Radiography of a lateral periodontal cyst

Radiography of a lateral periodontal cyst DEPARTMENT

OF MENTAL

TITGIENE,

PORTERVILLE

STATE

HO8PITM.

The CCLSC of :L patient with :L r:uliolucer~t &ion in the mnndibular left lateral and central inc-isor region demonstrates the amount of bone destruction that may occul in the period of 1 year ant1 cmphasizcs the ncwssity of n thorough clinical exami~ nation snpplementcd wit,h adequate mtliogrnphs. I:ntlingnosctl areas that appear ax anatomic mriations or artifacts should be thoroughly chec?kcd radiographically :I t frequent intervals.

A

lateral periodontal cyst has been described as a q-st forming from an epithelial rest in the periodontal nzcmbranc, as a ratlicular cyst arising or developing on the lateral side of a root, and as a lateral follicular cyst. This cast report presents the progress of an incipient radiolucent lesion that, later enlarged progressively and typifies the classic nomenclature for a lateral periodontal cyst.. The necessity of a thorough clinical csamination, supplemented by a series of radiographs for any suspicious radiolucency, is tlcmonstratcd. The lesion is usually found in the anterior wgion of the oral cavit,y in t,llc periodontal membrane and may lx: I’onnd on the buccal, lingual, mcsial, or distal surfaces of the root. Contributing et,iologic factors may be trauma from chronic periodontal disease or from a lateral callal in a pulpless tooth. The lesion shows no predisposition for age Or SPS. It, is a relatively rare, solitaq lesion and may occur on cithw vital or nonvital teeth. Cysts may lY?mixill asymptomatic and unnoticed until espansion or destructiolt of bone occurs, in which ease they may h~xcJItle scnsiti\c to [wcI~SsiOli and palpation or produce tooth mobility. CASE h slight incisor to the (Fig.

REPORT 3%year-old Caucasian man reported to the clinic with n complaint of swelling and of the mnnclibular left lateral and central tenderness on the inferior lingual surface region. Bwause of the concnvity of the mnndible, the swelling was not readily apparent examiner; upon closer inspection, however. a small, soft, rnisrd :rren was palpable 1).

“Staff

498

I)cntist

; Member,

hmcrican

Ac:r(lrmy

of l)etlt:rl

Radiology.

Radiography

Volume 32 Number 3

Pig. 2. Oral view of mandibular swelling and slight tenderness.

Dental

and

medical

left

inferior

lingual

of lateral

quadrant

periodontal

of patient

cyst

complaining

499

of

history

The patient related that he had been struck in the mouth with a baseball as a youth and that the accident caused displacement of the maxillary left lateral incisor, which No complications from the usual childhood subsequently received endodontic treatment. diseases Tvere reported. The patient had been hospitalized for treatment of a mastoid infection and for hemorrhoid surgery. Clinical

examination

The patient’s physical development pattern was normal, with no obvious swelling or asymmetry. The lesion, which measured approximately 10 by 6 mm., was a soft, slightly raised, palpable mass on the left inferior lingual surface of the mandible. Lymphadenopathy was negative. All of the mandibular anterior teeth mere vital. The left lateral and central incisors mere slightly mobile but not particularly sensitive to palpation or percussion. NO traumatic occlusion was detected. Areas of varying degrees of periodontitis were measured in all quadrants of the dental arch, with only slight involvement recorded in the lower anterior region. Xupragingival calculus was present in this area. No outside communication to the lesion could be detected with a periodontal probe, and the teeth gave normal responses to vitality tests; a periodontal abscess was thus ruled out. Radiographic

examination

An intraoral periapical radiograph revealed a well-demarcated radiolucency extending to the apices of the mandibular left lateral and central incisor teeth on their proximal surfaces (Fig. 2, B). The interproximal cortical plate of bone and the trabecular bone appeared to be destroyed. A Pxnorex radiograph (Fig. 3) was made in a search for more extensive demineralization, benign, malignant, or systemic lesions (osteomyelitis, ameloblastoma, cementoblastoma, neurofibroma, lymphosarcoma, fibrous dysplasia, osteosarcomn, metastatic carcinoma, multiple myeloma, and hyperpnrnthyroidism) . The lesion was clearly identifiable on the Panorex film and probably would have been observable on this type of film in its early stage of development. Approximately one year prior to development of the patient’s current problem, a complete intraoral series of radiographs had been taken. A small radiolucent area appeared to be developing in the interproximal space (Fig. 2, a). At this stage of development, the lamina dura appeared destroyed on the mesial surface of the lateral root. One might attribute this lack of lamina dura to tube-angulation projection and consider the small radiolucency to be an artifact on the radiograph.

500

Degering

Pig. 8. 8, Intraoral perinpicnl radiograph from routine dental survc~y in .-\ugust, 1969. Interproximal radiolucency indicates loss of laminn dura midway on root of mnntlihulnr left lateral incisor. This small rndiolucency might easily he misdiagnosed as an artifact. trahecular hone space, traumatic bone cyst, etc. 3, Similar radiograph taltcn in October, 1970, after patient’s complaint of s\relling on inferior kft lingual surf:rc~x of mandible. All teeth in anterior region were vital, negative lo percussion and mobility. Ihdiographir diagnosis of lateral periodontal cyst was valid.

Fig. 3. Panorex radiograph nlar central and lateral incisors. Pathology

of patient

with

lateral

periodontal

cyst between

left

mandih-

report

A specimen consisting of a saeular mass of soft tissue was submitted to the laboratory. The microscopic section consisted of a cyst wall made of dense collections of collagen bundles, within which were numerous fibroblnst cells. Lining the wall at various aspects were sections of epithelium of a squamous type. In some areas the epithelium was disrupted and infiltrated by chronic inflammatory cells. Tissue findings were consistent with a diagnosis of lateral periodontal cyst.

Volume 32 Number 3

Radiography

of lateral

periodontal

cyst

501

DISCUSSION

The case just presented emphasizes the necessity of a thorough clinical examination, including palpation of the soft and hard tissues for tenderness, swelling, and asymmetry, as this may be the first indication of pathosis. Such an examination must then be supplemented with adequate radiographs. In prescribing radiographic coverage, the examining dentist must weigh the slight amount of radiation to the patient, with the potential bone destruction and its effect on the dcntition, with resulting long-range complications to the patient’s health. In the annual or semiannual dental examination, bitewing radiographs would have been of little diagnostic value with regard to the cystic region. Undiagnosed areas that appear as anatomic variations or artifacts should be thoroughly checked radiographically at 3-month and 6-month intervals, and if no change has occurred, they should be rechecked with additional radiographs in approximately 1 year. The amount of bone destruction that may result in a period of 1 year is evident in Fig. 2. A yearly Panorex examination, supplemented with bitewing films, might be considered good diagnostic procedure for some patients. Fortunately, the prognosis for a patient with a lateral periodontal cyst is excellent. The foregoing case of a 39-year-old Caucasian man with a radiolucent lesion in the mandibular left lateral and central incisor region demonstrates the amount of bone destruction that may occur in the period of 1 year, The pathology report confirmed the radiographic diagnosis of a lateral periodontal cyst. Reprint requests to : Dr. Charles I. Degering Department of Mental Hygienn Porterville State Hospital Porterville, Calif. 93257