Local Factors in Periodontal Disease

Dan Holtzclaw, DDS, MS - Diplomate American Board of Periodontology

While the primary etiology of periodontal disease is bacterial plaque in a susceptible host, a number of "local factors" may contribute to the disease process.  This short review provides a concise summary of many local factors :

Open Contacts

(Hancock 1980) Evaluated tooth contacts in 40 Navy recruits (1040 sites).  By themselves, no association was found between open/loose contacts and probing depths.  However, when sites with open/loose contacts had food impaction associated with them, probing depth increasesd 0.3-1.0mm with concomitant inflammation.

(Jernberg 1983) Compared open and closed contacts in 104 patients.  60% of patients had increased attachment loss and increased probing depths when open contacts present versus 17% of patients having increased loss of attachment and increased attachment loss with closed contacts.  Probing depth increased ~0.3mm with open contacts.  Attachment loss increased ~0.5mm with open contacts.  Study found increased prevalence of food impaction with open contacts.

 Figure 1: Open contact with impacted food between teeth 18/19


(Highfield 1978) Removal of overhangs led to more effective plaque removal and improved gingival health.

(Rodriguez-Ferrer 1980) Overhang removal led to ~0.5-0.8mm probing depth reduction

(Jeffcoat 1980) Small overhangs do not result in bone loss.  Large overhangs are plaque retentive, difficult to clean, and result in chronic inflammation and alveolar bone destruction. 

(Lang 1983) Placed MOD inlays with overhangs in dental students.  Restorations with overhangs produced change in subgingival microflora to that which resembled chronic periodontitis (increase in gram negative anaerobes).  Removal of the overhang by replacement of the restoration led to restoration of the subgingival microflora to one associated with health.

 Figure 2: Maxillary teeth with overhanging amalgam restorations

Palatogingival Grooves

(Withers 1981) Palatogingival grooves found on 2.3% of maxillary incisors (4.4% maxillary laterals and 0.28% of maxillary centrals)

(Everett 1972) Palatogingival grooves found on 2.8% of lateral incisors

(Kogon 1986) Examined 3168 extracted maxillary central and lateral incisors.  Palatogingival grooves found on 4.6% of maxillary incisors (3.4% maxillary centrals and 5.6% on maxillary lateral incisors)  54% of palatogingival grooves terminated on the root with 43% of those extending less than 5mm and 47% extending 6-10mm.  Did not find a high association between palatogingival grooves and periodontal defects.

 Figure 3: Palatogingival groove on MP surface of tooth 7

 Figure 4: Palatogingival groove with 5.5mm probing depth

Enamel Pearls

(Moskow 1990) Review of enamel pearls.  Incidence 1.1-9.7% with mean of 2.69%).  Size ranged from 0.3-4.0mm.  Most enamel pearls had dentin core with some having pulp tissue.  Most commonly found on the distal surfaces of 2nd and 3rd maxillary molars.

 Figure 5: Enamel pearl on extracted maxillary 2nd molar

Cervical Enamel Projections

(Masters & Hoskins 1964) Developed CEP grading system.  Observed CEP's on extracted teeth.  28.6% incidence in mandibular molars.  17% incidence in maxillary molars.  Noted that 90% of isolated bifurcations defects were associated with CEP's.

(Leib 1967) Used crystal violet stain to assess furcation invasion-CEP association.  25% incidence in mandibular molars.  22% incidence in maxillary molars.  Concluded that there was no association between CEP's and furcation invasions.  *This conclusion was most likely due to the fact that 78% of the CEP's in this study were grade 1 CEP's. 

(Hou & Tsai 1987) 68% incidence of CEP's in Chinese population.  CEP incidence greater in mandibular molars than maxillary molars.  82.5% of teeth with CEP's had isolated furcation involvement

 Figure 6: Grade 3 CEP and isolated furcation involvement

Marginal Ridge Discrepancies

(Kepic & O'Leary 1978) Evaluated marginal ridge relationships and their correlation to probing depth, clinical attachment loss, plaque, and calculus.  Concluded that marginal ridge discrepancies had no effect on attachment loss.

(Pihlstrom 1986) found that marginal ridge discrepancies were associated with ~0.24mm increased probing depths and ~0.41mm increased attachment loss.

*My personal spin: Increased probing depths and attachment loss associated with marginal ridge discrepancies may be due to the following: Marginal ridge discrepancies on unrestored teeth likely also means that there is a discrepancy in the CEJ relationship between the two teeth in question.  According to (Richey & Orban 1953) the crest of interdental septa should parallel the CEJ's of adajent teeth.  As such, if a discrepancy exists between the marginal ridges of two adjancent teeth, it is highly likely that the CEJ's and the crestal bone will have a similar discrepancy.  According to (Schluger 1949) a bony slope greater than 30 degrees will result in "soft tissue bridging".  It is this soft tissue bridging that may lead to the increased probing depth and clinical attachment loss associated with marginal ridge discrepancies.


(Blank 1979) found increased plaque retention, inflammation, and probing depths associated with carious lesions versus properly restored restorations.

 Figure 7: Tooth 30 with distal open carious lesion

Mouth Breathing

(Wagaiyu 1991) Mouth breathers tend to have increased plaque, bleeding on probing, and erythema compared to non-mouth breathers.  These findings were limited to maxillary anterior teeth.

Cemental Tears

(Leknes 1997) Cemental tears are complete separation along the cemento-dentinal border.  More commonly found in older patients.  Can result in rapid and site specific loss of attachment.

Hopeless Teeth

(Machtei 1989) Retained hopeless teeth with NO peridontal treatment produced 10 times more bone loss on adjacent teeth than when the hopeless tooth was removed.

(deVore 1988) Retained hopeless teeth with periodontal treatment resulted in no significant difference in probing depth, clinical attachment loss, and bone loss versus when the hopeless tooth was removed.

3rd Molar Defects

(Kugelberg 1991) Studied periodontal healing for 176 3rd molar extractions in patients <20 years old and >30 years old at baseline and 1 year s/p surgery.  In the younger group, >50% bone loss on the distal of the 2nd molar was seen in 18.3% of patients initially and in only 2.2% of patients at 1 year.  In the older group, >50% bone loss on the distal of the 2nd molar was seen in 41% of patients initially and in 37.3% of patients at 1 year.  (Kugelberg 1990) had similar findings with slightly different age groups.

 Figure 8: 3rd molar defect distal to tooth 18

 Figure 9: Intrasurgical photo of defect from figure 8

Plunger Cusps

Plunger cusps are cusps that tend to wedge food in the embrasures between opposing teeth during mastication.  While I have not come across any studies that specifically examine plunger cusps, they can be related to the findings of the studies by (Hancock 1980), (Jernberg 1983), and (Pihlstrom 1986).  My personal experience has been that elimination of plunger cusps is necessary for sucessful periodontal treatment.

 Figure 10: Plunger cusp at distobuccal of tooth 14

 Figure 11: Intrabony defect caused by plunger cusp in figure 10

  *This review contains my personal interpretation of dental literature.  I highly recommend that you read and understand the articles mentioned in this review.  The pictures used in this review are from my personal collection and are subject to copyright protection under guidelines of the JIACD website.