QUINTESSENCE INTERNATIONALDiverse morphological tooth deformities aref - PDF document

QUINTESSENCE INTERNATIONALDiverse morphological tooth deformities arefound in various shapes, textures, and preva-lence. They can be sporadic or syndromes,nutritional, environmental, genetic, and eth-nic related. Most of these tooth-born (ie,patient born with the deformation) deforma-tions (eg, shovel-shaped incisors, tubercu-lum Carabelli, variations in number andshape of cusps, dens invaginatus, taurodon-tism) have been extensively investigated.1…10Labial-cervical-vertical groove (LCVG),which starts on the cervical enamel andextends to the radicular surface, has also beendescribed as a notch.11…17It is assumed that Department of Pediatric Dentistry,Goldschleger School ofDental Medicine,Tel Aviv University,Tel Aviv,Israel.Private practice,Tel Aviv,Israel.Department of Orthodontics,Goldschleger School ofDental Medicine,Tel Aviv University,Tel Aviv,Israel.Reprint requests:Dr E.Mass,Department of PediatricDentistry,Goldschleger School of Dental Medicine,Tel AvivUniversity,Tel Aviv,69978,Israel.Fax:972-3-6409250.E-mail:elimas@post.tau.ac.il VOLUME €NUMBER€APRIL QUINTESSENCE INTERNATIONALMass et al gradually grows deeper in the apical directionand may, occasionally, run throughout the rootsurface.on the palatal aspect of maxillary inci-sors.11,12,18,19The etiology of the malformationmay be similar to enamel hypoplasia, causedby impaired function of ameloblasts duringtooth development.19,20Causative factors forthis malfunction may be due to trauma, dis-ease, and nutritional issues (eg, rickets), orcan be genetic or idiopathic.Anatomic factors, such as cervical enamelprojections, enamel pearls, and radiculargrooves, may be associated with advancedlocalized periodontal destruction. Kozlovskyet aldescribe a 25-year-old female in whicha periodontal lesion with vertical bone losswas directly related to the labial groove on amaxillary central incisor. Brin and Ben-define the groove as a labial notchŽon the enamel of central incisors. A preva-lence of 6.5% was found in a sample of 1,880children, with no gender preference. Kovacsdescribes the anomaly in the junction linebetween enamel and cementum on maxillarycentral incisors as fossacoronoradicular,Ž inthe same category as syndesmocorono-radicularŽ on maxillary lateral incisors. Thejunction is often divided into two unequalparts and is hollow at that place which is near-ly always present in the crown, very often inthe root, and can also continue on the latterup to the apex. Fifteen such teeth (3%) werefound in a collection of 500 dry maxillary inci-sors. This feature was often found, but wasless pronounced, on the other teeth.The presence of LCVG may exacerbatesome clinical aberrations, such as estheticdeficiency of the gingival marginal contour,accumulation of plaque and, consequently,gingival pocket with bone loss, as well as fail-ure in endodontic and periodontal treat-21…23This type of dental deformity hasbeen scarcely investigated and reported inthe dental literature. Hence, the purpose ofthis study was to examine the prevalence ofLCVG in maxillary permanent incisors interms of specific tooth (central vs lateral inci-sor), side (unilateral vs bilateral, left vs right)and gender, and to characterize LCVG interms of size (severity) and the related gingi-val tissue (contour and sulcus depth).METHOD AND MATERIALSThe study group consisted of 600 childrenand adolescents (293 boys and 307 girls), 12to 17 years of age, (mean 13.6 ±1.99 years)treated in the Departments of Orthodonticsand Pediatric Dentistry of the School ofDental Medicine, Tel Aviv University. All par-ticipants in the study were examined in adental chair, using a periodontal probe (WisePerio probe, Premier), by one investigator.The periodontal probe was used to deter-mine LCVG presence, its severity, and depthof the gingival sulcus. A total of 2,392 centraland lateral maxillary incisors were