found that the configuration of the mandibular ramus appears to be discrete in many aspects in the erupted other than impacted lower third molars subjects, which might be a possible cause for the impaction.