examined.LCVG severitySeverity of LCVG was ranked in three stages:a mild subgingival shallow groove belowthe marginal gingiva that can be felt only byprobing (Fig 1); a moderate groove that canbe detected with the eyes, extending subgingi-vally as in , and additionally supragingivallyon the labial crown surface, not more than 2mm from the marginal gingiva in the incisaldirection (Fig 2); and a severe defectextending supragingivally more than 2 mmfrom the marginal gingiva on the labial crownsurface and further subgingivally (Fig 3). Fig 1Unilateral mild labial-cervical-vertical groove,characterized by a sub-gingival shallow groove below the gingival margin with a gingival contourtype partial coverage (ie,gingiva partially covers the groove with mildchange in contour). VOLUME €NUMBER€APRIL QUINTESSENCE INTERNATIONALMass et al Gingival contourWhen an LCVG was present, the gingivalcontour was described in three categories:normal coverage, ie, the gingiva covers thegroove with no change in the regular shapeof the gingival margin; partial coverage, ie,the gingiva partially covers the groove withmild change in the contour (Fig 1); and irreg-ular coverage, ie, the gingiva covers thegroove with a severe change in the contourDepth of subgingival sulcusSulcus depth was measured on the mesial,distal, and middle parts of the labial toothsurface. In teeth with the groove, the subgin-gival depth was also measured in the groove. Fishers exact test was used to examinethe differences of categorical variables withone free variable between LCVG and non-LCVG teeth. Student -test was used in con-tinuous variables to compare the means ofthe two groups. RESULTSPrevalenceA total of 30 LCVGs were found in 27 chil-dren (3 children with bilateral groove) in 14girls and 13 boys. This means a prevalenceof 4.5% for a unilateral or bilateral LCVG(Table 1). Only one lateral incisor was foundwith a LCVG. Therefore, all further analyseswere referred to central and lateral incisorsas one entity. No difference was foundbetween occurrence on the left (15 teeth)and the right (15 teeth) side.LCVG severity The 30 LCVG were divided into 22 mild(73.3%), 7 moderate (23.3%) LCVG, and 1severe case (3.3%) (Table 2). There was nodifference in severity of the grooves betweenthe left and right sides (= 0.897). Fig 2(above)Bilateral moderate labial-cervical-verticalgroove,characterized by a groove that extends supragingi-vally less than 2 mm from the gingival margin with a gingivalcontour type irregular coverage (ie,the gingiva covers thegroove with severe change in contour).Fig 3Unilateral severe labial-cervical-vertical groove,characterized by a groove that extends supragingivally morethan 2 mm from the gingival margin with irregular gingivalcontour. VOLUME €NUMBER€APRIL QUINTESSENCE INTERNATIONALMass et al Gingival contourGingival contour of the 22 mild LCVG caseswas normal in 18 instances (81.8%), that is,the LCVG was completely covered subgingi-vally and could be detected only with a peri-odontal probe beneath the marginal gingiva.In 3 subjects (13.6%) the gingival contourpartially covered the deformity (Fig 1), and inone case (4.5%), a severe irregular shape inthe gingival margin was found (Fig 2, Table2). The 7 moderate and one severe groovescould clearly be detected without probing,since the LCVG extended coronally from thegingival margin. In 5 patients (62.5%) the gin-gival contour demonstrated a partial cover-age (Fig 1), and in 3 an irregular coverage(37.5%) (Figs 2 and 3; Tables 1 and 2). Depth of subgingival sulcusFishers exact test was used to compare thedepth of the gingival sulcus at three points onthe labial side of all incisors between childrenwith and without LCVG. There were no differ-ences in the mesiolabial (= .168) and disto-labial measurements (= .437). However, themid-labial gingival sulcus was highly signifi-cantly different (= .001) between childrenwith (1.55 ±0.90 mm) and without (1.18 ±0.75 mm) LCVG (Table 3). Nevertheless, theincrease in sulcus depth� (1 mm) was foundin 37% of the LCVG subjects (Table 3).Changes in tooth size, number, and morphol-ogy have been widely discussed in the litera-ture.1…10Some tooth abnormalities are fre-quent and some sporadic, some are relatedto genetic influences and some are causedby systemic developmental aberrations. Littleattention has been given to the LCVG defor-mity. An important goal in dentistry is earlyprevention of disease of the oral cavity andteeth. As LCVG deformity could have futureimplications that may be expressed as a localgingival disease,caries and possible esthet-ic problems, it is important to record LCVGpresence and severity in the routine dentalexamination and to raise awareness inpatients and their caregivers. In the present study, the prevalence of4.5% of LCVG in maxillary central incisors Girls (%)Boys (%)Total (%)Subjects307 (100)293 (100)600 (100)Right central incisor6 (2.0)6 (2.0)12 (1.8)Left central incisor5 (1.6)6 (2.0)11 (1.8)Right lateral incisor„*„„Left lateral incisor1 (0.3)„1 (0.2)Subjects with 12 (3.9)12 (4.1)24 (4.0)unilateral LCVGSubjects with 2 (0.7)1 (0.3)3 (0.5)bilateral LCVGSubjects with LCVG14 (4.6)13 (4.4)27 (4.5) Teeth with LCVG16 (5.2)14 (4.8)30 (5.0)*LCVG (labial-cervical-vertical groove) not found. Table 1Prevalence of unilateral orbilateral LCVG in permanentmaxillary incisors of 600 GingivalSeverity of LCVG(%) coverageMildModerateSevereNormal18 (81.8)„* „Partial3 (13.6)5 (71.4)„Irregular1 (4.5)2 (28.6)1 (100) Total22 (73.3)7 (23.3)1 (3.3)*LCVG (labial-cervical-vertical groove) not found. Table 2Distribution of gingival contour according to LCVGseverity in maxillary incisorswith LCVG (n = 30) With LCVGWithout LCVGMLGS
1 mm17 (63%)505 (88.3%)MLGS 1 mm10 (37.0%)68 (11.7%)Mean (mm)1.55 ±0.901.18 ±0.75 Total27573LCVG = labial-cervical-vertical groove; MLGS = mid-labial gin-gival sulcus. Table 3Depth of the MLGS in maxillary incisors with andwithout LCVG VOLUME €NUMBER€APRIL QUINTESSENCE INTERNATIONALMass et al was similar to the frequency of 6.5% foundby Brin and Ben-Bassatin their study of1,880 children. In addition, there was no pref-erence related to gender or side of themouth. Bilaterally LCVG was found in 3 chil-dren and on one lateral incisor in 1 child.This indicates that, although less frequent,LCVG may show on more than one maxillaryincisor. The question of whether LCVG is a pre-disposed condition for a local periodontaldisease was addressed in this study. Thedata suggested a possible cause and effectrelationship. First, a direct relation was foundbetween LCVG severity and gingival contour.LCVGs with moderate grade of severity werefound to be 5 times more susceptible to par-tial coverage of the gingival margin and 6times more prone to irregular gingival cover-age than LCVG with a mild grade of severity.That is, the greater the deformity of theLCVGs the more aberration of the gingivalcoverage was presented. Second, the gingi-val sulcus at the site of the LCVG defectdemonstrated a significant increase in depth(31%) compared to patients without LCVG.This mean depth is still in the normal range,however, the examined population was ofadolescents with a mean age of 13.6 ±1.99years, which suggests that with increasingage LCVG incisors may become moreinclined to develop periodontal sequelae, ashas been shown by Kozlovsky et al.However, 63% of the LCVG incisors demon-strated a normal sulcus depth of less than 1mm, implying that only one-third of the LCVGdeformities are susceptible in developing aperiodontal sequelae and two-thirds are like-ly to maintain a healthy peridontium. Never-theless, no participant, or their parents, com-plained or was even aware of the presence ofthe deformity. It is strongly recommendedthat whenever LCVG is detected, the dentistshould alert the patient to this deformity sothat cautious oral hygiene can be imple-mented. 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